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Microchip-AN1476-Combining-the-CLC-and-NCO-to-Implement-a-High-Resolution-PWM
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2013 - 2016 Microchip Technology Inc. DS00001561C-page 1
General Description
The SEC1110 and SEC1210 provide a single-chip
solution for a Smart Card bridge to USB and UART
interfaces. These bridges are controlled by an
enhanced 8051 micro controller and all chip peripherals
are accessed and controlled through the SFR or
XDATA register space. TrustSpanTM Technology
enables digital systems to securely communicate, process,
move and store information on system boards,
across networks and through the cloud.
Feature Highlights
• Smart Card
- The SEC1110 provides one Smart Card interface
and the SEC1210 provides two
- Fully compliant with ISO/IEC 7816, EMV 4.2/
4.3, ETSI TS 102 221 and PC/SC standards
- Versatile ETU rate generation, supporting
current and proposed rates (up to 826 Kbps)
- Full support of both T=0 and T=1 protocols
- Full-packet FIFO (261 bytes), for transmit
and receive
- Half-duplex operation (no software intervention
required between transmit and receive
phases of exchange)
- Loose real-time response required of software
(approximately 180 ms)
- Dynamically programmable FIFO threshold
with byte granularity
- Time-out FIFO flush interrupt, independent of
threshold
- Programmable Smart Card clock frequency
- UART-like register file structure
- Supports Class A, Class B, Class C, or Class
AB Smart Cards (1.8 V, 3.0 V and 5.0 V
cards)
- Automatic character repetition for T=0 protocol
parity error recovery
- Automatic card deactivation on card removal
and on other system events, including persistent
parity errors
- Internal procedure byte filtering for T=0 protocol
- Protocol timers (Guard, Timeout, and CWT)
for EMV-defined timing parameters
–Detection of an unresponsive card
–Activation/deactivation sequences
–Cold/warm resets
–Monitoring for all EMV timing constraints
–16-bit general purpose down counter for software
timing use
- Fully compliant ESD protection on card pins
• USB
- 12 Mbps USB operation compliant to the
USB 2.0 Specification
- Integrated USB 1.5 K pull-up resistor and
Dp,Dm series termination resistors
- Integrated USB devices controller with:
–8/16/32/64 byte control buffer
–Five 8/16/32/64 byte programmable (bulk/
interrupt) endpoint buffers
• 8051 Processor
- Reduced instruction cycle time (approximately
9 times 80C51)
- 9.6 MHz max clock speed
- Enhanced peripherals; three 16-bit timers,
watchdog timer, interrupt controller, JTAG
- OTP (One Time Programmable)
ROM : 16 KB RAM : 1.5 KB
• Boot ROM : 16 KB UART (SEC1210 only)
— Standard PC baud rates supported
— 3 M baud high-speed rate (not PC standard)
• SPI (SEC1210 only)
- Master capability with 12 MHz max performance
• General
- 5.0 V tolerance on user accessible IO pins
- Self-clocking internal oscillator, no external
crystal required
- 3.6 V - 5.5 V supply input
–Internal 4.8 V comparator disables Class A card
support if the input voltage is too low
- Available in commercial (0ºC to +70ºC) and
industrial (-40ºC to +85ºC) temperature
ranges
Applications
• USB Smart Card reader
• UART-based Smart Card reader
• Dual Smart Card reader
SEC1110/SEC1210
Smart Card Bridge to USB and UART Interfaces
SEC1110/SEC1210
DS00001561C-page 2 2013 - 2016 Microchip Technology Inc.
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The last character of the literature number is the version number, (e.g., DS30000000A is version A of document DS30000000).
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To determine if an errata sheet exists for a particular device, please check with one of the following:
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2013 - 2016 Microchip Technology Inc. DS00001561C-page 3
SEC1110/SEC1210
Table of Contents
1.0 Introduction ..................................................................................................................................................................................... 4
2.0 Block Diagrams ............................................................................................................................................................................... 7
3.0 Pin Table ......................................................................................................................................................................................... 9
4.0 Pin Configurations ......................................................................................................................................................................... 11
5.0 Pin Descriptions ............................................................................................................................................................................ 13
6.0 Pin Reset States ........................................................................................................................................................................... 16
7.0 8051 Embedded Controller ........................................................................................................................................................... 19
8.0 EC External Interrupts ................................................................................................................................................................... 24
9.0 8051 Special Function Registers .................................................................................................................................................. 27
10.0 Smart Card Interface ................................................................................................................................................................... 46
11.0 USB Controller Description ......................................................................................................................................................... 92
12.0 GPIO and LED Interface ........................................................................................................................................................... 117
13.0 Two Pin Serial Port (UART) ...................................................................................................................................................... 132
14.0 Serial Peripheral Interconnect (SPI1) - Master ......................................................................................................................... 145
15.0 Clock and Reset ........................................................................................................................................................................ 150
16.0 OTP ROM Test Interface .......................................................................................................................................................... 176
17.0 TEST Modes, JTAG, and XNOR .............................................................................................................................................. 187
18.0 DC Parameters ......................................................................................................................................................................... 188
19.0 8051 Timers .............................................................................................................................................................................. 196
20.0 Timing Diagrams ....................................................................................................................................................................... 205
21.0 Package Outlines
................................................................................................................................................................................................. 207
Appendix A: Acronyms, Definitions and Conventions ....................................................................................................................... 209
Appendix B: References ................................................................................................................................................................... 212
Appendix C: Revision History ........................................................................................................................................................... 213
The Microchip Web Site .................................................................................................................................................................... 214
Customer Change Notification Service ............................................................................................................................................. 214
Customer Support ............................................................................................................................................................................. 214
Product Identification System ........................................................................................................................................................... 215
SEC1110/SEC1210
DS00001561C-page 4 2013 - 2016 Microchip Technology Inc.
1.0 INTRODUCTION
The SEC1110 and SEC1210 provide a single-chip solution for a Smart Card bridge to USB and UART interfaces. These
bridges are controlled by an enhanced 8051 micro controller and all chip peripherals are accessed and controlled
through the SFR or XDATA register space.
1.1 Features
• Smart Card
- Fully compliant with standards: ISO/IEC 7816, EMV 4.2/4.3, ETSI TS 102 221 and PC/SC
- Versatile ETU rate generation, supporting current and proposed rates (to 826 Kbps and beyond)
- Full support of both T=0 and T=1 protocols
- Full-packet FIFO (261 bytes), for transmit and receive
- Half-duplex operation, with no software intervention required between Transmit and Receive phases of an
exchange
- Very loose real-time response required of software: approximately 180 ms worst case
- Dynamically programmable FIFO threshold, with byte granularity
- Time-out FIFO flush interrupt, independent of threshold
- Programmable Smart Card clock frequency
- UART-like register file structure
- Supports Class A, Class B, Class C, or Class AB Smart Cards (all 1.8 V, 3.0 V and 5.0 V cards)
- Automatic character repetition for T=0 protocol parity error recovery
- Automatic card deactivation on card removal and on other system events, including persistent parity errors
- Internal procedure byte filtering for T=0 protocol
- Protocol timers (guard, time-out and CWT) for EMV-defined timing parameters
- Detection of an unresponsive card
- Activation/deactivation sequences
- Cold/warm resets
- Monitoring for all EMV timing constraints
- 16-bit general purpose down counter for software timing use
- Fully compliant ESD protection on card pins per JESD22-A114D (March 2006) and JESD22-A115A “Machine
Model” from AN1181
- Fully EMV compliant, internal signal current limits
- 3.3 V internal operation with 5.0 V tolerant buffers where required
- Self-contained management of Smart Card power:
- SC1_VCC and SC2_VCC, supply output
- Regulator for 1.8 V, 3.0 V, and 5.0 V from supply input
- Current limiter with over-current sense interrupt (short circuit detect)
- Hardware-ensured, compliant deactivation sequence on card removal
- Synchronous card support
• USB
- 12 Mbps USB operation compliant with the USB 2.0 Specification
- Integrated USB 1.5 K pull-up resistor
- Integrated Series resistors on USB_DP, USB_DM
- Integrated USB devices controller with:
- 8/16/32/64 byte control endpoint 0 buffer
- Five 8/16/32/64 byte programmable (bulk/interrupt) endpoint buffers
• 8051
- Reduced instruction cycle time (approximately 9 times 80C51)
- 9.6 MHz max clock speed
- Enhanced peripherals: two 16-bit timers, watch dog timer, interrupt controller, JTAG
- 16 KB One Time Programmable (OTP) ROM
- 1.5 KB RAM
- 4 KB (SEC1100/SEC1200)/ 16KB (SEC1110/SEC1210) ROM
2013 - 2016 Microchip Technology Inc. DS00001561C-page 5
SEC1110/SEC1210
• UART
- Standard PC (9600, 19200, 38400 and 115200) baud rates supported
- 3 M baud high-speed rate (non-PC standard)
• SPI
- Master capability with 12 MHz max performance
• General
- 5.0 V tolerance on user accessible IO pins
- Self-clocking internal oscillator, no external crystal required
- 3.6 V-5.5 V supply input
- Internal 4.8 V comparator disables Class A card support if the input voltage is too low
1.2 Smart Card Subsystem
The SEC1110 and SEC1210 are fully compliant with the prevailing Smart Card standards: ISO7816, EMV, and PC/SC.
It meets and exceeds all existing requirements for communication bit rate (ETU duration) and includes support for proposed
bit rates up to 826 Kbps. Signal levels and current limits are also fully compliant.
The Smart Card power is regulated and switched internally, supporting all 5.0 V, 3.0 V, and 1.8 V Smart Cards (classes
A, B, and C, respectively). Over-current protection is provided, and a detected over-current condition is available as an
interrupt. The required standard activation and deactivation sequences are provided with software interaction. However,
deactivation is handled in hardware as the card is being removed. This scenario ensures the required sequence regardless
of software participation. If the system clock is inactive at the time, the card movement is detected asynchronously,
and the Wake-On Event feature is used to re-start the system clock so that the de-activation sequence can continue.
Interface signals to the Smart Card are designed to meet both standard drive levels and current limitations internally,
requiring no external series resistors. ESD protection on these signals meets the full standard requirements.
The device is a superset of the familiar 16450 UART architecture, with extensions in the form of a larger FIFO, specialized
state machines for T=0 protocol parsing, automatic half-duplex turnaround at the completion of a transmitted message,
and a specially-designed set of timers to enforce standards compliance in timing (as required of a terminal by the
ISO7816 and EMV standards).
With the full-packet-depth FIFO on-chip, software is almost totally excluded from real-time requirements. It loads an outgoing
message into the FIFO, triggers the transfer, and reads the returned data at any time after it becomes available.
The reset sequence (cold or warm) is equally hands-off: software sets up the sequence and activates the reset, and is
alerted when the ATR message has been received (via the FIFO Threshold Interrupt). The threshold is dynamically programmable
with byte granularity, so that threshold interrupts can be received at various stages in the processing of a
message of initially unknown length (such as ATR).
For detecting data time-outs, and for other mandatory timing tasks having to do with communication with a Smart Card,
a set of three protocol timers is provided:
• Time-out timer, for monitoring the standard WWT, BWT and WTX time-out intervals
• CWT timer, for monitoring the T=1 CWT time-out interval
• Guard timer, for ensuring the BGT and EGT transmission intervals, with special usage during a Reset sequence.
A separate general purpose timer is provided for software driver use.
Synchronous card support using GPIOs controlled via registers in the Smart Card device.
SEC1110/SEC1210
DS00001561C-page 6 2013 - 2016 Microchip Technology Inc.
1.3 USB Subsystem
The USB Subsystem is made up of the following 3 functional blocks
• FS USB PHY
• USB Device Controller (UDC)
• Interface Bridge with USB endpoint buffers
1.3.1 FS USB PHY AND DEVICE CONTROLLER
The FS USB PHY contains the D+ pull-up resistor and handles the reception of USB data. The D+ and D- signals are
passed through the differential receiver (which is external to the device controller core) to get a single-ended bit stream.
The device controller has a digital phase-locked loop (DPLL) to extract the clock and data information. The clock and
data are passed to the SIE (serial interface engine) block to identify the sync pattern and for NRZI-NRZ conversion. This
NRZ data is then passed through a bit-stripper which strips off excessive inserted zeros. The data stream is passed
through a PID decoder and checker to identify different PID’s. The SIE block handles the protocol according to the type
of PID and the endpoint to which the current transaction is addressed. If it is a data PID, the serial data is assembled
into byte format and the received data is CRC is checked, then put into a one-byte buffer. The protocol layer takes the
data from the buffer and forwards it to the Interface Bridge. On control transfers to endpoint 0, the protocol layer forwards
the transfers to the endpoint block. If the application violates the data transfer protocol during the transfer of data from
the buffer to the application bus, the protocol layer controls the SIE to recover from this error.
1.3.2 INTERFACE BRIDGE AND ENDPOINT BUFFERS
These act as the interface between the 8051 micro controller and the USB device controller. The USB endpoint buffers
are memory mapped on the 8051 XDATA bus. A simple buffer scheme is employed, which assigns a single/ping-pong
buffer to each USB endpoint for ease of software control. Each buffer must be cleared before the next data transfer can
be started.
When USB OUT data is received, it is placed into the appropriate OUT endpoint buffer and the 8051 is signaled with an
interrupt (polling is also available)
When an IN request is received, the 8051 is signaled with an interrupt and the 8051 will transfer data to the appropriate
IN endpoint buffer and set a ready flag. The data will automatically be encoded for transfer over the USB bus.
1.4 Power Management Unit
The programmable clock divider supports division of the 48 MHz main clock. Additionally it enables power down under
program or hardware control. Exit from power down is accomplished through a single input pin. The power management
methods employed will enable a USB Suspend current of 200 A typical (400 A typical including Rpu current). In STOP
Mode, 1 A is the maximum current for a bare bones design.
FIGURE 1-1: USB SUBSYSTEM BLOCK
USB
FS
PHY
USB 1.1
Device Controller
Interface
Bridge
+
Endpoint
Buffers
USB D+
USB DXDATA
Interrupt
2013 - 2016 Microchip Technology Inc. DS00001561C-page 7
SEC1110/SEC1210
2.0 BLOCK DIAGRAMS
FIGURE 2-1: SEC1110 BLOCK DIAGRAM
3.0 V - 5.5 V or VBUS
Smart
Card
Regulators
5.0 V
3.0 V
1.8 V
16
KB
OTP
ROM
1.5
KB
RAM
USB
PHY
CLK_PWR
USB
Device
Controller
ISO7816 /
Smart
Card
Interface
Smart
Card
Power
Control
Power On Reset
Power Fail Detect
Reset
8051
CPU
256 x 8
RAM
On Chip
Debug
JTAG
Timer 0
Timer 1
Watchdog
Timer
External
Interrupts
CPU Clock
Management
CPU Power
Management
USB/GPIO/Core
Regulators
3.3 V
1.2 V
4
XDATA
48 MHz
Oscillator GPIO
Smart Card 1
7 pins
Miscellaneous
D+
DVDD33
1 1 1
4
6 6
2
4/16
KB
ROM
Timer 2
SEC1110/SEC1210
DS00001561C-page 8 2013 - 2016 Microchip Technology Inc.
FIGURE 2-2: SEC1210 BLOCK DIAGRAM
3.0 V - 5.5 V or VBUS
Smart
Card
Regulators
5.0 V
3.0 V
1.8 V
16
KB
OTP
ROM
1.5 KB
RAM
USB
PHY
CLK_PWR
USB
Device
Controller
ISO7816 /
Smart
Card
Interface
Smart Card
Power
Control
Power On Reset
Power Fail Detect
Reset
8051
CPU
256 x 8
RAM
On Chip
Debug
JTAG
Timer 0
Timer 1
Watchdog
Timer
External
Interrupts
CPU Clock
Management
CPU Power
Management
USB/GPIO/Core
Regulators
3.3 V
1.2 V
XDATA
48 MHz
Oscillator
SPI1 UART
16550
GPIO
Smart Card1
7 pins
1
Miscellaneous
D+
DSmart
Card
Regulators
5.0 V
3.0 V
1.8 V
Smart Card
Power
Control
SAM2
4
VDD33
1 1 1
4 4
6
1
3
2
8
6
6 + 3
Timer 2
4/16
KB
OTP
ROM
2013 - 2016 Microchip Technology Inc. DS00001561C-page 9
SEC1110/SEC1210
3.0 PIN TABLE
3.1 SEC1110 16-Pin QFN
3.2 SEC1210 24-Pin QFN
TABLE 3-1: SEC1110 16-PIN PACKAGE
SMART CARD (7 PINS)
SC1_VCC Sc1_rst_N sc1_clk sc1_io
SC1_C8
SC1_PRSNT_N/
JTAG_TMS
SC1_C4
USB INTERFACE (2 PINS)
USB_DP usb_DM
MISC (5 PINS)
RESET_N SC_LED_ACT_N/
JTAG_TDO TEST JTAG_CLK
JTAG_TDI
DIGITAL, POWER (2 PINS)
VDD33 VDD5
TOTAL 16 (VSS - THERMAL SLUG)
TABLE 3-2: SEC1210 24-PIN PACKAGE
SMART CARD (7 PINS)
SC1_VCC Sc1_rst_N sc1_clk sc1_io
SC1_C8
SC1_PRSNT_N/
JTAG_TMS
SC1_C4
SMART CARD 2/SECURITY AUTHENTICATION MODULE (5 PINS)
SC2_VCC Sc2_rst_N sc2_clk sc2_io
SC2_PRSNT_N/
JTAG_TDI
USB INTERFACE (2 PINS)
USB_DP usb_DM
SPI1/UART (4 PINS)
SPI1_MISO/RXD SPI1_MOSI/TXD SPI1_CLK/CTS_OUT SPI1_CE/RTS_IN
MISC (4 PINS)
SEC1110/SEC1210
DS00001561C-page 10 2013 - 2016 Microchip Technology Inc.
RESET_N SC_LED_ACT_N/
JTAG_TDO TEST JTAG_CLK
DIGITAL, POWER (2 PINS)
VDD33 VDD5
TOTAL 24 (VSS - THERMAL SLUG)
Note: The NC pins are “No Connects”. There are no NC pads in the Known Good Die (KGD).
TABLE 3-2: SEC1210 24-PIN PACKAGE
2013 - 2016 Microchip Technology Inc. DS00001561C-page 11
SEC1110/SEC1210
4.0 PIN CONFIGURATIONS
FIGURE 4-1: SEC1110 16-PIN QFN PACKAGE
Thermal Slug
(must be connected to
VSS)
SEC1110
(Top View QFN-16)
SC1_VCC
1
SC1_RST_N
2
SC1_CLK
3 SC1_C4
4
VDD33
13
TEST
16
USB_DM
15
USB_DP
14
12
RESET_N
11
JTAG_CLK
10
SC_LED_ACT_N/JTAG_TDO
9
SC1_C8
8
7
SC1_IO
6
SC1_PRSNT_N/JTAG_TMS
5
VDD5
JTAG_TDI
Indicates pins on the bottom of the device
SEC1110/SEC1210
DS00001561C-page 12 2013 - 2016 Microchip Technology Inc.
FIGURE 4-2: SEC1210 24-PIN QFN PACKAGE
Thermal Slug
(must be connected to VSS)
SEC1210
(Top View QFN-24) SC1_VCC
1
SC1_RST_N
2
SC1_CLK
3
SC2_RST_N
4
SC1_PRSNT_N/JTAG_TMS
5
SC2_IO
6
12
11
SC1_IO
10
SC2_VCC
9
SC2_PRSNT_N/JTAG_TDI
8
SC1_C8
SC2_CLK 7
SPI1_MISO/RXD
19
SPI1_MOSI/TXD
20
VDD33
21
TEST
24
USB_DP
23
USB_DM
22
17
SPI1_CE/ RTS
16
RESET_N
15
JTAG_CLK
14 SC1_C4
13
SC_LED_ACT_N/JTAG_TDO
18
SPI1_CLK/CTS
VDD5
Indicates pins on the bottom of the device
2013 - 2016 Microchip Technology Inc. DS00001561C-page 13
SEC1110/SEC1210
5.0 PIN DESCRIPTIONS
This section provides a detailed description of each signal. The signals are arranged in functional groups according to
their associated interface.
An N at the end of a signal name indicates that the active (asserted) state occurs when the signal is at a low voltage
level. When the N is not present, the signal is asserted when it is at a high voltage level. The terms assertion and negation
are used exclusively in order to avoid confusion when working with a mixture of active low and active high signals.
The term assert, or assertion, indicates that a signal is active, independent of whether that level is represented by a high
or low voltage. The term negate, or negation, indicates that a signal is inactive.
5.1 SEC1110 and SEC1210 Pin Descriptions
TABLE 5-1: SEC1110 AND SEC1210 PIN DESCRIPTIONS
Name Symbol Buffer
Type Description
SMART CARD INTERFACE
SC Reset
Output
SC1_RST_N/
GPIO2
Note 5-1 SC1_RST_N, SC2_RST_N: A low pulse resets the card and
triggers an “answer to reset” (ATR) response message. This
pin should be held low when the interface is not active.
SC2_RST_N/
GPIO18
GPIO2, GPIO18: These pins may alternatively be configured
as a general purpose I/O pins.
SC Clock Output SC1_CLK/
GPIO1
Note 5-1 SC1_CLK, SC2_CLK: The clock reference for communication
with the flash media card. This pin should be held low when
the interface is not active.
SC2_CLK/
GPIO17
GPIO1, GPIO17: These pins may alternatively be configured
as general purpose I/O pins.
SC Data I/O SC1_IO/
GPIO0
Note 5-1 SC1_IO, SC2_IO: The bidirectional serial data pin, which
should be held low when the interface is not active.
SC2_IO/
GPIO16
GPIO0, GPIO16: These pins may alternatively be configured
as general purpose I/O pins.
SC Voltage for
Card
SC1_VCC/
SC2_VCC
The voltage supply pin, where the output of the pin can be set
to 1.8, 3.0, or 5.0 volts, depending on the type of Smart Card
detected. These pins require an external1 F capacitor.
The same voltage must be applied to power SCx_RST#,
SCx_CLK, SCx_IO, SCx_C4, and SCx_C8 pins as digital
inputs.
SC Standard or
Proprietary Use
Contact
SC1_C8
(SC1_SPU)/
Note 5-1 SC1_C8, SC1_SPU: These pins can be used for either
standard or proprietary use as an input and/or output.
GPIO4 This pin can alternatively be used as general purpose I/O pin.
SC Present SC1_PRSNT_N/
JTAG_TMS/
TIMER0_IN/
GPIO6
SC2_PRSNT_N/
JTAG_TDI/
GPIO19
I/O8PUD SC1_PRSNT_N, SC2_PRSNT_N: Active-low signals used to
detect the Smart Card device. These pins have an internal
pull-up which can be activated by software to detect the Smart
Card device.
JTAG_TMS, JTAG_TDI: These pins can alternatively be
configured in debug mode by software.
GPIO6, GPIO19: These pins can alternatively be used as
general purpose I/O pins, or as the Timer 0 input pin.
SC1_FCB SC1_C4
(SC1_FCB)/
Note 5-1 SC1_C4: This pin is to attach to C4 of the Smart Card for
cards that support Function Code.
GPIO3 GPIO3: This pin may alternatively be configured as a general
purpose I/O pin.
SEC1110/SEC1210
DS00001561C-page 14 2013 - 2016 Microchip Technology Inc.
SC Active
Indicator
SC_LED_ACT_N/ I/O8PUD The driver for the active LED.
JTAG_TDO/ This pin can alternatively be configured in debug mode by
software.
TIMER2_T2EX/
GPIO5
This pin may alternatively be used as general purpose I/O pin,
or as the Timer 2 “t2ex” input pin.
USB INTERFACE
USB Bus Data USB_DM,
USB_DP
I/O-U These pins connect to the upstream USB bus data signals.
SPI1/UART INTERFACE (QFN24)
SPI1 Chip
Enable
SPI1_CE_N/ I/O8PUD The active-low chip-enable output (Master mode).
If the SPI1 interface is disabled, this pin must be driven high
in idle state by software.
RTS/ This pin can alternatively function as the UART RTS signal,
when UART is used instead of SPI1.
GPIO11 This pin may also be used as a general purpose I/O pin.
SPI1 Clock SPI1_CLK/ I/O8PUD The SPI1 clock output (Master mode).
CTS/ This pin can alternatively function as the UART CTS signal,
when UART is used instead of SPI1.
GPIO10 This pin can alternatively be used as a general purpose I/O
pin.
SPI1 Data In SPI_MISO/ I/O8PUD The Master data in to the controller.
This pin must have a weak internal pull-down applied at all
times to prevent floating.
RXD/ This pin alternatively function as the UART RXD input signal,
when UART is used instead of SPI1.
GPIO8 This pin can alternatively be configured as a general purpose
I/O pin.
SPI1 Data Out SPI_MOSI/ I/O8PUD This is the Master data output from the controller.
This pin must have a weak internal pull-down applied when
used as input to prevent floating.
TXD/ This pin can alternatively function as the UART TXD output
signal, when UART is used instead of SPI1.
GPIO9 GPIO9: This pin can alternatively be used as a general
purpose I/O pin.
MISC
TEST TEST I/O8PUD This signal is used for testing the chip. If the test function is
not used, this pin must be tied low externally.
RESET input RESET_N IS This active low signal is used by the system to reset the chip
and enter STOP mode. The active low pulse should be at
least 1 s wide. This pin is an analog input signal with Vil=100
mV.
JTAG Clock JTAG_CLK I/O8PUD This input pad is used for JTAG debugging and has a weak
pull down. It can be left floating or grounded when not used.
If the JTAG is connected, this signal will be detected high, and
the software disables the pull-up after reset.
GPIO 28 GPIO28 I/O8PUD General Purpose I/O pin.
GPIO 29 GPIO29 I/O8PUD General Purpose I/O pin.
GPIO 30 GPIO30 I/O8PUD General Purpose I/O pin.
TABLE 5-1: SEC1110 AND SEC1210 PIN DESCRIPTIONS (CONTINUED)
Name Symbol Buffer
Type Description
2013 - 2016 Microchip Technology Inc. DS00001561C-page 15
SEC1110/SEC1210
Note 5-1 This pin has a unique function, detailed in Section 18.0, "DC Parameters," on page 188.
5.2 Buffer Type Descriptions
DIGITAL / POWER / GROUND
VBUS 5V Power VDD5 5.0 V (or VBUS) power input.
3.3V Analog
Power Output
VDD33 3.3 V analog power output for decoupling capacitor. This pad
requires an external 1 F capacitor.
Ground VSS Ground reference
Note: All pins OTP_VPP_MON, OTP_VREF, OTP_VREFA, OTP_VREF_SA are NC’s.
TABLE 5-2: SEC1110 AND SEC1210 BUFFER TYPE DESCRIPTIONS
Buffer Type Description
I Input
IPU Input with weak internal pull-up resistor
IS Input with Schmitt trigger
I/O12 Input/output buffer with 12 mA sink and 12 mA source
I/O8PD Input/output buffer with 8 mA sink and 8 mA source, with an internal weak
pull-down resistor
I/O8PU Input/output buffer with 8 mA sink and 8 mA source with an internal weak
pull-up resistor
I/O8PUPD Input/output buffer with 8 mA sink and 8 mA source, with a selectable pullup
and pull-down resistors
I/OD8PU Input/open drain output buffer with a 8 mA sink
I/O12PD Input/output buffer with 12 mA sink and 12 mA source, with an internal weak
pull-down resistor
I/O12PU Input/output buffer with 12 mA sink and 12 mA source with an internal weak
pull-up resistor
I/O12PUPD Input/output buffer with 12 mA sink and 12 mA source, with a selectable
pull-up and pull-down resistors
I/OD12PU Input/open drain output buffer with a 12 mA sink
O12 Output buffer with a 12 mA sink and a 12 mA source
O12PD Output buffer with 12 mA sink and 12 mA source, with a pull-down resistor
O12PU Output buffer with 12 mA sink and 12 mA source, with a pull-up resistor
ICLKx XTAL clock input
OCLKx XTAL clock output
I/O-U Analog input/output defined in USB specification
I-R RBIAS
TABLE 5-1: SEC1110 AND SEC1210 PIN DESCRIPTIONS (CONTINUED)
Name Symbol Buffer
Type Description
SEC1110/SEC1210
DS00001561C-page 16 2013 - 2016 Microchip Technology Inc.
6.0 PIN RESET STATES
TABLE 6-1: PIN RESET STATES
TABLE 6-2: LEGEND FOR PIN RESET STATES TABLE
Symbol Description
Y Hardware enables function
0 Output low
1 Output high
-- Hardware disables function
Z Hardware disables output driver (high impedance)
PU Hardware enables pull-up
PD Hardware enables pull-down
HW Hardware controls function, but state is protocol dependent
(FW) Firmware controls function through registers
VDD Hardware supplies power through pin, applicable only to
CARD_PWR pins
none Hardware disables pad
TABLE 6-3: SEC1110 QFN 16-PIN RESET STATES
Reset State
Pin Pin Name Function Output PU/PD Input
1 VDD5 5.0 V supply ANALOG
2 SC1_C8 Smart Card1 C8 pin Z
3 SC1_C4 Smart Card1 C4 pin Z
4 SC1_IO Smart Card1 IO pin Z
Voltage
Signal (V)
Time (t)
RESET
RESET
Hardware
Initialization
Firmware
Operational
VDD5
VSS
2013 - 2016 Microchip Technology Inc. DS00001561C-page 17
SEC1110/SEC1210
5 SC1_CLK Smart Card1 CLK pin Z
6 SC1_RST_N Smart Card1 RST_N pin Z
7 SC1_VCC Smart Card1 Power supply
output 5.0V/3.3V/1.8V
Note 6-1
Note 6-2 ANALOG
8 SC1_PRSNT_N/JTAG_TMS GPIO input for Smart Card1
presence detect. Z
9 TEST Test mode pin Z PD
Note 6-8
Yes
Note 6-6
10 USB_DM USB D- Z
11 USB_DP USB D+ Z
12 VDD33 3.3 V power supply output Note 6-3 ANALOG
13 JTAG_CLK JTAG clock pin Z PD
Note 6-4
Yes
Note 6-6
14 SC_LED_ACT_N/JTAG_TDO GPIO output for
Smart Card1 LED Z
15 JTAG_TDI JTAG data in pin Z PD
Note 6-8
Yes
Note 6-6
16 RESET_N Reset input Z ANALOG
Note 6-5
- VSS Package ground ANALOG
TABLE 6-4: SEC1210 QFN 24-PIN RESET STATES
Reset State
Pin Pin Name Function Output PU/PD Input
1 SC2_RST_N Smart Card2 RST_N pin Z
2 SC2_VCC Smart Card2 power supply
output 5.0V/3.3V/1.8V
Note 6-1
Note 6-2 ANALOG
3 VDD5 5.0 V supply ANALOG
4 SC1_C8 Smart Card1 C8 pin Z
5 SC1_C4 Smart Card1 C4 pin Z
6 SC1_IO Smart Card1 IO pin Z
7 SC1_CLK Smart Card1 CLK pin Z
8 SC1_RST_N Smart Card1 RST_N pin Z
9 SC1_VCC Smart Card1 Power supply
output 5.0V/3.3V/1.8V
Note 6-1
Note 6-2 ANALOG
10 SC1_PRSNT_N/JTAG_TMS GPIO input for Smart Card1
presence detect. Z
11 SPI1_MISO/RXD GPIO pin for SPI1 data Z
TABLE 6-3: SEC1110 QFN 16-PIN RESET STATES
Reset State
Pin Pin Name Function Output PU/PD Input
SEC1110/SEC1210
DS00001561C-page 18 2013 - 2016 Microchip Technology Inc.
Note 6-1 The Smart Card1 and Smart Card2 power supply output is powered down at reset state.
Note 6-2 The Smart Card1 and Smart Card2 power supply output requires an external 1.0 F capacitor.
Note 6-3 Internal voltage regulator output for USB, GPIO 3.3 V IO Supply. This pin requires an external 1.0 F
capacitor.
Note 6-4 A weak pull down is present on the TEST, JTAG_CLK, and JTAG_TDI pads. If JTAG is connected,
and this pad is pulled high, then the reset state of the pins 8 (JTAG_TMS), 13(JTAG_CLK),
14(JTAG_TDO), and 15(JTAG_TDI) functions in JTAG Mode. The weak pull-down can be disabled
after reset release by software.
Note 6-5 RESET_N is an analog input, which when low, powers down all internal voltage regulators and the
pads are in high impedance state. The pads function as input, including pull-ups pull-downs
functionality after internal 3.3V power (VDD33) is good.
Note 6-6 The TEST, JTAG_CLK, and JTAG_TDI/GPIO[19] values at internal power on reset release (after
RESET_N release) is captured in the chip to enter various functional or test modes.
Note 6-7 Smart Card2 power supply output is powered down at reset state.
Note 6-8 A weak pull-down is present on TEST, JTAG_CLK, and JTAG_TDI pads if JTAG is connected, and
this pad is pulled high. The reset state of the pins 10(JTAG_TMS), 19(JTAG_CLK), 20(JTAG_TDO),
and 21(JTAG_TDI) function in JTAG Mode. The weak pull-down can be disabled after reset release
by software.
Note 6-9 The LCD regulator LDO4 and Smart Card2 output is powered down at reset state.
12 SPI1_CLK/CTS GPIO pin for SPI1 clock Z
13 SPI1_CE/RTS GPIO pin for SPI1 chip enable Z
14 SPI1_MOSI/TXD GPIO pin for SPI1 data Z
15 TEST Test mode pin Z PD
Note 6-8
Yes
Note 6-6
16 USB_DM USB D- Z
17 USB_DP USB D+ Z
18 VDD33 Note 6-3 ANALOG
19 JTAG_CLK JTAG clock pin Z PD
Note 6-8
Yes
Note 6-6
20 SC_LED_ACT_N/JTAG_TDO GPIO output for
Smart Card1 LED Z
21 SC2+PRSNT_N/JTAG_TDI GPIO input for Smart Card1
presence detect. Z PD
Note 6-8
Yes
Note 6-6
22 RESET_N Reset input Z ANALOG
Note 6-5
23 SC2_IO Smart Card2 IO pin Z
24 SC2_CLK Smart Card2 CLK pin Z
- VSS Package ground ANALOG
TABLE 6-4: SEC1210 QFN 24-PIN RESET STATES
Reset State
Pin Pin Name Function Output PU/PD Input
2013 - 2016 Microchip Technology Inc. DS00001561C-page 19
SEC1110/SEC1210
7.0 8051 EMBEDDED CONTROLLER
The embedded controller used in the SEC1110 and SEC1210 is an R8051XC2 from Evatronix. The R8051XC2 is a high
performance 8-bit embedded processor. The processor core is a low gate count core, with low-latency interrupt processing
that features:
• Single clock per machine cycle: an average of 2.12 machine cycles per instruction
• Industry standard MCS51 instruction set
• Dual Data Pointers (2 x DPTR)
The R8051XC2’s interrupt controller is closely integrated with the processor core to achieve low latency interrupt processing,
incorporating the following features:
• 13 external interrupts
• 4 priority levels for each interrupt
The embedded controller provides low-cost debug solutions, including:
• JTAG port for debugging using EASE OCDS debugging
• Software and 4 hardware breakpoints
The R8051XC2 bus interfaces include:
• 256 bytes internal data memory RAM
• Program Memory Write Mode
• Supports 128 KB program memory space with banking
• Supports 128 KB of external data memory space with banking
SEC1110/SEC1210
DS00001561C-page 20 2013 - 2016 Microchip Technology Inc.
.
7.1 Sleep/Power Management
The R8051XC2 has a power management control unit that generates clock enable signals for the main CPU and for
peripherals; serves Power Down Modes IDLE and STOP; and generates an internal synchronous reset signal (upon
external reset, watchdog timer overflow, or software reset condition). The IDLE Mode leaves the clock of the internal
peripherals running. Any interrupt will wake the CPU.
The STOP Mode turns off all internal clocks. The CPU will exit this state when an external interrupt (0 or 1)or reset
occurs and internally generated interrupts are disabled since they require clock activity.
The Wake-up From Power-Down Mode control unit services two external interrupts during power-down modes. They
can combinationally force the clock enable outputs back to active state so the clock generation can be resumed.
FIGURE 7-1: R8051XC2 Block Diagram
R8051XC2
CPU
256 Bytes IRAM
SFR
Registers
OCDS
EASE on-chip
Debugging block and
JTAG Interface
Timer 0
Timer 1
Watchdog
Timer
External
Interrupts
Power Management,
Reset & Wake-Up
Control Units
SFR Mux
CLK_PWR
SmartCard1,
2*
ISR
8051-compatible
External
Memory
Reset
ref_clk
SPI1
UART
JTAG
SC1, SC2
Engine Clock
Peripheral Clock
Peripheral Clock
Enable
SMSC Trace FIFO,
SPI XIP SPI2
XDATA
SRAM
Oscillators
Clkper Peripherals
GPIO GPIO
USB
ROM
Timer 2Engine Clock Enable
SPI
Master
16550
UART
UDC
OTP
ROM
* SEC1210 only
2013 - 2016 Microchip Technology Inc. DS00001561C-page 21
SEC1110/SEC1210
7.1.1 EC DATA MEMORY
The EC has 1.5 KB data memory that is accessed through the XDATA Bus which is implemented with static RAM and
organized as 1.5 K x 8 bits. The base address of the memory is 8000h in the EC address space and extends to location
85FFh.
7.1.2 EC OTP INSTRUCTION MEMORY
The primary instruction memory for the EC is a 16 Kx 8 bit OTP ROM memory, located at locations 0000h through 3FFFh
in the EC address space. There is also a 4 K x 8 bit ROM that is used to overlay the OTP memory when it has not been
programmed. A bit in the OTP disables the ROM overlay. The OTP memory is also mapped into the XDATA space when
the overlay is active so that the CPU can program the OTP from the USB bus.
7.2 EC Registers
The truth table indicates which memory is mapped into the 8051 CODE space depending on the three signals ROM_EN,
defined in the OTP_CFG Register. OTP_ROM_EN, and the EXT_SPI_EN (BOND2 bond option).
7.3 EC Memory Map
TABLE 7-1: CODE EXECUTION TRUTH TABLE
OTP_CFG.FORCE_OTP_ROM OTP_CFG.OTP_ROM_EN
EXT_SPI_EN/
BOND[2]
CODE
EXECUTION
0 X 1 External SPI2
0 0 0 ROM
0 1 0 OTP
1 X X OTP
TABLE 7-2: CODE SPACE
Name Address Range
INTERNAL ROM (4 K) (SEC1110 and SEC1210)
INTERNAL ROM (16 K) (later versions)
0000h-0FFFh
C000h-CFFFh (alias address range) (deprecated)
18000h-18FFFh (alias address range)
1A000h-1DFFFh (alias address range) (later
versions)
OTP ROM (16 K) 0000h-3FFFh
EXTERNAL SPI 0000-FFFFh
SRAM (1.5 K) 19000h-195FFh (alias address range)
SEC1110/SEC1210
DS00001561C-page 22 2013 - 2016 Microchip Technology Inc.
Note 7-1 OTP ROM is only visible in the XDATA space if the Internal ROM is enabled (see Table 7-1).
There is 128 KB of program space available. The lower 32 KB always is mapped to 0000-7FFFh. The higher ranges
32 KB to 128 KB are accessed through a window at 8000h-FFFFh using the pagesel registers.The ROM and SRAM are
also mapped to address at 96 KB. This enables access to ROM code while executing from OTP_ROM. This also
enables downloading code to SRAM and executing for test modes.
TABLE 7-3: XDATA SPACE RANGES
Name Address Range
OTP ROM (Note 7-1) 0000h-7FFFh
SRAM (1.5 K) 8000h-85FFh
Smart Card1,2 9000h-93FFh
UART 9500h-95FFh
USB DEVICE CONTROLLER 9600h-96FFh
SPI2 CODE MASTER 9A00h-9A18h
GPIO 9C00h-9DFFh
CLK_PWR A000h-A3FFh
OTP_TEST A400h-A7FFh
SPI2 CODE MASTER (TRACE FIFO) BFFEh-BFFFh
INTERNAL ROM (4 K) (SEC1110 and SEC1210)
INTERNAL ROM (16 K) (later versions)
C000h-CFFFh (alias address range) (deprecated)
18000h-18FFFh (alias address range)
1A000h-1DFFFh (alias address range) (later
versions)
TABLE 7-4: CPU BOOT ADDRESS MAPPING
CPU CODE
MAPPED
ADDRESS[15:
0] CPU UNMAPPED ADDRESS[16:0] COMMENT
INTERNAL ROM
BOOTING
INTERNAL
OTP_ROM
BOOTING
EXTERNAL SPI
BOOTING
FORCE_OTP_ROM
=0
OTP_ROM_EN=0
(FORCE_OTP_RO
M=1) | (
EXT_SPI_EN=0 &
OTP_ROM_EN=1)
FORCE_OTP_ROM=
0 &
EXT_SPI_EN=1
00000h-7FFFh ROM=
00000h-00FFFh
OTP_ROM_16K=
00000h-03FFFh
EXT_SPI=
00000h-07FFFh
If size of internal ROM/
OTP_ROM/ External
SPI is less than 32KB,
then rest of the region
is reserved.
pagesel[2:0]=000 must
not be used.
8000h-FFFFh Reserved=
(OTP_ROM_16K)
08000h-0FFFFh
EXT_SPI=
08000h-07FFFh
pagesel[1:0]=01
Upper 32K of
ROM/OTP_ROM/EXT_
SPI code execution
8000h-FFFFh pagesel[1:0]=10
32KB OTP_ROM code
execution
2013 - 2016 Microchip Technology Inc. DS00001561C-page 23
SEC1110/SEC1210
8000h-FFFFh Reserved=
18000h-1FFFFh
ROM=
18000h-18FFFh
ROM=
18000h-18FFFh
pagesel[1:0]=11
SRAM code execution
SRAM_1.5K=
19000h-195FFh
SRAM_1.5K=
19000h-195FFh
SRAM_1.5K=
19000h-195FFh
Reserved=
(SRAM_1.5K)
19600h-19FFFh
Reserved=
(SRAM_1.5K)
19600h-19FFFh
Reserved=
(SRAM_1.5K)
19600h-19FFFh
In
SEC1110/SEC1210
ROM=
1A000h-1DFFFh else
Reserved=
1A000h-1FFFFh
In
SEC1110/SEC1210
ROM=
1A000h-1DFFFh else
Reserved=
1A000h-1FFFFh
In
SEC1110/SEC1210
ROM=
1A000h-1DFFFh else
Reserved=
1A000h-1FFFFh
TABLE 7-4: CPU BOOT ADDRESS MAPPING
CPU CODE
MAPPED
ADDRESS[15:
0] CPU UNMAPPED ADDRESS[16:0] COMMENT
SEC1110/SEC1210
DS00001561C-page 24 2013 - 2016 Microchip Technology Inc.
8.0 EC EXTERNAL INTERRUPTS
8.1 General Description
The R8051XC2 is 80515-compatible and will be configured to support thirteen external interrupt sources and four priority
levels. In addition, there are individual internal interrupt sources for the R8051XC2 configured peripherals such as
the timers and SPI1 interfaces. Each source has its own request flag(s). Each interrupt requested by the corresponding
flag can be individually enabled or disabled by dedicated enable bits in the SFRs.
8.2 Interrupt Summary
TABLE 8-1: INTERRUPT VECTOR MAPPING
INTERRUPT
INTPUT/
VECTOR
SOURCE DESCRIPTION
int_vect_03 ie0 External Interrupt 0 - all interrupts ORed except GPIOs
In SEC1110/SEC1210 version, the SPI1, Power Status interrupts will not
cause an ie0 interrupt.
int_vect_0B t0_f0 Timer 0 overflow
int_vect_13 ie1 External Interrupt 1 - GPIO Port 0,1,2 interrupts
int_vect_1B tf1_gate Timer 1 overflow
int_vect_23 uart_int Serial Port 0 Interrupt
int_vect_2B unused Reserved
int_vect_43 iex7_gate External Interrupt 7 - Reserved
int_vect_4B iex2_gate External Interrupt 2 - SPI1 Interrupt
int_vect_53 EP3INT External Interrupt 3 - Endpoint 3 Interrupt. Also is active for Timer2 crc/cc0
comparator output.
int_vect_5B EP4INT External Interrupt 4 - Endpoint 4 Interrupt. Also is active for Timer2 cc1
comparator output.
int_vect_63 USB_INT_REG External Interrupt 5 - USB Interrupt. Also is active for Timer2 cc2 comparator
output.
In SEC1110/SEC1210, the Timer2 cc2 comparator output will not cause an
interrupt.
int_vect_6B POWER_STS External Interrupt 6 - Power status event. Also is active for Timer2 cc3
comparator output.
In SEC1110/SEC1210, the Timer2 cc3 comparator output will not cause an
interrupt.
int_vect_83 unused External Interrupt -Reserved
int_vect_8B EP1INT External Interrupt 8 - Endpoint 1 Interrupt
int_vect_93 EP2INT External Interrupt 9 - Endpoint 2 Interrupt
int_vect_9B EP5INT External Interrupt 10 - Endpoint 5 Interrupt
int_vect_A3 EP0INT External Interrupt 11 - Endpoint 0 Interrupt
int_vect_AB iex12 External Interrupt 12 - Smart Card1 and Smart Card2 Interrupt
Note: In SEC1110/SEC1210 version, External Interrupts 4, 5, and 6 are not active when TImer2 comparator outputs
for cc1, cc2, and cc3 respectively are active. This Anomaly 24 is fixed in later versions.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 25
SEC1110/SEC1210
8.3 EC ISR
The Interrupt Service Routine (ISR) unit, is a subcomponent responsible for interrupt handling. It receives up to 19 interrupt
requests. Each of the interrupt sources can be individually enabled or disabled by the corresponding enable flag in
the ien0, ien1, ien2, and ien4 SFR registers. Additionally all interrupts can be globally enabled or disabled by the ea flag
in the ien0 Special Function Register.
All interrupt sources are divided into 6 interrupts groups. The definition of each group is shown in Table 8-2.
Inside a group, hardware dictates the interrupt priority structure. Interrupt sources from the first column have the highest
priority, sources from second column have middle priority, and sources from last column have the lowest priority. The
interrupt priority inside the group cannot be changed, where there is also an interrupt priority structure between the
groups. Group0 has the highest priority and Group5 has the lowest. The priority between groups can be programmed
by changing priority level (priority level can be set from 0 to 3) that is assigned to each group. The priority level of an
interrupt group is defined by flags of the ip0 and ip1 SFRs. When the priority levels for two groups are programmed to
the same level, the priority among them is in the order, from high to low (Group0 down to Group5).
To determine which interrupt has the highest priority (which must be serviced in the first order) the following steps are
completed:
1. From all groups, those with the highest priority level are chosen.
2. From those with the highest priority level, the one with the highest natural priority between the groups in chosen.
3. From the group with highest priority, the interrupt with the highest priority inside the group is chosen.
The currently running interrupt service subroutine can be interrupted only by interrupts with a higher priority level. No
interrupt with the same or lower priority level can interrupt the currently running interrupt service subroutine. Therefore
there can be a maximum of four interrupts in service at the same time.
TABLE 8-2: INTERRUPT PRIORITY GROUPS
GROUP
Highest Priority in Group Lowest Priority in
Group
INTERRUPT
VECTOR
INTERRUPT
ENABLE BIT
NAME(BIT)
INTERRUPT
VECTOR
INTERRUPT
ENABLE BIT
INTERRUPT
VECTOR
INTERRUPT
ENABLE BIT
INTERRUPT
VECTOR
INTERRU
PT
ENABLE
BIT
Group0 int_vect_03
(External
Interrupt 0 - all
interrupts
ORed except
GPIOs)
ien0(0) int_vect_83
(unused)
ien2(0) int_vect_43
(External
Interrupt 7 -
reserved)
ien1(0)
Group1 int_vect_0B
(Timer 0
Interrupt)
ien0(1) int_vect_8B
(External
Interrupt 8 -
Endpoint 1)
ien2(1) int_vect_4B
(External
Interrupt 2 -
SPI1
Interrupt)
ien1(1)
Group2 int_vect_13
(External
Interrupt 1 -
GPIO 0,1,2)
ien0(2) int_vect_93
(External
Interrupt 9 -
Endpoint 2)
ien2(2) int_vect_53
(External
Interrupt 3-
Endpoint 3)
ien1(2)
Group3 int_vect_1B
(Timer 1
Interrupt)
ien0(3) int_vect_9B
(External
Interrupt 10 -
Endpoint 5)
ien2(3) int_vect_5B
(External
Interrupt 4-
Endpoint 4)
ien1(3)
Group4 int_vect_23
(16550 UART
Interrupt)
ien0(4) int_vect_A3
(External
Interrupt 11 -
Endpoint 0)
ien2(4) int_vect_63
(External
Interrupt 5-
USB
Interrupt)
ien1(4)
Group5 int_vect_2B
(Timer 2
Interrupt)
ien0(5) int_vect_AB
(External
Interrupt 12 -
Smart Card
1/2)
ien2(5) int_vect_EB
(reserved)
ien4(5) int_vect_6B
(External
Interrupt 6 -
Power Status
Event)
ien1(5)
SEC1110/SEC1210
DS00001561C-page 26 2013 - 2016 Microchip Technology Inc.
The ISR block inserts two CPU clock cycle delays between an interrupt request sent to the ISR and an interrupt request
sent by ISR to the CPU. When the ISR sends an interrupt request to the CPU, it responds by executing an interrupt
acknowledge cycle.
The interrupt vector table is located at 0000h, which is in the Internal ROM or OTP.
8.4 Wake-up Interrupt Source Register
The R8051XC2 controller contains a WAKEUP feature that allows either the EXT0 or EXT1 Interrupt to wake-up the
processor from the STOP or IDLE Mode. Since the clocks to the processor will be stopped, the interrupt sources for
EXT0 and EXT1 must be combinatorial. An additional register will provide masking for the available wake-up sources.
If the interrupt is active and the corresponding bit in the Wakeup Enable Register is set, then the EXT0 Interrupt will be
active. If in IDLE or STOP Mode, this will wakeup the 8051.
The External Interrupt 1 (EXT1_INT) is connected to GPIO (0,1,2) interrupts. For a GPIO interrupt to occur, the CPU
clock must be active. The rest of the interrupt sources are ORed and connected to External Interrupt 0 (EXT0_INT),
including WOE_GPIO_INT. Additionally, the wake on event GPIO interrupt can occur when the clocks are in Sleep
Mode. Hence, the software can exit CPU_STOP Mode by any of the external interrupts.
In the SEC1110/SEC1210 version, the GPIO block runs off cpu_clk, and if the 8051 is in CPU_IDLE state, the GPIO
debounce feature does not function, as cpu_clk is gated.
In subsequent revisions, if the OSC48_SETTLE_CLKS.A1_COMPATIBILITY bit is set, the GPIO block runs off cpu_per_clk.
Hence if the 8051 is in CPU_IDLE state, the GPIO debounce feature functions normally.
FIGURE 8-1: WAKE-UP INTERRUPT
USB_INT
EP0INT
USB_WU_INT
POWER_STS_INT
SPI1_INT
UART_INT
GPIO_INT (ie1)
GPIO 0, 1, 2
WOE_GPIO_INT
WOE (CLK_PWR)
EXT1_INT
EXT0_INT
UART
SmartCard1/2
SC_INT
SPI1_INT
CLK_PWR
EP1INT
EP2INT
EP3INT
EP4INT
EP5INT
8051
WAKEUPCTRL
Endpoint DMA
USB Interface
2013 - 2016 Microchip Technology Inc. DS00001561C-page 27
SEC1110/SEC1210
9.0 8051 SPECIAL FUNCTION REGISTERS
9.1 Special Function Registers Locations
The map of special function registers is shown below in Table 9-1. Some addresses are occupied, while others are not
implemented. Read and write access to addresses that are not implemented will have no effect.
9.1.1 ACCUMULATOR REGISTER – ACC
The Accumulator Register is used by most of the R8051XC2 instructions to hold the operand and to store the result of
an operation. The mnemonics for accumulator-specific instructions refer to accumulator as A, not ACC.
TABLE 9-1: SPECIAL FUNCTION REGISTER LOCATIONS
HEX 0X0 0X1 0X2 0X3 0X4 0X5 0X6 0X7 HEX
F8 FF
F0 B SRST F7
E8 EF
E0 ACC SPSTA SPCON SPDAT SPSSN E7
D8 DF
D0 PSW D7
C8 T2CON CRCL CRCH TL2 TH2 CF
C0 CCEN CCL1 CCH1 CCL2 CCH2 CCL3 CCH3 C7
B8 IEN1 IP1 BF
B0 B7
A8 IEN0 IP0 AF
A0 A7
98 IEN2 9F
90 DPS DPC PAGESE
L
D_PAGE
SEL 97
88 TCON TMOD TL0 TL1 TH0 TH1 8F
80 SP DPL DPH DPL1 DPH1 WDTREL PCON 87
Note: The boxes shaded regions are undefined registers.
TABLE 9-2: ACC
ACC
(SFR 0XE0 - RESET=0X00) ACCUMULATOR
BIT NAME R/W DESCRIPTION
7:0 A R/W Accumulator
SEC1110/SEC1210
DS00001561C-page 28 2013 - 2016 Microchip Technology Inc.
9.1.2 B REGISTER – B
9.1.3 PROGRAM STATUS WORD REGISTER – PSW
The PSW Register contains status bits that reflect the current state of the CPU.
The state of the rs1 and rs0 bits selects the working register bank as outlined in Table 9-5.
TABLE 9-3: B REGISTER
B
(SFR 0XF0 - RESET=0X00) B
BIT NAME R/W DESCRIPTION
7:0 B R/W Used during multiplying and division instructions. It can also be used
as a scratch-pad register to hold temporary data.
Note: The parity bit can only be modified by hardware by the state of ACC Register.
TABLE 9-4: PROGRAM STATUS WORD REGISTER
PSW
(SFR 0XD0 - RESET=0X00) STACK POINTER
BIT NAME R/W DESCRIPTION
7 cy R/W Carry flag:
The carry bit in arithmetic operations and the accumulator for Boolean
operations.
6 ac R/W Auxiliary Carry Flag:
Set if there is a carry-out from 3rd bit of the accumulator in BCD
operations.
5 f0 R/W General Purpose Flag 0:
Available for general use.
4 rs1 R/W Register Bank Select Control Bit 1:
Used to select the working register bank.
3 rs0 R/W Register Bank Select Control Bit 0:
Used to select the working register bank.
2 ov R/W Overflow Flag:
Set in case of overflow in accumulator during arithmetic operations.
1 f1 R/W General Purpose Flag 1:
Available for general use.
0 p R Parity Flag:
Reflects the number of 1s in the accumulator.
1 : If the accumulator contains an odd number of 1s
0 : If the accumulator contains an even number of 1s
TABLE 9-5: REGISTER BANK LOCATIONS
rs1 rs0 SELECTED REGISTER BANK LOCATION
0 0 Bank 0 (00H – 07H)
0 1 Bank 1 (08H – 0FH)
1 0 Bank 2 (10H – 17H)
1 1 Bank 3 (18H – 1FH)
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9.1.4 STACK POINTER REGISTER – SP
The Stack Pointer Register is used to store the return address of a program before executing an interrupt routine or
subprograms. The SP is incremented before executing a PUSH or CALL instruction, and it is decremented after executing
a POP or RET(I) instruction (it always points the top of stack).
9.1.5 DATA POINTER AND DATA POINTER 1 REGISTERS – DPH, DPL AND DPH1, DPL1
One of two data pointer registers can be accessed through DPL and DPH. The actual Data Pointer is selected by the
DPSEL Register.
These registers are intended to hold a 16-bit address in the Indirect Addressing Mode used by MOVX (move external
memory), MOVC (move program memory) or JMP (computed branch) instructions. They may be manipulated as a 16-
bit register or as two separate 8-bit registers. DPH holds the high byte and DPL holds the low byte of the indirect
address.
In general, the Data Pointer registers are used to access external code or data space (e.g., MOVC A,@A+DPTR or MOV
A,@DPTR, respectively).
The Data Pointer 1 Register can be accessed through DPL1 and DPH1. These SFR locations always refer to the
DPTR1, regardless of the actual data pointer selection by the DPS Register. This 16-bit register is used by all DPTRrelated
instructions when the LSB of the DPS Register is set to 1, otherwise the DPTR is taken from DPH and DPL.
TABLE 9-6: STACK POINTER REGISTER
SP
(SFR 0X81 - RESET=0X07) STACK POINTER
BIT NAME R/W DESCRIPTION
7:0 SP[7:0] R/W Clock Divide Low Byte:
Points to the top of the stack in the internal data memory space.
TABLE 9-7: DATA POINTER(1) LOW REGISTER
DPL
(SFR 0X82 - RESET=0X00)
DPL1
(SFR 0X84 - RESET=0X00)
DATA POINTER LOW
BIT NAME R/W DESCRIPTION
7:0 DPL[7:0] R/W Data Pointer Low Byte
TABLE 9-8: DATA POINTER(1) HIGH REGISTER
DPH
(SFR 0X83 - RESET=0X00)
DPH1
(SFR 0X85 - RESET=0X00)
DATA POINTER HIGH
BIT NAME R/W DESCRIPTION
7:0 DPH[7:0] R/W Data Pointer High Byte
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9.1.6 DATA POINTER SELECT REGISTER – DPS
The R8051XC2 contains up to two data pointer registers. Each of these registers can be used as 16-bit address source
for indirect addressing. The DPS Register serves for selecting the active data pointer register.
9.1.7 DATA POINTER CONTROL REGISTER – DPC
The R8051XC2 contains an optional DPTR-related arithmetic unit. It provides auto-increment/auto-decrement by 1 or
2, and auto-switching between active DPTRs. These functions are controlled by the DPC Register, where there are separate
DPC register bits for each DPTR, to provide high flexibility in data transfers. The DPC Register address 0x93
points to the window where the actual dpc is selected using the DPS Register, same as for the DPTR.
TABLE 9-9: DATA POINTER SELECT REGISTER
DPS
(SFR 0X92 - RESET=0X00) DATA POINTER SELECT REGISTER
BIT NAME R/W DESCRIPTION
7:1 Reserved R Always read as 0
0 dpsel0 R/W Data Pointer Register Select:
0 : Data pointer 0 selected
1 : Data pointer 1 selected
TABLE 9-10: DATA POINTER CONTROL REGISTER
DPC
(SFR 0X93 - RESET=0X00) DATA POINTER CONTROL REGISTER
BIT NAME R/W DESCRIPTION
7:6 Reserved R Always read as 0
5:4 dpc[5:4] R/W Not used
3 dpc.3 R/W Next Data Pointer Selection:
The contents of this field is loaded to the DPS Register bit 0 after
each MOVX @DPTR instruction.
Note: This feature is not always enabled. Therefore, for each of
the DPS registers this field has to contain a different value
pointing to itself so that the auto-switching does not occur
with default (reset) values.
2 dpc.2 R/W Auto-Modification Size:
When 0, the current DPTR is automatically modified by 1 after each
MOVX @DPTR instruction when dps.0=1. When 1, the current DPTR
is automatically modified by 2 after each MOVX @DPTR instruction
when dps.0=1.
1 dps.1 R/W Auto-Modification Direction:
When 0, the current DPTR is automatically incremented after each
MOVX @DPTR instruction when dps.0=1. When 1, the current DPTR
is automatically decremented after each MOVX @DPTR instruction
when dps.0=1.
0 dps.0 R/W Auto-Modification Enable:
When set, enables auto-modification of the current DPTR after each
MOVX @DPTR instruction
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9.1.8 PROGRAM MEMORY PAGE SELECTOR REGISTER – PAGESEL
The program memory address bus (memaddr) can be extended up to 17 bits with the use of banking. When the CPU
targets addresses between 0000h and 7FFFh, the additional bits of the address bus are always 0, as the lowest 32 kB
is the common bank to store reset and interrupt vectors, and all common/shared/root subroutines. When the CPU
address is higher than 7FFFh of the program memory, the 2-bit contents of the PAGESEL Register is placed into the
memaddr[16:15] bits. The maximum number of pages is 4 (the common one at 0-32 kB, and 3 pages (banks) logically
visible at addresses between 32 kB-64 kB).
9.1.9 DATA MEMORY PAGE SELECTOR REGISTER – D_PAGESEL
The external data memory address bus (memaddr) can be extended up to 17 bits with the use of banking. When the
CPU targets addresses between 0000h and 7FFFh, the additional bits of the address bus are always 0. When the CPU
addresses higher than 7FFFh of the program memory, the 2-bit contents of the D_PAGESEL Register is placed onto
the memaddr[16:15] bits. The maximum number of pages is 4 (the common one at 0-32 kB, and 3 pages (banks) logically
visible at addresses between 32 kB-64 kB).
TABLE 9-11: PROGRAM MEMORY PAGE SELECTOR REGISTER
PAGESEL
(SFR 0X94 - RESET=0X01) PROGRAM MEMORY PAGE SELECTOR REGISTER
BIT NAME R/W DESCRIPTION
7:2 Reserved R Always read as 0
1:0 pagesel[1:0] R/W Provides an additional address for program memory in banking
scheme for memaddr[16:15]. Note that the default value is 1, to
provide normal address generation (logical address of 8000h equals
the physical address) when the PAGESEL Register is not written at
all after reset. The value of 0 should not be used since it causes the
banked area (logical address between 8000h-FFFFh) to overlap
physically with the common bank (0000h-7FFFh).
Note: The 0 value of the PAGESEL Register should not be used since it leads to accessing the same physical
area at logical address space 8000h-FFFFh as 0000h-7FFFh. This causes the banked area to overlap with
the common bank.
TABLE 9-12: DATA MEMORY PAGE SELECTOR REGISTER
D_PAGESEL
(SFR 0X95 - RESET=0X01) DATA MEMORY PAGE SELECTOR REGISTER
BIT NAME R/W DESCRIPTION
7:2 Reserved R Always read as 0
1:0 d_pagesel[1:0] R/W Provides an additional address for data memory in banking scheme.
The default value is 1, to provide normal address generation (logical
address of 8000h equals the physical address) when the
D_PAGESEL Register is not written to after reset. The value of 0
should not be used since it causes the banked area (logical address
between 8000h-FFFFh) to overlap physically with the common bank
(0000h-7FFFh).
Note: The 0 value of the D_PAGESEL Register should not be used since it leads to accessing the same physical
area at logical address space 8000h-FFFFh as 0000h-7FFFh. This causes the banked area to overlap with
the common bank.
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9.1.10 TIMER/COUNTER CONTROL REGISTER – TCON
The TCON Register reflects the current status of R8051XC2 Timer 0 and Timer 1 and it is used to control operation of
these modules. The tf0, tf1 (Timer 0 and Timer 1 overflow flags), ie0 and ie1 (External Interrupt 0 and 1 flags) will be
automatically cleared by hardware when the corresponding service routine is called.
TABLE 9-13: TIMER/COUNTER CONTROL REGISTER
TCON
(SFR 0X88 - RESET=0X00) TIMER/COUNTER CONTROL REGISTER
BIT NAME R/W DESCRIPTION
7 tf1 R/W Timer 1 Overflow Flag:
Set by hardware when Timer 1 overflows. This flag can be cleared by
software and is automatically cleared when an interrupt is processed.
6 tr1 R/W Timer 1 Run Control:
If cleared, Timer 1 stops.
5 tf0 R/W Timer 0 Overflow Flag:
Set by hardware when Timer 0 overflows. This flag can be cleared by
software and is automatically cleared when an interrupt is processed.
4 tr0 R/W Timer 0 Run Control:
If cleared, Timer 0 stops.
3 ie1 R/W External Interrupt 1 Flag:
Set by hardware when an external interrupt int1 (edge/level,
depending on settings) is observed. It is cleared by hardware when
an interrupt is processed.
2 it1 R/W External Interrupt 1 Type Control:
If set, External Interrupt 1 is activated at falling edge on input pin. If
cleared, External Interrupt 1 is activated at low level on input pin.
1 ie0 R/W External Interrupt 0 Flag:
Set by hardware when an external interrupt int0 (edge/level,
depending on settings) is observed. Cleared by hardware when
interrupt is processed.
0 it0 R/W External Interrupt 0 Type Control:
If set, External Interrupt 0 is activated at falling edge on input pin. If
cleared, External Interrupt 0 is activated at low level on input pin.
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9.1.11 TIMER MODE REGISTER – TMOD
The TMOD Register is used in configuration of the R8051XC2 Timer 0 and Timer 1.
TABLE 9-14: TIMER MODE REGISTER
TMOD
(SFR 0X89 - RESET=0X00) TIMER MODE REGISTER
BIT NAME R/W DESCRIPTION
7 gate R/W Timer 1 Gate Control:
If set, enables external gate control (pin int(1)) for Counter 1. When
int(1) is high, and tr1 bit is set, the Counter 1 is incremented every
falling edge on the t1 input pin.
6 c/t R/W Timer 1 Counter/Timer Select:
Selects the timer or counter operation. When set to 1, a counter
operation is performed; when cleared to 0, the Timer/Counter 1 will
function as a timer.
5 m1 R/W Timer 1 Mode:
4 m0 Selects mode for Timer/Counter 1, as shown in Table 9-15 below.
3 gate R/W Timer 0 Gate Control:
If set, enables external gate control (pin int(0)) for Counter 0. When
int(0) is high, and tr0 bit is set, the Counter 0 is incremented every
falling edge on the t0 input pin
2 c/t R/W Timer 0 Counter/Timer Select:
Selects the timer or counter operation. When set to 1, a counter
operation is performed; when cleared to 0, the Timer/Counter 0 will
function as a timer.
1 m1 R/W Timer 0 Mode:
0 m0 Selects the mode for Timer/Counter 0, as shown in Table 9-15 below.
TABLE 9-15: TIMER/COUNTER MODES
M0 M1 MODE FUNCTION
0 0 Mode 0 13-bit Counter/Timer, with 5 lower bits in the TL0 (TL1) Register and 8 bits
in TH0 (TH1) Register (for Timer 0 or Timer 1, respectively). Note, that
unlike in the 80C51, the 3 high-order bits of TL0 (TL1) are zeroed
whenever Mode 0 is enabled.
0 1 Mode 1 16-bit Counter/Timer
1 0 Mode 2 8-bit auto-reload counter/timer. The reload value is kept in TH0 (TH1),
while TL0 (TL1) is incremented every machine cycle. When TL0 (TL1)
overflows, a value from TH0 (TH1) is copied to TL0 (TL1).
1 1 Mode 3 For Timer 1: Timer 1 is stopped.
For Timer 0: Timer 0 acts as two independent 8-bit timers / counters – TL0,
TH0.
• TL0 uses the Timer 0 control bits and sets the tf0 flag on overflow.
• TH0 operates as the timer, which is enabled by the tr1 bit and sets the
tf1 flag on overflow.
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9.1.12 TIMER 0,1,2 – TH0, TL0, TH1, TL1, TH2, TL2
• TH0, TL0 registers reflect the state of Timer 0. TH0 holds higher byte and TL0 holds lower byte.
• Timer 0 can be configured to operate as either a timer or counter.
• TH1, TL1 registers reflect the state of Timer 1. TH1 holds the higher byte and TL1 holds the lower byte.
• Timer 1 can be configured to operate as either a timer or counter.
• TH2, TL2 registers reflect the state of Timer 2. TH2 holds the higher byte and TL2 holds the lower byte.
• Timer 2 can be configured to operate in compare, capture or reload modes.
9.1.13 TIMER 2 CONTROL REGISTER – T2CON
The T2CON Register reflects the current status of the R8051XC2 Timer 2 and is used to control Timer 2 operation.
TABLE 9-16: TIMER 0, 1, AND 2 LOW BYTE
TL0
(SFR 0X8A - RESET=0X00)
TL1
(SFR 0X8B - RESET=0X00)
TL2
(SFR 0XCC - RESET=0X00)
TIMER 0/1/2 LOW BYTE
BIT NAME R/W DESCRIPTION
7:0 TL0[7:0]/TL1[7:0]/ TL2[7:0] R/W Timer 0/ Timer 1/Timer 2 Low Byte
TABLE 9-17: TIMER 0, 1, AND 2 HIGH BYTE
TH0
(SFR 0X8C - RESET=0X00)
TH1
(SFR 0X8D - RESET=0X00)
TH2
(SFR 0XCD - RESET=0X00)
TIMER 0/1/2 HIGH BYTE
BIT NAME R/W DESCRIPTION
7:0 TH0[7:0]/ TH1[7:0] R/W TImer 0/ Timer 1/Timer 2 High Byte
TABLE 9-18: TIMER 2 CONTROL REGISTER
T2CON
(SFR 0XC8 - RESET=0X00) TIMER 2 CONTROL REGISTER
BIT NAME R/W DESCRIPTION
7 t2ps R/W Prescaler Select:
0 : Timer 2 is clocked with 1/12 of the oscillator frequency.
1 : Timer 2 is clocked with 1/24 of the oscillator frequency.
6 i3fr R/W Active edge selection for external interrupt “int3”, (used also as a
compare and capture signal):
0 : Falling edge
1 : Rising edge
5 i2fr R/W Active edge selection for external interrupt “int2”:
0 : Falling edge
1 : Rising edge
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9.1.14 TIMER 2 COMPARE/CAPTURE ENABLE REGISTER – CCEN
The CCEN Register serves as a configuration register for the compare/capture unit associated with the Timer 2.
4 t2r1 R/W Timer 2 Reload Mode Selection:
0X : Reload disabled
10 : Mode 0
11 : Mode 1
3 t2r0
2 t2cm R/W Timer 2 Compare Mode Selection:
0 : Mode 0
1 : Mode 1
1 t2i1 R/W Timer 2 Input Selection (t2i1, t2i0):
00 : Timer 2 stopped
01 : Input frequency f/12 or f/24
10 : Timer 2 is incremented by falling edge detection at pin “t2”.
11 : Input frequency f/12 or f/24 gated by external pin “t2”.
0 t2i0
TABLE 9-19: TIME 2 COMPARE/CAPTURE ENABLE REGISTER
CCEN
(SFR 0XC1 - RESET=0X00) TIMER 2 CCEN REGISTER
BIT NAME R/W DESCRIPTION
7 cocah3 R/W Compare/Capture Mode for the CC3 Register:
00 : Compare/capture disabled
01 : Capture on rising edge at pin TIMER2_CC0
10 : Compare enabled
11 : Capture on write operation into register CC3
6 cocal3
5 cocah2 R/W Compare/Capture Mode for the CC2 Register:
00 : Compare/capture disabled
01 : Capture on rising edge at pin TIMER2_CC1
10 : Compare enabled
11 : Capture on write operation into register CC2
4 cocal2
3 cocah1 R/W Compare/Capture Mode for the CC1 Register:
00 : Compare/capture disabled
01 : Capture on rising edge at pin TIMER2_CC2
10 : Compare enabled
11 : Capture on write operation into register CC1
2 cocal1
1 cocah0 R/W Compare/Capture Mode for CRC Register
00 : Compare/capture disabled
01 : Capture on falling/rising edge at pin TIMER2_CC3 (not used)
10 : Compare enabled
11 : Capture on write operation into register CRCL
0 cocal0
TABLE 9-18: TIMER 2 CONTROL REGISTER (CONTINUED)
T2CON
(SFR 0XC8 - RESET=0X00) TIMER 2 CONTROL REGISTER
BIT NAME R/W DESCRIPTION
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9.1.15 TIMER 2 COMPARE/CAPTURE REGISTERS – CC1, CC2, CC3
Compare/Capture Registers (CC1, CC2, CC3) are 16-bit registers used in the operation of the compare/capture unit
associated with Timer 2. CCHn holds the higher byte and CCLn holds the lower byte of the CCn Register.
9.1.16 TIMER 2 COMPARE/CAPTURE REGISTERS – CRCH, CRCL
Compare/Capture Registers (CRCH, CRCL) are 16-bit registers used in the operation of the compare/capture unit associated
with the Timer 2. CRCH holds higher byte and CRCL holds lower byte.
TABLE 9-20: TIMER 2 COMPARE/CAPTURE REGISTERS LOW BYTE
CCL1
(SFR 0XC2 - RESET=0X00)
CCL2
(SFR 0XC4 - RESET=0X00)
CCL3
(SFR 0XC6 - RESET=0X00)
TIMER 2 COMPARE/CAPTURE 1,2,3 LOW BYTE
BIT NAME R/W DESCRIPTION
7:0 CCL1[7:0]/ CCL2[7:0]/
CCL3[7:0]
R/W TImer 2 Compare/Capture Register Low Byte
TABLE 9-21: TIMER 2 COMPARE/CAPTURE REGISTERS HIGH BYTE
CCH1
(SFR 0XC3 - RESET=0X00)
CCH2
(SFR 0XC5 - RESET=0X00)
CCH3
(SFR 0XC7 - RESET=0X00)
TIMER 2 COMPARE/CAPTURE 1,2,3 HIGH BYTE
BIT NAME R/W DESCRIPTION
7:0 CCH1[7:0]/ CCH2[7:0]/
CCH3[7:0]
R/W TImer 2 Compare/Capture Register High Byte
TABLE 9-22: TIMER 2 COMPARE/CAPTURE REGISTERS
CRCL
(SFR 0XCA - RESET=0X00) TIMER 2 COMPARE/CAPTURE 1,2,3 LOW BYTE
BIT NAME R/W DESCRIPTION
7:0 CRCL[7:0] R/W TImer 2 Compare/Capture Register Low Byte
TABLE 9-23: TIMER 2 COMPARE/CAPTURE REGISTER
CRCH
(SFR 0XCB - RESET=0X00) TIMER 2 COMPARE/CAPTURE 1,2,3 HIGH BYTE
BIT NAME R/W DESCRIPTION
7:0 CRCH[7:0] R/W TImer 2 Compare/Capture Register High Byte
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9.1.17 WATCHDOG TIMER RELOAD REGISTER – WDTREL
The WDTREL Register holds the reload value of 7 high-order bits of the watchdog timer. It also configures the frequency
prescaler for the watchdog timer.
9.1.18 INTERRUPT ENABLE 0 REGISTER – IEN0
TABLE 9-24: WATCHDOG TIMER RELOAD REGISTER
WDTREL
(SFR 0X86 - RESET=0X00) DATA POINTER LOW
BIT NAME R/W DESCRIPTION
7 WDTREL7 R/W Prescaler Select:
When set, the watchdog is clocked through an additional divide-by16
prescaler.
6:0 WDTREL[6:0] R/W Watchdog Reload Value:
Reload value for the highest 7 bits of the watchdog timer. This value
is loaded to the watchdog timer when a refresh is triggered by a
consecutive setting of bits IEN0.wdt and IEN1.swdt).
TABLE 9-25: INTERRUPT ENABLE 0 REGISTER
IEN0
(SFR 0XA8 - RESET=0X00) INTERRUPT ENABLE 0 REGISTER
BIT NAME R/W DESCRIPTION
7 eal R/W Interrupts Enable:
When set to 0 – all interrupts are disabled. Otherwise enabling each
interrupt is done by setting the corresponding interrupt enable bit.
6 wdt R/W Watchdog Timer Refresh Flag:
Set to initiate a refresh of the watchdog timer.
This bit must be set directly before IEN1.swdt is set to prevent an
unintentional refresh of the watchdog timer. The wdt bit is cleared by
hardware after the next instruction executed after the one that had
set this bit. Therefore, a watchdog refresh can only be done by
sequentially setting wdt followed by swdt.
5 et2 R/W Timer 2 Interrupt Enable:
et2=0 : Timer 2 Interrupt is disabled.
et2=1 : and eal=1 Timer 2 Interrupt is enabled.
4 es0 R/W 16550 Serial Port 0 Interrupt Enable:
es0=0 : Serial Port 0 Interrupt is disabled.
es0=1 and eal=1 : Serial Port 0 Interrupt is enabled.
3 et1 R/W Timer 1 Overflow Interrupt Enable:
et1=0 : Timer 1 Overflow Interrupt is disabled.
et1=1 and eal=1 : Timer 1 Overflow Interrupt is enabled.
2 ex1 R/W External Interrupt 1 Enable (GPIO Ports 0,1,2):
ex1=0 : External Interrupt 1 is disabled.
ex1=1 and eal=1 : External Interrupt 1 is enabled.
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9.1.19 INTERRUPT ENABLE 1 REGISTER – IEN1
1 et0 R/W Timer 0 Overflow Interrupt Enable:
et0=0 : Timer 0 Overflow Interrupt is disabled.
et0=1 and eal=1 : Timer 0 Overflow Interrupt is enabled.
0 ex0 R/W External Interrupt 0 Enable (or of all interrupts except GPIOs)
ex0=0 : External Interrupt 0 is disabled.
ex0=1 : and eal=1 External Interrupt 0 is enabled.
TABLE 9-26: INTERRUPT ENABLE 1 REGISTER
IEN1
(SFR 0XB8 - RESET=0X00) INTERRUPT ENABLE 1 REGISTER
BIT NAME R/W DESCRIPTION
7 exen2 R/W Timer 2 External Reload Interrupt Enable:
exen2=0 : Timer 2 External Reload Interrupt 2 is disabled.
exen2=1 and eal=1 : Timer 2 External Reload Interrupt 2 is enabled.
6 swdt R/W Watchdog Timer Start/Refresh Flag: set to activate/refresh the
watchdog timer.
When set directly after setting IEN0.wdt, a watchdog timer refresh is
performed. This bit is immediately cleared by hardware.
5 ex6 R/W External Interrupt 6 Enable (Power Status Event):
ex6=0 : External Interrupt 6 is disabled.
ex6=1 and eal=1 : External Interrupt 6 is enabled.
4 ex5 R/W External Interrupt 5 Enable (USB):
ex5=0 : External Interrupt 5 is disabled.
ex5=1 and eal=1 : External Interrupt 5 is enabled.
3 ex4 R/W External Interrupt 4 Enable (Endpoint 4):
ex4=0 : External Interrupt 4 is disabled.
ex4=1 and eal=1 : External Interrupt 4 is enabled.
2 ex3 R/W External Interrupt 3 Enable (Endpoint 3):
ex3=0 : External Interrupt 3 is disabled.
ex3=1 and eal=1 : External Interrupt 3 is enabled.
1 ex2 R/W External Interrupt 2 Enable (SPI1):
ex2=0 : External Interrupt 2 is disabled.
ex2=1 and eal=1 : External Interrupt 2 is enabled.
0 ex7 R/W External Interrupt 7 Enable (Interrupt not connected to any source)
TABLE 9-25: INTERRUPT ENABLE 0 REGISTER (CONTINUED)
IEN0
(SFR 0XA8 - RESET=0X00) INTERRUPT ENABLE 0 REGISTER
BIT NAME R/W DESCRIPTION
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9.1.20 INTERRUPT ENABLE 2 REGISTER – IEN2
TABLE 9-27: INTERRUPT ENABLE 2 REGISTER
IEN2
(SFR 0X9A - RESET=0X00) INTERRUPT ENABLE 2 REGISTER
BIT NAME R/W DESCRIPTION
7:6 Reserved R Always read as 0
5 ex12 R/W External Interrupt 12 Enable (Smart Card 1 or 2):
ex12=0 : External Interrupt 12 is disabled.
ex12=1 and eal=1 : External Interrupt 12 is enabled.
4 ex11 R/W External Interrupt 11 Enable (Endpoint 0):
ex11=0 : External Interrupt 11 is disabled.
ex11=1 and eal=1 : External Interrupt 11 is enabled.
3 ex10 R/W External Interrupt 10 Enable (Endpoint 5):
ex10=0 : External Interrupt 10 is disabled.
ex10=1 and eal=1 : External Interrupt 10 is enabled.
2 ex9 R/W External Interrupt 9 Enable (Endpoint 2):
ex9=0 : External Interrupt 9 is disabled.
ex9=1 and eal=1 : External Interrupt 9 is enabled.
1 ex8 R/W External Interrupt 8 Enable (Endpoint 1):
ex8=0 : External Interrupt 8 is disabled.
ex8=1 and eal=1 : External Interrupt 8 is enabled.
0 Reserved R Always read as 0
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9.1.21 INTERRUPT PRIORITY REGISTERS – IP0, IP1
The 18 interrupt sources are grouped into 6 priority groups. For each of the groups, one of four priority levels can be
selected. It is achieved by setting appropriate values in the IP0 and IP1 registers.
The contents of the interrupt priority registers define the priority levels for each interrupt source according to the tables
below.
TABLE 9-28: INTERRUPT PRIORITY 0 REGISTER
IP0
(SFR 0XA9 - RESET=0X00) INTERRUPT PRIORITY 0 REGISTER
BIT NAME R/W DESCRIPTION
7 Reserved R/W Always read as 0
6 wdts R/W Watchdog Timer Status Flag:
This bit is not set by hardware when the watchdog timer reset occurs.
If the RESET_SRC_WDOG bit in the CLKPWR_TEST4 Register is set,
it indicates that the chip reset was due to a watchdog timer reset.
5:0 - R/W Interrupt Priority:
Each bit together with the corresponding bit from the IP1 Register
specifies the priority level of the respective interrupt priority group.
TABLE 9-29: INTERRUPT PRIORITY 1 REGISTER
IP1
(SFR 0XB9 - RESET=0X00) INTERRUPT PRIORITY 1 REGISTER
BIT NAME R/W DESCRIPTION
7:6 Reserved R/W Always read as 0
5:0 - R/W Interrupt Priority:
Each bit together with the corresponding bit from the IP0 Register
specifies the priority level of the respective interrupt priority group.
TABLE 9-30: PRIORITY GROUPS
GROUP CORRESPONDING
INTERRUPT BITS INTERRUPTS IN EACH GROUP
0 IP1.0, IP0.0 Ext Interrupt 0 - or
of all interrupts
except GPIOs
Ext Interrupt 7 -
Reserved
1 IP1.1, IP0.1 Timer 0 Interrupt External Interrupt 8
- Endpoint 1
External Interrupt 2
- SPI1 Interrupt
2 IP1.2, IP0.2 External Interrupt 1
- GPIO port 0,1
External Interrupt 9
- Endpoint 2
External Interrupt 3
- Endpoint 3
3 IP1.3, IP0.3 Timer 1 Interrupt External Interrupt
10 - Endpoint 5
External Interrupt 4
- Endpoint 4
4 IP1.4, IP0.4 16550 UART
Interrupt
External Interrupt
11 - Endpoint 0
External Interrupt 5
- USB Interrupt
5 IP1.5, IP0.5 Timer 2 Interrupt External Interrupt
12 - Smart Card
1/2
Reserved External Interrupt 6
- Power Status
Event
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9.1.22 POWER CONTROL REGISTER – PCON
9.1.22.1 pmw
The MOVX instructions perform one of two actions depending on the state of pmw bit (PCON.4). The pmw bit selects the
standard or advanced behavior of the microcontroller during execution of MOVX instruction.
When the pmw is cleared or after reset, MOVX instructions allow read/write access to external data memory space. The
software can set the pmw bit to enable access to program memory space. Once pmw is set, MOVX data memory instructions
become MOVX program memory instructions with 8 or 16-bit addressing modes. The software clears pmw to
switch back to normal MOVX behavior.
Setting or clearing pmw does not influence the execution of MOVC instruction and it does not change the behavior of
program memory reading.
9.1.22.2 CPU_IDLE
When the CPU_IDLE Mode is invoked, the ISR and other peripherals are clocked normally and interrupts are generated
normally. Therefore the irq signal coming from the ISR module can directly wake-up the CPU from CPU_IDLE Mode.
TABLE 9-31: PRIORITY LEVELS
IP1.X IP0.X PRIORITY LEVEL
0 0 Level 0 (lowest)
0 1 Level 1
1 0 Level 2
1 1 Level 3 (highest)
Note: X represents the priority group
TABLE 9-32: POWER CONTROL REGISTER
PCON
(SFR 0X87 - RESET=0X08) POWER CONTROL REGISTER
BIT NAME R/W DESCRIPTION
7 smod R/W This bit is not used.
6 wdt_tm R/W Watchdog Timer Test Mode Flag:
When set to 1, the fclk/12 divider at the input of the watchdog timer
is skipped.
5 isr_tm R/W Interrupt Service Routine Test Mode Flag:
When set to 1, the interrupt vectors assigned to Timer 0 and 1, Serial
Port 0 and 1, and SPI interfaces can be triggered only with the use
of external inputs of the core.
4 pmw R/W Program Memory Write Mode:
Setting this bit enables the Program Memory Write Mode.
3 p2sel R/W This bit is not used.
2 gf0 R/W General Purpose Flag
1 stop R/W STOP Mode Control:
Setting this bit activates the STOP Mode. This bit is always read as 0.
0 idle R/W Idle Mode Control:
Setting this bit activates the IDLE Mode. This bit is always read as 0.
SEC1110/SEC1210
DS00001561C-page 42 2013 - 2016 Microchip Technology Inc.
9.1.22.3 CPU_STOP
When the CPU_STOP Mode is invoked, neither the clkcpu nor clkper are working. The ISR module can’t generate an
interrupt since no peripherals are working. The only interrupts that may be accepted in the CPU_STOP Mode are External
Interrupt 0 and 1. Hence before entering STOP Mode, the software must activate interrupts for the expected GPIO
port 0/1/2 interrupts (or USB Interrupt due to resume). An interrupt event would enable the clocks clkcpu, clkper to continue
CPU processing.
9.1.23 SOFTWARE RESET REGISTER – SRST
9.1.24 SPI1 SERIAL PERIPHERAL STATUS REGISTER – SPSTA
TABLE 9-33: SOFTWARE RESET REGISTER
SRST
(SFR 0XF7 - RESET=0X00) SOFTWARE RESET REGISTER
BIT NAME R/W DESCRIPTION
7:1 Reserved R Always read as 0
0 srstreq R/W Software Reset Request:
Writing a 0 to this bit will have no effect.
Single writing a 1 value to this bit will have no effect.
Double writing 1 value (in two consecutive instructions) will generate
an internal software reset.
Reading this bit will NOT provide feedback about the reset source.
The RESET_SRC_SRST bit in the CLKPWR_TEST4 Register if one
indicates that the chip reset was due to software reset request.
TABLE 9-34: SPI1 SERIAL PERIPHERAL STATUS REGISTER
SPSTA
(SFR 0XE1 - RESET=0X00) SERIAL PERIPHERAL (SPI1) STATUS REGISTER
BIT NAME R/W DESCRIPTION
7 spif R Serial Peripheral Data Transfer Flag:
Set by hardware upon data transfer completion.
Cleared by hardware when data transfer is in progress. Can also be
cleared by reading the SPSTA.spif bit set, and then reading the
SPDAT Register.
6 wcol R Write Collision Flag:
Set by hardware upon write collision to SPDAT.
Cleared by hardware upon data transfer completion when no collision
has occurred. Can be also cleared by an access to the SPSTA
Register and an access to SPDAT Register.
5 sserr R Synchronous Serial Slave Error Flag:
Set by hardware when SPI1_CE input is de-asserted before the end
of receive sequence. Cleared by disabling the SPI1 module (clearing
the SPCON.spen bit).
2013 - 2016 Microchip Technology Inc. DS00001561C-page 43
SEC1110/SEC1210
The SPSTA Register contains flags to signal data transfer complete, write collision, and inconsistent logic level on
SPI1_CE (Slave select) pin (mode fault error).
9.1.25 SPI1 SERIAL PERIPHERAL CONTROL REGISTER – SPCON
The Serial Peripheral Control Register is used to configure the SPI module. It selects the Master clock rate, selects the
serial clock polarity and phase, enables the SPI1_CE input, and enables/disables the whole SPI1 module.
4 modf R Mode Fault Flag:
Set by hardware when the SPI1_CE pin level is in conflict with the
actual mode of the SPI_MS controller (configured as Master while
externally selected as Slave).
Cleared by hardware when the ssn pin is at appropriate level. Can be
also cleared by software by reading the SPSTA Register with modf
set.
3:0 Reserved R Always read as 0
TABLE 9-35: SPI1 SERIAL PERIPHERAL CONTROL REGISTER
SPCON
(SFR 0XE2 - RESET=0X14) SERIAL PERIPHERAL (SPI1) CONTROL REGISTER
BIT NAME R/W DESCRIPTION
7 spr2 R/W Serial Peripheral Rate 2:
Together with spr[1:0] defines the clock rate in Master Mode.
6 spen R/W Serial Peripheral Enable:
When cleared, disables the SPI1 Interface. When set enables the
SPI1 Interface.
5 ssdis R/W SS Disable:
When cleared enables the SPI1_CE input. When set disables the
SPI1_CE input.
When ssdis is set, no SPSTA.modf interrupt request will be generated.
4 mstr R/W Serial Peripheral Master:
When set configures the SPI1 as a Master.
3 cpol R/W Clock Polarity:
When cleared, the SPI1_CLK is set to 0 in idle state. When set, the
SPI1_CLK is set to 1 in idle state.
2 cpha R/W Clock Phase:
When cleared, data is sampled when the SPI1_CLK leaves the idle
state (see SPCON.cpol). When set, data is sampled when the
SPI1_CLK returns to idle state (see SPCON.cpol).
1:0 spr[1:0] R/W Serial Peripheral Rate:
Together with spr2 specify the serial clock rate in Master Mode.
TABLE 9-34: SPI1 SERIAL PERIPHERAL STATUS REGISTER
SPSTA
(SFR 0XE1 - RESET=0X00) SERIAL PERIPHERAL (SPI1) STATUS REGISTER
BIT NAME R/W DESCRIPTION
SEC1110/SEC1210
DS00001561C-page 44 2013 - 2016 Microchip Technology Inc.
9.1.26 SPI1 SERIAL PERIPHERAL DATA REGISTER – SPDAT
The SPDAT Register is a read/write buffer for the “receive data” register. While writing to the SPDAT, data is placed
directly into the shift register (there is no transmit buffer).
9.2 Special Function Registers Summary
The R8051XC can access up to 128 Special Function Registers. These registers can only be accessed directly.
TABLE 9-36: SPI1 TRANSFER RATE
SPR2 SPR1 SPR0 SERIAL PERIPHERAL RATE (SPI1_RATE)
0 0 0 spi1_clk/2
0 0 1 spi1_clk/4
0 1 0 spi1_clk/8
0 1 1 spi1_clk/16
1 0 0 spi1_clk/32
1 0 1 spi1_clk/64
1 1 0 spi1_clk/128
1 1 1 The Master clock is not generated (when SPCON.cpol=1, the SPI1_CLK
output is high level, otherwise is low level)
TABLE 9-37: SPI1 SERIAL PERIPHERAL DATA REGISTER
SPDAT
(SFR 0XE3 - RESET=0X00) SERIAL PERIPHERAL (SPI1) DATA REGISTER
BIT NAME R/W DESCRIPTION
7:0 spdat[7:0] R/W Serial Peripheral Data:
Reading returns the value located in the receive buffer, not the shift
register.
TABLE 9-38: SPECIAL FUNCTION REGISTERS SUMMARY
REGISTER ADDRESS DEFAULT DESCRIPTION
SP 81h 07h Stack Pointer
DPL 82h 00h Data Pointer 0 Low
DPH 83h 00h Data Pointer 0 High
DPL1 84h 00h Data Pointer 1 Low
DPH1 85h 00h Data Pointer 1 High
WDTREL 86h 00h Watchdog Timer Reload Register
PCON 87h 00h Power Control
TCON 88h 00h Timer/Counter Control Register
TMOD 89h 00h Timer Mode Register
TL0 8Ah 00h Timer 0, Low Byte
TL1 8Bh 00h Timer 1, Low Byte
TH0 8Ch 00h Timer 0, High Byte
TH1 8Dh 00h Timer 1, High Byte
DPS 92h 00h Data Pointer Select Register
2013 - 2016 Microchip Technology Inc. DS00001561C-page 45
SEC1110/SEC1210
DPC 93h 00h Data Pointer Control Register
PAGESEL 94h 01h Program Memory Page Selector
D_PAGESEL 95h 01h External Data Page Selector
IEN2 9Ah 00h Interrupt Enable Register 2
IEN0 A8h 00h Interrupt Enable Register 0
IP0 A9h 00h Interrupt Priority Register 0
IP/IEN1 B8h 00h Interrupt Priority Register/Enable Register 1
IP1 B9h 00h Interrupt Priority Register 1
CCEN C1h 00h Compare/Capture Enable Register
CCL1 C2h 00h Compare/Capture Registers – CC1 Low Byte
CCH1 C3h 00h Compare/Capture Registers – CC1 High Byte
CCL2 C4h 00h Compare/Capture Registers – CC2 Low Byte
CCH2 C5h 00h Compare/Capture Registers – CC2 High Byte
CCL3 C6h 00h Compare/Capture Registers – CC3 Low Byte
CCH3 C7h 00h Compare/Capture Registers – CC3High Byte
T2CON C8h 00h Timer 2 Control Register
CRCL CAh 00h Compare/Capture Registers – CRC Low Byte
CRCH CBh 00h Compare/Capture Registers – CRC High Byte
TL2 CCh 00h Timer 2, Low Byte
TH2 CDh 00h Timer 2, High Byte
PSW D0 00h Program Status Word
IEN4 D1h 00h Interrupt Enable Register 4
ACC E0h 00h Accumulator
SPSTA E1h 00h Serial Peripheral Status Register
SPCON E2h 14h Serial Peripheral Control Register
SPDAT E3h 00h Serial Peripheral Data Register
B F0 00h B Register
SRST F7h 00h Software Reset Register
TABLE 9-38: SPECIAL FUNCTION REGISTERS SUMMARY (CONTINUED)
REGISTER ADDRESS DEFAULT DESCRIPTION
SEC1110/SEC1210
DS00001561C-page 46 2013 - 2016 Microchip Technology Inc.
10.0 SMART CARD INTERFACE
The SEC1110 provides one Smart Card Interface based on the ISO/IEC 7816 Standard, while the SEC1210 provides
two interfaces. The SEC1210, however, provides only one shared Packet FIFO. Hence, only one of the Smart Cards
can transfer data at any point of time, though both may be active and operational.
10.1 Interconnect to Smart Card Terminal
FIGURE 10-1: SMART CARD 1 INTERCONNECT
FIGURE 10-2: S.A.M INTERFACE (SMART CARD 2)
1 5
2 6
3 7
4 8
SC1_RST_N/GPIO2
SC1_CLK/GPIO1
SC1_IO/GPIO0
SC1_C4/GPIO3
SC1_C8/GPIO4
SC1_VCC (5.0 V/ 3.0 V/ 1.8 V)
SC1_LED_ACT_N/GPIO5
SC1_PRSNT_N(GPIO6)
SEC1110/
SEC1210
TERMINAL
1 5
2 6
3 7
4 8
SC2_RST_N/ GPIO[18]
SC2_CLK/ GPIO[17]
SC2_IO/ GPIO[16]
SC2_VCC
SEC1210
TERMINAL
SC2_PSNT_N/ GPIO[19]
2013 - 2016 Microchip Technology Inc. DS00001561C-page 47
SEC1110/SEC1210
10.2 Top Level of the Smart Card Interface
The Smart Card interface can alternatively be used as GPIOs. The synchronous ISO/IEC 7816-10 is supported by this
block by bit-addressable GPIOs (controls in the SC1 and SC2), or it can be configured to output the signals from the
GPIO block itself.
The muxing of the signals of the three different interfaces is shown in the figure below. The selection of whether the
GPIOs or the Smart Card logic controls the pins is controlled by auxiliary registers in GPIO block.
FIGURE 10-3: SMART CARD1,2 INTERCONNECT
SC1_VCC
SC1_PRSNT_N/
GPIO6
XDATA
SLAVE
3.0V
1.8V
5.0/3.0/1.8 VOLT
REGULATOR
GPIO5
SC_LED_ACT_N
SC_LED_ACT_N/
GPIO5
OCS1
SC_LED_SEL
VREG_CTL
(FROM
GPIO
BLOCK)
SC1_GPIO_EN
PAD
GPIO6 (SC_PRSNT_N)
(For Auto Disconnect)
PAD
VDD33
PAD
5.0V
(FROM
CLK_PWR
BLOCK)
SC
FIFO
(Async)SC_RST_N
(Async)SC_CLK
(Async)SC_IO
(Sync)SC_RST_N
(Sync)SC_CLK
(Sync)SC_IO
SC1
UART
IP
SC1
Sync
Intfc SYNC_MODE_SEL
SC_FCB
SC_SPU
WRAPPER
SC_LED_ACT_N
SC mux
(Async)SC_RST_N
(Async)SC_CLK
(Async)SC_IO
(Sync)SC_RST_N
(Sync)SC_CLK
(Sync)SC_IO
SC2
UART
IP
SC2
Sync
Intfc SYNC_MODE_SEL
SC_FCB
SC_SPU
WRAPPER
SC_LED_ACT_N
SC mux
SC_RST_N
SC_CLK
SC_IO
SC_SPU
SC_FCB
SC_RST_N
SC_CLK
SC_IO
SC_SPU
SC_FCB
GPIO2
GPIO1
GPIO0
GPIO4
GPIO3
PAD
PAD
PAD
PAD
PAD
PAD 1.8/3.0/5.0 V IO PAD
PAD 3.3V IO PAD
GPIO
Block m ux
SC2_RST_N/GPIO18
SC 2_CLK /G PIO 17
SC 2_IO /G PIO 16
GPIO18
GPIO17
GPIO16
PAD
PAD
PAD
GPIO
Block m ux
SC2_GPIO_EN
PAD
SC2_VCC
PAD 1.8/3.0/5.0 V IO PAD
PAD
SC2_PRSNT_N/
GPIO19
GPIO19 (SC_PRSNT_N)
(For Auto Disconnect)
OCS2
PAD 1.8/3.0/5.0 V Power PAD
SC1_IO/GPIO0
SC1_SPU /SC 1_C8/
GPIO4
SC1_FCB/SC1_C4/
GPIO3
SC1_RST_N/GPIO2
SC1_CLK/GPIO1
SEC1110/SEC1210
DS00001561C-page 48 2013 - 2016 Microchip Technology Inc.
10.3 General Description
The Smart Card Interface serves as the core of a Terminal, or Interface Device (IFD), which communicates with an
insertable Smart Card, also called an Integrated Circuit Card (ICC).
The Smart Card interface is a UART-like interface that supports the ISO 7816 asynchronous protocols named T=0 and
T=1. It transmits and receives serial data via the SCx_IO (x is 1 or 2) signal pin. Each byte transmitted or received is
transferred as a character with a start bit, 8 data bits, a parity bit, and an amount of Guard Time (stop bits) that depends
on the protocol used and the declared characteristics of the card.
To initiate communication with the Smart Card, the Smart Card must be inserted into the terminal device. A mechanical
or electrical sensor will detect this event, pulling the SCx_PRSNT_N(GPIO6 or GPIO19) pin low to indicate that the electrical
contacts are seated. The insertion of the card will cause a GPIO6 or GPIO19 Interrupt after the debounce period.
If the system is in suspend state, the GPIO transition will cause the system to be woken up first, followed by the interrupt
to the processor.
Once it is established that a Smart Card is present, firmware will use the VREG_CTL Register to apply power to the
card. Once the interface is powered, the terminal can initiate communication with the Smart Card by driving the SCx-
_RST_N pin low. There are two types of resets: a cold reset and a warm reset. The cold reset sequence is used immediately
after power is applied to the interface: it generates the SCx_CLK output, sets the SCx_IO pin as an input with a
weak pull-up, and keeps the SCx_RST_N pin low (its initial state) for a defined period of time after the clock starts running.
The warm reset only affects the SCx_RST_N pin, which is pulled low for a defined period of time: it requires that
the interface already be powered and a steady clock be already applied to the card. Bits have been provided in the
SC_ICR Register that may be controlled by software to initiate these sequences. When either of these resets terminates
(SCx_RST_N going high) the Smart Card will return a sequence of characters called the Answer to Reset (ATR) message
as defined by ISO 7816-3. The Smart Card is required to respond to a reset sequence as shown in the cold reset
and warm reset timing diagrams (see Figure 10-10 and FIGURE 10-11: on page 62).
The first character of the ATR message, called TS, is interpreted by hardware in the SEC1110 and SEC1210, determining
the bit encoding convention used by the card (direct or inverse) as defined by ISO 7816-3, which defines the polarity
and the order of the data and parity bits in the character. The TS byte, interpreted according to the convention it selects,
is placed into the FIFO, and data received from that point onward is assembled according to the selected convention
and loaded into the FIFO to be read by software.
The rest of the ATR response from the Smart Card returns the operational limits of the Smart Card. Software must interpret
this response and set the SEC1110 and SEC1210 runtime registers accordingly. During the ATR message, data
will be received based on a default value of the bit time, called the Elementary Time Unit (etu). Two ATR parameters
named F and D are used to define a new etu time. Once this is determined, software can program the BRG Divisor
(SC_DLM and SC_DLL) and the sampling rate for the baud rate generator accordingly. The hardware divides the
Mhzsc1_clk (typically 48 MHz) system clock, by the BRG divisor and the sampling rate to determine the etu value (bit
time). The SCx_CLK frequency is generated by dividing the sc1_clk clock by the SC_CLK_DIV DIVISOR field. Software
will also set up the Extra Guard Time Register (SC_EGT), the Block Guard Time (SC_BGT) Register and the protocol
Mode (T=0 or T=1 Mode) to set the required amount of Guard Time between character transmissions.
A negotiation phase called PPS may occur, or communication may begin immediately using the parameters provided
by the card’s ATR message. In either case, all communication after the ATR message consists of individual exchanges,
in which the IFD transmits a block of data and the ICC responds with a return message. For this reason, and because
the response time from the ICC can be too short for software intervention, software will enable both the SEC1110 and
SEC1210 transmitter and receiver at the same time, and the receiver hardware will remain inactive until the transmission
phase of the exchange has completed.
An additional stop clock feature has been provided to hold the SCx_CLK output at a particular voltage level between
exchanges, as may be allowed by the card for power savings. Clock switching is glitch free.
Hardware protocol timers, set according to default timings, will monitor the Smart Card interface during the reset/ATR
sequence for an unresponsive or defective card, based on the EMV, ISO and PC/SC timing requirements. If the ATR
response is not received within the given time, or does not obey the required timings, a Timer Interrupt will result. The
software can then take corrective action or initiate the deactivation sequence to stop and power-down the card.
After the ATR sequence, the same set of hardware timers are used, based on ATR parameters EGT, CWT, BWT, and/or
WWT, to monitor timings for the subsequent data exchanges.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 49
SEC1110/SEC1210
One of two protocols is selected, defined by a parameter T in the ATR message, and potentially negotiated in a PPS
exchange. The protocol T=0 is character-oriented, with parity error detection and re-transmission on a character-bycharacter
basis. The protocol T=1 is block-oriented, with an error-free link layer based on block re-transmission, resembling
the X.25 communication standard. In the T=1 protocol, both individual character parity and a block check field are
used to detect errors.
The SEC1110 and SEC1210 SC_FIFO is deep enough to hold an entire message of maximum length (259 bytes in
SEC1110/SEC1210 and 261 bytes in SEC1110/SEC1210). It transmits data, pre-loaded into the SC_FIFO, when the
transmit control bit is set by software. It immediately turns around, enabling the Receiver to put data received back into
the SC_FIFO. The SC_FIFO Threshold Interrupt is triggered by received data only, though a separate interrupt is available
to signal when the transmit phase has ended. The hardware has significant knowledge of the protocol being implemented,
and can be set up to filter out bytes that would lead to a message longer than the SC_FIFO depth.
After deactivation of the ICC, it is required to perform a block reset to the smart clock block using SC1_RESET or
SC2_RESET, or initialize all the registers to desired values.
10.4 Character Framing
The SEC1110 and SEC1210 meets the requirements for a character frame as defined by ISO 7816-3. The T=0 and T=1
protocol differ in the minimum amount of Guard Time: 2 etus for T=0, and 1 etu for T=1, which does not require a character-by-character
parity error response.
Character parity is checked as each byte is received by hardware. If a parity error is detected when a byte is received,
the parity error status bit will be set. This status bit can be polled by software, or it can be programmed to generate an
interrupt and/or to deactivate the card in hardware. If character repetition is enabled (used in the T=0 protocol) the
SEC1110 and SEC1210 will pull the SCx_IO line low following a received parity error, for the duration of 1 etu as defined
by ISO 7816-3. If the card signals receipt with a parity error while the SEC1110 and SEC1210 is transmitting, it will repeat
the character up to 4 additional times. Whether transmitting or receiving, failure after 5 transmissions of the same character
will cause a Parity Error Interrupt and/or hardware deactivation of the ICC.
Note: Software should not try to initiate a RESYNCH until the transaction has completed, because the card may
still be trying to send data to the IFD. Timeout timers and an Activity Detection bit are provided to assist
software in this determination, in case of an error.
FIGURE 10-4: T=0 MODE CHARACTER TRANSMISSION AND REPETITION DIAGRAM
Note: Timing is measured in etus. 1 etu = time to transmit 1 bit. The default etu is equal to 372/f, where f is the
clock frequency.
SEC1110/SEC1210
DS00001561C-page 50 2013 - 2016 Microchip Technology Inc.
10.5 Clocking and Baud Rate Generation
The frequency of the SCx_CLK signal to the ICC, and the rate at which bits are transmitted and sampled, are determined
from the frequency of sc1_clk clock, which is a divided version of 48 MHz clock.
No other clock frequency is available in the SEC1110 and SEC1210.
10.5.1 CLOCK RATE GENERATION
The internal clock rate generator determines the frequency of the clock to be provided to the ICC on the SCx_CLK pin.
This is expressed in the least-significant 6 bits of the SC_CLK_DIV Register as a divisor on the system clock. To find
the correct value, the Fi value is read from the card, and Fmax is determined. The divisor is chosen such that SCx_CLK
is the highest possible frequency without violating the Fmax parameter. The frequency of the clock to the Smart Card
blocks is selected to be the minimum required to satisfy SCx_CLK frequency and the etu rate. This is done to lower
dynamic power dissipation of the block.
Frequency of clock to Smart Card 1 block is Fsc1_clk = 48 MHz / SC1_CLK_DIV.
Frequency of SC1_CLK pin = Fsc1_clk / DIVISOR[4:0]
10.5.2 ETU RATE GENERATION
The internal Baud Rate Generator (BRG) sets the duration of an etu (bit time). In the ATR message from the ICC, a
divisor term (F) and a multiplier term (D) come from two 4-bit values Fi and Di. (If the ICC does not provide these values,
the default is Fi=1 and Di=1, which specify a simple division by 372). The Fi and Di values are specified relative to the
SCx_CLK frequency. But within SEC1110 and SEC1210, this must be translated to a simple divisor of the system clock.
There are two components to this divisor: a Sampling Mode and a Divisor Latch value (DL). The divisor latch value is
held as a 16-bit value in the SC_DLL/SC_DLM register pair. The sampling mode is contained in the most-significant two
bits of the SC_CLK_DIV Register.
TABLE 10-1: CHARACTER FRAME FORMAT
TRANSMISSION DEFINITION
Start Bit The I/O signal is held low for the duration of one etu after the Guard Time before
transmitting data.
Data Byte The 8 bits immediately following the start bit that represents a single character byte. The
logical value of the data byte transmitted is dependent on the convention selected by TS
of the ATR.
Direct Convention: logical 1 equals VCC and bits are transmitted LSB first.
Inverse Convention: logical 0 equals VCC and bits are transmitted MSB first.
Note: Data received is interpreted according to the encoding convention selected by the
ICC.
Parity Bit The parity bit is used for error detection. It is used to provide even parity, operating on 1
and 0 as defined by the convention. The parity bit itself is also represented with the same
polarity as the data field, according to the selected encoding convention.
Guard Time The Guard Time is defined as the time between the transmission of the parity bit and the
next start bit transmitted. During this time, both the Transmitter and Receiver release the
bus. Only the Receiver is permitted to pull the bus low during this time (in all except T=1)
to indicate a parity error has occurred.
Guard time = minimum Guard Time + Extra Guard Time (N); for 0 N 254
Guard time = minimum Guard Time; for N=255.
T=0 (including ATR and PPS) requires a minimum Guard Time of 2 etus. T=1 requires a
minimum Guard Time of 1 etu. The minimum Guard Time is determined by whether T=0
or T=1 Mode is chosen in the Protocol Mode Register.
Extra Guard Time (N) is programmable from 0 to 254 etus, as requested by the card in
the ATR message. The default value is 0. The value of N received in the ATR should be
directly programmed in the EGT Register.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 51
SEC1110/SEC1210
The value in the DLL/DLM registers is interpreted according to the separate Sampling Mode, held in the most-significant
two bits of the SC_CLK_DIV Register. The sampling mode is a pre-scaler and one of three valid settings:
• 00b : prescaler of 31
• 10b : prescaler of 16
• 01b : no prescaler. The divisor directly specifies the etu rate in units of the sc1_clk clock, and each bit is sampled
directly by that clock. This form gives better accuracy. Also, even in a non-standard application, it is not allowed to
specify fewer than 16 sample times per etu.
For example assume during ATR,TA bits 8~5 = 0010b (Fi=558), and bits 4~1 = 0011b (Di=4) then Fmax = 6 MHz, and
the desired divisor = 139.5.
This means:
• Fmax = 6 MHz (based on Fi)
• Desired divisor = 558/4 = 139.5
Desired baud rate = 4.8 MHz/139.5 = 34408.6 bps. This means based on a 48 MHz clock the divisor latch value must
be: 48 MHz/34408 = 1395. To set the SCx_CLK frequency close to Fmax, then SCx_CLK divisor (DIVISOR[4:0]) must
be set to 48 M/4.8 M = 10.
The single bit error due to the terminal’s sampling rate = (1 / 48 MHz) / (1 ETU) = (1/48e6) / (1/34408.6) = 0.071%. The
error accumulated over a byte (starting from START bit, 8 data bits, parity bit, pause sample) = 10 * 2% = 20%.
The maximum error allowed per bit is determined by maximum rise/fall times (8%), minimum sampling time (0.2 etu,
i.e., 20%), and maximum clock jitter (1% p-p).
When the Receiver samples, the maximum allowed error per bit = 0.2 etu/10 = 20.0% /10 = 2.00%
For some of the Fi/Di ratios, lower power consumption can be achieved by reducing the Smart Card block frequency,
while maintaining the maximum line rate. This requires operating within the maximum allowed error rate per bit.
10.5.3 RECOMMENDED ETU RATES AND SETTINGS
Table 10-2 lists the valid etu rates supported, and the recommended settings of the DL divisor (in the DLL/DLM registers)
and the sampling field of the CLK Register that are used to select them.
The settings shown are for the maximum block frequency (48 MHz, i.e., SCx_CLK_DIV=1) to the Smart Card block to
reduce error to a minimum.
TABLE 10-2: RECOMMENDED SETTINGS FOR VALID TA1 ETU RATES
FI
(DEC)
DI
(DEC)
FI/DI
(REAL)
SAMPLING
FIELD
(BINARY)
SCLK
(ACTUAL)
MHZ
DL DIVISOR
VALUE
(DECIMAL)
BAUD RATE
(BITS/SEC)
BIT
ERROR (%)
0 1 372 01 4.8 3720 12903.23 0.00%
0 2 186 01 4.8 1860 25806.45 0.00%
0 3 93 01 4.8 930 51613.90 0.00%
0 4 46.5 01 4.8 465 103226.81 0.00%
0 5 23.25 01 4.8 233 206008.58 0.22%
0 6 11.625 01 4.8 116 413793.10 -0.22%
0 7 5.813 01 4.8 58 827586.21 -0.22%
0 8 32 01 4.8 31 154838.71 0.00%
0 9 18.6 01 4.8 186 258064.52 0.00%
1 1 372 01 4.8 3720 12903.23 0.00%
1 2 186 01 4.8 1860 25806.45 0.00%
1 3 93 01 4.8 930 51613.90 0.00%
1 4 46.5 01 4.8 465 103226.81 0.00%
1 5 23.25 01 4.8 233 206008.58 0.22%
1 6 11.625 01 4.8 116 413793.10 -0.22%
1 7 5.813 01 4.8 58 827586.21 -0.22%
SEC1110/SEC1210
DS00001561C-page 52 2013 - 2016 Microchip Technology Inc.
1 8 31 01 4.8 31 154838.71 0.00%
1 9 18.6 01 4.8 186 258064.52 0.00%
2 1 558 01 4.8 5580 8602.15 0.00%
2 2 279 01 4.8 2790 17204.30 0.00%
2 3 139.5 01 4.8 1395 34408.60 0.00%
2 4 69.75 01 4.8 698 68767.91 0.07%
2 5 34.875 01 4.8 349 137535.82 0.07%
2 6 17.438 01 4.8 174 275862.07 -0.22%
2 7 8.719 01 4.8 87 551724.14 -0.22%
2 8 46.5 01 4.8 465 103225.81 0.00%
2 9 27.9 01 4.8 279 172043.01 0.00%
3 1 744 01 4.8 7440 6451.61 0.00%
3 2 372 01 4.8 3720 12903.23 0.00%
3 3 186 01 4.8 1860 25806.45 0.00%
3 4 93 01 4.8 930 51612.90 0.00%
3 5 46.5 01 4.8 465 103225.81 0.00%
3 6 23.25 01 4.8 233 206008.58 0.22%
3 7 11.625 01 4.8 116 413793.10 0.22%
3 8 62 01 4.8 620 77419.35 0.00%
3 9 37.2 01 4.8 372 129032.26 0.00%
4 1 1116 01 4.8 11160 4301.08 0.00%
4 2 558 01 4.8 5580 8602.15 0.00%
4 3 279 01 4.8 2790 17204.30 0.00%
4 4 139.5 01 4.8 1395 34408.60 0.07%
4 5 69.75 01 4.8 698 68767.91 0.07%
4 6 34.875 01 4.8 349 137535.82 0.07%
4 7 17.438 01 4.8 174 275862.07 -0.22%
4 8 93 01 4.8 930 51612.90 0.00%
4 9 55.8 01 4.8 558 86021.51 0.00%
5 1 1488 01 4.8 14880 3225.81 0.00%
5 2 744 01 4.8 7440 6451.61 0.00%
5 3 372 01 4.8 3720 12903.23 0.00%
5 4 186 01 4.8 1860 25806.45 0.00%
5 5 93 01 4.8 930 51612.90 0.00%
5 6 46.5 01 4.8 465 103225.81 0.00%
5 7 23.25 01 4.8 233 206008.58 0.22%
5 8 124 01 4.8 1240 38709.68 0.00%
5 9 74.4 01 4.8 744 64516.13 0.00%
6 1 1860 01 4.8 18600 2580.65 0.00%
6 2 930 01 4.8 9300 5161.29 0.00%
6 3 465 01 4.8 4650 10322.58 0.00%
6 4 232.5 01 4.8 2325 20645.16 0.00%
6 5 116.25 01 4.8 1163 41272.57 0.04%
TABLE 10-2: RECOMMENDED SETTINGS FOR VALID TA1 ETU RATES (CONTINUED)
FI
(DEC)
DI
(DEC)
FI/DI
(REAL)
SAMPLING
FIELD
(BINARY)
SCLK
(ACTUAL)
MHZ
DL DIVISOR
VALUE
(DECIMAL)
BAUD RATE
(BITS/SEC)
BIT
ERROR (%)
2013 - 2016 Microchip Technology Inc. DS00001561C-page 53
SEC1110/SEC1210
6 6 58.125 01 4.8 581 82616.18 -0.04%
6 7 29.063 01 4.8 291 164948.45 -0.13%
6 8 155 01 4.8 1550 30967.74 0.00%
6 9 93 01 4.8 930 51612.90 0.00%
9 1 512 01 4.8 5120 9375.00 0.00%
9 2 256 01 4.8 2560 18750.00 0.00%
9 3 128 01 4.8 1280 37500.00 0.00%
9 4 64 01 4.8 640 75000.00 0.00%
9 5 32 01 4.8 320 150000.00 0.00%
9 6 16 01 4.8 160 300000.00 0.00%
9 7 8 01 4.8 80 600000.00 0.00%
9 8 42.667 01 4.8 427 112412.18 0.08%
9 9 25.6 01 4.8 256 187500.00 0.00%
10 1 768 01 4.8 7680 6250.00 0.00%
10 2 384 01 4.8 3840 12500.00 0.00%
10 3 192 01 4.8 1920 25000.00 0.00%
10 4 96 01 4.8 960 50000.00 0.00%
10 5 48 01 4.8 480 100000.00 0.00%
10 6 24 01 4.8 240 200000.00 0.00
10 7 12 01 4.8 120 400000.00 0.00
10 8 64 01 4.8 640 75000.00 0.00%
10 9 38.4 01 4.8 384 125000.00 0.00%
11 1 1024 01 4.8 4688 4687.50 0.00%
11 2 512 01 4.8 9375 9375 0.00%
11 3 256 01 4.8 18750 18750 0.00%
11 4 128 01 4.8 37500 37500 0.00%
11 5 64 01 4.8 75000 75000 0.00%
11 6 32 01 4.8 150000 150000 0.00%
11 7 16 01 4.8 300000 300000 0.00%
11 8 85.333 01 4.8 56250 56271.98 0.04%
11 9 51.2 01 4.8 93750 93750 0.00%
12 1 1536 01 4.8 15360 3125.00 0.00%
12 2 768 01 4.8 7680 6250.00 0.00%
12 3 384 01 4.8 3840 12500.00 0.00%
12 4 192 01 4.8 1920 25000.00 0.00%
12 5 96 01 4.8 960 50000.00 0.00%
12 6 48 01 4.8 480 100000.00 0.00%
12 7 24 01 4.8 240 200000.00 0.00%
12 8 128 01 4.8 1280 37500.00 0.00%
12 9 76.8 01 4.8 768 62500.00 0.00%
13 1 2048 01 4.8 20480 2343.75 0.00%
13 2 1024 01 4.8 10240 4687.50 0.00%
13 3 512 01 4.8 5120 9375.00 0.00%
TABLE 10-2: RECOMMENDED SETTINGS FOR VALID TA1 ETU RATES (CONTINUED)
FI
(DEC)
DI
(DEC)
FI/DI
(REAL)
SAMPLING
FIELD
(BINARY)
SCLK
(ACTUAL)
MHZ
DL DIVISOR
VALUE
(DECIMAL)
BAUD RATE
(BITS/SEC)
BIT
ERROR (%)
SEC1110/SEC1210
DS00001561C-page 54 2013 - 2016 Microchip Technology Inc.
Note 10-1 Some of the test equipment are not capable of operating with non-integer values of Fi/Di ratios.
10.6 16-bit General Purpose Counter
A 16-bit general-purpose down counter is located in the SC_DCL and SC_DCM register pair. Writing to these registers
stores the preload value for the counter. Reading these registers will yield the current count value. Once the counter is
enabled and begins counting, it will continue counting down either until it reaches 0000h or until a new preload value is
written to the counter. At 0000h the counter wraps around to FFFFh and will generate the General Purpose Down
Counter Interrupt.
The counter is clocked by a 10 kHz clock input (i.e., 100 sec/lsb) derived from the system clock.
The counter loads the stored preload value and begins counting when the Counter Enable bit is set to 1. On a POR or
when the Counter Interrupt Enable bit is cleared to 0, the preload value used by the counter is initialized to FFFFh. Setting
the Counter Enable bit to 1 loads the current preload value. This allows software to write the preload value before
enabling the counter. Therefore, when this enable bit is set to 1 the counter begins counting down from the preload
value, which will be either the default preload value (FFFFh) or a programmed preload value. The Counter Enable bit
is located in the LCR Register.
To write the Pre-load value:
If the counter is disabled, the SC_DCL and SC_DCM registers may be written in any order. If the counter is enabled,
write the LSB first into the SC_DCL Register. Writing the MSB into the SC_DCM Register loads the pre-load value into
the counter and resets the divider used to scale the clock. The counter, if enabled, begins counting down as soon as
the preload value is loaded into the register and the clock is re-initialized.
To read the Count value:
Read the LSB first from the SC_DCL Register. Reading the SC_DCL Register latches the MSB of the count value into
the SC_DCM Register.
10.7 T=1 Operation
In T=1 Mode, a transmission is immediately followed by received data. Therefore, when the Receiver is newly enabled
(see the FCR Register), this is interpreted as meaning that the Receiver will begin accepting data only when transmission
is finished. According to the various standards, the card is supposed to have a minimum turnaround delay before
it starts transmitting data, but in practice the controller does not rely on that, and will accept data as soon as the last
character has been transmitted.
10.7.1 OPERATION OF TIMERS IN T=1 MODE
Transactions between the controller and a Smart Card are performed in an exchange of data: the controller transmits a
command, and the Smart Card must respond. Because the Smart Card is allowed to respond very quickly after receiving
the last byte of the command, the timers must be set up before the command is sent, and software cannot interact with
the exchange until the response has been received, or a timeout has occurred. Both of these events trigger an interrupt.
13 4 256 01 4.8 2560 18750.00 0.00%
13 5 128 01 4.8 1280 37500.00 0.00%
13 6 64 01 4.8 640 7500.00 0.00%
13 7 32 01 4.8 320 150000.00 0.00%
13 8 170.667 01 4.8 1707 28119.51 0.02%
13 9 102.4 01 4.8 1024 46875.00 0.00%
TABLE 10-2: RECOMMENDED SETTINGS FOR VALID TA1 ETU RATES (CONTINUED)
FI
(DEC)
DI
(DEC)
FI/DI
(REAL)
SAMPLING
FIELD
(BINARY)
SCLK
(ACTUAL)
MHZ
DL DIVISOR
VALUE
(DECIMAL)
BAUD RATE
(BITS/SEC)
BIT
ERROR (%)
2013 - 2016 Microchip Technology Inc. DS00001561C-page 55
SEC1110/SEC1210
In FIGURE 10-5: on page 55, T=1 Exchange, the sequence of events is shown in the exchange of data with the Smart
Card. The operation of the controller at points A, B, C, D and E is described in the sections below.
10.7.1.1 Setup Before First T=1 Transmission
• Software directly pre-loads the Guard Timer SC_BGT Reload Register with a value based on the BGT parameter
from the ATR message. The Guard Timer resolution is one etu.
• Software loads the Guard Timer SC_EGT Reload Register with a value based on the current EGT.
• Software enables the Guard Timer, which is used to inhibit transmission until it underflows.
• The initial state of the Guard Timer is waiting for a transmitted character for EGT timing. Therefore, the first time it
is enabled, the first BGT value must be ensured by software using different means prior to progressing to point A.
10.7.1.2 Point A: Software Initiates Exchange
• Software writes the entire message to be transmitted into the SC_FIFO.
• Software writes the value 0x02 to the SC_FIFO Threshold Register, to get an interrupt when three bytes have
been received in response.
• Software loads the Timeout Timer with the current BWT value, in units of 1.25 milliseconds.
• Software loads the CWT Timer with a value based on the current CWT value, and enables the CWT timer.
• Software enables both the Transmitter and the Receiver. Transmission begins after any delay imposed by the
Guard Time, proceeding to point B.
• Software waits for interrupts occurring at point E.
10.7.1.3 Point B: Transmission Begins
• The first character is fetched from FIFO.
• Transmission of the first character begins.
• At each transmitted character, the Guard Timer reloads from its SC_EGT Reload Register (EGT value).
• At the end of each character, after the 1 etu of mandatory guard time, the Guard Timer counts down, and it inhibits
transmission until it underflows. On underflow, the Guard Timer permits transmission and stops.
• Characters will be fetched from the FIFO and are held until the EGT value from the Guard Timer expires.
• When the SC_FIFO becomes empty of characters to be transmitted, the SEC1110 and SEC1210 will immediately
disable the Transmitter (clearing the FTE bit in the SC_FCR Register), and will transition to the receive phase of
the exchange.
FIGURE 10-5: T=1 EVENTS
TERMINAL
SIDE
CARD
SIDE
T = 1 Protocol,
Sequence of Events
A B C
SCx_IO
D E
Command Response
CWT: no
underrun
BGT
min BGT min, BWT max CWT+4: max. char. spacing
Character min. Guard times are guaranteed on transmit and monitored on receipt.
EGT: as
demanded
by card
SEC1110/SEC1210
DS00001561C-page 56 2013 - 2016 Microchip Technology Inc.
10.7.1.4 Point C: Preparation for Reception
When the entire Transmit message has been sent, the Timeout Timer begins monitoring for the first received character.
When it is received, the Timeout Timer stops and does nothing else until software re-enables it. If instead the Timeout
Timer underflows (at the BWT time), it stops, disables the Receiver (by clearing the FRE bit in the SC_FCR Register)
and presents the TMO Interrupt.
In a second Mode of operation (WTX), the Timeout Timer will continue running and posting interrupts, for counting down
(in software) the number of underflows of this timer before detecting an error. In this Mode, the underflow simply reloads
and continues, posting the interrupt, but it does not automatically disable the Receiver. When the appropriate number
of underflows has occurred, the software will place the timer back into BWT Mode, and it will then interrupt, stop, and
disable the Receiver if it underflows again.
10.7.1.5 Point D: Message Being Received
At the first received start bit, the CWT Timer begins operation. This timer counts in units of etu. It has been loaded by
software, before transmission, with the maximum distance between received characters. The value also includes the
tolerance value (4 or 5 etu) which is required by the EMV standard. This timer is reloaded, and retriggered, on receipt
of each character. If it elapses, it stops, clears the FRE bit to disable the Receiver to the SC_FIFO, and posts the CWT
Interrupt request.
After the first three bytes have been received, the FIFO Threshold Interrupt is posted. Software reads three bytes from
the SC_FIFO, and interprets them to determine the remaining length of the response from the card. Software re-sets
the FIFO Threshold to the expected number of bytes, minus 1.
10.7.1.6 Point E: End of Message
The end of a message will be detected either by software, seeing the FIFO Threshold Interrupt, or by the CWT Timer
Interrupt if not enough characters come in. (The CWT Timer event will also set the Threshold Interrupt automatically.) If
too many characters are received, software will detect this from extra bytes in the SC_FIFO. If enough characters are
received that the SC_FIFO overflows, the OE Interrupt is set. Both the OE and CWT Timer event disable the Receiver
from placing any more characters into the SC_FIFO, by clearing the FRE bit in the FIFO Control Register.
10.8 T=0 Operation
The T=0 protocol is highly interactive, and there is no timeout constraint placed on the controller side. For this Mode, to
support high bit rates, there are timer interactions defined for this Mode, and a pair of state machines to filter incoming
data.
In T=0 Mode, unless ATR Mode is also specified, a transmission is immediately followed by received data. Therefore,
when in T=0 Mode and not ATR Mode, and the Receiver is newly enabled (see the SC_FCR Register), this is interpreted
as meaning that the Receiver will begin accepting data only when transmission is finished. According to the various
standards, the card is supposed to have a minimum turnaround delay before it starts transmitting data, but in practice
the controller does not rely on that, and will accept data as soon as the last character has been transmitted.
T=0 protocol commands specify the length of the expected response from the card. Therefore, software can be interrupted
once by the FIFO Threshold Interrupt, when the entire expected message has been received, or when it has
been ended prematurely by the card (Timeout Timer [WWT] error, EOM Interrupt for early SW1/SW2 presentation, or
Parity error).
10.8.1 T=0 TIMER OPERATION
In T=0 Mode, the Guard Timer will be used to ensure the DGT requirement (turnaround Guard Time) when beginning
transmission, and to insert the Extra Guard Time (EGT) delay between characters. DGT and EGT are not monitored
when receiving from the card.
As when beginning T=1 Mode, the Guard Timer is not effective until at least one character has been transmitted or
received. Therefore, when software enables the Guard Timer for the first time, it must ensure by other means that the
DGT Guard Time has elapsed before enabling the Transmitter.
In T=0 Mode, the Timeout Timer will be used to monitor the card’s performance relative to WWT, which defines both the
maximum allowed turn-around time in a card’s response, and the maximum allowed spacing between characters while
the card is transmitting. In this Mode, the Timeout Timer will start on the last transmitted character, will reload and continue
on each received character, but will post an interrupt, disable the Receiver and stop if it underflows.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 57
SEC1110/SEC1210
The minimum character Guard Time (2 etu) on transmission will be ensured by the fact that T=0 Mode is selected in the
Protocol Mode Register. On transmission, the guard period will be monitored only for a Parity Error response from the
Smart Card, and not for any other form of interference.
10.9 T=0 Byte Filtering
There is a new consideration regarding FIFO space. The Smart Card may insert NULL characters at various points in
the communication, whose purpose is to reset the Timeout Timer (being used for WWT). Also, there are an unpredictable
number of INS bytes, which signal when a card is prepared to transfer only one byte instead of the whole remaining
block. A pair of state machines are provided to filter out these extra bytes in a T=0 exchange, thus ensuring that no valid
exchange will ever overflow the SC_FIFO.
Both state machines filter only bytes that are being received from the card, but they are called Incoming and Outgoing
based on the nature of the command being executed. The direction is defined relative to the card, so that Outgoing
means reading data out of the card, and Incoming means writing data into the card.
The special procedure bytes are those bytes sent by the card that are not data. These are:
• NULL, encoded as 0x60, which is used as padding to reset the WWT timing monitor
• SW1, encoded as 0x61-0x6F and 0x90-0x9F. This is the first byte of status, which flags the end of a transfer. It is
always followed by one byte, SW2, which completes the status indication and is the last byte of the transaction.
• INS and INS are used as flags, and represent a true (INS) and complemented (INS) echo of the Instruction byte
(sent by the terminal) that is being executed by the card. The encodings of INS and INS are such that they can
never be confused with NULL or SW1.
10.9.1 T=0 OUTGOING BYTE FILTER
The first (outgoing) state machine is used when a command is being issued that reads data from the card. In this scenario,
the card responds on receipt of the command, and it does not stop transmitting until the entire requested block
of data has been transferred. The format of this response is variable depending on the card’s performance. The Outgoing
state machine, then, filters out the variable portions of this response, leaving only the outgoing data and status, which
will be of a predictable maximum size of 258 bytes (256 bytes of information data plus the status bytes SW1 and SW2).
If the firmware requires a maximum packet size greater than 258 bytes (CCID firmware needs 259), then firmware can
split the packet.
To operate this filter, software specifies in the register set the number of data bytes it intends to read from the Smart
Card, and the INS byte value that it intends to send. It then enables the state machine with the dedicated Enable bit
(OSME, in the Protocol Mode Register), and transmits its command. When the transmission is completed (as determined
by the Message Length Register used for transmission), the state machine becomes active. As the card
responds, any NULL characters at appropriate places are detected and discarded, and all INS and INS procedure bytes
are discarded, leaving only the data bytes and the two status bytes (SW1 and SW2) to be placed into the SC_FIFO.
A typical sequence of events for a T=0 outgoing exchange is shown in the figure below.
SEC1110/SEC1210
DS00001561C-page 58 2013 - 2016 Microchip Technology Inc.
A state diagram for the Outgoing Byte Filter is shown in FIGURE 10-6: on page 58. It accepts from software:
• A 9-bit count of the number of data bytes expected from the card, initialized by software to be in the range of 1 to
256 (00h written by software to the 8-bit SC_FLL Register sets the count to 256, not zero). This number of data
bytes are collected and placed into the FIFO, followed by the SW1 and SW2 bytes, for a total of 258 bytes maximum.
• The INS byte being sent to the card. This defines the encodings of the INS and INS procedure bytes.
• An enable bit (OSME, in the Protocol Mode Register) for this specific state machine. When the Enable bit is turned
on, the state machine will wait for the Transmitter to finish transmitting the command to the card, then it will start
filtering the response.
When the state machine detects the end of a message, or a fatal error in communication, it activates the EOM Interrupt
(End of Message), and disables the Receiver. If it is terminating communication because of an error in encoding, it will
also set the CV (Code Violation) error status bit. If the Timeout Timer (measuring WWT) underflows during a received
message, it will also disable the Receiver and stop the state machine. The EOM Interrupt will be posted in this case,
and also the TMO Interrupt from the Timeout Timer itself.
As characters are received, the least-significant 8 bits of count may be examined by reading the SC_FLL Register. The
value 00h, which might mean 0 or 256, can be interpreted by looking at the FIFO count to determine whether any characters
have been received.
FIGURE 10-6: OUTGOING T=0 COMMAND SEQUENCE
TERMINAL
SIDE
CARD
SIDE
T=0 Protocol, Sequence of Events
(Outgoing Data from Card)
SCx_IO
Command Response
DGT min,
no max
DGT min, WWT max
(DGT not enforced) WWT: max. char. spacing
End of Message
determined by presence
of SW1/SW2
Character min. Guard Times are guaranteed on transmit and monitored on receipt.
EGT: as
demanded
by card
SW1, SW2
DGT min, no max
The Response block consists of:
~INS followed by one data byte, repeated as desired by the card
INS followed by the rest of the requested data
SW1 followed by SW2, flagging the end of the response
NULL(s) appearing before any INS, ~INS or SW1 byte
NULL(s), INS or ~INS appearing after all data and before SW1.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 59
SEC1110/SEC1210
10.9.2 T=0 INCOMING BYTE FILTER
This state machine is active when a command is being executed that writes data into the card. In spite of this, the bytes
being filtered are only the responses that are coming from the card. When the controller is intending to transmit data,
the state machine is simpler, because there are fewer ways that the Smart Card can respond. The command is executed
in multiple exchanges between the controller and the card, and as far as the controller hardware is concerned, each of
these (starting with transmission of a 5-byte command header from the controller) is an independent exchange. See
Figure 10-8 for an example of an T=0 incoming command sequence.
A state diagram for the Incoming Byte Filter is shown in FIGURE 10-9: on page 61.
FIGURE 10-7: T=0 OUTGOING BYTE FILTER STATE DIAGRAM
INS (8 bits)
Last Character
Transmitted
(Turnaround)
and
ENABLE == 1
IDLE
S/W INPUTS: COUNT (9 bits)
ENABLE (1 bit)
Note: COUNT is modified by this state machine.
It is specified by software as an 8-bit value with
hex '00' meaning 256 rather than zero. This
state machine will not be activated for counts of
0; the Incoming Filter will be used instead.
Awaiting Procedure Byte Collect 1 Data
Collect Multiple
Data Awaiting SW2
NULL
(INS || ~INS) &&
(COUNT == 0)
WWT
Violation /
WWT Flag;
EOM; Disable
Receiver
(Any Character) &&
(COUNT > 1) /
COUNT--; FIFO
Else /
CV Flag;
EOM;
Disable
Receiver
IDLE
IDLE IDLE
IDLE
Any Char /
EOM; Disable
Receiver
WWT
Violation /
WWT Flag;
EOM; Disable
Receiver
WWT
Violation /
WWT Flag;
EOM; Disable
Receiver
SW1 &&
(COUNT ==
0) / FIFO
(~INS) &&
(COUNT > 0)
IDLE
WWT
Violation /
WWT Flag;
EOM; Disable
(Any Character) && Receiver
(COUNT > 0) /
COUNT--; FIFO
IDLE
Else /
CV Flag;
EOM;
Disable
Receiver
Else /
CV Flag;
EOM;
Disable
Receiver
IDLE
Else /
CV Flag;
EOM;
Disable
Receiver
INS &&
(COUNT > 0)
(Any Character) &&
(COUNT == 1) /
COUNT--; FIFO
SW1 &&
(COUNT > 0) /
FIFO
SEC1110/SEC1210
DS00001561C-page 60 2013 - 2016 Microchip Technology Inc.
When expecting an INS or INS response, this filter will remove only initial NULL bytes from the Smart Card’s responses,
leaving the INS or INS response byte in the FIFO for software to interpret. When expecting an SW1 byte (when the count
of data to be transferred is zero), any initial NULL, INS or INS byte is discarded. Software must provide a valid Count
value, along with INS and the Enable bit (ISME, in the Protocol Mode Register), for each Transmit/Receive exchange of
information in the command sequence.
The Incoming byte filter does not interpret the Count in the same way as the Outgoing byte filter. For the Incoming byte
filter, a value of 00h provided by software in the SC_FLL Register actually means zero, and the maximum valid count
value is 254 for T=0 Incoming traffic. The SC_FLL Register is not changed except by software, so there is no ambiguity
in values as there is when software reads the SC_FLL Register under the Outgoing filter.
FIGURE 10-8: INCOMING T=0 COMMAND SEQUENCE EXAMPLE
TERMINAL
SIDE
CARD
SIDE
T = 0 Protocol,
Sequence of Events
(Incoming Data to Card)
SCx_IO
Command
DGT
min, no
max DGT min,
WWT max
(DGT not
enforced)
WWT:
max.
char.
spacing
End of Message is determined by
appearance of SW1
Character min. Guard Times are guaranteed on transmit and monitored on receipt.
EGT: As
demanded by
card.
No max.
1 byte
data INS Rest of Data SW1, SW2
DGT
min,
no
max
DGT min, no
max
EGT: As
demanded
by card.
No max.
DGT
min,
no
max
...
Command
Format CLA INS P1 P2 P3
Length
DGT min,
WWT max
(DGT not
enforced)
DGT min,
WWT max
(DGT not
enforced)
NULL characters may appear from card before any INS, INS or SW1 bytes.
If present, the interval between them may be no more than WWT.
Defines
INS, INS
above
INS
2013 - 2016 Microchip Technology Inc. DS00001561C-page 61
SEC1110/SEC1210
FIGURE 10-9: T=0 INCOMING BYTE FILTER STATE DIAGRAM
Awaiting
Response
IDLE
NULL
Awaiting SW2
S/W INPUTS:
ENABLE (1 bit)
WWT Violation /
WWT Flag;
EOM; Disable
Receiver
Any Character /
FIFO; EOM;
Disable Receiver
INS || ~INS / FIFO;
Disable Receiver
SW1 / FIFO
COUNT (9 bits)
Awaiting Final
Response
(End Transmission)
&& (Count == 0) &&
(ENABLE == 1)
NULL ||
INS ||
~INS
Other Data / FIFO; SW1 / FIFO
CV Flag; End of
Message
INS (8 bits)
Note: COUNT is not decremented by this state machine.
Effectively, COUNT is only a mode flag, provided by software.
Software provides non-zero here unless SW1 is expected.
If it is 0, INS and ~INS are also discarded, as well as NULL.
If SW1 occurs when it is not expected (COUNT>0), then it
and SW2 are both received. Software must parse the SW1
byte to determine that it expects an SW2 byte from the FIFO.
(End
Transmission)
&&
(Count > 0) &&
(ENABLE == 1)
IDLE
WWT Violation /
WWT Flag;
EOM; Disable
Receiver
WWT Violation /
WWT Flag;
EOM; Disable
Receiver
IDLE
IDLE
Other Data /
CV Flag; EOM;
Disable Receiver
SEC1110/SEC1210
DS00001561C-page 62 2013 - 2016 Microchip Technology Inc.
10.9.3 ATR RECEPTION
The Answer to Reset (ATR) sequence is a series of bytes sent by the Smart Card in response to the Reset signal from
the controller. Certain timers and specialized circuitry are used in receiving the ATR information.
FIGURE 10-10: ATR SEQUENCE, COLD RESET
FIGURE 10-11: ATR SEQUENCE, WARM RESET
TERMINAL
SIDE
CARD
SIDE
Answer to Reset
(ATR): Sequence of
Events
Cold Reset
SCx_IO
TS
Guard
Timer
(EGT
Reload)
max
Guard Timer
(BGT Reload)
defines
duration
CWT
Timer
max
SCx_RST_N
. . .
. . .
T0 TAi, TBi, TCi, TDi, HIST . . . TCK
SCx_CLK
CWT
Timer
max
CWT
Timer
max
CWT
Timer
max
(Running)
CWT Timer
signals end,
disables receiver
SCx_VCC
TERMINAL
SIDE
CARD
SIDE
Answer to Reset
(ATR): Sequence of
Events
Warm Reset
SCx_IO
TS
Guard
Timer
(EGT
Reload)
max
Guard Timer
(BGT Reload)
defines duration
CWT
Timer
max
SCx_RST_N
. . .
. . .
T0 TAi, TBi, TCi, TDi, HIST . . . TCK
SCx_CLK
CWT
Timer
max
CWT
Timer
max
CWT
Timer
max
(Running)
CWT Timer
signals end,
disables receiver
SCx_VCC
2013 - 2016 Microchip Technology Inc. DS00001561C-page 63
SEC1110/SEC1210
To anticipate the ATR sequence, the controller is placed by software into a special Mode called ATR. In the ATR Mode,
two of the timers are in a special Mode to validate the timing of the sequence. Figure 10-10 shows the sequence of
events in a Cold Reset, where power has been removed from the card. Figure 10-11 shows the sequence of events in
a Warm Reset, where power is maintained, but a new SCx_RST_N pulse is applied to reset the card.
In preparing for the ATR sequence, the software must establish the default etu time: the equivalent of TA1=0x11, or 372
periods of the selected SCx_CLK frequency.
At the beginning of the sequence, the two reload registers of the Guard Timer determine the duration of the Reset pulse
and measure the response time from the Smart Card to enforce a valid delay. After the first character, the CWT Timer
starts, and counts the maximum amount of time the card is allowed to spend between characters. When the CWT Timer
expires, an interrupt (CWT) is sent to the software, which can then read the message from the SC_FIFO. This event will
also set the FIFO Threshold Interrupt active. Software will be able to parse the message and determine whether it is
complete.
Software may, rather than using the CWT Timer for this purpose, set thresholds for the SC_FIFO such that it is periodically
interrupted either by the individual characters or by larger expected fields. The CWT Timer will still be useful as
an error indication.
The first byte (TS) is interpreted by hardware. One of two values is allowed, which from that point onward determines
the convention used by the card. The possible conventions used are listed below. L means a bit time with the SCx_IO
pin held low, and H means a bit time with the SCx_IO pin held high.
• Direct Convention, which is signaled by the TS bit sequence LHHLHHHLLHHH. In this convention, bits of a character
are sent least-significant bit first, 0 bits in the data field are represented by the Low state, and a true Even
parity is used. The first byte will always appear in the SC_FIFO, in Direct/Indirect convention as was seen on the
SCx_IO pin. Subsequent bytes will be decoded as per the convention and loaded into the SC_FIFO. The first byte
will appear as 0x3B in the SC_FIFO in Direct convention.
• Inverse Convention, which is signalled by the TS bit sequence LHHLLLLLLHHH. In this convention, bits of a character
are sent most-significant bit first, 0 bits in the data field are represented by the High state, and an inverted
Even parity bit is used (appearing as a parity error to any circuit reading it according to the Direct convention). This
byte will appear as 0x03 in the SC_FIFO.
• The Direct or Inverse Convention will be selected automatically by hardware after receiving the TS byte after a rising
edge on the SCx_RST_N signal. This setting will be reported in the TSM bit of the Protocol Status Register,
and will be used to interpret all characters until the next SCx_RST_N pulse. If any TS value other than the two
above is seen, the Receiver will be disabled, and the CV bit (Code Violation) will be set in the PRIP Register to
indicate the error. If a FIFO threshold larger than one byte was selected, the eventual CWT Timer Interrupt will
both set the FIFO Threshold Interrupt and alert the software to look at the error flag.
While power is not applied to the card, the terminal is required to hold the SCx_RST_N, SCx_CLK and SCx_IO pins low
(not floating). When power is first applied to the card (a Cold Reset, shown in FIGURE 10-10: ATR Sequence, Cold
Reset on page 62), the SCx_RST_N pin must be held low until SCx_CLK begins running. SCx_IO must rise to its idle
state (high) after power has been applied, and no later than 200 cycles of SCx_CLK. The SCx_RST_N pin must then be
set high between 108 and 120 default etu times after the clock starts.
When the card has already been initialized from a Cold Reset, it may be reset without removing power (Warm Reset,
as shown in FIGURE 10-11: ATR Sequence, Warm Reset on page 62). In this case, the clock keeps running, SCx_IO
should remain high, and the time range of 108 to 120 default etu times applies to the width of the SCx_RST_N pulse.
10.9.4 GUARD TIME ALGORITHM
A special case occurs under some circumstances, in which software thinks that an exchange is finished, but the card
does not, and keeps transmitting characters. One such case is when a parity error occurs in a T=1 message. The
SC_FIFO stops receiving characters after the faulty one (for diagnostic purposes, to indicate the character with the
error), and signals to software an End of Message with an error.
In this circumstance, it is necessary that any transmission commanded by the software (e.g., the packet complaining
about the parity error) must wait until the card is finished transmitting. However, if the card is misbehaving and does not
stop transmitting, then software must be informed of this error so that the card can be deactivated. The Guard Time
algorithm hardware serves both of these purposes.
A specific error flag is provided (TF), and a timing register (GSR), to support this feature. The feature is not optional,
and so it cannot be disabled.
SEC1110/SEC1210
DS00001561C-page 64 2013 - 2016 Microchip Technology Inc.
The Guard Spacing Register (GSR) is programmed by software with the expected maximum spacing between received
characters in units of etus, including Extra Guard Time EGT. (This is required in a separate register by the implementation).
The value in the GSR is interpreted as a maximum amount of time allowed from start bit to start bit, and so it
must be at least 12 etus.
As each new character is received within this window, an internal counter (CPT) is decremented once. This counter
restarts, starting from the maximum legal number of characters in a packet (258 for T=0, 259 for T=1) as soon as characters
start being received in an exchange, regardless of whether the Receiver remains enabled or not, and regardless
of errors. The CPT counter reloads and stops when no character is received within the GSR window.
If software attempts to transmit while this counter is still active, the transmission is inhibited and held pending. If, however,
while a transmission is pending, the CPT count underflows, then the transmission is abandoned, and the TF error
(Transmit Failure) is posted, which is an interrupt. See Figure 10-12 for this case. Note that, in T=0 Mode, the Incoming
or Outgoing filter remains applied as selected, so that any procedure bytes (NUL, INS, and INS) are not counted.
If there is no such error, then, after the vacant window time has passed, the Transmitter waits for the Designated Guard
Time amount (DGT or BGT) and begins transmitting. See FIGURE 10-13: Guard Time Algorithm, No Error, Transmit
Held on page 65 for this case.
FIGURE 10-12: GUARD TIME ALGORITHM WITH ERROR, TRANSMIT ABANDONED
. . .
Last
Expected
1st
Unexpected
2nd
Unexpected Last Legal 1st Illegal
FRE
FTE
LSR bit 5
Error: Transmit attempted and Card has been transmitting too long.
All durations within limit
Interrupt
posted
SCx_IO
Count Violated
Limit = GSR register at offset 0x001B
SW attempts new
exchange, Transmitter waits
SW reads
LSR
2013 - 2016 Microchip Technology Inc. DS00001561C-page 65
SEC1110/SEC1210
10.9.5 CARD POWER FOR SMART CARD INTERFACE
The pins on this interface are powered by SCx_VCC. If the Smart Card interface is not used, the SCx_VCC can be used
to implement variable voltage GPIOs. The control for the regulator is in the CLK_PWR block.
The power to the Smart Card should not be turned on till a card is detected. When there is no card present, enable the
synchronous Smart Card interface, turn all the bits to inputs, and enable the pull-down resistors. This will ensure that
the output signals are held at ground. Once a card is detected, enable the power first, wait at least 1 mS, then enable
the asynchronous or synchronous interface as necessary.
FIGURE 10-13: GUARD TIME ALGORITHM, NO ERROR, TRANSMIT HELD
. . .
Last
Expected
1st
Unexpected
2nd
Unexpected
FRE
FTE
LSR bit 5
Most Normal Case: early cut-off (e.g., T=1 Parity Error).
Transmitted response is delayed until Card is idle.
Durations within limit
SCx_IO
GSR Limit = from GSR (Guard Spacing Register) at location 0x001B
SW requests
new exchange
Last
Unexpected
(Legal count)
1st
Transmitted
GSR
Limit
BGT
reg
Line detected idle;
Guard Time pause begins
Error or SW:
stops receiving
SEC1110/SEC1210
DS00001561C-page 66 2013 - 2016 Microchip Technology Inc.
10.9.6 LED CONTROL FOR SMART CARD INTERFACE
The Smart Card LED can be driven in one of three ways. It can be driven directly by the Smart Card IP in asynchronous
Mode. This Mode is selected by selecting the GPIO5 to be Auxiliary Port A Mode (SC_LED_ACT_N bit in the GPIO block).
When running in synchronous Mode firmware must control the LED directly by controlling SC_LEDC Register. The LED
can either be set to blink automatically, or run under full manual control. Blinking is controlled by the LED1_GPIO1_CTL.
Alternatively, the firmware can set the GPIO5 to be in GPIO Mode, and can control the LED directly by writing to GPIO_POR0_OUT
bit 5. Full manual is done by controlling the register directly.
FIGURE 10-14: SMART CARD POWER-UP
High (Pull up)
Reset deasserted
SCx Module
Enabled
Software assert pull
up on SCx_PRSNT_N
Card insertion
detected
SCx_VCC turned on
Interface enabled
Hi Z
1 ms
Power Stable
Interface
active
SCx_VCC
SCx_PRSNT_N
RESET_N
Interface Idle (Pull Down)
Smart Card
Interface
Hi Z
Software sets
INF_IDLE_CTL_EN
SCx_IO Pad
Input Enabled
Software
Control
2013 - 2016 Microchip Technology Inc. DS00001561C-page 67
SEC1110/SEC1210
10.9.7 ENABLING THE SYNCHRONOUS SMART CARD INTERFACE
The synchronous interface is enabled through the Control Register in the Wrapper Block.
10.10 Register Map
The Smart Card Controller Register offsets to the base addresses are defined below.
TABLE 10-3: SMART CARD MEMORY MAP
(0X9000-0X93FF) SMART CARD CONTROL REGISTER
ADDRESS NAME DESCRIPTION
0x9000-0x90FF Smart Card 1 registers Base address of Smart Card 1 registers. The register offsets from
this base address are defined in Table 10-5 on page 68.
0x9100-0x92FF Smart Card SC_FIFO Common SC_FIFO for Smart Card 1 and 2. The SC1_SC_FIFO_DIS
bit in the SC_CTL Register controls which of the Smart Card
controllers are using the SC_FIFO.
In the SEC1110, the SC_FIFO is controlled only by Smart Card 1
controller.
0x9300-0x90FF Smart Card 2 Registers Base address of Smart Card 2 registers. The register offsets from
this base address are defined in Table 10-5, “Smart Card Control
Register,” on page 68.
TABLE 10-4: SMART CARD1, 2 CONTROLLER REGISTERS
OFFSET
ADDRESS NAME R/W DESCRIPTION PAGE
0x0000 SC_TBR_RBR R/W 8 bit FIFO Data 74
0x0001 SC_IEN R/W Interrupt enable 74
0x0002 SC_INT_ID R Interrupt ID 75
0x0003 SC_LCR R/W Line control 76
0x0004 SC_INTF_MON R/W Interface Monitor 77
0x0005 SC_LSR R Line status 78
0x0006 SC_BMC R/W Block Master Control 78
0x0007 SC_ICR R/W Interface Control 79
0x0008~ 0x000B SC_DATA R/W 32 bit FIFO Data 79
0x000C SC_PRS R/W Protocol Status 80
0x000D SC_PRIP R/W Protocol/Timer Interrupts Pending 80
0x000E SC_PRIE R/W Protocol/Timer Interrupts Enables 81
0x000F SC_TMS R Timer Status 82
0x0010~
0x0011
SC_DLL/SC_DLM R/W Baud Rate Divisor 82
0x0012 SC_FCR R/W FIFO Control 82
0x0013~ 0x0015 SC_TOL/SC_TOM R/W Timeout Timer 83
0x0016 ~ 0x0017 SC_DCL/SC_DCM R/W Down Counter 84
0x0018 ~ 0x0019 SC_CWTL/SC_CWTM R/W CWT Timer reload value 84
0x001B SC_GSR_MSB R/W Guard Algorithm Spacing Register 84
0x001C SC_EGT R/W Guard Timer Reload A 85
0x001D SC_BGT R/W Guard Timer Reload B 85
0x001E SC_PRM R/W Protocol Mode 86
0x001F SC_TCTL R/W Timer Control 86
0x0025 SC_CLK_DIV R/W Frequency control 87
0x0026 SC_CFG R/W SC Configuration 87
SEC1110/SEC1210
DS00001561C-page 68 2013 - 2016 Microchip Technology Inc.
10.11 Smart Card Wrapper Control Registers
0x0027 SC_LEDC R/W LED Control 88
0x0028~ 0x0029 SC_FTHL/SC_FTHM R/W FIFO Threshold 88
0x002A~ 0x002B SC_FCL/SC_FCM R Number of bytes in FIFO 89
0x002C SC_FLL R/W Filter Length 89
0x002D SC_FINS R/W Filter INS Byte 90
0x0030 ~ 0x0035 SC_TEST3 R/W Test Registers 91
0x0080 SC_CTL R/W SC Control Register 68
0x0081 PAD_CTL_SC R/W Pad current control 69
0x0090 SC_Sync_RST R/W Synchronous Mode Reset 69
0x0094 SC_Sync_CLK R/W Synchronous Mode Clock 70
0x0098 SC_Sync_FCB R/W Synchronous Mode FCB 70
0x009C SC_Sync_SPU R/W Synchronous Mode SPU 71
0x00A0 SC_Sync_IO R/W Synchronous Mode Data 72
0x00A4 SC_Sync_ALL R/W Synchronous Mode ALL 72
TABLE 10-5: SMART CARD CONTROL REGISTER
SC_CTL
(0X0080- RESET=0X00) SMART CARD CONTROL REGISTER
BYTE NAME R/W DESCRIPTION
7 INTERFACE_ENABLE R/W If the interface is not enabled, the interface pins are tri-stated.
6 INF_IDLE_CTL_EN R/W Enable automatic control of interface idle condition.
Setting this bit will automatically drives SCx_CLK, SCx_RST_N, SCx_C4, SCx_C8 pins to logic LOW and SCx_IO pin to a value
programmed in INF_IDLE_IO_VAL bit when INTERFACE_ENABLE=0.
When INTERFACE_ENABLE=1 all IOs are controlled by the SCC,
where the state of the SYNC_MODE_SEL does not matter.
5 Reserved R Always read as 0
4 INF_IDLE_IO_VAL R/W This bit indicates the value to be driven on the SCx_IO line when
INF_IDLE_CTL_EN bit is set.
This bit is available in SEC1110/SEC1210
3 SC1_SC_FIFO_DIS R/W This bit indicates if Smart Card 1 is using the SC_FIFO.
0: SC1 using SC_FIFO
1: In SEC1210, SC2 is using SC_FIFO. In SEC1110 this bit is a don’t
care.
2 SC_SLOW_CLK R/W Must be set when SCx_CLK is running under 10 MHz.
This bit is not used in the SEC1110/SEC1210 parts.
1 SC_MODE R/W Forces the pads into a low current Smart Card Mode with increased
hysteresis. This applies to all Smart Card pins except SC_CLK.
This bit is not used in the SEC1110/SEC1210 parts.
0 SYNC_MODE_SEL R/W Setting this bit put the Smart Card interface into the synchronous
Mode.
TABLE 10-4: SMART CARD1, 2 CONTROLLER REGISTERS (CONTINUED)
OFFSET
ADDRESS NAME R/W DESCRIPTION PAGE
2013 - 2016 Microchip Technology Inc. DS00001561C-page 69
SEC1110/SEC1210
The pads SCx_RST_N, SCx_CLK, SCx_IO, SCx_C4, SCx_C8 are controlled by the SCC block when GPIO[4:0] for
Smart Card1 and GPIO[18:16] for Smart Card2 are in GPIO Auxiliary A Mode. The GPIO5 must also be in Auxiliary A
Mode to support LED functionality for both Smart Cards.
The INF_IDLE_IO_EN, INF_IDLE_IO_VAL bits may be used during Smart card activation and deactivation sequence
to ensure SCx_RST_N, SCx_CLK, SCx_IO, SCx_C4, SCx_C8 pins are low even in the presence of external pull-up
loads.
10.11.1 AUTOMATIC CONTROL OF IDLE CONDITION ON SMART CARD INTERFACE
Smart Card specification requires that the interface signals be held at zero until a card is inserted, power is applied to
the card, and the reset sequence is started. The INF_IDLE_CTL_EN bit works in conjunction with the INTERFACE_ENABLE
bit to do this. When the interface is in the idle state, (INTERFACE_ENABLE=0), pull-downs are enabled, and the
control signals are driven zero. As soon as the interface is enabled, (INTERFACE_ENABLE=1) control of IO pad signals
reverts to the Smart Card Controller (SCC). See figure FIGURE 10-14: on page 66.
The INF_IDLE_CTL_EN bit asserts the pull-down (67 K) to the Smart Card pads, which may be insufficient to ensure
VOL is met in the presence of external pull-up loads. Hence the GPIO mode must be used during the activation and
deactivation sequence.
10.12 Synchronous Interface Registers
All registers in the Synchronous Interface are byte addressable. This allows the firmware to toggle the output using byte
writes without affecting any other register bits. There are five control lines associated with the interface that are controlled
by five identical registers.
Each of the Synchronous Interface registers consists of two bytes, a low address byte and a high address byte.
Note: In SEC1110/SEC1210 version of the chip, the INF_IDLE_CTL_EN bit asserts the pull-down (67 k) to the
Smart Card pads, which may be insufficient to ensure Vol is met in the presence of external pull-up loads.
Hence the GPIO mode must be used during the activation and deactivation sequence.
TABLE 10-6: SMART CARD CURRENT CONTROL REGISTER
PAD_CTL_SC
(0X0081 - RESET=0X00) PAD CURRENT CONTROL
BIT NAME R/W DESCRIPTION
7:2 Reserved R Always read as 0
1:0 SEL R/W This register is not used.
TABLE 10-7: SMART CARD SYNC RST CONTROL REGISTER
SC_SYNC_RST
(0X0091- RESET=0X00) SMART CARD CONTROL REGISTER
BIT NAME R/W DESCRIPTION
7:6 Reserved R Always read as 0
5 INPUT_EN R/W 1 : Input is enabled
0 : Input is disabled
4 OUTPUT_EN R/W 1 : Output is enabled
0 : Output is disabled
3 FAST_OPEN_DRAIN R/W If this bit is set, and the Mode is Output, the signal is driven low when
the data is 0. When the data transitions to 1, it is actively driven high
for one clock cycle before being tri-stated.
2 OPEN_DRAIN R/W If this bit is set, and the Mode is Output, the SCx_RST_N output is
driven open drain; 0 are driven, 1 are tri-stated.
1 PULL_UP_EN R/W When set, it enables the pull-up to this pin.
SEC1110/SEC1210
DS00001561C-page 70 2013 - 2016 Microchip Technology Inc.
0 PULL_DN_EN R/W When set, it enables the pull-down to this pin.
(0X0090- RESET=0X00)
7:2 Reserved R Always read as 0
1 RST_IN R This bit reflects the state of the SCx_RST_N pin when select muxes
are set to Smart Card Mode and synchronous Mode.
0 RST_OUT R/W This bit reflects the state of the SCx_RST_N pin when select muxes
are set to Smart Card Mode and synchronous Mode.
Note: In the SEC1110/SEC1210 version, the OPEN_DRAIN bit is not functional. The FAST_OPEN_DRAIN bit can
be used instead. This Anomaly 16 is fixed in later versions.
TABLE 10-8: SMART CARD SYNC CLK CONTROL REGISTER
SC_SYNC_CLK
(0X0095- RESET=0X00) SMART CARD SYNC CLOCK CONTROL REGISTER
BIT NAME R/W DESCRIPTION
7:6 Reserved R Always read as 0
5 INPUT_EN R/W 1 : Input is enabled
0 : Input is disabled
4 OUTPUT_EN R/W 1 : Output is enabled
0 : Output is disabled
3 FAST_OPEN_DRAIN R/W If this bit is set, and the Mode is Output, the signal is driven low when
the data is 0. When the data transitions to 1, it is actively driven high
for one system clock cycle before being tri-stated.
2 OPEN_DRAIN R/W If this bit is set, and the Mode is output, the SC_CLK output is driven
open drain. 0 are driven, 1 are tri-stated.
1 PULL_UP_EN R/W When set, it enables the pull-up to this pin.
0 PULL_DN_EN R/W When set, it enables the pull-down to this pin.
(0X0094- RESET=0X00)
7:2 Reserved R Always read as 0
1 CLK_IN R This bit reflects the state of the SCx_CLK pin when select muxes are
set to Smart Card Mode and synchronous Mode.
0 CLK_OUT R/W This bit reflects the state of the SCx_CLK pin when select muxes are
set to Smart Card Mode and synchronous Mode.
TABLE 10-9: SMART CARD SYNC FCB CONTROL REGISTER
SC_SYNC_FCB
(0X0099)- RESET=0X00) SMART CARD FCB CONTROL REGISTER
BIT NAME R/W DESCRIPTION
7:6 Reserved R Always read as 0
5 INPUT_EN R/W 1 : Input is enabled
0 : Input is disabled
4 OUTPUT_EN R/W 1 : Output is enabled
0 : Output is disabled
TABLE 10-7: SMART CARD SYNC RST CONTROL REGISTER (CONTINUED)
SC_SYNC_RST
(0X0091- RESET=0X00) SMART CARD CONTROL REGISTER
BIT NAME R/W DESCRIPTION
2013 - 2016 Microchip Technology Inc. DS00001561C-page 71
SEC1110/SEC1210
3 FAST_OPEN_DRAIN R/W If this bit is set, and the Mode is output, the signal is driven low when
the data is 0. When the data transitions to 1, it is actively driven high
for one system clock cycle before being tri-stated.
2 OPEN_DRAIN R/W If this bit is set, and the Mode is output, the SCx_C4 output is driven
open drain; 0 are driven, 1 are tri-stated.
1 PULL_UP_EN R/W When set, it enables the pull-up to this pin.
0 PULL_DN_EN R/W When set, it enables the pull-down to this pin.
(0X0098)- RESET=0X00)
7:2 Reserved R Always read as 0
1 FCB_IN R This bit reflects the state of the SCx_C4 pin when select muxes are
set to Smart Card Mode. Synchronous or asynchronous Mode does
not matter.
0 FCB_OUT R/W This bit reflects the state of the SCx_C4 pin when select muxes are
set to Smart synchronous Mode. Synchronous or asynchronous Mode
does not matter.
TABLE 10-10: SMART CARD SYNC SPU CONTROL REGISTER
SC_SYNC_SPU
(0X009D- RESET=0X00) SMART CARD SPU CONTROL REGISTER
BIT NAME R/W DESCRIPTION
7:6 Reserved R Always read as 0
5 INPUT_EN R/W 1 : Input is enabled
0 : Input is disabled
4 OUTPUT_EN R/W 1 : Output is enabled
0 : Output is disabled
3 FAST_OPEN_DRAIN R/W If this bit is set, and the Mode is output, the signal is driven low when
the data is 0. When the data transitions to 1, it is actively driven high
for one system clock cycle before being tri-stated.
2 OPEN_DRAIN R/W If this bit is set, and the Mode is output, the SCx_C8 output is driven
open drain; 0 are driven, 1 are tri-stated.
1 PULL_UP_EN R/W When set, it enables the pull-up to the SCx_C8 pin.
0 PULL_DN_EN R/W When set, it enables the pull-down to the SCx_C8 pin.
(0X009C- RESET=0X00)
7:2 Reserved R Always read as 0
1 SPU_IN R This bit reflects the state of the SCx_SPU pin when select muxes are
set to Smart Card Mode. Synchronous or asynchronous Mode does
not matter.
0 SPU_OUT R/W This bit reflects the state of the SCx_SPU pin when select muxes are
set to Smart Card Mode. Synchronous or asynchronous Mode does
not matter.
TABLE 10-9: SMART CARD SYNC FCB CONTROL REGISTER (CONTINUED)
SC_SYNC_FCB
(0X0099)- RESET=0X00) SMART CARD FCB CONTROL REGISTER
BIT NAME R/W DESCRIPTION
SEC1110/SEC1210
DS00001561C-page 72 2013 - 2016 Microchip Technology Inc.
The SC_SYNC_ALL Register provides parallel control to read and write all of the Smart Card pads at the same time.
The bits CARD_RST_CNTL, CARD_CLK_CNTL, CARD_IO_CNTL, CARD_FCB_CNTL, and CARD_SPU_CNTL provide read
(and write) access to the respective Synchronous registers IN (and OUT) bits respectively.
The Synchronous Register controls for each pad, such as INPUT_EN, OUTPUT_EN, FAST_OPEN_DRAIN, OPEN_DRAIN,
PULL_UP, and PULL_DOWN in the respective registers need to be programmed before write access to this register.
TABLE 10-11: SMART CARD SYNC IO CONTROL REGISTER
SC_SYNC_IO
(0X00A1- RESET=0X00) SMART CARD IO CONTROL REGISTER
BIT NAME R/W DESCRIPTION
7:6 Reserved R Always read as 0
5 INPUT_EN R/W 1 : Input is enabled
0 : Input is disabled
4 OUTPUT_EN R/W 1 : Output is enabled
0 : Output is disabled
3 FAST_OPEN_DRAIN R/W If this bit is set, and the Mode is output, the signal is driven low when
the data is 0. When the data transitions to 1, it is actively driven high
for one system clock cycle before being tri-stated.
2 OPEN_DRAIN R/W If this bit is set, and the Mode is output, the SC_IO output is driven
open drain; 0 are driven, 1 are tri-stated.
1 PULL_UP_EN R/W When set, it enables the pull-up to this pin.
0 PULL_DN_EN R/W When set, it enables the pull-down to this pin.
(0X00A0- RESET=0X00)
7:2 Reserved R Always read as 0
1 IO_IN R This bit reflects the state of the SCx_IO pin when select muxes are
set to Smart Card Mode as well as synchronous Mode.
0 IO_OUT R/W This bit reflects the state of the SCx_IO pin when select muxes are
set to Smart synchronous Mode.
Note: The Smart Card 2 interface does not have C4, C8 pins defined.
TABLE 10-12: SMART CARD SYNC ALL CONTROL REGISTER
SC_SYNC_ALL
(0X00A4- RESET=0X00) SMART CARD ALL CONTROL REGISTER
BIT NAME R/W DESCRIPTION
7:6 Reserved R Always read as 0
5 CARD_SPU_CNTL
(CARD_C8_CNTL)
R/W A read indicates the status of the SC_SYNC_SPU.SPU_IN bit.
A write to this bit writes the SC_SYNC_SPU.SPU_OUT bit.
4 CARD_FCB_CNTL
(CARD_C4_CNTL)
R/W A read indicates the status of the SC_SYNC_FCB.FCB_IN bit.
A write to this bit writes the SC_SYNC_FCB.FCB_OUT bit.
3 CARD_IO_CNTL R/W A read indicates the status of the SC_SYNC_IO.IO_IN bit.
A write to this bit writes the SC_SYNC_IO.IO_OUT bit.
2 CARD_CLK_CNTL R/W A read indicates the status of the SC_SYNC_CLK.CLK_IN bit.
A write to this bit writes the SC_SYNC_CLK.CLK_OUT bit.
1 CARD_RST_CNTL R/W A read indicates the status of the SC_SYNC_RST.RST_IN bit.
A write to this bit writes the SC_SYNC_RST.RST_OUT bit.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 73
SEC1110/SEC1210
10.12.1 SYNCHRONOUS INTERFACE OUTPUT
The timing diagram shows how the output behaves under different register setting for the synchronous interface when
configured as an output.
0 CARD_VCC_CNTL R/W This bit when reset disables power to the Smart Card 1 (or 2) pads.
Resetting this bit causes masking of PWR_SC1_EN (or PWR_SC2_EN)
bit in the POWER_CTL1 Register, controlling the voltage regulators to
the Smart Card pads.
This bit when set enables the PWR_SC1_EN (or PWR_SC2_EN) bit to
control the voltage regulators to the Smart Card pads. The voltage
applied is indicated by non-zero values of the PWR_SC1_EN (or
PWR_SC2_EN) bit.
FIGURE 10-15: SMART CARD SYNCHRONOUS OUTPUT CONFIGURATIONS
TABLE 10-12: SMART CARD SYNC ALL CONTROL REGISTER (CONTINUED)
SC_SYNC_ALL
(0X00A4- RESET=0X00) SMART CARD ALL CONTROL REGISTER
BIT NAME R/W DESCRIPTION
INPUT
OUTPUT
OPEN_DRAIN = 0 FAST_OPEN_DRAIN = X
PULL_UP_EN = X, PULL_DN_EN = X
OUTPUT
OPEN_DRAIN = 1 FAST_OPEN_DRAIN = 0
PULL_UP_EN = 0, PULL_DN_EN = 0
OUTPUT
OPEN_DRAIN = 1 FAST_OPEN_DRAIN = 0
PULL_UP_EN = 1, PULL_DN_EN = 0
OUTPUT
OPEN_DRAIN = 1 FAST_OPEN_DRAIN = 1
PULL_UP_EN = 0, PULL_DN_EN = 0
OUTPUT
OPEN_DRAIN = 1 FAST_OPEN_DRAIN = 1
PULL_UP_EN = 1, PULL_DN_EN = X
Z
(Pull up)
System Clock
Z
High
High Pull up
High
SEC1110/SEC1210
DS00001561C-page 74 2013 - 2016 Microchip Technology Inc.
10.13 Power
The Smart Card block is enabled when the SC1_CLK_EN (or SC2_CLKEN) is turned on in the SC1_CLK_DIV (or SC2_-
CLK_DIV) Register.
10.14 Asynchronous Interface Registers
The SEC1110 and SEC1210 have Smart Card Interfaces based on the ISO/IEC 7816 Standard.
10.14.1 ASYNCHRONOUS MODE REGISTERS
TABLE 10-13: SMART CARD TRANSMIT/RECEIVE BUFFER REGISTER
SC_TBR_RBR
(0X0000- RESET=0XXX) SMART CARD TRANSMIT/RECEIVE BUFFER REGISTER
BIT NAME R/W DESCRIPTION
7:0 DATA R/W Writing to this register causes the byte to be written to the FIFO, and
an internal count is incremented for determining the length of the
message to be transmitted. Writing too much information will cause
the message to be silently truncated to the length of the FIFO.
Reading from this register causes a byte to be read from the FIFO.
This decrements the FIFO Count Register. If the FIFO Count Register
is already zero, this causes the UE bit in the Line Status Register to
be set to 1, and the Receiver is disabled from writing to the FIFO.
TABLE 10-14: SMART CARD INTERRUPT ENABLE REGISTER
SC_IEN
(0X0001- RESET=0X00) SMART CARD INTERRUPT ENABLE REGISTER
BIT NAME R/W DESCRIPTION
7 PRTI R/W 1: Enables the Protocol and Timer Interrupt. The sources of this
interrupt are itemized in register PRIP.
6 AUTO_DA_PWR_OFF R/W For the SEC1110 and SEC1210 A0 version, this bit is not used.
In the SEC1110 and SEC1210 A1 version onwards, the behavior is as
follows:
When this bit is set to 1, it indicates that SCx_VCC power is turned
off automatically during auto-deactivation. Auto-deactivation occurs
when a Smart Card is removed (SCx_PRSNT_N goes high), or the
APDE bit is set and a non-recoverable parity error is encountered.
This bit must not be set to 1 in SEC1110 and SEC1210 A1 version,
for Class A, Class B modes.
When this bit is set to 0 (default), it indicates that the hardware will
go through the auto-deactivation sequence of driving RST, CLK, and
IO lines low, but not power down SCx_VCC. An interrupt is raised
when auto-deactivation occurs and software must follow the power
down sequence. The interrupt source is from the GPIO (Card remove)
due to the RLSI (non-recoverable parity error).
5 GPI R/W Set to 0. Do not use for SEC1110 and SEC1210.
4 PTI R/W Set to 0. Do not use for SEC1110 and SEC1210.
3 Reserved R/W Always write 0
2 RLSI R/W 1 : Enables an interrupt on Line Status errors: Parity, Framing,
Overflow or Underflow.
1 THRRI R/W 1 : Enables an interrupt when the Transmitter has finished
transmission of a message, including the minimum Guard Time (stop
bits).
0 RDAI R/W 1 : Enables an interrupt when FIFO data is available to read, either
by the threshold value or by any data at all in the FIFO after a timeout
condition (e.g., the CWT Timer).
2013 - 2016 Microchip Technology Inc. DS00001561C-page 75
SEC1110/SEC1210
10.14.1.1 Interrupt Identification
By accessing this register, the host CPU can determine the highest priority interrupt and its source. Four levels of priority
interrupt exist with a descending order of priority as follows:
1. Receiver line status (highest priority)
2. Received data ready
3. Transmitter holding register empty or threshold has been reached
4. Protocol/Timer Interrupt
Information indicating that a prioritized interrupt is pending and the source of that interrupt is stored in the SC Interrupt
Identification Register (refer to interrupt control table). When the CPU accesses the IIR, the Smart Card Interface
freezes all interrupts and indicates the highest priority pending interrupt to the CPU. During this CPU access, even if the
Smart Card Interface records new interrupts, the current indication does not change until either the interrupt is reenabled
or the event causing the interrupt is cleared and re-asserted. The contents of the SC_IIR are described below.
Note: The traditional UART FIFO Control Register functions are no longer in a write-only register at this address.
Instead, the FCR Register is a read/write register at location offset 0x0012, and the Threshold is in a
separate pair of registers.
Note: Interrupts are re-enabled by writing a 1 to the interrupt enable bit. This bit does not need to be cleared to
re-enable interrupts.
TABLE 10-15: SMART CARD INTERRUPT IDENTIFICATION REGISTER
SC_INT_ID
(0X0002- RESET=0B00XX00XX1) SMART CARD INTERRUPT IDENTIFICATION REGISTER
BIT NAME R/W DESCRIPTION
7 PRTI R/W 1 : Indicates the presence of a Protocol or Timer Interrupt. The
sources of this interrupt are itemized in register PRIP, and are cleared
by reading that register.
6 AUTO_DA_PWR_OFF R/W This bit is not used in the SEC1110/SEC1210 version.
In SEC1110/SEC1210 version onwards, the behavior is as follows:
This bit is set to 1 if the SC_IEN.AUTO_DA_PWR_OFF bit is set, and an
auto-deactivation event occurred.
This bit is cleared when both the SC_INTF_MON.CRMV bit and
SC_LCR.APDE bits are cleared by software.
5 GPI R/W Do not use, SC_IEN to keep disabled
4 PTI R/W Do not use, SC_IEN to keep disabled
3 FTO R/W FIFO Timeout:
1 : Indicates a FIFO Data Timeout caused by the CWT Timer, or by
the Timeout Timer in T=0 Mode, rather than the amount of received
data reaching the Threshold value. It also indicates that the Receiver
will be delivering no more data bytes to the FIFO.
This bit is not an interrupt source, but is instead a status bit, which
should be examined when processing the RDAI Interrupt. This bit is
cleared by emptying or resetting the FIFO.
2:1 PRI R/W If the IP bit in this register is 0 (active), then this field holds the source
of the interrupt
0 IP R/W 0 : Indicates that an interrupt is pending, and that the PRI field of this
register indicates the highest priority level pending.
1 : Indicates that no interrupt is pending.
SEC1110/SEC1210
DS00001561C-page 76 2013 - 2016 Microchip Technology Inc.
TABLE 10-16: INTERRUPT CONTROL TABLE
INTERRUPT ID REGISTER FIELDS
PRTI OCSI GPI PTI FTO PRI IP
BITS
7 6 5 4 3 21 0
PRIORITY
LEVEL
& ENABLE INTR. TYPE
INTR.
SOURCE
INTR.
RESET
CONTROL
X NA NA NA X X X 1 - None None -
X 1 NA NA X 1 1 0 First
SC_IEN
bit 6
AUTO_DA_PW
R_OFF
Autodeactivation
due to Smart
Card removal or
non-recoverable
parity error
Clearing the
SC_IEN.AUTO_
DA_PWR_OFF
bit
X NA NA NA X 1 1 0 First
&
SC_IEN bit 2
Line Status Overrun
Error, Parity
Error,
Frame
Error,
Underflow
Error, or TF
(Guard
Algorithm
Timeout)
Reading the
Line Status
Register
X NA NA NA 0 1 0 0 Second
&
SC_IEN bit 0
Received Data
available
Receiver Data
available
Reading from
the FIFO until its
level drops
below the
threshold level
X NA NA NA 1 1 0 0 Second
&
SC_IEN bit 0
Character
Timeout
indication
CWT or
Timeout Timer
underflow with
data in FIFO.
Reading from
the FIFO
X NA NA NA X 0 1 0 Third
&
SC_IEN bit 1
Transmit
Finished
Transmit Phase
of Exchange is
complete
Reading the IID
Register
1 NA NA NA X 0 0 0 Fourth
&
SC_IEN bit 7
Protocol Timer
Timeout
GP Counter
underflow
(normal) or
Timeout, CWT
or Guard Timer
underflow
(errors)
Reading the
PRIP Register
TABLE 10-17: SMART CARD LINE CONTROL REGISTER
SC_LCR
(0X0003- RESET=0X00) SMART CARD LINE CONTROL REGISTER
BIT NAME R/W DESCRIPTION
7:6 DLAB R/W These bits are forced to zero.
5 DCEN R/W General Purpose Down Counter Enable:
1 : Starts the counter. See Section 10.5.3, "Recommended etu Rates
and Settings," on page 51 for details.
4 CARD_FAKE R/W In SEC1110/SEC1210, always read as 0.
In SEC1110/SEC1210 this bit is used to fake the SCx_PRSNT_N
input as active.
0 : No card fake. (default). The card presence is based on
SCx_PRSNT_N pin through the GPIO block.
1 : Fake card presence. This bit if set, causes the Smart card
hardware to ignore SCx_PRSNT_N pin, and assume card is present.
The fake card presence is still validated through debounce delays.
This feature enables usage of SCx_PRSNT_N pin for other purposes.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 77
SEC1110/SEC1210
3 PER_SIG_MODE R/W In SEC1110/SEC1210, always read as 0.
In SEC1110/SEC1210 this bit indicates the assertion time of parity
error.
0 : Parity error is signaled for one ETU, as measured by internal block
sc_clk. The actual width of parity error depends on rise/fall delays of
SCx_IO line. (default)
1 : Parity error is signaled for 1.25 ETU, as measured by internal
block sc_clk. This setting ensures, that the parity error assertion width
is independent of rise/fall time on SCx_IO line.
2 TMO_CONFIG R/W This bit defines the unit resolution of Timeout Timer.
0 : Timeout Timer Unit Resolution is in 1.25 milliseconds.
1 : Timeout Timer Unit Resolution is one ETU.
1 APDE R/W Automatic Parity-Error Deactivate Enable:
1 : Causes the ICC to be deactivated by hardware upon a nonrecoverable
parity error. The device must also be in T=0 Mode for this
to occur. If the CRE bit is also 0, this will occur without performing
character repetition or signalling to the ICC.
0 CRE R/W Character Repeat Enable:
1 : Enables character repeat in T=0 Mode if a Parity Error is signalled
by the ICC.
TABLE 10-18: SMART CARD INTERFACE MONITOR REGISTER
SC_INTF_MON
(0X0004- RESET=0B00X10XX0) SMART CARD INTERFACE MONITOR REGISTER
BIT NAME R/W DESCRIPTION
7 FFULL R/W FIFO Full: indicates that the FIFO is completely full with data to be
transmitted.
6 Reserved R Always read as 0
5 PSNT R/W This pin reflects the state of the SCx_PRSNT_N pin.
4 CRMV R/W Card Removed:
This bit is set to 1 when a card is being removed. It is a read-only 1,
and cannot be cleared by software, as long as the debounced version
of the SCx_PRSNT_N signal is high.
When SCx_PRSNT_N goes low, this bit can be cleared by writing a 1
to it. While this bit is 1, the SC_ICR Register is held to its default
state, which holds the signals SCx_IO, SCx_CLK and SCx_RST_N
low.
3 FTH R/W 1 : Indicates the presence of a FIFO Threshold Interrupt request.
2 RST_N R/W Indicates the current state of the SCx_RST_N pin.
1 IO R/W Indicates the current state of the SCx_IO pin.
0 CRPT R/W Indicates, in T=0 Mode, whether any characters needed to be
repeated to the ICC. This bit may be cleared by writing a 1 to it. This
is an indicator only.
TABLE 10-17: SMART CARD LINE CONTROL REGISTER (CONTINUED)
SC_LCR
(0X0003- RESET=0X00) SMART CARD LINE CONTROL REGISTER
BIT NAME R/W DESCRIPTION
SEC1110/SEC1210
DS00001561C-page 78 2013 - 2016 Microchip Technology Inc.
TABLE 10-19: SMART CARD LINE STATUS REGISTER
SC_LSR
(0X0005- RESET=0XXX) SMART CARD LINE STATUS REGISTER
BIT NAME R/W DESCRIPTION
7 ETR R/W Indicates whether a Parity Error (bit 2) occurred in the Transmit phase
(0) or the Receive phase (1) of an exchange.
6 TRANSMIT_EMPTY R/W This bit is cleared to 0 at the beginning of transmission, and is set to
1 when the transmission completes, including Guard Time (stop bit(s))
of the last character.
5 TRANSMIT_FAILURE R/W Indicates that a Guard Time algorithm failure occurred.
4 UNDERFLOW_ERROR R/W 1 : Indicates that a software error has caused an attempt to read from
the FIFO while it is empty. Since this can add indeterminate bytes to
a message, the Receiver is disabled to the FIFO, by clearing the FRE
bit.
3 FRAMING_ERROR R/W 1 : Indicates that a Framing Error has been seen on received data. It
disables the Receiver from the FIFO, by clearing the FRE bit in the
FCR Register upon its occurrence, after placing the character with the
error into the FIFO.
Reading this register clears this bit.
2 PARITY_ERROR R/W 1 : Indicates a Parity Error. It disables the Receiver or the Transmitter
from the FIFO upon its occurrence, by clearing the FRE or FTE bit in
the FCR Register.
If the error is seen while receiving, the FRE bit will be cleared after
receiving the character with the error into the FIFO. Reading this
register clears this bit. If the APDE bit in the LCR Register is 1, the
error will also deactivate the ICC immediately by hardware action.
1 OVERRUN_ERROR R/W 1 : Indicates that too much data has been received from the ICC, so
that the FIFO became completely full and lost a character. This error
disables the Receiver or the Transmitter from the FIFO upon its
occurrence, by clearing the FRE bit.
Note: Attempting to transmit a message longer than the FIFO
length will silently truncate the message, but will not set this
bit.
0 DATA_READY R/W 1 : Indicates that the FIFO is not empty of received data. This bit is
not affected by reading this register.
Note: All bits except SC_LSR.DATA_READY (bit 0) are automatically cleared after reading this register.
TABLE 10-20: SMART CARD BLOCK MASTER CONTROL REGISTER
SC_BMC
(0X0006- RESET=0X00) SMART CARD BLOCK MASTER CONTROL REGISTER
BIT NAME R/W DESCRIPTION
7:2 Reserved R Always read as 0
1 GIE R/W Global Interrupt Enable:
A 0 in this bit position disables all interrupts from the Smart Card
interface.
0 MRST R/W Software-Controlled Master Reset Control:
Set this bit to 1 to reset the Smart Card block. The configuration
section is not affected, and the GPIO section is not affected except
that interrupts are disabled in the IEN Register. When the bit returns
to 0, hardware is indicating that the reset is complete.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 79
SEC1110/SEC1210
TABLE 10-21: SMART CARD INTERFACE CONTROL REGISTER
SC_ICR
(0X0007- RESET=0B00001000) SMART CARD INTERFACE CONTROL REGISTER
BIT NAME R/W DESCRIPTION
7 RST_N R/W SCx_RST_N Pin Control:
The default value (0) holds the SC_RST_N pin low. A 1 in this bit
causes the SCx_RST_N pin to drive high. This bit may be written to 1
or 0 by software, and the first underflow of the Guard Timer, while the
Protocol Mode Register is indicating ATR Mode, sets this bit to 1, and
causes the SC_RST_N pin to rise as part of the Reset/ATR sequence.
6 ENG R/W Enable Guard Timer:
Writing 1 enables the Guard Timer to begin counting at the next
triggering event. Writing 0 has no effect: to clear this bit, write 1 to the
RSG bit in the Timer Control Register. This bit is cleared by hardware
in ATR Mode when the first start bit is seen, or on an underflow from
the BGT reload. In the second case, an interrupt request is also
presented
5:4 VPIN R/W Not used.
3 CSTP R/W Clock Stop:
1 : Stops the SCx_CLK signal either high or low, depending on the
CSTL bit.
0 : Causes the SCx_CLK signal to run. This signal is initially 1 on
reset, causing SCx_CLK to be stopped in the low state.
When setting this bit, the CPU clock must be multiple of SCx_CLK
and CPU frequency must not be changed. Otherwise a clock glitch
can occur on SCx_CLK. To avoid this, software synchronization must
be done to read SCx_CLK and CSTP bit must be set with CSTL=0
when SCx_CLK is low.
2 CSTL R/W Clock Stop Level:
When the CLKSTP bit is set, this bit indicates the state in which the
SCx_CLK pin should stop: 1 means stop the clock high, 0 means stop
the clock low. This bit is initially 0 on reset, causing SCx_CLK to be
stopped in the low state.
1 IO R/W SCx_IO Pin Control:
The default value (0) forces the SCx_IO pin low. Writing a 1 to this bit
enables the SCx_IO pin to float and to drive high.
0 IOPU R/W 1 : Enables a weak pull-up device on the SCx_IO pin. This device is
internally disabled while the Transmitter is actively driving the SCx_IO
pin.
TABLE 10-22: SMART CARD DATA REGISTER
SC_DATA
(0X0008~0X000B- RESET=0XXX) SMART CARD DATA REGISTER
BIT NAME R/W DESCRIPTION
7:0 DATA R/W Perform all transfers at the location DATA, regardless of size.
Transferring a value at the DATA location has the same effect as
transferring the individual bytes (LS byte first) at the SC_TBR_RBR
location (0000), but is more efficient for the larger data types.
In the SEC1110 and SEC1210, these registers are present for
software compatibility to other parts.
SEC1110/SEC1210
DS00001561C-page 80 2013 - 2016 Microchip Technology Inc.
TABLE 10-23: SMART CARD PROTOCOL STATUS REGISTER
SC_PRS
(0X000C- RESET=0X04) SMART CARD PROTOCOL STATUS REGISTER
BIT NAME R/W DESCRIPTION
7 Reserved R Always read as 0
6 INVALID_START_STS R This bit is set when an invalid start bit received.
Invalid start bit is detected when any of the below checks fail.
• Start bit period less than 0.5 etu
• A level LOW check on SCx_IO pin at the sample time specified in
the START_WIDTH_TOL register
This bit is reset when read or when RSE bit in SC_FCR register is set.
In SEC1110/SEC1210, always read as 0.
5 SMB R/W State Machine Busy:
1 : Indicates that a transfer is in progress
0 : Indicates that no transfer is in progress (idle/finished)
4 PWR R/W This bit is forced to 0
3 ACTV R/W Activity Bit:
1 : Indicates that a character has been received since the last time
this bit was cleared by software. This bit is cleared by software, by
writing a 0 to this bit location (this is the only writable bit in this
register). Only the RSE bit in the SC_FCR Register has to be 1 in
order for this bit to detect activity, and the FRE bit does not have to
be 1.
2 GPH R/W Guard Timer Phase:
Indicates the current phase of operation for the Guard Timer:
0 : next reload will be from the SC_EGT Register
1 : next reload will be from the BGT Register
1 TSM R/W TS Mode:
Indicates the current convention: 0 = direct, 1 = inverse. Writing a 1
to the ATR bit in the Protocol Mode Register initializes this bit to 0,
and it can be manipulated using some test register features.
Otherwise, it is a read-only bit.
0 TSC R/W TS Captured:
1 : Indicates that a convention has been automatically captured from
an ATR TS byte. Writing a 1 to the ATR bit in the Protocol Mode
Register initializes this bit to 0, and it can be manipulated using some
test register features. Otherwise, it is a read-only bit.
TABLE 10-24: SMART CARD PROTOCOL INTERRUPT PENDING REGISTER
SC_PRIP
(0X000D- RESET=0X00) SMART CARD PROTOCOL INTERRUPT PENDING REGISTER
BIT NAME R/W DESCRIPTION
7 GPT R/W 1 : General Purpose Down Counter Interrupt
6 TSW R/W 1 : Timeout waiting for the TS byte in ATR Mode. (Guard Timer, EGT
reload phase.)
5 TMO R/W 1 : Timeout on the Timeout Timer (WWT, BWT or WTX)
4 CWT R/W 1 : Timeout on the CWT Timer (CWT, or timeout waiting for the ATR
TS byte)
2013 - 2016 Microchip Technology Inc. DS00001561C-page 81
SEC1110/SEC1210
3 NULL R This bit if set indicates to the processor that a NULL byte was
received. This bit may be used in T=0 Mode, to detect NULL byte
reception, and indicate to host software.
2 EOM R/W 1 : End of Message indication from one of the T=0 Filter State
Machines. If communication terminates prematurely or with an error,
the CV bit will also be 1.
1 COLL R/W This bit gets set on a collision detection, when the chip is transmitting
on the SCx_IO line, and the feedback value on the SCx_IO line
sampled at the middle of ETU, is different from the value transmitted.
This error raises an interrupt if SC_PRIE.COLL bit This error indication
causes resets to all Smart Card block state machines and clears FRE
and FTE.
If this bit is disabled, hardware ignores the collision and proceeds
normally. However, the collision status will be available to SW. There
is a possibility that further collisions will cause parity or timeout errors.
This bit is also set if SCx_RST_N collision occurs (i.e., Terminal is
asserting SCx_RST_N low, and this line is high, or vice-versa).
0 CV R/W This is a status bit, not an interrupt source. 1 indicates that a code
violation has occurred; either a bad TS value during ATR.In T=0 Mode
with a Filter State Machine enabled, a code violation can be either an
unrecognized Procedure Byte or an SW1 byte earlier than expected.
Note: Some erroneous Smart Cards assert SCx_IO at 11 etu instead of 10.5 etu.
TABLE 10-25: SMART CARD PROTOCOL INTERRUPT ENABLE REGISTER
SC_PRIE
(0X000E- RESET=0X00) SMART CARD PROTOCOL INTERRUPT ENABLE REGISTER
BIT NAME R/W DESCRIPTION
7 GPT R/W 1 : Enables General Purpose Down Counter Timeout
6 TSW R/W 1 : Enables TSW Timeout waiting for the TS byte in ATR Mode.
(Guard Timer, EGT reload phase)
5 TMO R/W 1 : Enables TMO Timeout on the Timeout Timer
4 CWT R/W 1 : Enables CWT Timeout on the CWT Timer
3 NULL R This bit if set enables an interrupt to the processor when a NULL byte
is received. This bit may be enabled in T=0 Mode, to detect NULL
byte reception, and indicate to host software.
2 EOM R/W 1 : Enables EOM End of Message
1 COLL R/W 1 : Enables COLL error detection
If this bit is enabled, and a collision occurs, then only COLL status bit
is updated, and the current transaction is aborted by the hardware.
0 CV R/W 1 : Enables CV Interrupt
Note: This register enables the interrupts coming from the PRIP Register.
TABLE 10-24: SMART CARD PROTOCOL INTERRUPT PENDING REGISTER (CONTINUED)
SC_PRIP
(0X000D- RESET=0X00) SMART CARD PROTOCOL INTERRUPT PENDING REGISTER
BIT NAME R/W DESCRIPTION
SEC1110/SEC1210
DS00001561C-page 82 2013 - 2016 Microchip Technology Inc.
TABLE 10-26: SMART CARD TIMER STATUS REGISTER
SC_TMS
(0X000F- RESET=0X10) SMART CARD TIMER STATUS REGISTER
BIT NAME R/W DESCRIPTION
7:5 Reserved R Always read as 0
4 GS_MAX_TIMEOUT R This bit if set indicates that the maximum guard spacing timeout has
happened.
3 TORUN R 1 : Indicates that the Timeout Timer has been triggered and is running
2 Reserved R Always read as 0
1 CRUN R 1 : Indicates that the CWT Timer has been triggered and is running
0 GRUN R 1 : Indicates that the Guard Timer has been triggered and is running
TABLE 10-27: SMART CARD BAUD DIVISOR LSB REGISTER
SC_DLL
(0X0010- RESET=0X01) SMART CARD BAUD DIVISOR LSB REGISTER
BIT NAME R/W DESCRIPTION
7:0 BAUD_DIV_7_0 R/W These are the lower 8 bits of the 16 bit baud rate divisor. The most
significant 8 bits are held in the SC_DLM Register.
The baud rate divisor, with the Sampling field of the CLK Register,
divides the etu rate from the sc1_clk/sc2_clk input clock from the
CLK_PWR block.
TABLE 10-28: SMART CARD BAUD DIVISOR MSB REGISTER
SC_DLM
(0X0011- RESET=0X00) SMART CARD BAUD DIVISOR MSB REGISTER
BIT NAME R/W DESCRIPTION
7:0 BAUD_DIV_15_8 R/W These are the most significant 8 bits of the 16 bit baud rate divisor.
The least significant 8 bits are held in the SC_DLL Register.
The baud rate divisor, with the Sampling field of the CLK Register,
divides the etu rate from the sc1_clk/sc2_clk input clock from the
CLK_PWR block.
TABLE 10-29: SMART CARD FIFO CONTROL REGISTER
SC_FCR
(0X0012- RESET=0X00) SMART CARD FIFO CONTROL REGISTER
BIT NAME R/W DESCRIPTION
7:6 Reserved R Always read as 0
5 RFS R Receiver FIFO Status:
This bit indicates whether the Receiver is actively prepared to place
characters into the FIFO. It may not match the FRE bit, if the Receiver
is still waiting for a trigger to begin (e.g., waiting for transmission to
complete).
4 RSS R Receiver Sampling Status:
This bit indicates whether the Receiver is actively sampling for
characters. It may not match the RSE bit, if the Receiver is still waiting
for a trigger to begin. For example, in ATR Mode, it may not yet be
active, pending a rising edge on the SCx_RST_N pin.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 83
SEC1110/SEC1210
Note 1: This register provides control for FIFO access, and enables the Receiver and the Transmitter.
2: In SEC1110/SEC1210 version, if the FIFO is disabled before a GSR timeout occurs, then the GSR timer is
not reset. The software work-around is to wait for the GSR timer to expire. This Anomaly 6 is fixed in later
versions (SEC1110/SEC1210).
3 RSE R/W Receiver Sampling Enable:
1 written to this bit enables the Receiver to sample the SCx_IO pin
for characters. In ATR Mode, the sampling does not occur
immediately, but waits for a rising edge on the SCx_RST_N pin first.
This bit is cleared by an incoming error (e.g., repeated parity error in
T=0 Mode, or CWT violation in T=1 Mode, or Overrun Error). While
the Receiver is sampling, the BGT or DGT value in the Guard Timer
Register continues to be used to inhibit the Transmitter, regardless of
the state of the FRE bit.
2 FRST W FIFO Reset:
Always reads as 0. A 1 written to this bit resets the FIFO to an Empty
state. If an error has occurred while transmitting to the card, this
function must be used to re-initialize the FIFO.
1 FRE R/W FIFO Receive Enable:
Allows reception into the FIFO. Except in ATR Mode, a transmission
has to occur before the Receiver is actually activated. In ATR Mode,
a rising edge must occur on the SCx_RST_N pin before the Receiver
is activated. This bit is turned off by errors occurring during reception
or transmission (e.g., CWT timeout error); otherwise software must
turn it off after receipt of a message, to prepare for the next exchange
0 FTE R/W FIFO Transmit Enable:
Writing 1 to this bit triggers transmission from the FIFO. This bit is
turned off by the normal end of transmission, when all bytes in the
FIFO have been transmitted. It is also turned off by errors occurring
during transmission (e.g., parity error after retransmissions in T=0
Mode).
TABLE 10-30: SMART CARD TIMEOUT TIMER LEAST SIGNIFICANT BYTE (LSB) RELOAD
REGISTER
SC_TOL
(0X0014- RESET=0X00) SMART CARD TIMEOUT TIMER LSB RELOAD REGISTER
BIT NAME R/W DESCRIPTION
7:0 TIMER_RELOAD_LO R/W This register holds the LSB of the reload value for the Timeout Timer.
TABLE 10-31: SMART CARD TIMEOUT TIMER MIDDLE SIGNIFICANT BYTE (MSB) RELOAD
REGISTER
SC_TOM
(0X0015- RESET=0X00)
SMART CARD TIMEOUT TIMER MIDDLE MSB RELOAD
REGISTER
BIT NAME R/W DESCRIPTION
7:0 TIMER_RELOAD_MI R/W This register holds the middle MSB of the reload value for the Timeout
Timer.
TABLE 10-29: SMART CARD FIFO CONTROL REGISTER (CONTINUED)
SC_FCR
(0X0012- RESET=0X00) SMART CARD FIFO CONTROL REGISTER
BIT NAME R/W DESCRIPTION
SEC1110/SEC1210
DS00001561C-page 84 2013 - 2016 Microchip Technology Inc.
The Timeout Reload Register is a 24-bit register (SC_TOH, SC_TOM, SC_TOL) with unit resolution of 1.25 ms.
TABLE 10-32: SMART CARD TIMEOUT TIMER HIGH SIGNIFICANT BYTE (HSB) RELOAD
REGISTER
SC_TOH
(0X0013- RESET=0X00) SMART CARD TIMEOUT TIMER HSB RELOAD REGISTER
BIT NAME R/W DESCRIPTION
7:0 TIMER_RELOAD_HI R/W This register holds the HSB of the reload value for the Timeout Timer.
TABLE 10-33: SMART CARD DOWN COUNTER LSB REGISTER
SC_DCL
(0X0016- RESET=0XFF) SMART CARD DOWN COUNTER LSB REGISTER
BIT NAME R/W DESCRIPTION
7:0 DOWN_CNT_LO R/W This register holds the LSB of the General Purpose Down Counter.
TABLE 10-34: SMART CARD DOWN COUNTER MSB RELOAD REGISTER
SC_DCM
(0X0017- RESET=0XFF) SMART CARD DOWN COUNTER MSB REGISTER
BIT NAME R/W DESCRIPTION
7:0 DOWN_CNT_HI R/W This register holds the MSB of the General Purpose Down Counter.
TABLE 10-35: SMART CARD CWT TIMER LSB RELOAD REGISTER
SC_CWTL
(0X0018- RESET=0X00) SMART CARD CWT TIMER LSB RELOAD REGISTER
BIT NAME R/W DESCRIPTION
7:0 TIMER_RELOAD_LO R/W This register holds the LSB of the reload value for the CWT Timer.
TABLE 10-36: SMART CARD CWT TIMER MSB RELOAD REGISTER
SC_CWTM
(0X0019- RESET=0X00) SMART CARD CWT TIMER MSB RELOAD REGISTER
BIT NAME R/W DESCRIPTION
7:0 TIMER_RELOAD_HI R/W This register holds the MSB of the reload value for the CWT Timer.
TABLE 10-37: SMART CARD GUARD ALGORITHM SPACING REGISTER
SC_GSR_MSB
(0X001B- RESET=0X00) SMART CARD GUARD ALGORITHM SPACING REGISTER
BIT NAME R/W DESCRIPTION
7:0 GUARD_ETUS_MSB R/W This register holds the MSB of maximum spacing between characters,
specified as the number of etus from the leading edges of consecutive
start bits.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 85
SEC1110/SEC1210
10.14.1.2 Protocol Mode Register
The Guard Time reload registers EGT and BGT must be initialized to their desired values before writing to this register.
Changing them afterward may fail to register the change.
All non-reserved bits are read/write. The ATR bit may be set to 1 only if the TE1 bit is also set to 0. Valid settings for these
two bits are:
• ATR Mode: ATR=1 and TE1=0. In this Mode, the Protocol Timers and the Receiver are conditioned to expect an
ATR message from the ICC. Character framing is as per the T=0 protocol. This is the one case where the
Receiver does not wait for the SEC1110 and SEC1210 to transmit first; instead, it waits for a rising edge on the
SCx_RST_N pin, which is being controlled by the Guard Timer.
TABLE 10-38: SMART CARD GUARD ALGORITHM SPACING REGISTER
SC_GSR_LSB
(0X001B- RESET=0X00) SMART CARD GUARD ALGORITHM SPACING REGISTER
BIT NAME R/W DESCRIPTION
7:0 GUARD_ETUS_LSB R/W This register holds the LSB of maximum spacing between characters,
specified as the number of etus from the leading edges of consecutive
start bits.
TABLE 10-39: SMART CARD GUARD TIMER RELOAD A REGISTER
SC_EGT
(0X001C- RESET=0X00) SMART CARD GUARD TIME RELOAD A REGISTER
BIT NAME R/W DESCRIPTION
7:0 RELOAD_A R/W This register holds the Extra Guard Time value in T=0 or T=1 Mode.
In ATR Mode, this register holds the maximum number of etus
allowed from the rising edge of SCx_RST_N to the start bit of the TS
byte. If the timer elapses, the TSW Interrupt is asserted, and the
Receiver is disabled to the FIFO.
Values are expressed in units of etu.
The SC_PRM Register must be written after writing to this register, in
order to latch the change.
TABLE 10-40: SMART CARD GUARD TIMER RELOAD B REGISTER
SC_BGT
(0X001D- RESET=0X00) SMART CARD GUARD TIME RELOAD B REGISTER
BIT NAME R/W DESCRIPTION
7:0 RELOAD_B R/W This register holds the BGT value in T=1 Mode, or the DGT value in
T=0 Mode, preventing transmission until the specified number of etus
has elapsed since the last received character. Monitoring of
characters for this purpose does not depend on whether the Receiver
is enabled to the FIFO. This timer must be enabled, or it will not delay
transmission.
In ATR Mode, this register holds the desired width of the SCx_RST_N
pulse (Warm Reset) or the duration of the clock before the removal of
SCx_RST_N.
Values are expressed in units of etu.
The SC_PRM Register must be written after writing to this register, in
order to latch the change.
SEC1110/SEC1210
DS00001561C-page 86 2013 - 2016 Microchip Technology Inc.
• T=0 Mode: ATR=0 and TE1=0. In this Mode, character framing and parity handling are as per the T=0 protocol.
The Receiver waits until a message has been transmitted before it becomes active.
• T=1 Mode: ATR=0 and TE1=1. In this Mode, character framing and parity handling are as per the T=1 protocol.
The Receiver waits until a message has been transmitted before it becomes active.
The OSME and ISME bits are mutually exclusive: only one of them may be set to 1, and neither may be set to 1 without
the TE1 bit also being set to 0 and the ATR bit set to 0.
TABLE 10-41: SMART CARD PROTOCOL MODE REGISTER
SC_PRM
(0X001E- RESET=0X00) SMART CARD REGISTER
BIT NAME R/W DESCRIPTION
7:5 Reserved R Always read as 0
4 ISME R/W 1 : Indicates that the Incoming Filter State Machine is enabled. The
TE1 bit and ATR bit must also be set to 0.
3 OSME R/W 1 : Indicates that the Outgoing Filter State Machine is enabled. The
TE1 bit and ATR bit must also be set to 0.
2 Reserved R Always read as 0
1 TE1 R/W 0 : Indicates that T=0 character framing is being used, either in T=0
protocol communication or receiving the ATR message.
1 : Indicates that the T=1 protocol is being used. This bit may not be
set to 1 with any of bits ATR, OSME or ISME also set to 1.
0 ATR R/W Answer to Reset Mode:
1 : Indicates that a Reset sequence is to be presented, expecting a
response from the card. The TE1 bit must also be 0 in this Mode.
Writing a 1 to this bit also clears the TSC and TSM bits in the Protocol
Status Register, which causes the first byte received to be interpreted
by hardware as the TS byte, setting the bit encoding convention
based on what is received.
ATR bit in SC_PRM Register should not be set once the ATR from the
card is received.
TABLE 10-42: SMART CARD TIMER CONTROL REGISTER
SC_TCTL
(0X001F- RESET=0X00) SMART CARD TIMER CONTROL REGISTER
BIT NAME R/W DESCRIPTION
7 RSG R/W Reset Guard Timer:
This bit always reads as 0. Writing a 1 to this bit clears the ENG bit in
the Interface Control Register to 0, and removes any pending interrupt
request from the Guard Timer. (The ENG bit, which enables the Guard
Timer, is in the Interface Control Register so that the Guard Timer
may be started atomically with the presentation of SC_RST_N and
SC_CLK to the Smart Card.)
6:5 Reserved R Always read as 0
4 RSC R/W Resets the CWT Timer:
This bit always reads as 0. Writing a 1 to this bit clears the ENC bit to
0, and removes any pending interrupt request from the CWT Timer.
3 ENC R/W Writing 1 enables the CWT Timer to begin counting at the next
triggering event.
Writing 0 has no effect: to clear this bit, write 1 to the RSC bit in the
Timer Control Register. This bit is cleared by hardware action in order
to stop the timer.
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SEC1110/SEC1210
2 WTX R/W 1 : Places the Timeout Timer in WTX Mode
0 : Places it in BWT Mode. In WTX Mode, the Timeout Timer
underflow reloads the Timeout Timer instead of stopping it, and the
Receiver is not disabled on underflow.
1 RSTO R/W Reset the Timeout Timer:
This bit reads as 0 always. Writing a 1 to this bit clears the ENTO bit
to 0, and removes any pending interrupt request from the Timeout
Timer.
0 ENTO R/W Writing 1 enables the Timeout Timer to begin counting at the next
triggering event.
Writing 0 has no effect: to clear this bit, write 1 to the RSTO bit in the
Timer Control Register. This bit is cleared by hardware action in order
to stop the timer.
TABLE 10-43: SMART CARD CLOCK DIVISOR REGISTER
SC_CLK_DIV
(0X0025- RESET=0X58) SMART CARD CLOCK DIVISOR REGISTER
BIT NAME R/W DESCRIPTION
7:6 SAMPLING This field indicates a divisor to apply from the DLL/DLM value in order
to get the final etu rate:
00 : divide by 31
10 : divide by 16
01 : divide by 1
11 : reserved for future use
The SC_CLK_DIV divisor field is reduced in size to 6 bits
5:0 DIVISOR R/W This field gives the divisor to apply to the SEC1110 and SEC1210
system clock in order to generate the SCx_CLK signal to the ICC.
TABLE 10-44: SMART CARD CONFIGURATION BLOCK REGISTER
SC_CFG
(0X0026- RESET=0X60) SMART CARD CONFIGURATION BLOCK REGISTER
BIT NAME R/W DESCRIPTION
7:0 Reserved R Always read as 0
Note: In SEC1110 and SEC1210, the SC_CFG is hardwired to zero.
TABLE 10-42: SMART CARD TIMER CONTROL REGISTER (CONTINUED)
SC_TCTL
(0X001F- RESET=0X00) SMART CARD TIMER CONTROL REGISTER
BIT NAME R/W DESCRIPTION
SEC1110/SEC1210
DS00001561C-page 88 2013 - 2016 Microchip Technology Inc.
10.14.1.3 FIFO Threshold Registers
These registers hold the FIFO threshold for received bytes. The FIFO Threshold Interrupt is asserted when the number
of received/written bytes in the FIFO exceeds the number provided here. For example, set these registers to 0000h to
be interrupted on every byte received. The interrupt is also asserted on a timeout of the CWT Timer, or of the Timeout
Timer in T=0 Mode, regardless of the contents of these registers.
These registers have no effect on transmission: the number of bytes present in the FIFO at the time that the FTE bit is
set to 1 determines the length of the message transmitted.
TABLE 10-45: SMART CARD LED CONTROL REGISTER
SC_LEDC
(0X0027- RESET=0X00) SMART CARD LED CONTROL REGISTER
BIT NAME R/W DESCRIPTION
7:4 BLINK[3:0] R/W This field is reserved for the SEC1110/SEC1210 version.
In SEC1110/SEC1210, this field indicates the LED blinking time in
units of 25 ms. For instance, a value of 4 would indicate 5 blinks per
second.
3 LED_PRGM_TIME_EN R/W This field is reserved for the SEC1110/SEC1210 version.
In SEC1110/SEC1210, this bit controls the blinking of LED.
0 : (default). LED ON/OFF time is fixed as defined by LMD, LCTL
fields.
1 : LED ON/OFF time is based on the value programmed in BLINK
field. If LMD is set, then the LED blinking (BLINK field controls the
rate) is based on SCx_IO pin activity.
2 LMD R/W LED Mode:
0 : LED is controlled by the LED control field in this register.
1 : LED is controlled by activity on the SCx_IO pin. When there is
activity on the SCx_IO pin the LED will blink at an approximate
6.25 Hz rate with a 50% duty cycle (80 msec on, 80 msec off).
1:0 LCTL R/W LED Control, when LED_PRGM_TIME_EN bit is 0.
00 = Off
01 = Blink at 1Hz rate with a 50% duty cycle (0.5 sec on, 0.5 sec off)
10 = Blink at ½ HZ rate with a 25% duty cycle (0.5 sec on, 1.5 sec off)
11 = On
When LED_PRGM_TIME_EN bit is set to 1,
00 = Off
01 = BLINK * 25 ms ON and BLINK * 25 ms OFF
10 = BLINK * 25 ms ON and BLINK * 3 * 25 ms OFF (25% duty cycle)
11 = ON
TABLE 10-46: SMART CARD FIFO THRESHOLD LSB REGISTER
SC_FTHL
(0X0028- RESET=0X00) SMART CARD FIFO THRESHOLD LSB REGISTER
BIT NAME R/W DESCRIPTION
7:0 FIFO_THRESHOLD_LO R/W This register hold the LSB FIFO threshold for received bytes.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 89
SEC1110/SEC1210
10.14.1.4 FIFO Count Registers
This register pair holds the number of bytes currently in the FIFO.
While setting up for transmission, and during transmission, this register tracks bytes being transmitted. If there is an
error in transmission, the Transmitter stops and this register holds the number of bytes remaining in the FIFO. In case
of a transmission error, the FIFO must be reset using the FRST bit in the FCR Register. This action will also clear these
registers to zero. During transmission (i.e., while the Receiver is not active), the value in these registers is not compared
against the Threshold value in the FTHL/FTHM register pair.
While the Receiver is active, this register pair also tracks the number of bytes in the FIFO, and this value is compared
against the FIFO Threshold in the FTHL/FTHM register pair in order to provide the FIFO Threshold Interrupt.
To determine whether an error happened during the Transmit or Receive phase of an exchange (and hence which count
is being displayed in this register), software may inspect the ETR bit in the Line Status Register.
TABLE 10-47: SMART CARD FIFO THRESHOLD MSB REGISTER
SC_FTHM
(0X0029- RESET=0X00) SMART CARD FIFO THRESHOLD MSB REGISTER
BIT NAME R/W DESCRIPTION
7:0 FIFO_THRESHOLD_HI R/W This register hold the MSB FIFO threshold for received bytes.
TABLE 10-48: SMART CARD FIFO COUNT LSB REGISTER
SC_FCL
(0X002A- RESET=0X00) SMART CARD FIFO COUNT LSB REGISTER
BIT NAME R/W DESCRIPTION
7:0 FIFO_COUNT_LO R/W This register holds the LSB of the FIFO count in bytes.
TABLE 10-49: SMART CARD FIFO COUNT MSB REGISTER
SC_FCM
(0X002B- RESET=0X00) SMART CARD FIFO COUNT MSB REGISTER
BIT NAME R/W DESCRIPTION
7:0 FIFO_COUNT_HI R/W This register holds the MSB of the FIFO count in bytes.
TABLE 10-50: SMART CARD FILTER LENGTH REGISTER
SC_FLL
(0X002C- RESET=0X00) SMART CARD FILTER LENGTH REGISTER
BIT NAME R/W DESCRIPTION
7:0 FILTER_LEN R/W This register holds the number of expected data bytes in a T=0
exchange, for the sake of the T=0 filter state machines.
This register is decremented as needed by the outgoing filter state
machine. An initial value of 00h, when the outgoing filter is activated,
is interpreted as 256. An initial value of 00h, when the incoming filter
is activated, is interpreted as 0. Any T=0 command that does not
involve a data transfer will use the incoming filter with an initial count
of 00h. This register returns the least-significant 8 bits of the current
count value when read.
SEC1110/SEC1210
DS00001561C-page 90 2013 - 2016 Microchip Technology Inc.
TABLE 10-51: SMART CARD INS CODE REGISTER
SC_FINS
(0X002D- RESET=0X00) SMART CARD FILTER STATE MACHINE INS CODE REGISTER
BIT NAME R/W DESCRIPTION
7:0 INS R/W This register holds the INS byte for the current T=0 exchange, so that
the T=0 Filter state machines can recognize the INS and INS
Procedure Bytes
TABLE 10-52: SMART CARD DEBOUNCE REGISTER
SC_TEST1
(0X0030, - RESET=0X14) SMART CARD TEST REGISTERS
BIT NAME R/W DESCRIPTION
7:0 DEBOUNCE_MAX R/W This register indicates the debounce counter value for the
SCx_PRSNT_N signal, in 1 ms resolution. If a value of zero is written,
then the debounce logic is avoided, and the SCx_PRSNT_N signal is
sampled directly.
The DEBOUNCE_CLK_EN and DEBOUNCE_FREQ bits in
OSC48_SETTLE_CLKS Register must be enabled for the debouncing
to work.
TABLE 10-53: SMART CARD DEBOUNCE REGISTER
SC_TEST2
(0X0031, - RESET=0X1F) SMART CARD TEST REGISTERS
BIT NAME R/W DESCRIPTION
7:2 START_WIDTH_TOL[7:2] R/W After the leading edge of the start bit, a check is done for a low on
the SCx_IO line, for the sample number indicated by this start bit
tolerance register before the next bit.
If SCx_IO is not low at start bit tolerance sample before the next bit,
that start bit will be invalidated and the Receiver will search for next
start byte.
This width check if violated, will likely result in wrong data received
with a parity error or TMO.
1 OEN_EXT RW When this bit is 0, it disables the OEN extension feature. The Output
enable for the SCx_IO pad is driven for one internal Smart Card clock,
at the end of transmit, and at the end of parity error signaling. This
setting may cause insufficient time, for the SCx_IO pad to switch from
0 to 1, before tristating and enabling the pull-up, during high Smart
Card block frequencies.
When this bit is 1 (default), it indicates that the Output enable
extension for SCx_IO is enabled. This setting ensures that a 0 to 1
transition occurs on the pad, and then the pad is tristated and pull-up
enabled on SCx_IO.
The OEN_CLKS field indicates the OEN extension time.
0 START_BIT_NEG_EDGE RW When this bit is 0, it indicates the detection of start bit (after a parity
error is signaled) occurs when a negative edge is seen on SCx_IO.
When this bit is 1 (default), it indicates the detection of start bit (after
a parity error is signaled) occurs when a 0 level is seen on SCx_IO.
This setting may cause a parity error signaling to be wrongly identified
as the next start bit when the Smart Card block runs internally at high
frequencies.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 91
SEC1110/SEC1210
TABLE 10-54: SMART CARD TEST REGISTER
SC_TEST3
(0X0032 - RESET=0XFF) SMART CARD TEST REGISTERS
BIT NAME R/W DESCRIPTION
7:0 TEST3[7:0] R/W This field defines the number of SC block clock time between the
events
• Reset assertion and clock stop during hardware auto-deactivation
• Clock stop and SCx_VCC switch off signal to smart card pins
TABLE 10-55: SMART CARD TEST REGISTER
SC_TEST4
(0X0033~0033, - RESET=0X00) SMART CARD TEST REGISTERS
BIT NAME R/W DESCRIPTION
7:0 START_WIDTH_TOL[15:8] R/W The start width tolerance is a 16-bit wide register. Bits 1:0 are used
for OEN_EXT, START_BIT_NEG_EDGE also.
TABLE 10-56: SMART CARD TEST DEBOUNCE REGISTER
SC_TEST0
(0X0035, - RESET=0X00) SMART CARD TEST REGISTERS
BIT NAME R/W DESCRIPTION
7:4 Reserved R Always read as 0
3:1 OEN_CLKS R/W These 3 bits of FAST_DEBOUNCE[2:0] are reused as OEN_CLKS field.
It indicates the number of internal Smart Card block clocks to extend
OEN for SCx_IO pad. This field is used when OEN_EXT bit is set.
000 : 2 clocks
001 : 2 ~ 4 clocks in SEC1110/SEC1210. 4 clocks in later versions
010 : 4 ~ 8 clocks in SEC1110/SEC1210. 8 clocks in later versions
011 : 8 ~ 16 clocks in SEC1110/SEC1210. 16 clocks in later versions
100 : 16~ 32 clocks in SEC1110/SEC1210. 32 clocks in later versions
101 : 32 ~ 64 clocks in SEC1110/SEC1210. 64 clocks in later versions
0 Reserved R/W Must be 0.
TABLE 10-57: SMART CARD FIFO TEST REGISTER
SC_FIFO_TEST
(0X0100~02FF, - RESET=0XXX) SMART CARD FIFO TEST1
BIT NAME R/W DESCRIPTION
7:0 FIFO_TEST R/W The SC_FIFO is memory mapped to the 8051 CPU on the XDATA
bus. Only the first 261 (259 for SEC1110/SEC1210) bytes are valid,
and rest is an alias access.
SEC1110/SEC1210
DS00001561C-page 92 2013 - 2016 Microchip Technology Inc.
11.0 USB CONTROLLER DESCRIPTION
The SEC1110 and SEC1210 implements a USB device controller supporting 12 Mbps data transfer. In addition to the
default control Endpoint 0, it provides 5 other endpoints, which can be configured in Control, Bulk, Interrupt or Isochronous
modes:
• Endpoint 0: 8/16/32/64-byte buffer, default control endpoint
• Endpoints 1,2,3,4,5: 8/16/32/64 -byte buffer or buffers in ping-pong Mode.
The Digital Phase-Locked Loop (DPLL) blocks main function is to extract the USB clock and data from the USB cable.
Its main input is an external differential transceiver. The DPLL block has a built-in digital PLL that runs on a user-provided
48 MHz clock in 12 Mbps configuration. The DPLL block also extracts from the 48 MHz clock, a 12 MHz clock that
it can supply to the SIE and UBL blocks.
The D+ and D- signals on the USB lines are passed through a differential receiver (external to the UDC core) and NRZIformatted
data is obtained from the differential receiver output. The DPLL uses this differential receiver output to extract
clock information. The DPLL block also has single-ended zero (SE0) detection logic to detect SE0 signals in the data
stream on the USB transceiver.
The clock and reset block generates a separate 12 MHz clock, by dividing the reference 48 MHz clock by 4 (for 12 Mbps
applications). The UDC core uses this 12 MHz clock, which is also provided on the application bus.
The Serial Interface Engine (SIE) block performs all front-end USB protocol functions, such as SYNC field identification,
NRZI-NRZ conversion, token packet decoding, bit stripping, bit stuffing, NRZ-NRZI conversion, CRC5 checking, and
CRC16 generation and checking. The SIE block also converts serial packets to 8-bit parallel data. The SIE block has a
built-in 1-byte buffer for buffering data during transmission and reception of IN, OUT, and setup transactions. The SIE
block interfaces to the device logic through the USB bridge layer.
The SIE runs on the 1x clock provided by the DPLL block, even though the data from the USB is received on the USB
clock. For actual packet data, the SIE assembles the bits into bytes and forwards them to the application.
The main SIE block functions include:
• SYNC field identification
• NRZI-NRZ conversion during data reception
• Token packet identification
FIGURE 11-1: USB BLOCK DIAGRAM
2013 - 2016 Microchip Technology Inc. DS00001561C-page 93
SEC1110/SEC1210
• Data packet identification
• Handshake packet identification
• Bit stripping during packet reception
• Bit stuffing during packet transmission
• NRZ-NRZI conversion during data transmission
• CRC5 checking for token packets
• CRC16 generation and checking for data packets
• Time-out checking
• Serial-to-parallel and parallel-to-serial data conversion
• Data/handshake packet assembly
• Identifying the USB Reset signal
• Identifying USB Suspend Mode
• Remote wake-up capability
The USB Bridge Layer (UBL) sits between the SIE block and the function interface on the device side (see FIGURE 11-
1: USB Block Diagram on page 92). The UBL’s main purposes are to control the SIE block by providing the necessary
handshake signals and to transfer data between the SIE block and application bus while handling the application bus
protocol.
The UBL handles the error recovery mechanism during transactions while interfacing to the application, and decodes
and handles all standard control transfers addressed to Endpoint 0. The UBL passes all vendor and class commands
onto the application bus for the application to decode and act on. This provides the flexibility of using the UDC core in
multiple applications. The UBL supports an additional single programmable configuration (Configuration 0 has only Endpoint
0), with this configuration having a maximum of 4 interfaces. Each interface can have up to 4 alternate settings.
The configuration is loaded from the on-chip ERAM at USB block initialization time to the EPINFO block.
The UBL receives information from the EPINFO block about the characteristics of the endpoint to which the current
transaction is addressed. Based on this endpoint information, the UBL issues necessary control signals to the SIE block.
The UBL also decodes the standard commands received in Endpoint 0 control transfer setup packets. The UBL forwards
vendor and class commands to Endpoint 0 onto the application bus. The Get Descriptor command is forwarded to the
application bus.
The USB Bridge:
• Provides a simple read/write interface on the device side.
• Handles all transactions to the standard Endpoint 0, shielding those transactions from the device side of the application
bus except for the following:
- Get_Descriptor command, enabling the SW to have programmable configurations
- Set_Descriptor command
- Class and Vendor Specific commands
- Sync_Frame command
• Supports all USB standard commands, decoding and acting on the USB standard commands received in a control
transfer’s setup transaction.
• Provides a state machine for the current device state (default, addressed, configured, suspended).
• Maintains each endpoint’s enabled, disabled, or stalled status. If an endpoint is stalled or disabled, the UDC
issues an appropriate handshake to the host. The transaction is not reflected on the application bus (UDC interface)
side.
• Forwards all class or vendor control transfers to Endpoint 0 and transactions to non-zero control endpoints. The
application must decode 8 setup packet bytes and act on them. The transaction flow is explained in FIGURE 11-3:
on page 95.
The UBL block contains two sub-blocks, called the Protocol Layer (PL) and Endpoint (EP) blocks.
The PL block controls the SIE block by providing necessary handshake signals to the SIE and by interfacing with the
application bus logic. It also has an error recovery mechanism for data transfer protocol violations on the application
bus. The protocol layer receives input about the endpoint characteristics from the EPINFO block and transfers the data
between the SIE interface and the application bus (device interface). In transactions to Endpoint 0 (standard commands),
the setup packet is routed to the EP block for decoding.
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The EP block handles all control transfers to Endpoint 0. The EP block decodes and responds to all USB standard commands
and passes the USB class and vendor commands to the application bus. The EP block maintains buffers for the
device address and for storing the present active configuration, and logic for determining the present device state. All
other vendor/class commands are forwarded onto the application bus (this includes the control transaction’s setup, data
and the status stages). The EP block has a buffer that stores the information received in the setup packet and a state
machine to decode the setup data. The EP block also maintains the state machine for the current device state.
FIGURE 11-2: USB BRIDGE LAYER
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11.1 Transaction Flow
An endpoint should first be enabled and configured before being able to receive bulk or interrupt packets. The PingPong
bit is reset for this endpoint.
FIGURE 11-3: TYPICAL TRANSACTION
Note: FIFOs are shown. Should be DPRAM.
FIGURE 11-4: BULK/INTERRUPT OUT TRANSACTION
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When a valid OUT packet is received on an endpoint, the RXOUTB (and BUF0_RDY) bit is set by the USB controller. This
triggers an interrupt, if enabled. The firmware has to select the corresponding endpoint, and store the number of data
bytes by reading the COUNT0 Register. If the received packet is a ZLP (Zero Length Packet), the COUNT0 Register
value is equal to 0 and no data must be read.
When all the endpoint data bytes have been read, the firmware should clear the RXOUTB (or BUF0_RDY) bit to allow the
USB controller to accept the next OUT packet on this endpoint. Until the RXOUTB (or BUF0_RDY) bit has been cleared
by the firmware, the USB controller will answer a NAK handshake for each OUT requests for this endpoint.
If the Host sends more bytes than supported by the endpoint data buffer, the overflow data would not be stored, but the
USB controller will consider that the packet is valid if the CRC is correct and the endpoint byte counter contains the
number of bytes sent by the Host.
An endpoint should be first enabled and configured before being able to receive bulk or interrupt packets. The PingPong
bit is set. When a valid OUT packet is received on the Endpoint Bank 0, the RXOUTB (and BUF0_RDY) bit is set by the
USB controller. This triggers an interrupt, if enabled. The firmware has to select the corresponding endpoint, store the
number of data bytes by reading the USB_EPN_BYTE_CNT_REG Register. If the received packet is a ZLP (Zero
Length Packet), the COUNT0 Register value is equal to 0 and no data has to be read.
When all the endpoint data bytes have been read, the firmware should clear the BUF0_RDY bit to allow the USB controller
to accept the next OUT packet on the Endpoint Buffer 0.
When a new valid OUT packet is received on the Endpoint Bank 1, the RXOUTB (and BUF1_RDY) bit is set by the USB
controller. This triggers an interrupt, if enabled. The firmware empties the bank 1 endpoint data before clearing the
BUF1_RDY bit.
The BUF0_RDY and BUF1_RDY bits are alternatively set by the USB controller at each new valid packet receipt.
FIGURE 11-5: BULK / INTERRUPT OUT TRANSACTION IN PING-PONG MODE
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The firmware has to clear one of these two bits after having read all the data to allow a new valid packet to be stored in
the corresponding bank.
A NAK handshake is sent by the USB controller only if the banks 0 and 1 have not been released by firmware.
The firmware can reset the hardware pointers by writing a 1 to both BUF0_RDY and BUF1_RDY in a single write.
An endpoint will first be enabled and configured before being able to send bulk or interrupt packets with the PingPong
bit set.
The firmware will fill the data bank 0 with the data to be sent and set the TXRDY (or BUF0_RDY) bit in the USB_EPn_CTL_REG
(or USB_EPn_BUFRDY_REG) Register to allow the USB controller to send the data stored in data at the next
IN request concerning the endpoint. The firmware can immediately write into the Endpoint 1 data bank. The firmware
can set BUF1_RDY bit when this buffer is ready.
When the IN packet concerning the bank 0 has been sent and acknowledged by the Host, the TXRDY (and BUF0_RDY)
bit is reset by the USB controller. This triggers a USB interrupt if enabled. The firmware will check if the BUF0_RDY bit
is reset before filling the Endpoint 0 Data Bank with new data.
When the IN packet concerning the bank 1 has been sent and acknowledged by the Host, the TXRDY (and BUF1_RDY)
bit is reset by the USB controller. This triggers a USB interrupt if enabled. The firmware will check if the BUF1_RDY bit
is reset before filling the Endpoint 1 Data Bank with new data.
The bank switch is performed by the USB controller after each packet. Until the TXRDY bit has been set by the firmware
for an endpoint bank, the USB controller will answer a NAK handshake for each IN requests concerning this bank.
The firmware will never write more bytes than supported by the endpoint data buffer.
FIGURE 11-6: BULK/INTERRUPT IN TRANSACTIONS IN PING-PONG MODE
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11.2 Control Transactions
11.2.1 SETUP STAGE
Receiving Setup packets is the same as receiving bulk out packets, except that the RXSETUP bit in the USB_EPn_CTL_REG
Register is set by the USB controller instead of the RXOUTB bit to indicate that an Out packet with a Setup PID
has been received on the Control Endpoint. When the RXSETUP bit has been set, all the other bits of the USB_EPn_CTL_REG
Register are cleared and an interrupt is triggered, if enabled. The firmware has to read the Setup request stored
in the Control Endpoint data before clearing the RXSETUP bit to free the endpoint data for the next transaction.
11.2.2 DATA STAGE: CONTROL ENDPOINT 0 DIRECTION
The data stage management is similar to bulk management.
A control endpoint is managed by the USB controller as a full-duplex endpoint: IN and OUT. All other endpoint types are
managed as half-duplex endpoint: IN or OUT.
There are separate Read and Write buffers for Control Endpoint 0.
• If the data stage consists of INs, the firmware writes the data buffer and sets to 1 the TXRDY (or BUF0_RDY) bit in
the USB_EPn_CTL_REG (or USB_EPn_BUFRDY_REG) Register. The IN transaction is complete when the
TXRDY (or BUF0_RDY) bit has been reset by the hardware.
• If the data stage consists of OUTs, the RXOUTB (and BUF0_RDY) bit is set by hardware when a new valid packet
has been received on the endpoint. The firmware must read the data stored into the buffer and then clear the
RXOUTB (or BUF0_RDY) bit to reset the buffer and to allow the next transaction.
To send a STALL handshake, see Section 11.4.
11.2.3 STATUS STAGE
The status stage management is similar to bulk management.
• For a Control Write transaction or a No-Data Control transaction, the status stage consists of a IN Zero Length
Packet (see “Bulk/Interrupt IN Transactions In Standard Mode” on page). To send a STALL handshake, see
Section 11.4.
• For a Control Read transaction, the status stage consists of an OUT Zero Length Packet.
11.3 USB Reset
The USB_RESET_INT bit in the USB_INT_REG Register is set by hardware when a Reset has been detected on the USB
bus. This triggers a USB interrupt, if enabled. The USB controller is still enabled. The End of USB Reset can be determined
by reading the USB_RESET_STS bit in UDC Status Register.
11.4 STALL Handshake
This function is only available for Control, Bulk, and Interrupt endpoints. The firmware has to set the STALLRQ bit in the
USB_EPn_CTL_REG Register to send a STALL handshake at the next request of the Host on the endpoint. The
RXSETUP, TXRDY, RXOUTB bits must be first reset to 0. The bit UNSUCESSFUL is set to 1 by the USB controller when a
STALL has been sent. This triggers an interrupt if enabled.
The firmware should clear the STALLRQ and UNSUCESSFUL bits after each STALL sent. The STALLRQ bit is cleared
automatically by hardware when a valid SETUP PID is received on a Control type endpoint.
11.5 Start of Frame Detection
The USB_SOF_INT bit in the USB_INT_REG Register is set when the USB controller detects a Start of Frame PID. This
triggers an interrupt if enabled. The firmware should clear the SOFINT bit to allow the next Start of Frame detection. The
SOF_MISSED bit is set if within 16383 FS bits times, a SOF frame is not received. The SOF_GOOD bit is set if SOF frame
is received and the timestamp matches the expected value. After initialization or loss of frame sync, the timestamp value
is loaded when an SOF is received.
11.6 Data Toggle Bit
The Data Toggle bit is set by hardware when a DATA 0 packet is received and accepted by the USB controller and
cleared by hardware when a DATA 1 packet is received and accepted by the USB controller. This bit is reset when the
firmware resets the endpoint data buffer using the UEPRST Register.
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For Control endpoints, each SETUP transaction starts with a DATA 0 and data toggling is then used as for Bulk endpoints
until the end of the Data stage (for a control write transfer). The Status stage completes the data transfer with a
DATA 1 (for a control read transfer).
11.7 NAK Handshakes
When a NAK handshake is sent by the USB controller to a IN or OUT request from the Host, the UNSUCESSFUL bit will
not be set by hardware.
11.8 Suspend
The Suspend state can be detected by the USB controller if all the USB clocks are enabled and if the USB controller is
enabled. The bit USB_SUSPEND_INT is set by hardware when an idle state is detected for more than 3 ms. This triggers
a USB interrupt, if enabled.
In order to reduce current consumption, the firmware can put the USB pads in suspend Mode, stop the clocks and put
the chip in Idle or Power-Down Mode. The Resume detection is still active.
The USB suspend Mode is entered when the firmware sets PWR_CORE_DIS0 to shutdown LDO3A regulator and then
writes to the OSC48_CTL Register. The two writes to these registers must be consecutive. If operating from external
clock then EXT_OSC_SLEEP bit is set in the second write, and if operating from the internal clock, then OSC_MODE[2] bit
is set.
The hardware shuts the clocks and the oscillator. It also powers down all the logic except for the USB subsystem, ERAM
(optional), IRAM (optional), GPIO logic. Hence the firmware must save all the CPU registers in ERAM before entering
suspend Mode. The USB PAD automatically exits from idle Mode when a wake-up event is detected on GPIO or USB
pads.
The stop of the 48 MHz clock from the oscillator should be done in the following order:
1. Disable all other peripherals not required during suspend Mode. Save CPU and SFR registers state in ERAM.
2. Disable the oscillator by writing OSC_MODE[2] as 0 in the OSC48_CTL Register or enter low power Mode by writing
000b to OSC_MODE bits (4 MHz). In case of external oscillator Mode EXT_OSC_SLEEP bit is set.
11.9 Resume
When the USB controller is in Suspend state, the Resume detection is active even if all the clocks are disabled and if
the chip is in Idle or Power-Down Mode. The USB_WU_INT bit is set by hardware when a non-idle state occurs on the
USB bus. This triggers an interrupt if enabled. This interrupt wakes up the oscillator and CPU from its idle or powerdown
state and the interrupt function is then executed. The firmware will first enable the 48 MHz generation.
The firmware has to clear the USB_WU_INT bit in the USB_INT_REG Register before any other USB operation in order
to wake up the USB controller from its Suspend Mode. The USB controller is then re-activated.
11.10 Remote Wake-Up
A USB device can be allowed by the Host to send an upstream resume for Remote Wake-Up purpose. The firmware
must set the USB_REMOTE_WU_CAP bit indicating to the core that the device is remote wake-up capable. The USB controller
automatically responds to Set Feature and Clear Feature commands for the Remote Wake-Up capability.
If the device is in SUSPEND Mode, and the device is in low power state, the USB controller can send an upstream
Resume by setting to 1 the USB_REMOTE_WU bit in the USB_UDC_CTL Register. All clocks must be enabled first. The
UDC core ensures that the bus was idle for 6 ms before indicating Suspend. Hence the Resume would be initiated
immediately after USB_REMOET_WU bit is set. When the upstream Resume is completed, the USB_REMOTE_WU bit is
reset to 0 by hardware. The firmware should then clear the USB_WU_INT interrupt bit.
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11.11 USB Registers Summary
The USB registers are at XDATA base address 0x9600.
FIGURE 11-7: USB REMOTE SUSPEND/RESUME
TABLE 11-1: USB REGISTER OFFSETS
XDATA OFFSET REGISTER NAME EC TYPE
0x00 USB_CFGL_ADDR_REG R/W
0x01 USB_CFGH_ADDR_REG R/W
0x02 USB_CFG_STS_REG R
0x03 USB_UDC_CONTROL R/W
0x04 USB_STS_REG R
0x05 USB_SOF_REG R
0x06 USB_INT_REG R/W
0x07 USB_ISR_EN_REG R/W
0x08 USB_EP0_CTL_REG R/W
0x09 USB_EP1_CTL_REG R/W
0x0A USB_EP2_CTL_REG R/W
0x0B USB_EP3_CTL_REG R/W
0x0C USB_EP4_CTL_REG R/W
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0x0D USB_EP5_CTL_REG R/W
0x0E USB_EP0W_ADDRL_REG R/W
0x0F USB_EP0W_ADDRH_REG R/W
0x10 USB_EP0W_BYTE_CNT_REG R/W
0x11 USB_EP0R_ADDRL_REG R/W
0x12 USB_EP0R_ADDRH_REG R/W
0x13 USB_EP0R_BYTE_CNT_REG R/W
0x14 USB_EP1_ADDRL_REG R/W
0x15 USB_EP1_ADDRH_REG R/W
0x16 USB_EP1_CNT_REG R/W
0x17 USB_EP1_BUFRDY_REG R/W
0x18 USB_EP2_ADDRL_REG R/W
0x19 USB_EP2_ADDRH_REG R/W
0x1A USB_EP2_CNT_REG R/W
0x1B USB_EP2_BUFRDY_REG R/W
0x1C USB_EP3_ADDRL_REG R/W
0x1D USB_EP3_ADDRH_REG R/W
0x1E USB_EP3_CNT_REG R/W
0x1F USB_EP3_BUFRDY_REG R/W
0x20 USB_EP4_ADDRL_REG R/W
0x21 USB_EP4_ADDRH_REG R/W
0x22 USB_EP4_CNT_REG R/W
0x23 USB_EP4_BUFRDY_REG R/W
0x24 USB_EP5_ADDRL_REG R/W
0x25 USB_EP5_ADDRH_REG R/W
0x26 USB_EP5_CNT_REG R/W
0x27 USB_EP5_BUFRDY_REG R/W
0x28 USB_EP_ISR_REG R/W
0x29 USB_EP_ISR_EN_REG R/W
0x2A USB_EP1_CNT1_REG R/W
0x2B USB_EP2_CNT1_REG R/W
0x2C USB_EP3_CNT1_REG R/W
0x2D USB_EP4_CNT1_REG R/W
0x2E USB_EP5_CNT1_REG R/W
TABLE 11-1: USB REGISTER OFFSETS (CONTINUED)
XDATA OFFSET REGISTER NAME EC TYPE
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11.12 USB Configuration Registers
The USB core is configured at initialization time. The configuration data is written to on-chip ERAM memory, and the
start address is written to the USB_CFGL_ADDR Register, then the USB_CFGH_ADDR Register. The UDC core loads
this data once at initialization time.
The UDC core automatically handles commands such as Set Configuration, Set Interface (with Alternative Interface settings).
The current configuration, Interface and Alternate Interface values are indicated in Table 11-4, "USB Config Status
Register". Any update to this register would cause an interrupt.
The configuration data for the 6 maximum physical endpoints possible, consists of 6 40-bit values (30 bytes), with each
value written most significant byte first (at lower address memory). This format is shown in Table 11-5, "EndPoint 0-5
Config Memory".
TABLE 11-2: USB CONFIG ADDRESS LOW REGISTER
USB_CFGL_ADDR_REG
(0X9600 RESET=0X00 USB Config Address Low Register
BIT NAME R/W DESCRIPTION
7:0 USB_CFG_AdrPtr[7:0] R/W Address pointer (lower 8 bits) in on-chip ERAM for the configuration
data. The USB core loads 30 bytes from this location.
TABLE 11-3: USB CONFIG ADDRESS HIGH REGISTER
USB_CFGH_ADDR_REG
(0X9601 RESET=0X00 USB Config Address High Register
BIT NAME R/W DESCRIPTION
15 USB_CFG_LoadCfgData R/W This bit if set enables the USB to be configured. This must be done
only once after reset. The USB core reads 30 bytes from
USB_CFG_AdrPtr to the EPINFO block.
14 USB_CFG_LoadCfgDone R This bit if set indicates that the USB core has read all 30 bytes from
USB_CFG_AdrPtr to the EPINFO block, and load configuration is
done. The USB core is ready for normal operation.
13:12 Reserved R Always read as 0
11:8 USB_CFG_AdrPtr[11:8] R/W Address pointer (higher 4 bits) in on-chip ERAM for the
configuration data.
The USB core loads 30 bytes from this location.
TABLE 11-4: USB CONFIG STATUS REGISTER
USB_CFG_STS_REG
(0X9602 RESET=0X00 USB Config Status Register
BIT NAME R/W DESCRIPTION
7:6 Reserved R Always read as 0
5:4 Alt_InterfaceVal[1:0] R These bits indicate the Alternate Settings value to which a Set
Interface Setup Command is addressed.
3:2 InterfaceVal[1:0] R These bit indicate the Interface value to which a Set Interface
Setup Command is addressed.
1:0 ConfigVal[1:0] R These bits indicate the new Configuration value of a Set
Configuration Setup Command.
On an update to the ConfigVal field, the InterfaceVal and
Alt_InterfaceVal fields are reset to zero.
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The Endpoint 0 is common to all configurations and interfaces of the device. The UDC core ignores the programmed
value of Ep_Config, Ep_Interface, Ep_AltSettings for Endpoint 0.
Note: The USB core successfully completes the status stage for the SET_INTERFACE command as long as the
interface and alternate setting specified in the command is less than five, regardless of the actual number
of interfaces/alternate settings reported in the configuration descriptor and interface descriptor by firmware.
Typically hosts do not send SET_INTERFACE to interface/alternate settings that is not reported by the
device. For example, if the device reports 2 interfaces and 3 alternate settings, the commands will complete
successfully, which is correct. A problem would arise only if a host issues SET_INTERFACE to interface 4
even if the device supports only 3 interfaces.
TABLE 11-5: ENDPOINT 0-5 CONFIG MEMORY
USB_EP_0_CFG(0X00~0X04 RESET=0XXX
USB_EP_1_CFG
(0X05~0X09 RESET=0XXX
USB_EP_2_CFG
(0X0A~0X0E RESET=0XXX
USB_EP_3_CFG
(0X0F~0X13 RESET=0XXX
USB_EP_4_CFG
(0X14~0X18 RESET=0XXX
USB_EP_5_CFG
(0X19~0X1D RESET=0XXX
EndPoint 0-5 Config Memory
BIT NAME BYTE DESCRIPTION
7:4 EpNum
0
Logical Endpoint Number:
The valid values are 0, 1, 2, 3, 4, 5.
3:2 Ep_Config Configuration number to which the endpoint belongs:
• Must be 0 for Endpoint 0
• Value for other endpoints is 1 (one other configuration supported)
1:0 Ep_Interface Interface number to which the endpoint belongs:
• Must be 0 for Endpoint 0
• Value for other endpoints is up to the maximum number of interfaces
supported as reported in the Descriptor
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7:6 Ep_AltSetting
1
Alternate setting to which the endpoint belongs:
• Must be 0 for Endpoint 0
• Value for other endpoints is up to the maximum number of interfaces
supported as reported in the Descriptor
5:4 Ep_Type Endpoint type:
00 : Control
01 : Reserved
10 : Bulk
11 : Interrupt
Must be 00 for Endpoint 0.
The values for other endpoints is user programmable as 01, 10, 11,
and is same as reported in the Descriptor.
3 Ep_Dir Endpoint direction:
0 : OUT Endpoint
1 : IN Endpoint
This bit is ignored for control endpoints.
Must be 0 for Endpoint 0.
Value for other endpoints is programmable, and is the same as
reported in the Descriptor.
2:0 Ep_MaxPktSize[9:7] Maximum packet size for this endpoint (64 Max). The valid values
are 8: 00_0000_1000b
16: 00_0001_0000b
32: 00_0010_0000b
64: 00_0100_0000b
7:1 Ep_MaxPktSize[6:0]
2 0 Ep_UserBit This bit is reflected to the application bus as the UDC_UserBit
signal for the transaction to this particular endpoint.
• Must be 1 for endpoints 2 and 3
• It is 0 for all other endpoints
7:0 Ep_BufAdrPtr[15:8],
Ep_BufAdrPtr[7:0]
3,
4
Address pointer for the associated endpoint is encoded as follows:
Ep_BufAdrPtr15 = EP_Dir
Ep_BufAdrPtr[14:12] = EpNum[2:0] (The physical endpoint number
0~5)
Ep_BufAdrPtr[11:10] = Ep_Config[1:0]
Ep_BufAdrPtr[9:8] = Ep_Interface[1:0]
Ep_BufAdrPtr[7:6] = Ep_AltSettings[1:0]
Ep_BufAdrPtr[5:4] = Ep_Type[1:0]
Ep_BufAdrPtr[3:0] = Ep_MaxPktSize[6:3]
TABLE 11-5: ENDPOINT 0-5 CONFIG MEMORY
USB_EP_0_CFG(0X00~0X04 RESET=0XXX
USB_EP_1_CFG
(0X05~0X09 RESET=0XXX
USB_EP_2_CFG
(0X0A~0X0E RESET=0XXX
USB_EP_3_CFG
(0X0F~0X13 RESET=0XXX
USB_EP_4_CFG
(0X14~0X18 RESET=0XXX
USB_EP_5_CFG
(0X19~0X1D RESET=0XXX
EndPoint 0-5 Config Memory
BIT NAME BYTE DESCRIPTION
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11.13 USB Control, Status and Interrupt Registers
TABLE 11-6: USB UDC CONTROL REGISTERS
USB_UDC_CONTROL
(0X9603RESET=0X01 USB UDC Control Registers
BIT NAME R/W DESCRIPTION
7 USB_RTEST R/W This test bit must be 0 for proper USB operation.
Setting this bit to 0 (default) causes opening of SW2 for Resistor
pull-up (causes high impedance) in transmission Mode. When this
bit is set to 1, SW2 for resistor pull-up is closed in transmission
Mode.
6 Reserved R/W Reserved as a test bit
If this bit is zero, the Rpu SW2 switch toggles on a J-to-K transition
detected on USB bus in Receive mode within 0.5 to 0.75 bit time.
If this bit is one, the Rpu SW2 switch toggles on a J-to-K transition
detected on USB bus in Receive mode within 0.25 to 0.5 bit time.
5:4 Reserved R Always read as 0
3 USB_SELF_POWER R/W This bit if set indicates that the device is self powered. This bit if
reset indicates that the device is VBUS powered.
2 USB_REMOTE_WU R/W If the USB device is in SUSPEND and remote wake-up has been
enabled, setting this bit to 1 will generate a 3ms wake-up event on
the USB bus. This bit will auto clear.
1 USB_REMOTE_WU_CAP R/W This bit when set indicates to the UDC core that the device is
remote wake-up capable. The UDC core responds to the Set/Clear
Feature (DEVICE_REMOTE_WAKEUP) command if this bit is set.
If this bit is reset, then the UDC responds to such a Set/Clear
Feature (DEVICE_REMOTE_WAKEUP) command with a Stall.
0 USB_DETACH R/W Detach from USB: Remove 1.5 k pull-up
0 : Attach - the USB core follows the resistor_ecn specification
defined for USB 2.0 specification.
1 : Detach
TABLE 11-7: USB UDC STATUS REGISTER
USB_STS_REG
(0X9604 RESET=0X00 USB Status Register
BIT NAME R/W DESCRIPTION
7:5 USB_TIMESTAMP[10:8] R This field indicates the higher 3-bits of the time stamp received on
a valid SOF.
4 UDC_REMOTE_STS R This bit, if set indicates the host has enabled the device for Remote
wake-up using the Set_Feature (DEVICE_REMOTE_WAKEUP)
Command.
This bit is relevant only if USB_REMOTE_WU_CAP bit is 1.
3 SOF_GOOD R This bit is set when received SOF timestamps compare with the
expected value. This bit is reset when SOF is missed or when
timestamp does not compare with expected value.
2 SOF_MISSED R This bit is set when an SOF is not received within 16383 FS bit
times. This bit is reset when this register is read.
1 USB_RESET_STS R This bit is set when the core detects more than 2.5 S (32 FS bit
times) of SE0 on the D+ and D- lines. It continues to be set as long
as SE0 is seen on the D+/D- lines.
This bit resets when the USB lines change from SE0 after a USB
reset condition.
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The USB Interrupt register bits are cleared by software by writing a 1 in the corresponding bit.
0 USB_SUSPEND_STS R This bit is set by hardware when a USB Suspend is detected (idle
for 6 ms). This bit remains asserted until a non-idle (K) state is on
the USB cable or the USB_REMOTE_WU bit is asserted.
TABLE 11-8: USB SOF REGISTER
USB_SOF_REG
(0X9605 RESET=0X00 USB SOF Register
BIT NAME R/W DESCRIPTION
7:0 USB_TIMESTAMP[7:0] R This field indicates the lower 8-bits of the time stamp received on
a valid SOF.
TABLE 11-9: USB INTERRUPT REGISTER
USB_INT_REG
(0X9606 RESET=0X00 USB Interrupt Register
BIT NAME R/W DESCRIPTION
7 USB_WU_INT R/W1C USB Wake Up CPU Interrupt:
This bit is set when the USB controller is in the SUSPEND State
and is activated by a non-idle signal from the USB line.
This bit is cleared by software.
6 USB_RESET_INT R/W1 This bit is set when the core detects more than 2.5 S (32 FS bit
times) of SE0 on the D+ and D- lines. It continues to be set as long
as SE0 is seen on the D+/D- lines.
This bit should be reset by software.
5 USB_SOF_INT R/W1 This bit is set when an USB Start of Frame PID (SOF) has been
successfully received.This bit should be cleared by software.
4:2 Reserved R Always read as 0
1 USB_CFG_STS_INT R/W1 This bit is set when an update to the USB Configuration Status
Register occurs for the following conditions:
• A Set Configuration setup command is received and Config_Val[1:0]
is updated.
• A Set Interface setup command is received and Interface_Val[1:0]
and Alt_InterfaceVal[1:0] are updated.
0 USB_SUSPEND_INT R/W1 This bit is set by hardware when a USB Suspend is detected (idle
for 6 ms). This bit should be cleared by software before powering
down the microcontroller.
TABLE 11-7: USB UDC STATUS REGISTER (CONTINUED)
USB_STS_REG
(0X9604 RESET=0X00 USB Status Register
BIT NAME R/W DESCRIPTION
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11.14 USB Endpoint 0~5 Status and Control Registers
TABLE 11-10: USB INTERRUPT ENABLE REGISTER
USB_ISR_EN_REG
(0X9607 RESET=0X00 USB Interrupt Enable Register
BIT NAME R/W DESCRIPTION
7 USB_WU_INT_EN R/W Set this bit to enable the USB Wake Up CPU Interrupt.
Clear this bit to disable the USB Wake Up CPU Interrupt.
6 USB_RESET_INT_EN R/W Set this bit to enable the USB_RESET CPU Interrupt.
Clear this bit to disable the USB_RESET CPU Interrupt.
5 USB_SOF_INT_EN R/W Set this bit to enable the USB SOF CPU Interrupt.
Clear this bit to disable the USB SOF CPU Interrupt.
4:2 Reserved R Always read as 0
1 USB_CFG_STS_EN R/W Set this bit to enable the USB_CFG_STS Update Interrupt.
Clear this bit to disable the USB_CFG_STS Update Interrupt.
0 USB_SUSPEND_INT_EN R/W Set this bit to enable the USB SUSPEND CPU Interrupt.
Clear this bit to disable the USB SUSPEND CPU Interrupt.
TABLE 11-11: USB ENDPOINT 0~5 STATUS AND CONTROL REGISTER
USB_EP0_CTL_REG
(0X9608 RESET=0X00
USB_EP1_CTL_REG
(0X9609 RESET=0X00
USB_EP2_CTL_REG
(0X960A RESET=0X00
USB_EP3_CTL_REG
(0X960B RESET=0X00
USB_EP4_CTL_REG
(0X960C RESET=0X00
USB_EP5_CTL_REG
(0X960D RESET=0X00
USB Endpoint 0~5 Status and Control Register
BIT NAME R/W DESCRIPTION
7 TIMEOUT R This bit is valid when the UNSUCESSFUL bit is set. This bit is set
when a USB timeout occurs for this endpoint.
6 STALL_CLR_EP0_HLT R/W This bit is valid only for Endpoint 0:
This bit controls the behavior of response to the Clear Feature
(ENDPOINT0 HALT) command.
When this bit is set, the UDC core will send STALL for such a
command. If this bit is reset, the core will send an ACK response.
5 STALLRQ R/W Stall Handshake Request
Set this bit to request a STALL response to the next handshake.
Clear this bit otherwise. For Control endpoints, it is cleared by
hardware when a valid SETUP PID is received. This bit is cleared
when RXSETUP is set.
If a Clear Feature command is received, then any new transaction
on this endpoint will depend on the status of this bit, whether it will
be accepted (bit is reset), or it is stalled again (bit is still set).
SEC1110/SEC1210
DS00001561C-page 108 2013 - 2016 Microchip Technology Inc.
4 TXRDY R/W TX Packet Ready:
Set this bit after a valid packet has been placed into the endpoint
buffer for IN transfers. This bit is reset by hardware after the host
has acknowledged the packet for Control, Bulk, or Interrupt
endpoints.This bit is reset by hardware after data is transmitted for
Isochronous IN endpoints. When this bit is cleared, the Endpoint
Interrupt is triggered (if enabled).
In PingPong Mode, for an IN transaction, this bit is set if either
BUF0_RDY or BUF1_RDY are set.
3 UNSUCCESSFUL R/W1 Unsuccessful USB Transaction:
This bit is set for the following conditions:
• A STALL handshake has been sent as requested by STALLRQ
• USB timeout
• Error in data packet on USB
If this bit is set, the application must reset its buffer pointers to
restart the transaction and ignore the data received in the current
transaction.
If a NAK is issued, the NAK bit is set. The UNSUCCESSFUL bit is
write one to clear.
2 RXSETUP R/W1 Received SETUP:
This bit is set by hardware when a valid SETUP packet has been
received from the host. Then, all of the other bits of the register are
cleared by hardware and the Endpoint Interrupt is triggered (if
enabled). It should be cleared by the device software after reading
the SETUP data from the endpoint data buffer.
Any data on Endpoint 0 write buffer may be overwritten, on
reception of a setup packet.
Note: Even if an incomplete setup packet is received (i.e., an
error was detected, or the UDC core internally handles it),
the received bytes are written to the Endpoint 0 write
buffer. Additionally, the address and count registers are
reset.
The RXSETUP bit is write one to clear.
TABLE 11-11: USB ENDPOINT 0~5 STATUS AND CONTROL REGISTER (CONTINUED)
USB_EP0_CTL_REG
(0X9608 RESET=0X00
USB_EP1_CTL_REG
(0X9609 RESET=0X00
USB_EP2_CTL_REG
(0X960A RESET=0X00
USB_EP3_CTL_REG
(0X960B RESET=0X00
USB_EP4_CTL_REG
(0X960C RESET=0X00
USB_EP5_CTL_REG
(0X960D RESET=0X00
USB Endpoint 0~5 Status and Control Register
BIT NAME R/W DESCRIPTION
2013 - 2016 Microchip Technology Inc. DS00001561C-page 109
SEC1110/SEC1210
11.15 USB Endpoint 0 Buffer Registers
The endpoint buffers (0~5) are part of the on-chip ERAM memory, and its start locations are programmable. The firmware
views the buffers as memory mapped.
The bi-directional control Endpoint 0 has 2 DMA buffers, one for write, and one for read. It is possible that there is write
data in Endpoint 0 Write Buffer, when a Setup packet is received. The USB controller would reset the Address pointer
and Count for Endpoint 0 Write Buffer automatically, enabling reception of this packet. Some of the Setup packets are
handled by the UDC core automatically. As the USB bytes are received, the data is stored in Endpoint 0 Write Buffer.
But if the UDC core can handle it internally, then the Endpoint 0 Write Address and count registers are reset automatically,
and a packet reception is informed to the CPU as an OVERWRITE.
1 RXOUTB R/W1 Received OUT Data Bank:
This bit is set by hardware after a new packet has been stored in
the Endpoint 0 data buffer. If PingPong is enabled, then this bit is
set when either buffer 0 or 1 is full (BUF0_RDY or BUF1_RDY is set).
Then, the Endpoint Interrupt is triggered if enabled. All following
OUT packets to the Endpoint Bank 0 are rejected (NAK’d) until this
bit has been cleared. (If PingPong is enabled, NAK is sent if both
buffers are full), except for Isochronous endpoints. However, for
Control endpoints, an early SETUP transaction (RXOUTB is not
set), may overwrite the contents of the endpoint data buffer, even
if its data packet is received while this bit is set.
This bit should be cleared by software after reading the OUT data
from the endpoint buffer.
The RXOUTB bit is write one to clear.
0 NAK R This bit is set when a NAK handshake is issued for this endpoint.
TABLE 11-12: USB ENDPOINT 0 WRITE ADDRESS LOW REGISTER
USB_EP0W_ADDRL_REG
(0X960E RESET=0X00) USB Endpoint Write Address Low Register
BIT NAME R/W DESCRIPTION
7:0 AdrPtr[7:0] R/W Base Address lower bits pointing to on-chip ERAM for the Endpoint
0 Write Data. The address must be aligned to an address boundary
which is a multiple of the size.
8B buffer: AdrPtr[2:0] must be 000
16B buffer: AdrPtr[3:0] must be 0000
32B buffer: AdrPtr[4:0] must be 00000
64B buffer: AdrPtr[5:0] must be 000000
As each byte is transferred to USB, this register increments and
points to the next address. The address rolls over based on the
size of the buffer.
TABLE 11-11: USB ENDPOINT 0~5 STATUS AND CONTROL REGISTER (CONTINUED)
USB_EP0_CTL_REG
(0X9608 RESET=0X00
USB_EP1_CTL_REG
(0X9609 RESET=0X00
USB_EP2_CTL_REG
(0X960A RESET=0X00
USB_EP3_CTL_REG
(0X960B RESET=0X00
USB_EP4_CTL_REG
(0X960C RESET=0X00
USB_EP5_CTL_REG
(0X960D RESET=0X00
USB Endpoint 0~5 Status and Control Register
BIT NAME R/W DESCRIPTION
SEC1110/SEC1210
DS00001561C-page 110 2013 - 2016 Microchip Technology Inc.
TABLE 11-13: USB ENDPOINT 0 WRITE ADDRESS HIGH REGISTER
USB_EP0W_ADDRH_REG
(0X960F RESET=0X00) USB Endpoint 0 Write Address High Register
BIT NAME R/W DESCRIPTION
7 Reserved R Always read as 0
6 Reserved R Always read as 0
5:4 Size R/W This field indicates the Endpoint 0 buffer size:
00 : 8B buffer
01 : 16B buffer
10 : 32B buffer
11 : 64B buffer
3:0 AdrPtr[11:8] R/W Base Address higher bits pointing to on-chip ERAM for the
Endpoint 0 write data.
TABLE 11-14: USB ENDPOINT 0 WRITE BYTE COUNT REGISTER
USB_EP0W_BYTE_CNT_REG
(0X9610 RESET=0X00) USB Endpoint 0 Byte Count Register
BIT NAME R/W DESCRIPTION
7 OVERWRITE R This bit is set when a Setup packet is received from the USB, and
the previous buffer data has not been read by the software yet. The
software must ignore the previous USB command and respond to
the Setup command.
6:0 COUNT R/W Byte Count:
This is the number of valid bytes that have been received. This
value will never be greater than the MaxPktSize for the endpoint.
As bytes are received from the USB, this counter increments. If the
packet was not received successfully, then it is automatically reset
to 0. The Count Register is also cleared when the RXOUTB bit for
EP0 is reset by firmware.
Note: Anomaly 10 in SEC1110/SEC1210 chip: when a SETUP packet overwrites an earlier SETUP/OUT packet
in Endpoint 0 the write buffer may show a byte-count other than 8 in the USB_EP0W_BYTE_CNT_REG.
The byte-count could be the sum of the previous packet and the current packet. Since SETUP packets are
always 8 bytes, firmware must ignore the USB_EP0W_BYTE_CNT_REG and assume that 8 bytes were
received unless an error was indicated. This anomaly is fixed in SEC1110/SEC1210.
TABLE 11-15: USB ENDPOINT 0 READ ADDRESS LOW REGISTER
USB_EP0R_ADDRL_REG
(0X9611 RESET=0X00) USB Endpoint Read Address Low Register
BIT NAME R/W DESCRIPTION
7:0 AdrPtr[7:0] R/W Base Address lower bits pointing to on-chip ERAM for the Endpoint
0 read data. The address must be aligned to an address boundary
which is a multiple of the size.
8B buffer: AdrPtr[2:0] must be 000b
16B buffer: AdrPtr[3:0] must be 0000b
32B buffer: AdrPtr[4:0] must be 00000b
64B buffer: AdrPtr[5:0] must be 000000b
As each byte is transferred to USB, this register increments and
points to the next address. The address rolls over based on the
size of the buffer.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 111
SEC1110/SEC1210
11.16 Endpoints 1~5 Buffer Registers
Each endpoints numbered 1~5 may be configured to be used with the UDC core or SPI1 or UART, as indicated by the
PERIPHERAL[1:0] bits. Each of these may be configured as IN (data is transmitted) or OUT (data is received) endpoint
as indicated by the Direction bit.
TABLE 11-16: USB ENDPOINT 0 READ ADDRESS HIGH REGISTER
USB_EP0R_ADDRH_REG
(0X9612 RESET=0X00) USB Endpoint 0 Read Address High Register
BIT NAME R/W DESCRIPTION
7 Reserved R Always read as 0
6 Reserved R Always read as 0.
5:4 Size R/W This field indicates the Endpoint 0 buffer size:
00 : 8B buffer
01 : 16B buffer
10 : 32B buffer
11 : 64B buffer
3:0 AdrPtr[11:8] R/W Base Address higher bits pointing to on-chip ERAM for the
Endpoint 0 read data.
TABLE 11-17: USB ENDPOINT 0 READ BYTE COUNT REGISTER
USB_EP0R_BYTE_CNT_REG
(0X9613 RESET=0X00) USB Endpoint 0 Read Byte Count Register
BIT NAME R/W DESCRIPTION
7 Reserved R Always read as 0
6:0 COUNT R/W This field is the number of valid bytes to send in the next IN. This
value should never be greater than the MaxPktSize for the
endpoint.
As the bytes are transferred over USB, this register decrements,
and it indicates the number of bytes left in the buffer.
TABLE 11-18: USB ENDPOINT 1-5 ADDRESS LOW REGISTER
USB_EP1_ADDRL_REG
(0X9614 RESET=0X00)
USB_EP2_ADDRL_REG
(0X9618 RESET=0X00)
USB_EP3_ADDRL_REG
(0X961C RESET=0X00)
USB_EP4_ADDRL_REG
(0X9620 RESET=0X00)
USB_EP5_ADDRL_REG
(0X9624 RESET=0X00)
USB Endpoint 1-5 Address Low Register
BIT NAME R/W DESCRIPTION
7:0 AdrPtr[7:0] R/W Base Address lower bits pointing to on-chip ERAM for the Endpoint
1-5 read/write data. The address must be aligned to an address
boundary which is a multiple of the size.
8B buffer: AdrPtr[2:0] must be 000b
16B buffer: AdrPtr[3:0] must be 0000b
32B buffer: AdrPtr[4:0] must be 00000b
64B buffer: AdrPtr[5:0] must be 000000b
SEC1110/SEC1210
DS00001561C-page 112 2013 - 2016 Microchip Technology Inc.
The USB firmware must maintain a copy of the PingPong bit in firmware to distinguish which buffer was first
received/transmitted when both buffers are full.
TABLE 11-19: USB ENDPOINT 1~5 ADDRESS HIGH REGISTER
USB_EP1_ADDRH_REG
(0X9615 RESET=0X00)
USB_EP2_ADDRH_REG
(0X9619 RESET=0X00)
USB_EP3_ADDRH_REG
(0X961D RESET=0X00)
USB_EP4_ADDRH_REG
(0X9621 RESET=0X00)
USB_EP5_ADDRH_REG
(0X9625 RESET=0X00)
USB Endpoint 1~5 Write Address High Register
BIT NAME R/W DESCRIPTION
7 Direction R/W This bit indicates the direction of the endpoint.
0 : OUT (data is received)
1 : IN (data is transmitted)
6 PingPong R/W If the PingPong bit is set, then there are 2 Size buffers allocated for
this endpoint. The AdrPtr[7:0] field must be aligned to an address
boundary which is a multiple of twice that of Size.
5:4 Size R/W This field indicates the endpoint buffer size:
00 : 8B buffer
01 : 16B buffer
10 : 32B buffer
11 : 64B buffer
3:0 AdrPtr[11:8] R/W Base Address higher bits pointer to on-chip ERAM for the endpoint
1~5 data.
TABLE 11-20: USB ENDPOINT 1~5 BYTE COUNT0 REGISTER
USB_EP1_CNT_REG
(0X9616 RESET=0X00)
USB_EP2_CNT_REG
(0X961A RESET=0X00)
USB_EP3_CNT_REG
(0X961E RESET=0X00)
USB_EP4_CNT_REG
(0X9622 RESET=0X00)
USB_EP5_CNT_REG
(0X9626 RESET=0X00)
USB Endpoint 1~5 Byte Count0 Register
BIT NAME R/W DESCRIPTION
7 Reserved R Always read as 0
6:0 COUNT0 R/W Byte Count:
This field is the number of valid bytes that have been received for
an OUT endpoint or the number of valid bytes to send in the next
IN, for an IN endpoint. This value would never be greater than the
MaxPktSize for the endpoint.
As bytes are received (OUT)/transmitted (IN) from the USB, this
counter increments (IN)/decrements (OUT). If the packet was not
received successfully, then it is automatically reset to 0 for an OUT
endpoint.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 113
SEC1110/SEC1210
TABLE 11-21: USB ENDPOINT 1~5 BYTE COUNT1 REGISTER
USB_EP1_CNT1_REG
(0X962A RESET=0X00)
USB_EP2_CNT1_REG
(0X962B RESET=0X00)
USB_EP3_CNT1_REG
(0X962C RESET=0X00)
USB_EP4_CNT1_REG
(0X962D RESET=0X00)
USB_EP5_CNT1_REG
(0X962E RESET=0X00)
USB Endpoint 1~5 Byte Count1 Register
BIT NAME R/W DESCRIPTION
7 Reserved R Always read as 0
6:0 COUNT1 R/W Byte Count: used when BUF1_RDY bit is set.
This field is the number of valid bytes that have been received for
an OUT endpoint or the number of valid bytes to send in the next
IN, for an IN endpoint. This value would never be greater than the
MaxPktSize for the endpoint.
As bytes are received (OUT)/transmitted (IN) from the USB, this
counter increments (IN)/decrements (OUT). If the packet was not
received successfully, then it is automatically reset to 0 for an OUT
endpoint.
TABLE 11-22: USB ENDPOINT 0~5 BUFFER READY REGISTER
USB_EP1_BUFRDY_REG
(0X9617 RESET=0X00)
USB_EP2_BUFRDY_REG
(0X961B RESET=0X00)
USB_EP3_BUFRDY_REG
(0X961F RESET=0X00)
USB_EP4_BUFRDY_REG
(0X9623 RESET=0X00)
USB_EP5_BUFRDY_REG
(0X9627 RESET=0X00)
USB Endpoint 1~5 Buffer ready Registers
BIT NAME R/W DESCRIPTION
7:6 PERIPHERAL[1:0] R/W These bits indicate which peripheral device IO the endpoints are
mapped to.
00 : USB
01 : SPI1
10 : UART
11 : Reserved
5:2 Reserved R Always read as 0
1 BUF1_RDY R/W This bit is used only if the PingPong bit is enabled for the endpoint.
For an IN endpoint (data is transmitted), the firmware sets this bit
to indicate buffer 1 is ready. The hardware resets this bit after data
is transmitted.
The COUNT1 Register indicates the number of bytes (can be
maximum size packet or less than that for last packet) received or
transmitted.
SEC1110/SEC1210
DS00001561C-page 114 2013 - 2016 Microchip Technology Inc.
If the PERIPHERAL[1:0] bits indicate an endpoint as mapped to USB core, then for an OUT endpoint, setting of the
BUF0_RDY or BUF1_RDY bits would also cause setting the TXRDY bit in corresponding EPx_CTL_REG. Similarly, for an
IN endpoint mapped to USB core, resetting of BUF0_RDY or BUF1_RDY would also cause resetting the RXOUTB0 bit in
the corresponding EPx_CTL_REG.
The COUNT0 and COUNT1 registers indicate the byte count valid for buffers 0 and 1 when BUF0_RDY and BUF1_RDY
are set, respectively.
0 BUF0_RDY R/W For an IN endpoint (data is transmitted), this bit is set by the
firmware to indicate that data is ready to be sent. The COUNT0
Register indicates the number of bytes (can be maximum size
packet or less than that for last packet). After the data is transmitted
by the device, the hardware would reset this bit for Buffer 0 ready.
If PingPong is enabled, then the firmware sets the BUF0_RDY bit
for first packet, BUF1_RDY for the second packet and so on. The
hardware empties the buffers similarly, and resets the ready bits. If
data is not available (ready bit is not set), then a NACK would be
sent for that endpoint (USB), or an underflow (SPI1 or UART) may
occur.
For an OUT endpoint (data is received), this bit is set by the
hardware to indicate the buffer has data. The COUNT0 Register
indicates the number of bytes (can be maximum size packet or less
than that for last packet). After the firmware has read the data, it
indicates the buffer is available for hardware, by writing a 1 to reset
this bit. If the PingPong bit is enabled, then hardware fills Buffer 0
and 1 alternatively and sets the BUF0_RDY, then BUF1_RDY bits
accordingly. The firmware resets these bits when data is read. The
hardware will not write data to a buffer if its ready bit is set,
indicating that the firmware has not read the data. This may cause
a NACK to be sent for that endpoint (USB), or an overflow (SPI1
or UART) may occur.
If the firmware does a write with both bits (BUF0_RDY and
BUF1_RDY) set, then both hardware internal pointers to buffer and
BUF0_RDY, BUF1_RDY bits are reset, irrespective of the PingPong
bit setting.
TABLE 11-23: USB ENDPOINT INTERRUPT REGISTER
USB_EP_ISR_REG
(0X9628 RESET=0X00 USB Endpoint Interrupt Register
BIT NAME R/W DESCRIPTION
7:6 Reserved R Always reads as 0
5 EP5INT R/W1 Endpoint 5 Interrupt:
This bit is set when an interrupt has been detected on Endpoint 5.
The interrupt sources are part of the USB_EP5_CTL_REG Register
and can be: TXCMP, RXOUTB0 (BUF0_RDY/BUF1_RDY),
UNSUCESSFUL. A USB interrupt is triggered when
USB_EP_ISR_IE_REG.EP5INT_EN is set.
This bit is cleared by hardware when a 1 is written.
TABLE 11-22: USB ENDPOINT 0~5 BUFFER READY REGISTER
USB_EP1_BUFRDY_REG
(0X9617 RESET=0X00)
USB_EP2_BUFRDY_REG
(0X961B RESET=0X00)
USB_EP3_BUFRDY_REG
(0X961F RESET=0X00)
USB_EP4_BUFRDY_REG
(0X9623 RESET=0X00)
USB_EP5_BUFRDY_REG
(0X9627 RESET=0X00)
USB Endpoint 1~5 Buffer ready Registers
BIT NAME R/W DESCRIPTION
2013 - 2016 Microchip Technology Inc. DS00001561C-page 115
SEC1110/SEC1210
4 EP4INT R/W1 Endpoint 4 Interrupt:
This bit is set when an interrupt has been detected on Endpoint 4.
The interrupt sources are part of the USB_EP4_CTL_REG Register
and can be: TXCMP, RXOUTB0 (BUF0_RDY/BUF1_RDY),
UNSUCESSFUL. A USB interrupt is triggered when
USB_EP_ISR_IE_REG.EP4INT_EN is set.
This bit is cleared by hardware when a 1 is written.
3 EP3INT R/W1 Endpoint 3 Interrupt:
This bit is set when an interrupt has been detected on Endpoint 3.
The interrupt sources are part of the USB_EP3_CTL_REG Register
and can be: TXCMP, RXOUTB0 (BUF0_RDY/BUF1_RDY),
UNCESSFUL. A USB interrupt is triggered when
USB_EP_ISR_IE_REG.EP3INT_EN is set.
This bit is cleared by hardware when a 1 is written.
2 EP2INT R/W1 Endpoint 2 Interrupt:
This bit is set when an interrupt has been detected on Endpoint 2.
The interrupt sources are part of the USB_EP2_CTL_REG Register
and can be: TXCMP, RXOUTB0 (BUF0_RDY/BUF1_RDY),
UNSUCESSFUL. A USB interrupt is triggered when
USB_EP_ISR_IE_REG.EP2INT_EN is set.
This bit is cleared by hardware when a 1 is written.
1 EP1INT R/W1 Endpoint 1 Interrupt:
This bit is set when an interrupt has been detected on Endpoint 1.
The interrupt sources are part of the USB_EP1_CTL_REG Register
and can be: TXCMP, RXOUTB0 (BUF0_RDY/BUF1_RDY),
UNCESSFUL. A USB interrupt is triggered when
USB_EP_ISR_IE_REG.EP1INT_EN is set.
This bit is cleared by hardware when a 1 is written.
0 EP0INT R/W1 Endpoint 0 Interrupt:
This bit is set when an interrupt has been detected on Endpoint 0.
The interrupt sources are part of the USB_EP0_CTL_REG Register
and can be: TXCMPL, RXOUTB0, RXOUTB1, RXSETUP, or
UNSUCCESSFUL. A USB interrupt is triggered when
USB_EP_ISR_IE_REG.EP0INT_EN is set.
This bit is cleared by hardware when a 1 is written.
TABLE 11-24: USB ENDPOINT INTERRUPT ENABLE REGISTER
USB_EP_ISR_EN_REG
(0X9629 RESET=0X00 USB Endpoint Interrupt Enable Register
BIT NAME R/W DESCRIPTION
7:6 Reserved R Always read as 0
5 EP5INT_EN R/W Endpoint 5 Interrupt Enable:
Set this bit to enable the interrupts for this endpoint.
Clear this bit to disable the interrupts for this endpoint.
4 EP4INT_EN R/W Endpoint 4 Interrupt Enable:
Set this bit to enable the interrupts for this endpoint.
Clear this bit to disable the interrupts for this endpoint.
TABLE 11-23: USB ENDPOINT INTERRUPT REGISTER (CONTINUED)
USB_EP_ISR_REG
(0X9628 RESET=0X00 USB Endpoint Interrupt Register
BIT NAME R/W DESCRIPTION
SEC1110/SEC1210
DS00001561C-page 116 2013 - 2016 Microchip Technology Inc.
3 EP3INT_EN R/W Endpoint 3 Interrupt Enable:
Set this bit to enable the interrupts for this endpoint.
Clear this bit to disable the interrupts for this endpoint.
2 EP2INT_EN R/W Endpoint 2 Interrupt Enable:
Set this bit to enable the interrupts for this endpoint.
Clear this bit to disable the interrupts for this endpoint.
1 EP1INT_EN R/W Endpoint 1 Interrupt Enable:
Set this bit to enable the interrupts for this endpoint.
Clear this bit to disable the interrupts for this endpoint.
0 EP0INT_EN R/W Endpoint 0 Interrupt Enable:
Set this bit to enable the interrupts for this endpoint.
Clear this bit to disable the interrupts for this endpoint.
TABLE 11-24: USB ENDPOINT INTERRUPT ENABLE REGISTER (CONTINUED)
USB_EP_ISR_EN_REG
(0X9629 RESET=0X00 USB Endpoint Interrupt Enable Register
BIT NAME R/W DESCRIPTION
2013 - 2016 Microchip Technology Inc. DS00001561C-page 117
SEC1110/SEC1210
12.0 GPIO AND LED INTERFACE
The registers in this block are on the 8051 XDATA bus. They are defined as an offset.
The SEC1110 and SEC1210 GPIO Interface provides general purpose input monitoring and output control, as well as
managing many aspects of pin functionality; including, multi-function pin multiplexing control, output buffer type control,
PU/PD resistors, asynchronous wake-up and synchronous interrupt detection, GPIO direction, pad current control, and
polarity control.
Features of the GPIO Interface include:
• Inputs:
- Asynchronous rising and falling edge wake-up detection
- Interrupt High or Low Level
- Can disable input (always reads as 0) to disable wake-up detection
• Pull-up or pull-down resistor control
• Interrupt and wake capability available for all GPIOs
• Debounce filter with individual programmable timer (10 s - 256 ms)
12.1 GPIO Pin Mapping
Each GPIO pad may be operated as a General Purpose Input Output pin (GPIO), or connected through two auxiliary
interfaces (A or B) to an internal functional block. An internal functional block must be initialized first before switching its
GPIO pins to Auxiliary Mode. In Auxiliary Mode, the output, output enable, input, and input enable of the Auxiliary block
are connected to the corresponding pad signals. Additionally, if the pull-up/pull-down enable bit of the GPIO_PORTx-
_PUD_EN is zero, the functional block connected to the Auxiliary port controls the pull-up, and pull-down resistor of the
pads.
If an auxiliary block does not have pull-up/pull-down control, then the GPIO_PORTx_PUD_EN bit can be set to enable
pull-up or pull-down to the pad.
For GPIO0 (SC1_IO) and GPIO16 (SC2_IO) pads, there are additional register bits defined to indicate the strength of
pull-up resistor, as 20 k or 11 k.
The GPIO_IN Register is writable. If GPIO_IN_EN register bit is disabled, then a pad input may be disabled, and the input
value written by software.
The GPIO PORT3 is configured as a read-only port in SEC1110/SEC1210.
TABLE 12-1: GPIO PIN MAPPING
PORT# GPIO#
SEC1110 AND SEC1210 PACKAGE COMMENT
GPIO AUX A AUX B
POWER RAIL,
DEBOUNCE
PORT0
GPIO0 GPIO0 SC1_IO SC1_VCC
(Note 12-2)
GPIO1 GPIO1 SC1_CLK SC1_VCC
(Note 12-2)
GPIO2 GPIO2 SC1_RST_N SC1_VCC
(Note 12-2)
GPIO3 GPIO3 SC1_C4 SC1_VCC
(Note 12-2)
GPIO4 GPIO4 SC1_C8 SC1_VCC
(Note 12-2)
GPIO5 GPIO5/
TIMER2_T2EX
SC_LED_ACT_N JTAG_TDO VDD33
(Note 12-7)
GPIO6 SC1_PRSNT_N/
GPIO6/
TIMER0_IN
JTAG_TMS VDD33,
DEBOUNCE
(Note 12-8)
GPIO7 GPIO7 Reserved Reserved VDD33
(Note 12-10)
SEC1110/SEC1210
DS00001561C-page 118 2013 - 2016 Microchip Technology Inc.
PORT1
GPIO8 GPIO8 SPI1_MISO RXD VDD33,
DEBOUNCE
GPIO9 GPIO9 SPI1_MOSI TXD VDD33,
DEBOUNCE
GPIO10 GPIO10 SPI1_CLK CTS VDD33,
DEBOUNCE
GPIO11 GPIO11 SPI1_CE_N RTS VDD33,
DEBOUNCE
GPIO12 GPIO12 SPI2_MI Reserved VDD33
DEBOUNCE
(Note 12-1)
GPIO13 GPIO13 SPI2_MO Reserved VDD33
DEBOUNCE
(Note 12-1)
GPIO14 GPIO14 SPI2_CLK Reserved VDD33
DEBOUNCE
(Note 12-1)
GPIO15 GPIO15 SPI2_CE_N Reserved VDD33
DEBOUNCE
(Note 12-1)
PORT2
GPIO16 GPIO16/
TIMER2_CC_IN0
SC2_IO TIMER2_CC_OUT0 SC2_VCC
DEBOUNCE
(Note 12-1, Note 12-
3)
GPIO17 GPIO17/
TIMER2_CC_IN1
SC2_CLK TIMER2_CC_OUT1 SC2_VCC
DEBOUNCE
(Note 12-1, Note 12-
3)
GPIO18 GPIO18/
TIMER2_CC_IN2
SC2_RST_N TIMER2_CC_OUT2 SC2_VCC
DEBOUNCE
(Note 12-1, Note 12-
3)
GPIO19 SC2_PRSNT_N JTAG_TDI TIMER1_IN VDD33,
DEBOUNCE
(Note 12-1, Note 12-
9, Note 12-10)
GPIO20 GPIO20/TIMER2_C
C_IN3
PCLK_ENABLE TIMER2_CC_OUT3 VDD33
DEBOUNCE
GPIO21 GPIO21 JTAG_CLK TIMER2_IN VDD33,
DEBOUNCE
(Note 12-5)
GPIO22 GPIO22 TEST/
EXT_OSC_48MHZ
Unassigned VDD33
(Note 12-6)
GPIO23 PCLK_IN_48MHZ/G
PIO23
Reserved Reserved VDD33
DEBOUNCE
TABLE 12-1: GPIO PIN MAPPING (CONTINUED)
PORT# GPIO#
SEC1110 AND SEC1210 PACKAGE COMMENT
GPIO AUX A AUX B
POWER RAIL,
DEBOUNCE
2013 - 2016 Microchip Technology Inc. DS00001561C-page 119
SEC1110/SEC1210
The mapping of the GPIO pins to the package pins is shown in Table 12-1, “GPIO Pin Mapping,” on page 117.
Note 12-1 The SPI2_MI, SPI2_MO, SPI2_CLK, SPI2_CE pads are not available in the SEC1110 and SEC1210
packages. The SPI2 Master can also be observed using the SC2 pads in the SEC1210 package. The
selection of these alternate ports is based on Auxiliary Enable and Auxiliary Select registers
(aux_port2_b_en[3:0]) and if the SPI2 clock is enabled (SPI2_CLK_EN). If SPI2 is disabled, the
Timer 2 ccbus[2:0] is connected to the GPIO[18:16] as outputs. The SPI2 interface is enabled by
BOND2 in the QFN48 debug package.
Note 12-2 The SC1_CLK, SC1_IO, SC1_RST_N, SC1_C4, and SC1_C8 pads are in the SC1_VCC power rail
(5V/3.0V/1.8V/0V). The pad’s pull-ups and pull-downs are controlled by the Smart Card 1 Block in
Auxiliary A Mode.
Note 12-3 The SC2_CLK, SC2_IO, and SC2_RST_N pads are in the SC2_VCC power rail (5V/3.0V/1.8V/0V).
The pad’s pull-ups and pull-downs are controlled by the Smart Card 2 Block in Auxiliary A Mode.
Note 12-4 VDD33 power rail is powered down in STOP power mode.
Note 12-5 The power up state of the GPIO21 pin when RESET_N is released controls the JTAG Mode. The
JTAG_CLK pad has a weak pull-down at reset time. An external pull-up is applied to enable JTAG
at reset time. This pull-down can be disabled if software determines the chip is in Debug Mode. The
JTAG Mode is disabled if the OTP_JTAG_DIS bit is programmed. The GPIO21 pad powers up as
JTAG_CLK in Auxiliary A Mode if JTAG is enabled. If not in JTAG Mode, this pin may be used as
TIMER2_IN(t2) input or as GPIO21.
Note 12-6 The power up state of the TEST pin when RESET_N is released controls the Test Mode. The TEST
pad has a weak pull-down. In Functional Mode, the software disables the input enable for this bit and
disables the pull-down.
Note 12-7 The GPIO5/TIMER2_T2EX input may be used to control the Timer 2 in Reload Mode 1. The
TIMER2_CC_OUT[2:0] outputs of Timer 2 are output through GPIO[18:16] pins in Auxiliary B Mode.
These are used to generate a pulse-width modulated waveform. Alternatively, these pads may be
used as TIMER2_CC_IN[2:0] inputs in Capture Mode.
Note 12-8 The GPIO6/TIMER0_IN pin may be used as a t0 input for Timer 0 In Auxiliary A Mode, this pin may
be used as JTAG_TDI input (if JTAG is enabled), or SPI2_MI (If SPI2 is enabled in SEC1210
package). The GPIO19/TIMER1_IN pin may be used as an “t1” input for Timer 1. Additionally, the
Ref_Clk_Out signal is observed in Auxiliary B Mode for monitoring the frequency of the oscillator
clocks.
Note 12-9 The GPIO19/TIMER1_IN pin may be used as a t1 input for Timer 1. Additionally, the Ref_Clk_Out
signal is observed in Auxiliary B Mode for monitoring the frequency of the oscillator clocks.
Note 12-10 There is no GPIO7 package pin. The GPIO_PORT0_OUT7 Register, when zero, allows the GPIO5
pin to function normally. The GPIO_PORT0_DIR[7] Register, when zero, enables normal functionality
PORT3
GPIO24 BOND0 Reserved Reserved VDD33
GPIO25 BOND1 Reserved Reserved VDD33
GPIO26 BOND2/EXT_SPI2_
EN
Reserved Reserved VDD33
GPIO27 BOND3/GPIO27 Reserved Reserved VDD33
GPIO28 PJTAG_TMS Reserved Reserved VDD33
DEBOUNCE
GPIO29 PJTAG_TDI Reserved Reserved VDD33
DEBOUNCE
GPIO30 PJTAG_TDO Reserved Reserved VDD33
DEBOUNCE
GPIO31 Reserved Reserved Reserved VDD33
TABLE 12-1: GPIO PIN MAPPING (CONTINUED)
PORT# GPIO#
SEC1110 AND SEC1210 PACKAGE COMMENT
GPIO AUX A AUX B
POWER RAIL,
DEBOUNCE
SEC1110/SEC1210
DS00001561C-page 120 2013 - 2016 Microchip Technology Inc.
of the GPIO6 and GPIO19 pads. When the GPIO_PORT0_DIR[7] Register is set, it disables the
updates to the GPIO_PORT0_IN[6] and GPIO_PORT0_IN[19] register bits from the pads. This
functionality is used when JTAG_CLK_LAT is enabled and functionality of SC1_PRSNT_N and
SC2_PRSNT_N can be emulated by software.
Note 12-11 In the SEC1110/SEC1210 revision, the BOND3 pad is used as JTAG_TRSTN (active low) pins for
8051 JTAG and TEST_JTAG controllers. In SEC1110/SEC1210 version, the BOND3 is not used as
JTAG_TRSTN (not needed). The internal pull-up is enabled for this pin in functional and test modes.
Note 12-12 In QFN48 debug package, the PJTAG_TDI, PJTAG_TMS inputs are used for JTAG. In other
packages, these inputs are disabled.
Note 12-13 In other packages, these inputs are disabled.
Note 12-14 Though PJTAG_TDO is connected as GPIO[30] which is part of read-only GPIO3 ports, this pad is
an output in QFN48 debug package. It is driven when chip is out of reset. The input enable is
controlled by the GPIO registers.
The bond options are shown in Table 12-2, "Bond Options".
12.1.1 PROCEDURE FOR READING THE BOND_OPT REGISTER
To read the BOND bits:
1. Enable the pull-ups on the BOND GPIO pads.
2. Wait (at least) 1 sec for the pull-ups to take effect.
3. Read the GPIO_PORT3_IN Register.
4. Disable the pull-ups, tristate the BOND pads, and disable input reads.
The BOND2 input indicates if reset execution is from external SPI2 or internal ROM/OTP_ROM.
12.2 Functional Mode and Test Modes
The chip is in low power STOP Mode, when the RESET_N signal is asserted low. All the GPIO pads are powered down
in this state. On release of the internal RESET_N pin signal, the power to the pads is applied and the state of the TEST,
JTAG_CLK, and JTAG_TDI pins are latched. When latched, these values are referred to as the TEST_LAT, JTAG_-
CLK_LAT, and JTAG_TDI_LAT. The desired state of TEST, JTAG_CLK, and JTAG_TDI must be not changed for 1.4 ms
after the release of RESET_N. After this time, the TEST and JTAG_CLK pins may be used as described in Table 12-3,
“Functional Mode and Test Modes,” on page 121.
TABLE 12-2: BOND OPTIONS
PART BOND0 BOND1 BOND2 BOND3 DESCRIPTION
SEC1110 0 0 X H (internal
pull-up)
SEC1110 Mode
SEC1210 0 1 X H (internal
pull-up)
SEC1210 Mode
Reserved 1 0 X Reserved
Debug 1 1 0 1 SEC1110 Debug Package
SPI2 port present
CPU executes from internal ROM/ OTP ROM
CFG_DEBUG=1
Debug 1 1 1 1 SEC1110 Debug Package
SPI2 port present
CPU executes from external SPI2 ROM
EXT_SPI_EN=1 for this case, and EXT_SPI_EN=0
otherwise
CFG_DEBUG=1
2013 - 2016 Microchip Technology Inc. DS00001561C-page 121
SEC1110/SEC1210
The TEST and JTAG_CLK pads have a weak pull-down just after the reset state (internal regulators are powered up).
In normal functional modes, the TEST and JTAG_CLK pins are grounded.
If JTAG debugging support is required, then a pull-up may be applied on the JTAG_CLK and TEST pin is grounded.
The JTAG_TDI_LAT value is used by the boot ROM firmware to decide the MEM_CLK_DIV value at boot time for External
Clock Mode.
A power cycle is required to switch the chip mode.
12.3 GPIO Registers Summary
The register addresses indicated below are XDATA memory addresses. The GPIO ports are configured as 8-bits wide,
and there are four GPIO ports numbered 0,1,2,3. There are two memory decode regions for the GPIO registers. The
Alternate XDATA address decode enables access as a bit-indexed array.
TABLE 12-3: FUNCTIONAL MODE AND TEST MODES
RESET_N=0,
RESET_N RELEASED (T < 1.4 MS) T > 1.4 MS AFTER RESET_N RELEASE
RESET STATE
FUNCTION TEST
JTAG_
CLK/G
PIO21 TEST
JTAG_CLK/G
PIO21 RESET RELEASED FUNCTION
STOP Mode when
RESET_N=0
00 X PIO21/
TIMER2_IN
Functional Mode:
Chip Functional Mode with JTAG
disabled.
TEST_LAT=0, JTAG_CLK_LAT=0
STOP Mode when
RESET_N=0
0 1 X (0
recommended
)
JTAG_CLK Debug1 Mode:
Chip Functional Mode with JTAG
enabled, provided the JTAG_DIS bit
is 0 (OTP Register).
If the JTAG_DIS bit is 1, then the chip
functions in Functional Mode.
TEST_LAT=0, JTAG_CLK_LAT=1
STOP Mode when
RESET_N=0
1 1 EXT_OSC_48
MHZ
JTAG_CLK Debub2 Mode:
Chip Functional Mode with JTAG
enabled provided the JTAG_DIS bit is
0 (OTP Register). The TEST pin is
used as an external 48 MHz
oscillator input.
OSC48_CTL.EXT_OSC48_PRESENT is
1 in this Mode.
If the JTAG_DIS bit is 1, then the chip
functions in Functional Mode.
TEST_LAT=1, JTAG_CLK_LAT=1
STOP Mode when
RESET_N=0
1 0 X X Test Mode:
TEST_LAT=1, JTAG_CLK_LAT=0
SEC1110/SEC1210
DS00001561C-page 122 2013 - 2016 Microchip Technology Inc.
TABLE 12-4: GPIO REGISTER MAP
PORT# REGISTER NAME
XDATA
ADDRESS
ALTERNATE
XDATA
ADDRESS
EC
TYPE
PORT0
GPIO_AUX_PORT0_EN 0x9C00 0x9D00 R/W
GPIO_PORT0_DIR 0x9C01 0x9D04 R/W
GPIO_PORT0_IN 0x9C02 0x9D08 R/W
GPIO_PORT0_OUT 0x9C03 0x9D0C R/W
GPIO_PORT0_PUD_EN 0x9C04 0x9D10 R/W
GPIO_PORT0_DEBOUNCE_CNT 0x9C05 0x9D14 R/W
GPIO_AUX_PORT0_SEL 0x9C06 0x9D18 R/W
GPIO_PORT0_INT_EN 0x9C07 0x9D1C R/W
GPIO_PORT0_PUD 0x9C08 0x9D20 R/W
GPIO_PORT0_OE 0x9C09 0x9D24 R/W
GPIO_PORT0_INTYPE 0x9C0A 0x9D28 R/W
GPIO_PORT0_INT_EDGE 0x9C0B 0x9D2C R/W
GPIO_PORT0_IN_EN 0x9C0C 0x9D30 R/W
GPIO_PORT0_INT_STS 0x9C0D 0x9D34 R/W
GPIO_PORT0_PUS 0x9C0E 0x9D38 R/W
GPIO_PORT0_DEBOUNCE_EN 0x9C0F 0x9D3C R/W
PORT1
GPIO_AUX_PORT1_EN 0x9C10 0x9D01 R/W
GPIO_PORT1_DIR 0x9C11 0x9D05 R/W
GPIO_PORT1_IN 0x9C12 0x9D09 R/W
GPIO_PORT1_OUT 0x9C13 0x9D0D R/W
GPIO_PORT1_PUD_EN 0x9C14 0x9D11 R/W
GPIO_PORT1_DEBOUNCE_CNT 0x9C15 0x9D15 R/W
GPIO_AUX_PORT1_SEL 0x9C16 0x9D19 R/W
GPIO_PORT1_INT_EN 0x9C17 0x9D1D R/W
GPIO_PORT1_PUD 0x9C18 0x9D21 R/W
GPIO_PORT1_OE 0x9C19 0x9D25 R/W
GPIO_PORT1_INTYPE 0x9C1A 0x9D29 R/W
GPIO_PORT1_INT_EDGE 0x9C1B 0x9D2D R/W
GPIO_PORT1_IN_EN 0x9C1C 0x9D31 R/W
GPIO_PORT1_INT_STS 0x9C1D 0x9D35 R/W
GPIO_PORT1_PUS 0x9C1E 0x9D39 R/W
GPIO_PORT1_DEBOUNCE_EN 0x9C1F 0x9D3D R/W
2013 - 2016 Microchip Technology Inc. DS00001561C-page 123
SEC1110/SEC1210
12.4 GPIO Registers
In the SEC1110/SEC1210 version, the GPIO block uses the CPU clock. Therefore, if the CPU is in CPU_STOP mode,
the GPIO_PORTx_IN registers do not reflect the value of the pins. This is due to the absence of the CPU clock in
CPU_STOP mode when debounce clock is enabled. In SEC1110/SEC1210 version, the CPU peripheral clock is connected
to GPIO block and hence can wakeup the processor.
The GPIO_PORT3 registers are read only, with controls for pull-up and pull-down. They are used for reading the bond
options.
PORT2
GPIO_AUX_PORT2_EN 0x9C20 0x9D02 R/W
GPIO_PORT2_DIR 0x9C21 0x9D06 R/W
GPIO_PORT2_IN 0x9C22 0x9D0A R/W
GPIO_PORT2_OUT 0x9C23 0x9D0E R/W
GPIO_PORT2_PUD_EN 0x9C24 0x9D12 R/W
GPIO_PORT2_DEBOUNCE_CNT 0x9C25 0x9D16 R/W
GPIO_AUX_PORT2_SEL 0x9C26 0x9D1A R/W
GPIO_PORT2_INT_EN 0x9C27 0x9D1E R/W
GPIO_PORT2_PUD 0x9C28 0x9D22 R/W
GPIO_PORT2_OE 0x9C29 0x9D26 R/W
GPIO_PORT2_INTYPE 0x9C2A 0x9D2A R/W
GPIO_PORT2_INT_EDGE 0x9C2B 0x9D2E R/W
GPIO_PORT2_IN_EN 0x9C2C 0x9D32 R/W
GPIO_PORT2_INT_STS 0x9C2D 0x9D36 R/W
GPIO_PORT2_PUS 0x9C2E 0x9D3A R/W
GPIO_PORT2_DEBOUNCE_EN 0x9C2F 0x9D3E R/W
PORT3
GPIO_AUX_PORT3_EN 0x9C30 0x9D03 R/W
GPIO_PORT3_DIR 0x9C31 0x9D07 R/W
GPIO_PORT3_IN 0x9C32 0x9D0B R/W
GPIO_PORT3_OUT 0x9C33 0x9D0F R/W
GPIO_PORT3_PUD_EN 0x9C34 0x9D13 R/W
GPIO_PORT3_DEBOUNCE_CNT 0x9C35 0x9D17 R/W
GPIO_AUX_PORT3_SEL 0x9C36 0x9D1B R/W
GPIO_PORT3_INT_EN 0x9C37 0x9D1F R/W
GPIO_PORT3_PUD 0x9C38 0x9D23 R/W
GPIO_PORT3_OE 0x9C39 0x9D27 R/W
GPIO_PORT3_INTYPE 0x9C3A 0x9D2B R/W
GPIO_PORT3_INT_EDGE 0x9C3B 0x9D2F R/W
GPIO_PORT3_IN_EN 0x9C3C 0x9D33 R/W
GPIO_PORT3_INT_STS 0x9C3D 0x9D37 R/W
GPIO_PORT3_PUS 0x9C3E 0x9D3B R/W
GPIO_PORT3_DEBOUNCE_EN 0x9C3F 0x9D3F R/W
TABLE 12-4: GPIO REGISTER MAP (CONTINUED)
PORT# REGISTER NAME
XDATA
ADDRESS
ALTERNATE
XDATA
ADDRESS
EC
TYPE
SEC1110/SEC1210
DS00001561C-page 124 2013 - 2016 Microchip Technology Inc.
TABLE 12-5: GPIO AUXILIARY PORT 0,1,2,3 ENABLE REGISTER
GPIO_AUX_PORT0_EN
(0X9C00~0X9C00 - RESET= Table 12-21 on page 130)
GPIO_AUX_PORT1_EN
(0X9C10~0X9C10 - RESET= Table 12-21 on page 130
GPIO_AUX_PORT2_EN
(0X9C20~0X9C20 - RESET= Table 12-21 on page 130)
GPIO_AUX_PORT3_EN
(0X9C30~0X9C30 - RESET= Table 12-21 on page 130)
GPIO AUXILIARY PORT 0,1,2,3 ENABLE
REGISTER
BIT NAME R/W DESCRIPTION
7:0 GPIO_AUX_PORT_EN[7:0] R/W GPIO Auxiliary Port Enable:
0 : Pads controlled by GPIO registers
1 : Pads controlled by Auxiliary Ports A or B.
The GPIO_AUX_PORT3_EN Register is read only,
and is always 0.
TABLE 12-6: GPIO PORT 0,1,2,3 DIRECTION REGISTER
GPIO_PORT0_DIR
(0X9C01~0X9C01- RESET=0X00)
GPIO_PORT1_DIR
(0X9C11~0X9C11- RESET=0X00)
GPIO_PORT2_DIR
(0X9C21~0X9C21- RESET=0X00)
GPIO_PORT3_DIR
(0X9C31~0X9C31- RESET=0X00)
GPIO PORT 0,1,2,3 DIRECTION REGISTER
BIT NAME R/W DESCRIPTION
7:0 GPIO_PORT_DIR[7:0] R/W GPIO Direction:
Controlls the output enable of the pad, when the
GPIO_AUX_PORT_EN bit is 0.
0 : In, the input state is controlled by the
GPIO_IN_EN bits
1 : Out
The GPIO_PORT3_DIR register is read only, and is
always 0.
TABLE 12-7: GPIO PORT 0,1,2,3 IN REGISTER
GPIO_PORT0_IN
(0X9C02~9C02- RESET=0X00)
GPIO_PORT1_IN
(0X9C12~9C12- RESET=0X00)
GPIO_PORT2_IN
(0X9C22~9C22- RESET=0X00)
GPIO_PORT3_IN
(0X9C32~9C32- RESET=0X00)
GPIO PORT 0,1,2,3 IN REGISTER
BIT NAME R/W DESCRIPTION
7:0 GPIO_IN[7:0] R/W GPIO Pad Input Buffer Data
2013 - 2016 Microchip Technology Inc. DS00001561C-page 125
SEC1110/SEC1210
The pull-up/down resistor control to the Auxiliary ports are enabled for a GPIO bit only if the corresponding bit in the
GPIO_PORTx_PUD_EN Register is zero.
An internal peripheral using Auxiliary ports can ensure that the pin is pulled-up or pulled-low, when it is not driven, by
enabling the corresponding bit in these registers.
TABLE 12-8: GPIO PORT 0,1,2,3 OUTPUT REGISTER
GPIO_PORT0_OUT
(0X9C03~0X9C03- RESET=0X00)
GPIO_PORT1_OUT
(0X9C13~0X9C13- RESET=0X00)
GPIO_PORT2_OUT
(0X9C23~0X9C23- RESET=0X00)
GPIO_PORT3_OUT
(0X9C33~0X9C33- RESET=0X00)
GPIO PORT 0,1,2,3 OUT REGISTER
BIT NAME R/W DESCRIPTION
7:0 GPIO_OUT R/W GPIO Pad Output Buffer Data when
GPIO_PORT0_OE.GPIO_OE is enabled.
If the pad is configured as an input, then this register
bit acts as a GPIO interrupt polarity register.
0 : GPIO input changes to 0 (level) or falling edge
generates an interrupt.
1 : GPIO input changes to 1(level) or rising edge
generates an interrupt.
The GPIO_PORT3_OUT Register is read only, and
is always 0.
TABLE 12-9: GPIO PORT 0,1,2 PULL UP/DOWN ENABLE REGISTER
GPIO_PORT0_PUD_EN
(0X9C04~0X9C04- RESET=Table 12-21 on page 130)
GPIO_PORT1_PUD_EN
(0X9C14~0X9C14- RESET=Table 12-21 on page 130)
GPIO_PORT2_PUD_EN
(0X9C24~0X9C24- RESET=Table 12-21 on page 130)
GPIO_PORT2_PUD_EN
(0X9C34~0X9C34- RESET=Table 12-21 on page 130)
GPIO PORT 0,1,2,3 PULL UP/DOWN ENABLE
REGISTER
BIT NAME R/W DESCRIPTION
7:0 GPIO_PUD_EN[7:0] R/W 0 : Disables the pull-up/down resistor on the GPIO
pad.
1 : Enables the pull-up/down resistor on the GPIO
pad.
SEC1110/SEC1210
DS00001561C-page 126 2013 - 2016 Microchip Technology Inc.
The SEC1110 and SEC1210 GPIO_PORT3 does not have a debounce count register.
TABLE 12-10: GPIO PORT 0,1,2,3 DEBOUNCE COUNT REGISTER
GPIO_PORT0_DEBOUNCE_CNT
(0X9C05~0X09C05- RESET=0X00)
GPIO_PORT0_DEBOUNCE_CNT
(0X9C15~0X09C15- RESET=0X00)
GPIO_PORT0_DEBOUNCE_CNT
(0X9C25~0X09C25- RESET=0X00)
GPIO_PORT3_DEBOUNCE_CNT
(0X9C35~0X09C35- RESET=0X00)
GPIO PORT 0,1,2,3 DEBOUNCE COUNT
REGISTER
BIT NAME R/W DESCRIPTION
7:0 GPIO_DEBOUNCE_CNT[7:0] R/W This field indicates the number of debounce clocks
(1 ms or 0.01 ms) to wait after any change in a GPIO
pad, to ensure the pad has not changed its value.
The count restarts after every change of GPIO pad,
when enabled.
The GPIO_PORT3_DEBOUNCE_CNT Register is
read only, and is always 0.
A register value of 0, behaves as value 1.
TABLE 12-11: GPIO AUXILIARY PORT 0,1,2,3 SELECT A/B REGISTER
GPIO_AUX_PORT0_SEL
(0X9C06~0X9C06 - RESET= Table 12-21 on page 130)
GPIO_AUX_PORT1_SEL
(0X9C16~0X9C16 - RESET= Table 12-21 on page 130)
GPIO_AUX_PORT2_SEL
(0X9C26~0X9C26 - RESET= Table 12-21 on page 130)
GPIO_AUX_PORT3_SEL
(0X9C36~0X9C36 - RESET= Table 12-21 on page 130)
GPIO AUXILIARY PORT 0,1,2,3 A/B SELECT
REGISTER
BIT NAME R/W DESCRIPTION
7:0 GPIO_AUX_PORT_SEL[7:0] R/W GPIO Auxiliary Port A/B Select.
0 : Pads controlled by Auxiliary Port A
1 : Pads controlled by Auxiliary Port B.
The GPIO_AUX_PORT3_SEL Register is read only,
and is always 0.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 127
SEC1110/SEC1210
For GPIO PORT4, in auxiliary A mode (keyboard mode), the input enable, pull-up/pull-down enable values of the pad
are controlled by the GPIO register values, since the keyboard block does not control these values. Hence, before
enabling auxiliary port 4, the appropriate values have to be programmed for the above mentioned registers based on
the keyboard configuration.
TABLE 12-12: GPIO PORT 0,1,2,3 INTERRUPT ENABLE REGISTER
GPIO_PORT0_INT_EN
(0X9C07~0X9C07 - RESET=0X00)
GPIO_PORT1_INT_EN
(0X9C17~0X9C17 - RESET=0X00
GPIO_PORT2_INT_EN
(0X9C27~0X9C27 - RESET=0X00)
GPIO_PORT3_INT_EN
(0X9C37~0X9C37 - RESET=0X00)
GPIO PORT 0,1,2,3 INTERRUPT ENABLE
REGISTER
BIT NAME R/W DESCRIPTION
7:0 GPIO_PORT_INT_EN[7:0] R/W GPIO Interrupt Enable Register
The corresponding GPIO_PORT_IN_EN bit must be
enabled for the pad inputs to be seen.
0 : Interrupts from this GPIO pad is disabled
1 : Interrupts from this GPIO pad is enabled
The GPIO_PORT3_INT_EN Register is read only,
and is always 0.
TABLE 12-13: GPIO PORT 0,1,2,3 PULL UP/DOWN SELECT REGISTER
GPIO_PORT0_PUD
(0X9C08~0X09C08- RESET=Table 12-21 on page 130)
GPIO_PORT1_PUD
(0X9C18~0X09C18- RESET=Table 12-21 on page 130)
GPIO_PORT2_PUD
(0X9C28~0X09C28- RESET=Table 12-21 on page 130)
GPIO_PORT3_PUD
(0X9C38~0X09C38- RESET=Table 12-21 on page 130)
GPIO PORT 0,1,2,3 PULL UP/DOWN SELECT
REGISTER
BIT NAME R/W DESCRIPTION
7:0 GPIO_PUD[7:0] R/W 0 : Selects pull-down resistor on the GPIO pad.
1 : Selects pull-up resistor on the GPIO pad.
The corresponding GPIO_PUD_EN bit must be enabled
for pull-up or pull-down resistor to be active.
Note: Both the pull-up and pull-down resistors to the
pads are never active at the same time.
SEC1110/SEC1210
DS00001561C-page 128 2013 - 2016 Microchip Technology Inc.
TABLE 12-14: GPIO PORT 0,1,2,3 OUTPUT ENABLE REGISTER
GPIO_PORT0_OE
(0X9C09~0X09C09- RESET=0X00)
GPIO_PORT1_OE
(0X9C19~0X09C19- RESET=0X00)
GPIO_PORT2_OE
(0X9C29~0X09C29- RESET=0X00)
GPIO_PORT3_OE
(0X9C39~0X09C39- RESET=0X00)
GPIO PORT 0,1,2,3 OUTPUT ENABLE REGISTER
BIT NAME R/W DESCRIPTION
7:0 GPIO_OE[7:0] R/W The GPIO Output Enable to pad, when GPIO_AUX_PORTx_EN
bit is 0.
0 : GPIO pad is tri-stated
1 : GPIO pad is driven
The GPIO_PORT3_OE Register is read only, and is always 0.
TABLE 12-15: GPIO PORT 0,1,2,3 INPUT TYPE REGISTER
GPIO_PORT0_INTYPE
(0X9C0A~0X09C0A- RESET=0X00)
GPIO_PORT1_INTYPE
(0X9C1A~0X09C1A- RESET=0X00)
GPIO_PORT2_INTYPE
(0X9C2A~0X09C2A- RESET=0X00)
GPIO_PORT3_INTYPE
(0X9C3A~0X09C3A- RESET=0X00)
GPIO PORT 0,1,2,3 INPUT TYPE REGISTER
BIT NAME R/W DESCRIPTION
7:0 GPIO_INTYPE[7:0] R/W GPIO Input Capture Type:
0 : GPIO pad input is double synced on system clock.
1 : GPIO pad is registered on the system clock. If debounce
is enabled then register data after debounce time. Else,
register state change after double syncing.
The GPIO_PORT3_INTYPE Register is read only, and is
always 0.
TABLE 12-16: GPIO PORT 0,1,2,3 INTERRUPT EDGE ENABLE REGISTER
GPIO_PORT0_INT_EDGE
(0X9C0B~0X09C0B- RESET=0X00)
GPIO_PORT1_INT_EDGE
(0X9C1B~0X09C1B- RESET=0X00)
GPIO_PORT2_INT_EDGE
(0X9C2B~0X09C2B- RESET=0X00)
GPIO_PORT3_INT_EDGE
(0X9C3B~0X09C3B- RESET=0X00)
GPIO PORT 0,1,2,3 INTERRUPT EDGE REGISTER
BIT NAME R/W DESCRIPTION
7:0 GPIO_INT_EDGE[7:0] R/W GPIO Interrupt: it is either edge or level triggered.
0 : GPIO pad input is level triggered
1 : GPIO pad input is edge triggered
The GPIO_PORT3_INT_EDGE Register is read only, and is
always 0.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 129
SEC1110/SEC1210
Writing a 1 to a bit clears the bit and enables the detection of the next level transition. If enabled in the GPIO_PORTx-
_INT_EN Register, a 1 in corresponding bit in this register will force a 1 on the 8051 core’s external INT1 interrupt input.
The GPIO pull-up resistor strength is programmable only for the SC1_IO (GPIO0) and SC2_IO (GPIO16) pads. An internal
weak pull-up of 20 k or 11 k may be used. The register bits for other GPIOs are read only as 0.
TABLE 12-17: GPIO PORT 0,1,2,3 INPUT ENABLE REGISTER
GPIO_PORT0_IN_EN
(0X9C0C~0X9C0C - RESET= Table 12-21 on page 130)
GPIO_PORT1_IN_EN
(0X9C1C~0X9C1C - RESET= Table 12-21 on page 130)
GPIO_PORT2_IN_EN
(0X9C2C~0X9C2C - RESET= Table 12-21 on page 130)
GPIO_PORT3_IN_EN
(0X9C3C~0X9C3C - RESET= Table 12-21 on page 130)
GPIO PORT 0,1,2,3 INPUT ENABLE REGISTER
BIT NAME R/W DESCRIPTION
7:0 GPIO_IN_EN[7:0] R/W GPIO Input Enable register enables the pad input. If
this bit is disabled, then the input value seen is
default 0.
0 : Inputs from this GPIO pad are disabled
1 : Inputs from this GPIO pad are enabled
TABLE 12-18: GPIO PORT 0,1,2,3 INTERRUPT STATUS REGISTER
GPIO_PORT0_INT_STS
(0X9C0D~0X09C0D- RESET=0X00)
GPIO_PORT1_INT_STS
(0X9C1D~0X09C1D- RESET=0X00)
GPIO_PORT2_INT_STS
(0X9C2D~0X09C2D- RESET=0X00)
GPIO_PORT3_INT_STS
(0X9C3D~0X09C3D- RESET=0X00)
GPIO INTERRUPT STATUS REGISTER
BIT NAME R/W DESCRIPTION
7:0 GPIO_INT_STS[7:0] R/W1 GPIO Interrupt Polarity Register:
0 : If a bit is reset, then no interrupt event occurred
for this GPIO pad input.
1 : If a bit is set, then an interrupt event occurred for
this GPIO pad input. Write 1 to clear this interrupt bit.
The GPIO_PORT3_INT_STS Register is read only,
and is always 0.
TABLE 12-19: GPIO PORT 0,1,2,3 PULL UP STRENGTH REGISTER
GPIO_PORT0_PUS
(0X9C0E~0X9C0E- RESET=0X00)
GPIO_PORT1_PUS
(0X9C1E~0X9C1E- RESET=0X00)
GPIO_PORT2_PUS
(0X9C2E~0X9C2E- RESET=0X00)
GPIO_PORT3_PUS
(0X9C3E~0X9C3E- RESET=0X00)
GPIO PORT 0,1,2,3 PULL UP/DOWN ENABLE
REGISTER
BIT NAME R/W DESCRIPTION
7:1 Reserved R Always read as 0
0 GPIO_PUS0 R/W 0 : Weak pull-up resistor on the GPIO pad
1 : Strong pull-up resistor on the GPIO pad
SEC1110/SEC1210
DS00001561C-page 130 2013 - 2016 Microchip Technology Inc.
The debounce register bit must be disabled if operating in Auxiliary Port Mode, and debouncing is not required. Therefore,
an internal peripheral is required to directly control the GPIO pad. The debounce clock is gated off when oscillator
is in Sleep Mode.
The Debounce Register is valid only for the following pads:
• GPIO6/SC1_PRSNT_N
• GPIO19/SC2_PRSNT_N
• GPIO21/JTAG_CLK
• GPIO8/RXD
• GPIO9/TXD
• GPIO10/CTS
• GPIO11/RTS
TABLE 12-20: GPIO PORT 0,1,2,3 DEBOUNCE ENABLE REGISTER
GPIO_PORT0_DEBOUNCE_EN
(0X9C0F~0X09CFD- RESET=0X00)
GPIO_PORT1_DEBOUNCE_EN
(0X9C1F~0X09C1F- RESET=0X00)
GPIO_PORT2_DEBOUNCE_EN
(0X9C2F~0X09C2F- RESET=0X00)
GPIO_PORT3_DEBOUNCE_EN
(0X9C3F~0X09C3F- RESET=0X00)
GPIO DEBOUNCE ENABLE REGISTER
BIT NAME R/W DESCRIPTION
7:0 GPIO_DEBOUNCE_EN[7:0] R/W1 GPIO Input Data Debounce Enable:
0 : Debouncing on this input is disabled
1 : Debouncing is enabled on this input
The GPIO_PORT3_DEBOUNCE_EN Register is
read only, and is always 0.
Note: The other bits are read only as zero.
TABLE 12-21: POWER ON RESET STATE OF GPIO REGISTERS
GPIO# RESET STATE OF REGISTERS COMMENT
GPIO_AUX_POR
T_EN
GPIO_AUX_
PORT_SEL
GPIO_PORT_IN_
EN GPIO_PUD_EN GPIO_PUD
GPIO0 0 0 0 0 0 I/O disabled.
GPIO1 0 0 0 0 0 I/O disabled.
GPIO2 0 0 0 0 0 I/O disabled.
GPIO3 0 0 0 0 0 I/O disabled.
GPIO4 0 0 0 0 0 I/O disabled.
GPIO5 !CFG_DEBUG &
JTAG_CLK_LAT
1 0 !CFG_DEBUG &
JTAG_CLK_LAT
1 JTAG_TDO
GPIO6 !CFG_DEBUG &
JTAG_CLK_LAT
1 !CFG_DEBUG &
JTAG_CLK_LAT
!CFG_DEBUG &
JTAG_CLK_LAT
1 JTAG_TMS
GPIO7 0 0 0 0 0 Reserved
GPIO8 0 0 0 0 0 I/O disabled.
GPIO9 0 0 0 0 0 I/O disabled.
GPIO10 0 0 0 0 0 I/O disabled.
GPIO11 0 0 0 0 0 I/O disabled.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 131
SEC1110/SEC1210
12.4.1 GPIO WAKE-UP EVENT
The GPIO can be programmed as input with interrupt enabled, and a change in the pads can be detected to wake up
the CPU from SLEEP/IDLE states or wake up the oscillator. Refer to Table 15-14, “Wake on Event Register,” on
page 161.
GPIO12 EXT_SPI_EN 0 0 0 0 SPI2_MI
GPIO13 EXT_SPI_EN 0 0 0 0 SPI2_MO
GPIO14 EXT_SPI_EN 0 0 0 0 SPI2_CLK
GPIO15 EXT_SPI_EN 0 EXT_SPI_EN 1 SPI2_CE
GPIO16 0 0 0 0 0 I/O disabled.
GPIO17 0 0 0 0 0 I/O disabled.
GPIO18 0 0 0 0 0 I/O disabled.
GPIO19 !CFG_DEBUG &
JTAG_CLK_LAT
0 !CFG_DEBUG &
JTAG_CLK_LAT
!CFG_DEBUG &
JTAG_CLK_LAT
1 JTAG_TDI
GPIO20 1 0 1: A1 version
CFG_DEBUG :
later versions
1 0 CLK_ENABLE
GPIO21 JTAG_CLK_LAT 0 1 1 0 JTAG_CLK
GPIO22 1 0 1 1 0 TEST/
EXT_OSC_48
MHZ
GPIO23 0 0 1: A1 version
CFG_DEBUG :
later versions
1 0 PCLK_IN_48M
HZ
GPIO24 0 0 1 1 1 BOND0
GPIO25 0 0 1 1 1 BOND1
GPIO26 0 0 1 1 1 BOND2
GPIO27 0 0 1 1 1 BOND3/JTAG_
TRSTN
GPIO28 0 0 1: A1 version
CFG_DEBUG &
JTAG_CLK_LAT :
later versions
CFG_DEBUG 1 PJTAG_TMS
GPIO29 0 0 1: A1 version
CFG_DEBUG &
JTAG_CLK_LAT :
later versions
CFG_DEBUG 1 PJTAG_TDI
GPIO30 0 0 0: A1 version
CFG_DEBUG &
JTAG_CLK_LAT :
later versions
CFG_DEBUG 1 PJTAG_TDO
GPIO31 0 0 0 0 0 Reserved
TABLE 12-21: POWER ON RESET STATE OF GPIO REGISTERS (CONTINUED)
GPIO# RESET STATE OF REGISTERS COMMENT
GPIO_AUX_POR
T_EN
GPIO_AUX_
PORT_SEL
GPIO_PORT_IN_
EN GPIO_PUD_EN GPIO_PUD
SEC1110/SEC1210
DS00001561C-page 132 2013 - 2016 Microchip Technology Inc.
13.0 TWO PIN SERIAL PORT (UART)
The SEC1110 and SEC1210 incorporates full function UARTs. The UART is software compatible with the 16C450 and
16C550A. The UART performs serial-to-parallel conversion on received characters and parallel-to-serial conversion on
transmit characters. The character options are programmable for 1 start; 1, 1.5 or 2 stop bits; even, odd, sticky or no
parity; and prioritized interrupts. The UART contains a programmable baud rate generator that is capable of dividing the
input clock or crystal by a number from 1 to 65535. The UART is accessible on the EC_SPB.
• Programmable word length (5 to 8), stop bits (1, 1.5, 2) and parity (even, odd, sticky or no parity)
• Programmable baud rate generator
• Interrupt generator
• Loop-Back Mode
• Interface registers
• 16-byte Transmit FIFO
• 16-byte Receive FIFO
• Multiple clock sources
• Pin polarity control
• Low Power Sleep Mode
13.1 Transmit Operation
The SEC1110 and SEC1210 do not support external connections for the MODEM control inputs (nDSR, nRI and nDCD)
or for the MODEM control outputs (nDTR, OUT1 and OUT2).
Transmission is initiated by writing the data to be sent to the TX Holding Register or to the TX FIFO (if enabled). The
data is then transferred to the TX Shift Register together with a start bit and parity and stop bits as determined by settings
in the Line Control Register. The bits to be transmitted are then shifted out of the TX Shift Register in the order start bit,
data bits (LSB first), parity bit, and stop bit, using the output from the Baud Rate Generator (divided by 16) as the clock.
If enabled, a TX Holding Register Empty Interrupt will be generated when the TX Holding Register or the TX FIFO (if
enabled) becomes empty.
When FIFOs are enabled (i.e., bit 0 of the FIFO Control Register is set), the M16550S can store up to 16 bytes of data
for transmission at a time. Transmission will continue until the TX FIFO is empty. The FIFO’s readiness to accept more
data is indicated by an interrupt.
13.2 Receive Operation
Data is sampled into the RX Shift Register using the Receive clock, divided by 16. The Receive clock is provided by the
Baud Rate Generator. A filter is used to remove spurious inputs that last for less than two periods of the Receive clock.
When the complete word has been clocked into the Receiver, the data bits are transferred to the RX Buffer Register or
to the RX FIFO (if enabled) to be read by the CPU. (The first bit of the data to be received is placed in bit 0 of this register.)
The Receiver also checks that the parity bit and stop bits are as specified by the Line Control Register.
If enabled, an RX Data Received Interrupt will be generated when the data has been transferred to the RX Buffer Register
or, if FIFOs are enabled, when the RX Trigger Level has been reached. Interrupts can also be generated to signal
a RX FIFO character timeout, incorrect parity, a missing stop bit (frame error) or other line status errors.
When FIFOs are enabled (i.e., bit 0 of the FIFO Control Register is set), the M16550S can store up to 16 bytes of
received data at a time. Depending on the selected RX Trigger Level, the interrupt will go active to indicate that data is
available when the RX FIFO contains 1, 4, 8 or 14 bytes of data.
13.3 Power, Clocks and Reset
13.3.1 POWER
This block is only active if UART_CLK_DIV.UART_CLK_EN is set to 1, otherwise this block is disabled and the clocks are
shut off.
13.3.2 CLOCKS
The UART_CLK is sourced from the 48 MHz oscillator clock divided by UART_CLK_DIV as explained in 15.4.8 UART
Clock Register on page 157.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 133
SEC1110/SEC1210
13.3.3 RESET
Table 13-1 details the effect of a RESET event on each of the runtime registers of the Serial Port.
13.4 Interrupts
The Runtime registers are reset on a RESET event. Refer to Section 15.1, "Reset," on page 151 definitions of RESET
event.
The two-pin Serial Port (UART) can generate an interrupt event. The interrupt source (INTR) is a level, active high signal.
13.5 Registers
Table 13-3 is a register summary for one instance of the two-pin Serial Port (UART). Each EC address is indicated as
an offset address from the XDATA base address 0x9500. Table 13-2 summarizes the registers allocated for the controller.
TABLE 13-1: RESET FUNCTION TABLE
REGISTER/SIGNAL RESET CONTROL RESET STATE
Interrupt Enable Register
RESET
All bits low
Interrupt Identification Reg. Bit 0 is high; bits 1 - 7 low
FIFO Control
Line Control Reg. All bits low
MODEM Control Reg.
Line Status Reg. All bits low except bits 5 and 6 are high
MODEM Status Reg. Bits 0 - 3 low; bits 4 - 7 input
TXD1, TXD2 High
INTRPT (RCVR errs) RESET/Read LSR
INTRPT (RCVR Data Ready) RESET/Read RBR Low
INTRPT (THRE) RESET/Read IIR/Write THR
OUT2B
RESET High
RTSB
DTRB
OUT1B
RCVR FIFO RESET/
FCR1*FCR0/_FCR0 All bits low
XMIT FIFO RESET/
FCR1*FCR0/_FCR0
TABLE 13-2: TWO PIN SERIAL PORT (UART) REGISTER SUMMARY
REGISTER NAME
DLAB
(Note 13-1)
XDATAOFFSET
ADDRESS EC TYPE
Receive Buffer Register (RB) 0 0x00 R
Transmit Buffer Register (TB) 0 0x00 W
Programmable Baud Rate Generator (and Divisor) 1 0x00 R/W
Programmable Baud Rate Generator (and Divisor) 1 0x01 R/W
Interrupt Enable Register (IER) 0 0x01 R/W
FIFO Control Register (FCR), X 0x02 W
Interrupt Identification Register (IIR) X 0x02 R
Line Control Register (LCR) X 0x03 R/W
SEC1110/SEC1210
DS00001561C-page 134 2013 - 2016 Microchip Technology Inc.
Note 13-1 DLAB is bit 7 of the Line Control Register
13.6 Register Summary
Note 13-2 DLAB is bit 7 of the Line Control Register (ADDR = 3).
Note 13-3 Bit 0 is the least significant bit, and is the first bit serially transmitted or received.
Note 13-4 When operating in the XT Mode, this bit will be set any time that the Transmitter Shift Register is
empty.
Note 13-5 This bit no longer has a pin associated with it.
Note 13-6 When operating in the XT Mode, this register is not available.
Note 13-7 These bits are always zero in the Non-FIFO Mode.
Note 13-8 Writing a one to this bit has effect. DMA modes are supported in this chip.
Modem Control Register (MCR) X 0x04 R/W
Line Status Register (LSR) X 0x05 R
Modem Status Register (MSR) X 0x06 R
Scratchpad Register (SCR) X 0x07 R/W
UART_Configuration Select Register X 0x30 R/W
UART_Configuration Active Register X 0x31 R/W
TABLE 13-3: REGISTER SUMMARY
ADDRESS
(Note 13-2) R/W
REGISTER
NAME BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0
ADDR = 0
DLAB = 0
R Receive Buffer r Data Bit 7 Data Bit 6 Data Bit 5 Data Bit 4 Data Bit 3 Data Bit 2 Data Bit 1 Data Bit 0
(Note 13-3)
ADDR = 0
DLAB = 0
W Transmitter Holding r Data Bit 7 Data Bit 6 Data Bit 5 Data Bit 4 Data Bit 3 Data Bit 2 Data Bit 1 Data Bit 0
ADDR = 1
DLAB = 0
R/W Interrupt Enable r Reserved Enable
Modem
Status
Interrupt
(EMSI)
Enable
Receiver
Line Status
Interrupt
(ELSI)
Enable
Trans-mitter
Holding
Register
Empty
Interrupt
(ETHREI)
Enable
Received
Data Available
Interrupt
(ERDAI)
ADDR = 2 R Interrupt Ident. r FIFOs
Enabled
(Note 13-7)
FIFOs
Enabled
(Note 13-7)
Reserved Interrupt ID
Bit
(Note 13-7)
Interrupt ID
Bit
Interrupt ID
Bit
"0" if interrupt
pending
ADDR = 2 W FIFO Control r RCVR Trigger
MSB
RCVR Trigger
LSB
Reserved DMA Mode
Select
(Note 13-8)
XMIT FIFO
Reset
RCVR
FIFO
Reset
FIFO
Enable
ADDR = 3 R/W Line Control r Divisor
Latch
Access Bit
(DLAB)
Set Break Stick Parity Even Parity
Select
(EPS)
Parity
Enable
(PEN)
Number of
Stop Bits
(STB)
Word
Length
Select Bit 1
(WLS1)
Word
Length
Select Bit 0
(WLS0)
ADDR = 4 R/W MODEM Control r Reserved Loop OUT2
(Note 13-5)
OUT1
(Note 13-5)
Request to
Send
(RTS)
Data Terminal
Ready
(DTR)
ADDR = 5 R/W Line Status r Error in
RCVR
FIFO
(Note 13-7)
Transmitter
Empty
(TEMT)
(Note 13-4)
Transmitter
Holding
Regis-ter
(THRE)
Break
Interrupt
(BI)
Framing
Error (FE)
Parity Error
(PE)
Overrun
Error (OE)
Data
Ready
(DR)
ADDR = 6 R/W MODEM Status r Data Carrier
Detect
(DCD)
Ring
Indica-tor
(RI)
Data Set
Ready
(DSR)
Clear to
Send
(CTS)
Delta Data
Carrier
Detect
(DDCD)
Trailing
Edge Ring
Indicator
(TERI)
Delta Data
Set Ready
(DDSR)
Delta Clear
to Send
(DCTS)
ADDR = 7 R/W Scratch r (Note 13-6) Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0
ADDR = 0
DLAB = 1
R/W Divisor Latch (LS) Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0
ADDR = 1
DLAB = 1
R/W Divisor Latch (MS) Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8
TABLE 13-2: TWO PIN SERIAL PORT (UART) REGISTER SUMMARY (CONTINUED)
REGISTER NAME
DLAB
(Note 13-1)
XDATAOFFSET
ADDRESS EC TYPE
2013 - 2016 Microchip Technology Inc. DS00001561C-page 135
SEC1110/SEC1210
13.7 Detailed Description of Accessible Runtime Registers
13.7.1 RECEIVE BUFFER REGISTER (RB)
13.7.2 TRANSMIT BUFFER REGISTER (TB)
13.7.3 INTERRUPT ENABLE REGISTER (IER)
The lower four bits of this register control the enables of the five interrupt sources of the Serial Port Interrupt. It is possible
to totally disable the interrupt system by resetting bits 0 through 3 of this register. Similarly, setting the appropriate
bits of this register to a high, selected interrupts can be enabled. Disabling the interrupt system inhibits the Interrupt Identification
Register and disables any Serial Port Interrupt out of the SEC1110 and SEC1210. All other system functions
operate in their normal manner, including the Line Status and MODEM Status registers. The contents of the Interrupt
Enable Register are described below.
UART_RX_DATA (DLAB=0)
(OFFSET 0X00 RESET=0X00) UART RECEIVED DATA
BIT NAME R/W DESCRIPTION
7:0 DATA R This register holds the received incoming data byte. Bit 0 is the least
significant bit, which is transmitted and received first. Received data
is double buffered; this uses an additional shift register to receive the
serial data stream and convert it to a parallel 8-bit word which is
transferred to the Receive Buffer Register. The shift register is not
accessible.
If enabled via IER0, an RX Buffer Register Interrupt is generated
when the buffer contains data to read. If the FIFOs are disabled, this
register is undefined after reset. If the FIFOs are enabled, this register
will return zero after a reset, if the RX FIFO is empty.
UART_TX_DATA (DLAB=0)
(OFFSET 0X00 RESET=0X00) UART TRANSMIT DATA
BIT NAME R/W DESCRIPTION
7:0 TX_DATA W This register contains the data byte to be transmitted. The transmit
buffer/TX Holding Register is double buffered, utilizing an additional
shift register (not accessible) to convert the 8-bit data word to a serial
format. This shift register is loaded from the Transmit Buffer when the
transmission of the previous byte is complete, and transmission is bit
0 first.
UART_INTERRUPT_EN (DLAB=0)
(OFFSET 0X01 RESET=0X00) UART INTERRUPT ENABLE
BIT NAME R/W DESCRIPTION
7:4 Reserved R Always read as 0
3 EMSI R/W This bit enables the MODEM Status Interrupt when set to logic 1. This
is caused when one of the Modem Status register bits DDCD, TERI,
DDSR or DCTS (MSR[3:0]) changes state.
2 ELSI R/W This bit enables the Received Line Status Interrupt when set to logic
1. The error sources causing the interrupt are overrun, parity, framing,
and break (LSR[4:1]). The Line Status Register must be read to
determine the source.
SEC1110/SEC1210
DS00001561C-page 136 2013 - 2016 Microchip Technology Inc.
13.7.4 FIFO CONTROL REGISTER (FCR)
13.7.5 INTERRUPT IDENTIFICATION REGISTER (IIR)
1 ETHREI R/W This bit enables the Transmitter Holding Register or the TX FIFO
becomes empty (i.e., LSA5 becomes set).
0 ERDAI R/W This bit enables the Received Data Available Interrupt (i.e., LSR.0
becomes set) or, if FIFOs are enabled, the RX Trigger Level is
reached. If the FIFOs are enabled, setting this bit also enabled the
RX FIFO Character Timeout Interrupt.
UART_FIFO_CTL (DLAB=X)
(OFFSET 0X02 RESET=0X00) UART FIFO CONTROL REGISTER
BIT NAME R/W DESCRIPTION
7:6 RECV_FIFO_TRIG R These bits are used to set the trigger level for the RCVR FIFO
Interrupt
Value (trigger level):
00 : 1 Bytes
01 : 4 Bytes
10 : 8 Bytes
11 : 14 Bytes
5:4 Reserved R/W Always read as 0
3 DMA_MODE_SEL R/W This bit, if set, enables DMA Mode for RX and TX. Two of the unused
USB endpoints must be configured for RX and TX, and PERIPHERAL
bits set appropriately as indicated in Section 11.16, "Endpoints 1~5
Buffer Registers," on page 111.
2 CLR_XMIT_FIFO W Setting this bit to a logic 1 clears all bytes in the XMIT FIFO and
resets its counter logic to 0. The shift register is not cleared. However,
this bit is self-clearing
1 CLR_RCV_FIFO W Setting this bit to a logic 1 clears all bytes in the RCVR FIFO and
resets its counter logic to 0. The shift register is not cleared. However,
this bit is self-clearing.
0 EXRF W Enable XMIT and RECV FIFO. Setting this bit to a logic 1 enables
both the XMIT and RCVR FIFOs. Clearing this bit to a logic 0
disables both the XMIT and RCVR FIFOs and clears all bytes from
both FIFOs. When changing from FIFO Mode to Non-FIFO (16450)
Mode, data is automatically cleared from the FIFOs. This bit must be
a 1 when other bits in this register are written to or they will not be
properly programmed.
Note: This is a write only register at the same location as the IIR.
UART_INT_ID (DLAB=X)
(OFFSET 0X02 RESET=0X01) UART INTERRUPT IDENTIFICATION REGISTER
BIT NAME R/W DESCRIPTION
7:6 FIFO_EN R These two bits are set when the FIFO CONTROL Register bit 0
equals 1
5:4 Reserved R Always read as 0
UART_INTERRUPT_EN (DLAB=0)
(OFFSET 0X01 RESET=0X00) UART INTERRUPT ENABLE
BIT NAME R/W DESCRIPTION
2013 - 2016 Microchip Technology Inc. DS00001561C-page 137
SEC1110/SEC1210
By accessing this register, the CPU can determine the highest priority interrupt and its source. Four levels of priority
interrupt exist. They are in descending order of priority as follows:
1. Receiver Line Status (highest priority)
2. Received Data Ready
3. Transmitter Holding Register Empty
4. MODEM Status (lowest priority)
Information indicating that a prioritized interrupt is pending and the source of that interrupt is stored in the Interrupt Identification
Register (Table 13-4). When the CPU accesses the IIR, the Serial Port freezes all interrupts and indicates the
highest priority pending interrupt to the CPU. During this CPU access, even if the Serial Port records new interrupts, the
current indication does not change until access is completed. The contents of the IIR are described below.
3:1 INTLD R These three bits of the IIR are used to identify the highest priority
interrupt pending as indicated by Table 13-4, "Interrupt Control Table". In Non-FIFO Mode, bit 3 is a logic 0. In FIFO Mode, bit 3 is set along
with bit 2 when a timeout interrupt is pending.
0 IPEND R This bit can be used in either a hardwired prioritized or polled
environment to indicate whether an interrupt is pending. When bit 0
is a logic 0, an interrupt is pending and the contents of the IIR may
be used as a pointer to the appropriate internal service routine. When
bit 0 is a logic 1, no interrupt is pending.
TABLE 13-4: INTERRUPT CONTROL TABLE
FIFO
MODE
ONLY
INTERRUPT
IDENTIFICATION
REGISTER INTERRUPT SET AND RESET FUNCTIONS
BIT 3 BIT 2 BIT 1 BIT 0
PRIORITY
LEVEL INTERRUPT TYPE
INTERRUPT
SOURCE
INTERRUPT
RESET CONTROL
0 0 0 1 - None None -
1 1 0 Highest Receiver Line
Status
Overrun Error,
Parity Error,
Framing Error or
Break Interrupt
Reading the Line
Status Register
0 Second Received Data
Available
Receiver Data
Available or RX
Trigger Level
reached
Read Receiver
Buffer or the RX
FIFO drops below
the trigger level.
1 Character Timeout
Indication
No characters have
been removed from
or input to the
RCVR FIFO during
the last 4 char
times and there is
at least 1 char in it
during this time
Reading the
Receiver Buffer
Register
0 0 1 Third Transmitter Holding
Register Empty
Transmitter Holding
Register Empty
Reading the IIR
Register (if source
of interrupt) or
writing the
Transmitter Holding
Register or TX
FIFO (if enabled)
0 0 Fourth MODEM Status Clear to Send or
Data Set Ready or
Ring Indicator or
Data Carrier Detect
Reading the
MODEM Status
Register
UART_INT_ID (DLAB=X)
(OFFSET 0X02 RESET=0X01) UART INTERRUPT IDENTIFICATION REGISTER
BIT NAME R/W DESCRIPTION
SEC1110/SEC1210
DS00001561C-page 138 2013 - 2016 Microchip Technology Inc.
13.7.6 LINE CONTROL REGISTER (LCR)
This register contains the format information of the serial line.
UART_LINE_CTL (DLAB=X)
(OFFSET 0X03 RESET=0X01) UART LINE CONTROL REGISTER
BIT NAME R/W DESCRIPTION
7 DLAB R/W Divisor Latch Access Bit (DLAB):
This bit must be set to logic 1 to access the Divisor Latches of the
Baud Rate Generator during read or write operations. It must be set
to logic 0 to access the Receiver Buffer Register, the Transmitter
Holding Register, or the Interrupt Enable Register.
6 BREAK_CTL R/W Set Break Control Bit:
When set to logic 1, the transmit data output (TXD) is forced to the
spacing or logic 0 state and remains there (until reset by a low level
bit 6) regardless of other transmitter activity. This feature enables the
Serial Port to alert a terminal in a communications system.
5 STICK_PARITY R/W Stick Parity Bit:
When enabled, this bit is used in conjunction with bit 4 to select Mark
or Space Parity. When LCR bits 3, 4 and 5 are 1, the parity bit is
transmitted and checked as a 0 (Space Parity). If bits 3 and 5 are 1
and bit 4 is a 0, then the parity bit is transmitted and checked as 1
(Mark Parity). If bit 5 is 0 Stick Parity is disabled.
If bit 3 is a logic 1 and bit 5 is a logic 1, the parity bit is transmitted
and then detected by the Receiver in the opposite state indicated by
bit 4.
4 PARITY_SEL R/W Even Parity Select Bit:
When bit 3 is a logic 1 and bit 4 is a logic 0, an odd number of logic
1s are transmitted or checked in the data word bits and the parity bit.
When bit 3 is a logic 1 and bit 4 is a logic 1 an even number of bits
are transmitted and checked.
3 PARITY_EN R/W Parity Enable Bit:
When bit 3 is a logic 1, a parity bit is generated (transmit data) or
checked (receive data) between the last data word bit and the first
stop bit of the serial data. (The parity bit is used to generate an even
or odd number of 1s when the data word bits and the parity bit are
summed).
2 STOP_BITS R/W This bit specifies the number of stop bits in each transmitted or
received serial character. Table 13-5, "Stop Bits" summarizes the
information.
1:0 WORD_LEN R/W These two bits specify the number of bits in each transmitted or
received serial character. The encoding of bits 0 and 1 is as follows:
Value (word length):
00 : 5 bits
01 : 6 bits
10 : 7 bits
11 : 8 bits
The start, stop and parity bits are not included in the word length
2013 - 2016 Microchip Technology Inc. DS00001561C-page 139
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13.7.7 MODEM CONTROL REGISTER (MCR)
This 8-bit register controls the interface with the MODEM or data set (or device emulating a MODEM). The contents of
the MODEM control register are described below.
TABLE 13-5: STOP BITS
BIT 2 WORD LENGTH
NUMBER OF
STOP BITS
0 -- 1
1 5 bits 1.5
6 bits 2
7 bits
8 bits
Note: The Receiver will ignore all stop bits beyond the first, regardless of the number used in transmitting.
UART_MODEM_CTL (DLAB=X)
(OFFSET 0X04 RESET=0X01) UART MODEM CONTROL REGISTER
BIT NAME R/W DESCRIPTION
7:5 Reserved R Always read as 0
4 LOOPBACK R/W This bit provides the loopback feature for diagnostic testing of the
Serial Port. When bit 4 is set to logic 1, the following occur:
1. The TXD is set to the Marking State (logic 1).
2. The Receiver Serial Input (RXD) is disconnected.
3. The output of the Transmitter Shift Register is looped-back into
the Receiver Shift register input.
4. All MODEM control inputs (nCTS, nDSR, nRI and nDCD) are
disconnected.
5. The four MODEM control outputs (nDTR, nRTS, OUT1 and
OUT2) are internally connected to the four MODEM control
inputs (nDSR, nCTS, RI, DCD).
6. The Modem control output pins are forced inactive high.
7. Data that is transmitted is immediately received.
This feature allows the processor to verify the transmit and receive
data paths of the Serial Port. In the Diagnostic Mode, the Receiver
and the Transmitter interrupts are fully operational. The MODEM
control interrupts are also operational but the interrupts' sources are
now the lower four bits of the MODEM Control Register instead of the
MODEM control inputs. The interrupts are still controlled by the
Interrupt Enable Register
3 OUT2 R/W Output 2 (OUT2):
This bit is used to enable a UART interrupt. When OUT2 is a logic 0,
the serial port interrupt output is forced to a high impedance state
(disabled). When OUT2 is a logic 1, the serial port interrupt outputs
are enabled.
2 OUT1 R/W This bit controls the Output 1 (OUT1) bit. This bit does not have an
output pin and can only be read or written by the CPU.
1 RTS R/W This bit controls the Request To Send (nRTS) output. Bit 1 affects the
nRTS output in a manner identical to that described above for bit 0.
SEC1110/SEC1210
DS00001561C-page 140 2013 - 2016 Microchip Technology Inc.
13.7.8 LINE STATUS REGISTER (LSR)
0 DTR R/W This bit controls the Data Terminal Ready (nDTR) output. When bit 0
is set to a logic 1, the nDTR output is forced to a logic 0. When bit 0
is a logic 0, the nDTR output is forced to a logic 1.
UART_LINE_STAT (DLAB=X)
(OFFSET 0X05 RESET=0X60) UART LINE STATUS REGISTER
BIT NAME R/W DESCRIPTION
7 FIFO_ERROR R This bit is permanently set to logic 0 in the 450 Mode. In the FIFO
Mode, this bit is set to a logic 1 when there is at least one parity error,
framing error, or break indication in the FIFO. This bit is cleared when
the LSR is read if there are no subsequent errors in the FIFO.
6 XMIT_ERROR R Transmitter Empty (TEMT):
This bit is set to a logic 1 whenever the Transmitter Holding Register
(THR) and Transmitter Shift Register (TSR) are both empty. It is reset
to logic 0 whenever either the THR or TSR contains a data character.
5 XMIT_EMPTY R Transmitter Holding Register Empty (THRE):
This bit indicates that the Serial Port is ready to accept a new
character for transmission. In addition, this bit causes the serial port
to issue an interrupt when the Transmitter Holding Register interrupt
enable is set high. The THRE bit is set to a logic 1 when a character
is transferred from the Transmitter Holding Register into the
Transmitter Shift Register. The bit is reset to logic 0 whenever the
CPU loads the Transmitter Holding Register. In the FIFO Mode this
bit is set when the XMIT FIFO is empty, it is cleared when at least 1
byte is written to the XMIT FIFO.
4 BREAK_INT R Break Interrupt (BI).:
This bit is set to a logic 1 whenever the received data input is held in
the Spacing state (logic 0) for longer than a full word transmission
time (that is, the total time of the start bit + data bits + parity bits +
stop bits). BI is reset after the CPU reads the contents of the Line
Status Register. In the FIFO Mode this error is associated with the
particular character in the FIFO it applies to. This error is indicated
when the associated character is at the top of the FIFO. When break
occurs only one zero character is loaded into the FIFO. Restarting
after a break is received, requires the serial data (RXD) to be logic 1
for at least 1/2 bit time.
Bits 1 through 4 are the error conditions that produce a Receiver Line
Status interrupt bit 3.
Note: Whenever any of the corresponding conditions are detected
and the interrupt is enabled.
3 FRAME_ERROR R Framing Error (FE):
This bit indicates that the received character did not have a valid stop
bit. Bit 3 is set to a logic 1 whenever the stop bit following the last
data bit or parity bit is detected as a zero bit (Spacing level). The FE
is reset to a logic 0 whenever the Line Status Register is read. In the
FIFO Mode this error is associated with the particular character in the
FIFO it applies to. This error is indicated when the associated
character is at the top of the FIFO. The Serial Port will try to
resynchronize after a framing error. To do this, it assumes that the
framing error was due to the next start bit, so it samples this start bit
twice and then takes in the data.
UART_MODEM_CTL (DLAB=X)
(OFFSET 0X04 RESET=0X01) UART MODEM CONTROL REGISTER
BIT NAME R/W DESCRIPTION
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13.7.9 MODEM STATUS REGISTER (MSR)
This 8-bit register provides the current state of the control lines from the MODEM (or peripheral device). In addition to
this current state information, four bits of the MODEM Status Register (MSR) provide change information.
These bits are set to logic 1 whenever a control input from the MODEM changes state. They are reset to logic 0 whenever
the MODEM Status Register is read. The bits DDCD, TERI, DDSR, and DCTS are also reset by writing a 1 to the
respective bit.
2 PARITY_ERROR R Parity Error (PE):
This bit indicates that the received data character does not have the
correct even or odd parity, as selected by the even parity select bit.
The PE is set to a logic 1 upon detection of a parity error and is reset
to a logic 0 whenever the Line Status Register is read. In the FIFO
Mode this error is associated with the particular character in the FIFO
it applies to. This error is indicated when the associated character is
at the top of the FIFO.
1 OVERRUN_ERROR R Overrun Error (OE):
This bit indicates that data in the Receiver Buffer Register was not
read before the next character was transferred into the register,
thereby destroying the previous character. In FIFO Mode, an overrun
error will occur only when the FIFO is full and the next character has
been completely received in the shift register. The character in the
shift register is overwritten but not transferred to the FIFO. The OE
indicator is set to a logic 1 immediately upon detection of an overrun
condition, and reset whenever the Line Status Register is read
0 DATA_READY R Data Ready (DR):
This bit is set to a logic 1 whenever a complete incoming character
has been received and transferred into the Receiver Buffer Register
or the FIFO. DR is reset to a logic 0 by reading all of the data in the
Receive Buffer Register or the FIFO
UART_LINE_STAT (DLAB=X)
(OFFSET 0X06 RESET=0BXXXX0000) UART MODEM STATUS REGISTER
BIT NAME R/W DESCRIPTION
7 DCD# R This bit is the complement of the Data Carrier Detect (nDCD) input.
If bit 4 of the MCR is set to logic 1, this bit is equivalent to OUT2 in
the MCR.
6 RI# R This bit is the complement of the Ring Indicator (nRI) input. If bit 4 of
the MCR is set to logic 1, this bit is equivalent to OUT1 in the MCR.
5 DSR R This bit is the complement of the Data Set Ready (nDSR) input. If bit
4 of the MCR is set to logic 1, this bit is equivalent to DTR in the MCR.
4 CTS R This bit is the complement of the Clear To Send (nCTS) input. If bit 4
of the MCR is set to logic 1, this bit is equivalent to nRTS in the MCR.
3 DDCD RW1 Delta Data Carrier Detect (DDCD):
Bit 3 indicates that the nDCD input to the chip has changed state.
2 TERI RW1 Trailing Edge of Ring Indicator (TERI):
Bit 2 indicates that the nRI input has changed from logic 0 to logic 1.
UART_LINE_STAT (DLAB=X)
(OFFSET 0X05 RESET=0X60) UART LINE STATUS REGISTER
BIT NAME R/W DESCRIPTION
SEC1110/SEC1210
DS00001561C-page 142 2013 - 2016 Microchip Technology Inc.
The Modem Status Register (MSR) only provides the current state of the UART MODEM control lines in Loopback
Mode. The SEC1110 and SEC1210 do not support external connections for the MODEM control inputs (nDSR, nRI and
nDCD) or for the four MODEM control outputs (nDTR, OUT1 and OUT2).
13.7.10 SCRATCHPAD REGISTER (SCR)
13.7.11 PROGRAMMABLE BAUD RATE GENERATOR (AND DIVISOR)
The incoming clock is divided by the value held in the DLL and DLM registers(1 - 65535) to produce the Baud Rate
Generator Output signal (BAUD).
1 DDSR RW1 Delta Data Set Ready (DDSR):
Bit 1 indicates that the nDSR input has changed state since the last
time the MSR was read.
0 DCTS RW1 Delta Clear To Send (DCTS):
Bit 0 indicates that the nCTS input to the chip has changed state
since the last time the MSR was read.
Note: Whenever bit 0, 1, 2, or 3 is set to a logic 1, a MODEM Status Interrupt is generated.
UART_RX_DATA (DLAB=X)
(OFFSET 0X07 RESET=0X00) UART SCRATCH PAD REGISTER
BIT NAME R/W DESCRIPTION
7:0 SCRATCH R/W This register has no effect on the operation of the Serial Port. It is
intended as a scratchpad register to hold data temporarily.
UART_DIV_LAT_LO (DLAB=1)
(OFFSET 0X00 RESET=0X01) UART DIVISOR LATCH LOW
BIT NAME R/W DESCRIPTION
7:0 BAUD_DIVISOR[7:0] R/W Least significant 8 bits of the baud rate divisor is stored here.
UART_DIV_LAT_HI (DLAB=1)
(OFFSET 0X01 RESET=0X00) UART SCRATCH PAD REGISTER
BIT NAME R/W DESCRIPTION
7:0 BAUD_DIVISOR[14:8] R/W Most significant 8 bits of the baud rate divisor is stored here.
Note: DLL and DLM can only be updated if the DLAB bit is set (1). Additionally, unlike the original device, division
by 1 generates a BAUD signal that is constantly high.
UART_LINE_STAT (DLAB=X)
(OFFSET 0X06 RESET=0BXXXX0000) UART MODEM STATUS REGISTER
BIT NAME R/W DESCRIPTION
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The table below shows the divisor needed to generate a given baud rate from CLOCK inputs of 48 MHz. The effective
clock enable generated is 16x the required baud rate. For clock frequencies (fCLOCK) not covered by this table, the
required divisor can be calculated as follows:
Divisor value = uart_clk / (16x desired baud rate)
DESIRED
BAUD RATE
DIVISOR USED TO GENERATE 16X
CLOCK PERCENT ERROR
50 60000 0.00
75 40000 0.000
110 27273 0.00
134.5 22305 0.00
150 20000 0.00
300 10000 0.00
600 5000 0.00
1200 2500 0.00
1800 1667 -0.02
2000 1500 0.00
2400 1250 0.00
3600 833 0.04
4800 625 0.00
7200 417 -0.08
9600 313 -0.16
19200 156 0.16
38400 78 0.16
57600 52 0.16
115200 26 0.16
250000 12 0.00
500000 6 0.00
1000000 3 0.00
3000000 1 0.00
DESIRED
BAUD RATE
DIVISOR USED TO GENERATE 16X
CLOCK PERCENT ERROR
9600 26 0.16
19200 13 0.16
38400 7 -6.99
SEC1110/SEC1210
DS00001561C-page 144 2013 - 2016 Microchip Technology Inc.
13.7.12 UART CONFIGURATION SELECT REGISTER
UART_CTL1
(OFFSET 0X31 RESET=0X00) UART CONTROL REGISTER
BIT NAME R/W DESCRIPTION
7:4 Reserved R Always read as 0
3 baud_clk_src_alt R/W This bit must be 0.
2 POLARITY R/W 1 : UARTsin_outand UARTsin_in pins functions are inverted.
0 : UARTsin_outand UARTsin_in pins functions are not inverted.
1 power R/W This bit must be 0.
0 baud_clk_src R/W This bit must be 0.
This divider in CRM block is bypassed so that uart_clk directly goes
to the Inventra core when divisor is 1.
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14.0 SERIAL PERIPHERAL INTERCONNECT (SPI1) - MASTER
The SPI1 module allows full-duplex, synchronous, and serial communication between the EC and off-chip peripherals,
including other micro controllers (MCU).
The module works as a Master device.
The SPI_MS provides the following features:
The embedded controller has the following timers:
• Full Duplex Mode
• Three wire synchronous transfers
• Master Mode
• Seven SPI1 Master baud rates
• Serial clock with programmable polarity and phase
• Master Mode fault error flag with MCU interrupt capability
• Write collision flag protection
• 8-bit data transmitted Most Significant Bit (MSB) first, Least Significant Bit (LSB) last or the other way around
• 1-bit Slave Select Output port to control external slave devices
• Special function registers interface to the 8051 CPU
• No bi-directional ports; standard SPI pins to be externally connected to 3-state buffers, through the GPIO Auxiliary
ports
The component communicates with host microprocessor through SFR interface and INT interface (i.e., intspi). Communication
with other off-chip devices is realized through the TR interface (i.e., mosi: group/SPI1_MOSI, miso:
group/SPI1_MISO, sck: group/SPI1_CLK, ssn: /SPI1_CE_N).
The functional blocks of SPI_MS module are INT, SFR, TR blocks.
The SFR sub-block controls the write/read operations on SFR registers of SPI_MS module. It contains the following:
• Address decoder
• SFR registers, described in SPCON, SPSTA, SPDAT
• Output multiplexer
The TR block controls the SPI transmission process. It is composed of the following:
• The Finite State Machine which plays a key role in operation of the SPI_MS module; it controls the Master functionality
• System clock counter/divider, which is used to generate the SPI Master clock scko (SPI1_CLK); the Master clock
is selected from one of seven clock rates: the spi1_clk clock divided by 2, 4, 8, 16, 32, 64 or 128
• Transmission end detector
• Level and falling edge detector on ssn (SPI1_CE_N) input pin
• Data shift register
The INT block generates interrupt request upon spif and modf flags. The spif flag is when the transmission is finished
and the modf bit is set when the level on SPI1_CE_N input is in conflict with actual Mode, i.e., it is 0 in Master Mode (if
ssdis=0).
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DS00001561C-page 146 2013 - 2016 Microchip Technology Inc.
14.1 SPI1 Master Mode
In Master Mode (the mstr bit of SPCON Register is set) the SPI1 block waits on write operation to the SPDAT Register.
If write operation to the SPDAT Register is done, transmission is started. Data shifts out on the SPI1_MOSI output pin
at the SPI1_CLK serial clock output transition (send_edge). Simultaneously, another data byte shifts in from the Slave
on Master's SPI1_MISO input pin (capture_edge).
Depending on the settings of SPI1 module, the bits of data are sent in turn on rising edge (cpol= 0) or on falling edge
(cpol=1) of Master clock SPI1_CLK. Data are received at the falling edge (cpol=0) or rising edge (cpol=1) of Master
clock (scko). This applies either for Master or Slave Transmitter/Receiver, assuming that SPI1_CLK is the main clock
of the transmission. If cpha bit is set, the first bit (MSB) will be sent on the SPI1_MOSI output/SPI1_MISO output at the
first active edge of SPI1_CLK. If cpha bit is cleared, the first bit (MSB) will be sent half a period of SPI1_CLK signal
before active edge of this signal. In addition, the data input (SPI1_MISO) is sampled in the half of each bit transmitted,
at the opposite edge of the clock at which data are shifted out to SPI1_MOSI output.
FIGURE 14-1: SPI1 MASTER BLOCK DIAGRAM
spssn
spsta
spcon
spdat
SFR bus
intspi1
SPI1_MISO_in
SPI1_MOSI_in
SPI1_MISO_out
SPI1_MOSI_out
Spi_FSM
ctrl_shift_reg ctrl_send
clk_div
scki_edge_detect
ss_detect
tri_state_ctrl
SPI1_MOSI_oe_n
SPI1_MISO_oe_n
SPI1_CLK_oe_n
SPI1_CLK_out
SPI1_CLK_in
SPI1_CE_N
SFR
TR
Int_ctrl
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In Master Mode the SPCON Register is written to the setting desired. In this Mode, mstr=1, ssdis=0, spen=1, cpha=x,
cpol=x and spr[2:0] indicate the baud rate. Setting the spen bit, enables the SPI1_CE_N to be driven (assuming GPIO
is configured in SPI1 Mode). Then the SPI1 block waits on write operation to the spdat Register. If write operation to the
spdat Register is done, transmission is started (SPI1_MOSI pad is enabled). Data shifts out on the SPI1_MOSI pin at
the SPI1_CLK serial clock transition (send_edge). Simultaneously, another data byte shifts in from the Slave on Master's
misoi pin (capture_edge).
FIGURE 14-2: SPI1 DATA FORMAT IN MASTER MODE (CPHA=0, CPOL=0)
1st Capture edge
SPI1_CLK
S7 S6 S5 S4 S3 S2 S1 S0
Send edge
SPI1_MISO
M7 M6 M5 M4 M3 M2 M1 M0
MOSI enabled
SPI1_MOSI
ref_clk 48 MHz
spi1_clk 48 MHz
Last Capture edge
cpu_clk
4 MHz
spdat write
Bits mstr=1, spen=1, cpha=0, cpol=0, spr[2:0]=001
SPI1_CE_N
MOSI disabled
spif set
shift
Master
SEC1110/SEC1210
DS00001561C-page 148 2013 - 2016 Microchip Technology Inc.
FIGURE 14-3: SPI1 DATA FORMAT IN MASTER MODE (CPHA=0, CPOL=1)
FIGURE 14-4: SPI1 DATA FORMAT IN MASTER MODE (CPHA=1, CPOL=0)
1st Capture edge
SPI1_CLK
SPI1_MOSI
ref_clk 48 MHz
spi1_clk 48 MHz
Last Capture edge
cpu_clk
4 MHz
Bits mstr=1, spen=1, cpha=1, cpol=0, spr[2:0]=001
SPI1_CE_N
spif set
shift
Master
S7 S6 S5 S4 S3 S2 S1 S0
Send edge
SPI1_MISO
MOSI enabled
X
MOSI disabled
M7 M6 M5 M4 M3 M2 M1 M0
spdat write
1st Capture edge
SPI1_CLK
SPI1_MOSI
ref_clk 48 MHz
spi1_clk 48 MHz
Last Capture edge
cpu_clk
4 MHz
Bits mstr=1, spen=1, cpha=1, cpol=0, spr[2:0]=001
SPI1_CE_N
spif set
shift
Master
S7 S6 S5 S4 S3 S2 S1 S0
Send edge
SPI1_MISO
MOSI enabled
X
MOSI disabled
M7 M6 M5 M4 M3 M2 M1 M0
spdat write
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SEC1110/SEC1210
FIGURE 14-5: SPI1 DATA FORMAT IN MASTER MODE (CPHA=1, CPOL=1)
1st Capture edge
SPI1_CLK
SPI1_MOSI
ref_clk 48 MHz
spi1_clk 48 MHz
Last Capture edge
cpu_clk
4 MHz
Bits mstr=1, spen=1, cpha=1, cpol=1, spr[2:0]=001
SPI1_CE_N
spif set
shift
Master
S7 S6 S5 S4 S3 S2 S1 S0
Send edge
SPI1_MISO
MOSI enabled
X
MOSI disabled
M7 M6 M5 M4 M3 M2 M1 M0
spdat write
SEC1110/SEC1210
DS00001561C-page 150 2013 - 2016 Microchip Technology Inc.
15.0 CLOCK AND RESET
This block generates all the clocks for the CPU and sub-system peripherals. It also has the control registers needed for
oscillator testing and power controls. The block diagram of this block is shown in Figure 15-1.
FIGURE 15-1: Clock Generation
UDC
OSC48_CTL,
OSC32KHZ_CTL
OSC_STABLE
OSC_MODE OSC 4/
48Mhz
4~48 MHz
EN
REF_CLK
UART
SPI1
*_CLK_EN
USB_CLK_EN
UART_CLK_EN
SPI1_CLK_EN
8051 cpu_clk
clkper
clkcpuen,
clkperen
WAKE
UP WAKE SIGNAL
XDATA bus
LOGIC
BLOCK
DEFINED
REGISTER
Code
ROM,
OTP
ERAM
xdata bus
TEST_LAT |
CFG_DEBUG
EXT_CLK_48MHZ
S
÷
÷
E Q E Q
÷
usb_clk_4x
uart_clk
spi1_clk
mem_clk
cpu_clk
÷
Program
bus
dma bus
DEBUG
ONLY
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15.1 Reset
The following are the reset sources to the chip:
• Internal power on reset from voltage level detector.
• Exit from STOP Mode (low pulse on RESET_N pad). The regulators are off in STOP Mode, and this is similar to
power on reset.
• Watchdog timer overflow occurs.
• Reset from debug OCDS unit (through JTAG) is received.
• A software reset will be generated after two consecutive 1 value writes to the srstreq bit in the srst register (0F7h).
On the above reset events, the following occurs:
1. All registers are set to their default values.
2. All endpoints are disabled.
3. If the SEC1110 or SEC1210 was in the power down state, then it is cleared.
4. All peripheral IOs: SPI1, SPI2, UART, USB, SC1, SC2, and GPIOs go to their reset state.
A reset from debug OCDS unit (through JTAG) resets only the 8051 and SFR peripherals.
15.2 Oscillator
The internal oscillator frequency is 4 or 48 MHz. If the oscillator is turned off, a wake-up event (USB wake-up or GPIO
activity) can be programmed to start it. Once it has started, the 8051 can turn it off manually through the OSC48_CTL
Register.
15.2.1 SYSTEM CLOCK SHUTDOWN
To shutdown the 48 MHz oscillator, the 8051 clears the OSC_MODE2 bit.
15.2.2 SYSTEM CLOCK WAKE-UP
If the oscillator is turned off, a wake-up event can be programmed to start it. The WakeOn Event block enables various
wake-up events such as USB, or GPIO activity. When a wake-up event is detected, the following happens:
1. The system clock source is indicated by OSC48_SEL[1:0] bits. In case of 48 MHz oscillator selection, the OSC_-
MODE[1:0] bits indicate the frequency selected, before clock shutdown.
2. The hardware waits for the selected oscillator source to settle down.
3. Once the clock is stable, the system clock is enabled to the CPU sub-system. If the CPU sub-system was powered
down, then the CPU executes out of reset. If the CPU sub-system was powered but in a low-power state,
then the CPU resumes executing instructions, from where it was suspended.
4. If it was a USB wake-up event, the firmware will receive a USB_WU_INT interrupt from USB.
5. Firmware must ensure that the clocks to synchronous devices are enabled before accessing them.
6. Non-synchronous devices can be accessed at any time.
If the chip was expected to respond to a USB wake-up event, then the firmware must have selected the 48 MHz oscillator
before going to suspend. If fast response to a wake-up event is not required, then the firmware selects the low
frequency modes of the oscillator before going to suspend.
15.3 CLK_PWR Registers Summary
The register addresses indicated below are offset address to XDATA base memory address 0xA000.
TABLE 15-1: CLK_PWR REGISTER MAP
REGISTER NAME XDATA ADDRESS EC TYPE
OSC48_CTL 0x00 R/W
OSC48_SETTLE_CLKS 0x01 R/W
OSC32KHZ_CTL 0x02 R/W
OSC_TEST_REGS 0x03 ~ 0x09 R/W
MEM_CLK_DIV 0x0A R/W
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15.4 Oscillator Registers
15.4.1 OSCILLATOR CONTROL REGISTER
CPU_CLK_DIV 0x0B R/W
USB_CLK_CTL 0x0C R/W
UART_CLK_DIV 0x0D R/W
SPI1_CLK_DIV 0x0E R/W
SPI2_CLK_DIV 0x0F R/W
SC1_CLK_DIV 0x10 R/W
SC2_CLK_DIV 0x11 R/W
WOE_CTL 0x12 R/W
WOE_STS 0x13 R/W
POWER_STS1 0x14 R/W
POWER_CTL1 0x15 R/W
POWER_CTL2 0x16 R/W
POWER_STS2 0x17 R/W
OTP_CFG 0x18 R/W
Reserved 0x19~0x1A R
CLKPWR_VERSION 0x1B R
Reserved 0x1C~0x1F R
CLKPWR_TEST1 0x20 R/W
CLKPWR_TEST2 0x21 R/W
CLKPWR_TEST3 0x22 R/W
CLKPWR_TEST4 0x23 R
OSC4_FTRIM_LSB 0x26 R/W
OSC4_FTRIM_MSB 0x27 R/W
TABLE 15-2: OSCILLATOR 48 MHZ CLOCK CONTROL REGISTER
OSC48_CTL
(0X000~0X000 – RESET=0X00 OR 0X03) OSCILLATOR CONTROL REGISTER
BIT NAME R/W DESCRIPTION
7 EXT_OSC_SLEEP R/W If in external 48 MHz oscillator setting this bit enters Sleep Mode,
where the clock is gated.
6 OSC_DTRIM R/W When this bit is set, it enables the dynamic tuning of the internal
oscillator. The USB interface must also be enabled.
0 : Disable dynamic tuning (default)
1 : Enable dynamic tuning
TABLE 15-1: CLK_PWR REGISTER MAP (CONTINUED)
REGISTER NAME XDATA ADDRESS EC TYPE
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SEC1110/SEC1210
There are two primary sources of clock to the chip, the external or internal 48 MHz oscillator. Note that the external oscillator
input is disabled in production parts and is used for test only. The internal oscillator operates in 3 modes as indicated
by the OSC_MODE bits, at 48 MHz, 4 MHz or Sleep Mode. The above bits (OSC48_SEL and OSC_MODE) select
the clock named reference clock (ref_clk).
The default after power on reset or exiting STOP Mode or deassertion of RESET_N is to use the internal oscillator at
4 MHz. After reset is released (the later of power on reset or external RESET_N signal), the Clock and Reset block waits
for the oscillator to be stable. The settling times of the oscillator may be changed by writing to the OSC48_SETTLE_-
CLKS Register. This settling time is also used when the OSC48_SEL0 bit is reset or OSC_MODE[1:0] bits are changed.
In normal functional mode, the oscillator operates in 48 MHz mode, and the firmware can switch from 4 MHz to 48 MHz.
This mode is required for accurate timing reference, to operate peripheral blocks such as USB, UART, SPI1, SPI1, and
SC1. If the peripheral blocks such as USB, UART, SPI1, SPI2, and SC1 are not enabled, then Low Power Mode may
be entered by selecting OSC_MODE[2:0]=000b. In this mode, the oscillator output is approximately 4 MHz.
The reference clock is running in 8051 IDLE and STOP modes. If the oscillator source needs to be shutdown in Lower
Power Mode, then the firmware must write a one to the OSC_MODE2 bit.
5:3 OSC_MODE[2:0] R/W These bits indicate the mode of the internal oscillator. Bit 2 indicates
if the 48 MHz oscillator is in Sleep Mode. Bits 1:0 indicate the mode
of the 48 MHz internal oscillator.
000 : The oscillator is enabled in low power state and outputs
4 MHz. This setting is default when the external oscillator is not
selected (OSC48_SEL=0).
001 : Reserved.
010 : The oscillator is enabled and outputs 48 MHz
011/111 : Reserved in SEC1110/SEC1210. When Bit 2 is also set,
the 111 code indicates that the Oscillator is powered, but its output
is gated to lower power consumption. The OSC_MODE[1:0] bits are
not updated when OSC_MODE[2:0] is written with 111, thus
preserving the oscillator frequency mode. This feature is used when
instant start up time is required out of sleep modes.
Bit 2 = 1: The internal 48 MHz oscillator is in Sleep Mode. An
external event from the WIC block can enable the oscillator if the
OSC48_SEL0 bit is 0. On wake-up, the oscillator powers up to
48 MHz or 4 MHz depending on OSC_MODE[1:0] setting, after
settling time.
When OSC_MODE[1:0] bits are changed (and OSC_MODE2=0), the
clocks are gated until the oscillator setting time.
If External Oscillator Mode is selected, then the internal oscillator is
powered down automatically except when Trimming (OSC_DTRIM) is
enabled. In this case, the OSC_MODE[2:0] bits cannot be changed
when OSC48_SEL0 bit is set
2:1 OSC48_SEL[1:0] R/W These bits indicate the oscillator selection.
00 : Internal 48 MHz oscillator selected, and oscillator clocks is seen
after settling time.
01 : External 48 MHz oscillator selected. This state can be written to
only if EXT_OSC48_PRESENT is 1.
10 : Reserved
11 : Reserved.
0 EXT_OSC48_PRESENT R This bit indicates if external oscillator is connected.
0 : (default) No external oscillator.
1 : External 48 MHz oscillator connected
Note: In the SEC1110 and SEC1210 chips, the 32.768 kHz oscillator is not present.
TABLE 15-2: OSCILLATOR 48 MHZ CLOCK CONTROL REGISTER (CONTINUED)
SEC1110/SEC1210
DS00001561C-page 154 2013 - 2016 Microchip Technology Inc.
15.4.2 OSCILLATOR 48 MHZ SETTLE TIME REGISTER
The reset value of this register, after the following events, is 0x0A (100 s for 48 MHz):
• Power on reset, or RESET_N release
• Exit from STOP Mode
This value may be changed by firmware to 0x5 (50 s) before entering low power modes, in which the 48 MHz oscillator
is used after a wake-up event.
15.4.3 OSCILLATOR 32 KHZ REGISTERS
The 32.768 Khz Oscillator can be shutdown under the following conditions:
• When the reference clock (ref_clk) is in 4/8/48 Mhz mode and RTC and LCD are not enabled, and core regulators
are not going to be powered down (PWR_CORE_DIS[2:0]=000).
• When the reference clock is in 32.768 Khz mode, then resetting OSC32KHZ_ENABLE powers down this oscillator.
• When reference clock is in 32.768 Khz mode, and any of the PWR_CORE_DIS[2:0] bits are set and
OSC32KHZ_ENABLE bit is reset.
TABLE 15-3: OSCILLATOR 48 MHZ SETTLING TIME
OSC48_SETTLE_CLKS
(0X001~0X001 – RESET=0X0A) OSCILLATOR 48MHZ SETTLE TIME REGISTER
BIT NAME R/W DESCRIPTION
7 DEBOUNCE_CLK_EN R/W This bit if set, it enables a 100 kHz or 1 kHz debounce clock.
6 DEBOUNCE_FREQ R/W 0 : 1 kHz debounce clock
1 : 100 kHz debounce clock
5 A1_COMPATIBLE R/W In the SEC1110/SEC1210 version, this bit is always 0.
In other versions,
0: indicates the GPIO block runs off cpu_clk, and if the 8051 is in
CPU_IDLE state. The GPIO debounce feature would not function,
since cpu_clk is gated.
1: indicates the GPIO block runs off cpu_per_clk. Therefore, if the
8051 is in CPU_IDLE state, the GPIO debounce feature functions
normally.
4:0 OSC48_SETTLE_CLKS R/W This field indicates the time to wait before the internal oscillator is
stable at 48 MHz. Each increment of this field is approximately,
480 * (1/48) = 10 s, when OSC48_SEL1 is 0 (48 MHz).
The settling time is OSC48_SETTLE_CLKS * 10 s.
The default settling time is 100 s.
TABLE 15-4: OSCILLATOR 32 KHZ CLOCK CONTROL REGISTERS
OSC32KHZ_CTL
(0X002~0X002 - RESET=0X00) OSCILLATOR 32KHZ CONTROL REGISTER
BIT NAME R/W DESCRIPTION
7:4 Reserved R Always read as 0
3:2 Reserved R Always read as 0
1 Reserved R Always read as 0
0 OSC32KHZ_PRESENT R Always read as 0
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SEC1110/SEC1210
15.4.4 OSCILLATOR TEST REGISTERS
15.4.5 MEMORY CLOCK DIVIDE REGISTER
The reset value of this register, after the following events is 12:
• Power on reset, or RESET_N release
• Exit from STOP Mode
When the 48 MHz (or 4 MHz) oscillator (external or internal) is used, the memory clock frequency is 4 MHz
(333.33 kHz). The memory bandwidth of on-chip ERAM is shared by the CPU, and by the peripherals such as USB,
SPI1 or UART. The CPU clock is derived from memory clock, and both run at the same frequency after reset. This
ensures that the CPU would have zero wait states accessing on-chip ERAM. But if other peripherals such as USB, SPI1
or UART are enabled, then the CPU clock must be lower than the memory clock frequency to avoid wait states to onchip
ERAM.
If the USB block is enabled, then the memory clock frequency must be a minimum 8 MHz. The valid values of MEM_-
CLK_DIV with respect to divide factors of other peripherals is shown in Section 15.6, "Valid Clock Frequencies," on
page 162.
TABLE 15-5: OSCILLATOR TEST REGISTERS
OSC_TEST_REGS
(0X003~0X009) - RESET=0XXX) OSCILLATOR TEST REGISTER
BIT NAME R/W DESCRIPTION
7:0 Reserved R/W These bits are reserved for test and must not be written to. Writes
to this register may cause the part to be inoperable.
TABLE 15-6: MEMORY CLOCK DIVIDE REGISTER
MEM_CLK_DIV
(0X00A~0X00A – RESET=0X0C) MEMORY CLOCK DIVIDER REGISTER
BIT NAME R/W DESCRIPTION
7:4 Reserved R Always read as 0
3:0 MEM_CLK_DIV[3:0] R/W This field indicates the divide factor of the reference clock (48 MHz
or 4 MHz), to generate the CPU clock.
The Clock and Reset blocks stop the memory clock, and
consequently any clock derived from the memory clock. temporarily
when this register is written to, and before enabling the clock to the
new frequency. A value of zero indicates 16.
The default divide factor is 12.
mem_clk = ref_clk/MEM_CLK_DIV
Note: In the SEC1110/SEC1210 version, before updating the CPU_CLK_DIV register the MEM_CLK_DIV register
should be changed to 2 or higher first followed by writing to the CPU_CLK_DIV register. This is to avoid
Anomaly 4: writing to the CPU_CLK_DIV register when the MEM_CLK_DIV register is equal to 1 causes
the SRAM to malfunction. This anomaly is fixed in later SEC1110/SEC1210 versions.
SEC1110/SEC1210
DS00001561C-page 156 2013 - 2016 Microchip Technology Inc.
15.4.6 CPU CLOCK DIVIDE REGISTER
The reset value of this register, after the following events is 1:
• Power on reset, or RESET_N release
• Exit from STOP Mode
When the 48 MHz oscillator (external or internal) is used, the memory and CPU clock frequencies are 4 MHz. If other
peripherals such as USB, SPI1 or UART are enabled, then the CPU clock must be lower than memory clock frequency
to avoid wait states to on-chip ERAM.
The Clocks block generates a CPU phase signal with respect to the memory clock. Hence at least one slot of the memory
bandwidth is allocated to the CPU. The ERAM memory arbiter uses other slots of memory bandwidth for all peripherals
such as USB, SPI1, UART first. The CPU slot is used by the peripherals only in the worst case, when bandwidth
is insufficient. The CPU is held in wait if an access occurs at the same time, in such a case.
The valid values of CPU_CLK_DIV with respect to divide factors of other peripherals is shown in Table 15-16, “Valid Clock
Frequencies,” on page 162.
When reference clock is same as CPU_CLK/MEM_CLK, any change to CPU_CLK_DIV, MEM_CLK_DIV,
(SPI1/SPI2/UART/USB/SC1/SC2)_CLK_DIV registers requires 10 CPU clocks to take effect before any peripheral is
accessed, or other clock divider register is accessed.
To decrease the mem_clk frequency, then mem_clk_div must be written first and cpu_clk_div second. To increase the
mem_clk frequency, then cpu_clk_div needs to be written first, and then mem_clk_div. This will ensure that cpu_clk does
not exceed the maximum supported frequency.
The CPU peripheral clock is used by the 8051 CPU and internal peripherals such as Timer 0, Timer 1, Timer 2, WDT,
and GPIO blocks. The peripherals UART, SPI1, SPI2 (TraceFIFO), and USB also use the CPU clock for their register
interface. However, these peripherals also have separate IO function clocks.
After a reset event (power on reset, STOP Mode, soft resets such as watchdog timeout, or OCDS), the OTP is read to
determine the security configuration. Next, the reset to the CPU sub-system is released.
The cpu_clk is gated in 8051 CPU_IDLE Mode, but the internal 8051 peripherals (Timer 0, Timer 1, Timer 2) and GPIO
blocks are receiving cpu_clkper.
Both the cpu_clk and cpu_clkper are gated in 8051 CPU_STOP mode. Here the clocks to the external peripherals SPI1,
SPI2, UART, USB, SC1, SC2, etc. may have clocks running based on their clock enable bits. An interrupt from these
peripherals can wake up the CPU. If the external peripherals also have their clocks disabled, then only an external event
from the chip can wake-up the CPU.
This external event could be from GPIO blocks (if enabled) or USB resume.
TABLE 15-7: CPU CLOCK DIVIDE REGISTER
CPU_CLK_DIV
(0X00B–0X00B RESET=0X01) CPU CLOCK DIVIDER REGISTER
BIT NAME R/W DESCRIPTION
7 Reserved R Always read as 0
6 Reserved R Always read as 0
5 Reserved R Always read as 0
4:2 Reserved R Always read as 0
1:0 CPU_CLK_DIV[1:0] R/W This field indicates the divide factor of the reference clock(48 MHz or
4 MHz), to generate the CPU clock.
The Clock and Reset blocks stop the CPU clock, and the 8051
peripheral clock (clkper) temporarily when this register is written to,
and before enabling the clock to the new frequency.
The default divide factor is 1. A value of 0 indicates 4.
cpu_clk = mem_clk/CPU_CLK_DIV)
2013 - 2016 Microchip Technology Inc. DS00001561C-page 157
SEC1110/SEC1210
Note 1: In SEC1110/SEC1210 version, when writing to the CPU_CLK_DIV register when the MEM_CLK_DIV register
is equal to 1, causes the SRAM to malfunction. Before updating the CPU_CLK_DIV register the MEM_-
CLK_DIV register should be changed to 2 or higher first followed by writing to the CPU_CLK_DIV register.
This Anomaly 4 errata is fixed in later versions.
2: In SEC1110/SEC1210 silicon, the CPU_CLK_DIV value of 0, indicating divide by 4, must not be used. This
Anomaly 20 errata is fixed in later versions.
15.4.7 USB CLOCK REGISTER
The USB must be enabled by firmware only when the 48 MHz oscillator (external or internal) is used (OSC_MODE=010b
and OSC48_SEL=00b or 01b).
The firmware need not reset the USB_CLK_EN bit, before entering USB suspend.The hardware shuts off the USB clocks
automatically when PWR_CORE_DIS0 is set. In this case, on resumption from USB suspend, as detected by the Wake
on Event registers, the hardware would re-enable the USB clocks to continue USB operations.
15.4.8 UART CLOCK REGISTER
TABLE 15-8: USB CLOCK REGISTER
USB_CLK_CTL
(0X00C~0X00C – RESET=0X00) USB CLOCK REGISTER
BIT NAME R/W DESCRIPTION
7 USB_CLK_EN R/W When this bit is set, it enables the reference clock (48 MHz if
selected) to the USB block. It also supplies a further divide by 4 clock
(12 MHz) to the SIE engine. This bit must be enabled for a USB
resume condition (normal resume or remote wake-up).
The default value is 0.
The clocks to the USB block can be halted by resetting this bit,
without resetting the USB block (controlled by USB_RESET).
6 USB_RESET R/W This bit when set, resets the USB SIE block.
5 USB_PHY_SUSPEND R/W When this bit is set, it forces the USB PHY to into Suspend Mode.
This bit may be used to reduce power consumption of the PHY, if
USB is not used.
This bit is absent in SEC1110/SEC1210 but is present in later
versions.
4:0 Reserved R Always read as 0
TABLE 15-9: UART CLOCK REGISTER
UART_CLK_DIV
(0X00D~0X00D – RESET=0X01) UART CLOCK DIVIDER REGISTER
BIT NAME R/W DESCRIPTION
7 UART_CLK_EN R/W When this bit is set, it enables the reference clock after division by
UART_CLK_DIV to the USB block.
The default value is 0.
The clocks to the UART block can be halted by resetting this bit,
without resetting the UART block (controlled by UART_RESET).
6 UART_RESET R/W When this bit is set, it resets the UART block.
5:0 UART_CLK_DIV R/W This field indicates the division factor to reference clock (48 MHz if
selected), to generate uart_clk. The frequency however must be a
multiple of the cpu_clk frequency, which is enforced by software.
The default value is 1.
uart_clk = ref_clk/UART_CLK_DIV, with the constraint
MEM_CLK_DIV * CPU_CLK_DIV = UART_CLK_DIV * U, where U is
an integer.
SEC1110/SEC1210
DS00001561C-page 158 2013 - 2016 Microchip Technology Inc.
The frequency selected for the UART block depends on the maximum baud rate desired. For low baud rates such as
9600, and 19200 a UART clock frequency of 4 MHz (cpu_clk) is sufficient. But for higher baud rates, the UART clock
frequency must be 16 MHz or higher.
In Clock Bypass Mode (i.e., ref_clk = mem_clk = clk_clk since MEM_CLK_DIV=1 and CPU_CLK_DIV=1), any write to
enable the USB_CLK_DIV Register would require 10 CPU clocks for the UART clocks to be enabled again, after
UART_RESET is reset or UART_CLK_EN is set. Hence, the UART block must not be accessed during this time.
15.4.9 SPI1 CLOCK REGISTER
The SPI1 port is the functional Master SPI interface. The frequency selected for the SPI1 block depends on the maximum
baud rate desired.The SPI1 baud rate maximum is half the spi1_clk frequency. For low baud rates a SPI1 clock
frequency of 4 MHz is sufficient. But for higher baud rates, the SPI1 clock frequency must be higher.
In Clock Bypass Mode (i.e., ref_clk = mem_clk = clk_clk since MEM_CLK_DIV=1 and CPU_CLK_DIV=1), any write to
enable the SPI1_CLK_DIV Register would require 10 CPU clocks for the SPI1 clocks to be enabled again, after
SPI1_RESET is reset or SPI1_CLK_EN is set. Hence the SPI1 block must not be accessed during this time.
15.4.10 SPI2 CLOCK REGISTER
TABLE 15-10: SPI1 CLOCK REGISTER
SPI1_CLK_DIV
(0X00E~0X00E – RESET=0X01) SPI1 CLOCK DIVIDER REGISTER
BIT NAME R/W DESCRIPTION
7 SPI1_CLK_EN R/W When this bit is set, it enables the reference clock after division by
SPI1_CLK_DIV to the SPI1 block.
The default value is 0.
The clocks to the SPI1 block can be halted by resetting this bit,
without resetting the SPI1 block (controlled by SPI1_RESET).
6 SPI1_RESET R/W When this bit is set, it resets the SPI1 block.
5:0 SPI1_CLK_DIV R/W This field indicates the division factor to reference clock (48 MHz if
selected), to generate the spi1_clk. The frequency, however, must be
a multiple of the cpu_clk frequency, which is enforced by software.
The default value is 1.
spi1_clk = ref_clk/SPI1_CLK_DIV, with the constraint
MEM_CLK_DIV * CPU_CLK_DIV = SPI1_CLK_DIV * SP1, where
SP1 is an integer.
TABLE 15-11: SPI2 CLOCK REGISTER
SPI2_CLK_DIV
(0X00F~0X00F – RESET=0X0C/0X8C/
0X01/0X81)
SPI1 CLOCK DIVIDER REGISTER
BIT NAME R/W DESCRIPTION
7 SPI2_CLK_EN R/W When this bit is set, it enables the reference clock after division by
SPI2_CLK_DIV to the SPI2 block.
The default value is 0. The default is 1 if configured to execute out
of External SPI as indicated in TABLE 7-1: Code Execution Truth
Table on page 21 This occurs if BOND2 pin is high in Debug
package.
The clocks to the SPI2 block can be halted by resetting this bit,
without resetting the SPI2 block (controlled by SPI2_RESET).
6 SPI2_RESET R/W When this bit is set, it resets the SPI2 block.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 159
SEC1110/SEC1210
The SPI2 port is the Master SPI interface for external program space execution and instrumentation trace used in Debug
Mode. The frequency selected for the SPI1 block depends on the maximum baud rate desired. For low baud rates a
SPI2 clock frequency of 4 MHz is sufficient. But for higher baud rates, the SPI2 clock frequency must be higher.
In Clock Bypass Mode (i.e., ref_clk = mem_clk = clk_clk since MEM_CLK_DIV=1 and CPU_CLK_DIV=1), any write to
enable the SPI2_CLK_DIV Register would require 10 CPU clocks for the SPI2 clocks to be enabled again, after
SPI1_RESET is reset or SPI1_CLK_EN is set. Hence the SPI2 block must not be accessed during this time.
15.4.11 SMART CARD1 CLOCK REGISTER
The frequency selected for the SC1 block depends on the maximum baud rate desired. The SCC block has the ability
to divide this clock generated by the values in the SC_DLL/SC_DLM registers and the SC_CLK_DIV Register to generate
the etu. Hence this clock divider is to select the lowest frequency to the block to reduce dynamic power.
The SC1 clock frequency selected must a integer multiple of the CPU clock. For example, if the Smart Card must operate
at 16 MHz, the CPU clock is also at 4 MHz or 8 MHz, or if the Smart Card operates at 24 MHz, the CPU clock is
also at 4.8 MHz.
The SC1_CLK_EN bit must be enabled to write to the SC1_SC_FIFO_DIS bit in the Smart Card 1 registers.
In Clock Bypass Mode (i.e., ref_clk = mem_clk = clk_clk since MEM_CLK_DIV=1 and CPU_CLK_DIV=1), any write to
enable the SC1_CLK_DIV Register would require 10 CPU clocks for the SC1 clocks to be enabled again, after SC1_RESET
is reset or SC1_CLK_EN is set. Hence, the SC1 block must not be accessed during this time.
5:0 SPI2_CLK_DIV R/W This field indicates the division factor to reference clock (48 MHz if
selected), to generate spi2_clk. The frequency however must be a
multiple of the cpu_clk frequency, which is enforced by software.
The default value is 1.
uart_clk = ref_clk/SPI2_CLK_DIV, with the constraint
MEM_CLK_DIV * CPU_CLK_DIV = SPI2_CLK_DIV * SP2, where
SP2 is an integer.
If EXT_SPI_EN (BOND2) is high, then the reset value of this field is
12, otherwise the reset value is 1.
TABLE 15-12: SC1 CLOCK REGISTER
SC1_CLK_DIV
(0X010~0X010 – RESET=0X01) SC1 CLOCK DIVIDER REGISTER
BIT NAME R/W DESCRIPTION
7 SC1_CLK_EN R/W When this bit is set, it enables the reference clock after division by
SC1_CLK_DIV to the Smart Card 1 block.
The default value is 0.
The clocks to the SC1 block can be halted by resetting this bit,
without resetting the SC1 block (controlled by SC1_RESET).
6 SC1_RESET R/W When this bit is set, it resets the SC1 block.
5:0 SC1_CLK_DIV R/W This field indicates the division factor to reference clock (48 MHz if
selected), to generate sc1_clk.
The default value is 1.
sc1_clk = ref_clk/SC1_CLK_DIV, with the constraint
MEM_CLK_DIV * CPU_CLK_DIV = SC1_CLK_DIV * SC1, where
SC1 is an integer.
TABLE 15-11: SPI2 CLOCK REGISTER (CONTINUED)
SPI2_CLK_DIV
(0X00F~0X00F – RESET=0X0C/0X8C/
0X01/0X81)
SPI1 CLOCK DIVIDER REGISTER
BIT NAME R/W DESCRIPTION
SEC1110/SEC1210
DS00001561C-page 160 2013 - 2016 Microchip Technology Inc.
15.4.12 SMART CARD2 CLOCK REGISTER
This register is valid only in the SEC1110. It is read only for the SEC1210.
The frequency selected for the SC2 block depends on the maximum baud rate desired. The SCC block has the ability
to divide this clock generated by the values in SC_DLL/SC_DLM and SC_CLK_DIV registers to generate the “etu”.
Hence this clock divider is to select the lowest frequency to the block to reduce dynamic power.
The SC2 clock frequency selected must a integer multiple of the CPU clock. For example, if Smart Card must operate
at 16 MHz, the CPU clocks is also at 4 MHz or 8 MHz, or if the Smart Card operates at 4.8 MHz, the CPU clock is also
at 4.8 MHz or 9.6 MHz. Though there are 2 Smart Card interfaces, they share the same UART, and only one of them is
in operation at any point of time.
Though there are 2 Smart Card interfaces, they share the same SC_FIFO, and only one of them is in operation at any
point of time for data transfer. But both blocks may be active at the same time, and may be operating at different baud
rates. But both the Smart Card clocks must be a multiple of CPU clock. For example, if each operate at 4.8 MHz and
4 MHz, then 48 MHz clock is routed to both blocks (SC1_CLK_DIV=1, SC2_CLK_DIV=1).
In Clock Bypass Mode (i.e., ref_clk = mem_clk = clk_clk since MEM_CLK_DIV=1, CPU_CLK_DIV=1), any write to
enable SC2_CLK_DIV register would require 10 CPU clocks for the SC2 clocks to be enabled again, after SC1_RESET
is reset or SC1_CLK_EN is set. Hence the SC2 block must not be accessed during this time.
TABLE 15-13: SC2 CLOCK REGISTER
SC2_CLK_DIV
(0X011~0X011 – RESET=0X01) SC2 CLOCK DIVIDER REGISTER
BIT NAME R/W DESCRIPTION
7 SC2_CLK_EN R/W When this bit is set, it enables the reference clock after division by
SC_CLK_DIV to the Smart Card 2 block.
The default value is 0.
The clocks to the SC2 block can be halted by resetting this bit,
without resetting the SC2 block (controlled by SC2_RESET).
6 SC2_RESET R/W This bit when set, resets the SC2 block.
5:0 SC2_CLK_DIV R/W This field indicates the division factor to reference clock (48 MHz if
selected), to generate sc1_clk or sc2_clk.
The default value is 1.
sc1_clk = ref_clk/SC1_CLK_DIV, with the constraint
MEM_CLK_DIV * CPU_CLK_DIV = SC1_CLK_DIV * SC1, where
SC1 is an integer.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 161
SEC1110/SEC1210
15.5 Wake On Event Register
TABLE 15-14: WAKE ON EVENT REGISTER
WOE_CTL
(0X012~0X012 – RESET=0X00) WAKEON EVENT REGISTER
BIT NAME R/W DESCRIPTION
7:6 Reserved R Always read as 0
5 PWR_STS_WOE_MSK R/W Always read as 0 in SEC1110/SEC1210. Setting this bit enables
waking up on a power status event.
4 Reserved R/W Always read as 0
3 Reserved R Always read as 0
2 Reserved R Always read as 0
1 USB_WOE_MASK R/W Setting this bit enables waking up the oscillator (enabling the
reference clock) from power down state due to USB resume.
Resetting this bit disables wake-up on USB resume.
0 GPIO_WOE_MSK R/W Setting this bit enables waking up the oscillator (enabling the
reference clock) from power down state due to a GPIO event.
Resetting this bit disables wake-up on a GPIO event.
The GPIO registers must be enabled to detect a pad change.
TABLE 15-15: WAKE ON EVENT STATUS REGISTER
WOE_STS
(0X013~0X013 – RESET=0X00) WAKEON EVENT STATUS REGISTER
BIT NAME R/W DESCRIPTION
7:6 Reserved R Always read as 0
5 PWR_STS_WOE R/W Always read as 0 in SEC1110/SEC1210. This bit is set on waking
up on a power status event.
4 Reserved R/W Always read as 0
3 Reserved R Always read as 0
2 Reserved R Always read as 0
The firmware writes a 1 to reset it.
1 USB_WOE R/W1 Hardware sets this bit on USB resume. The firmware writes a 1 to
reset it.
0 GPIO_WOE R/W1 Hardware sets this bit on GPIO event. The firmware writes a 1 to
reset it.
SEC1110/SEC1210
DS00001561C-page 162 2013 - 2016 Microchip Technology Inc.
15.6 Valid Clock Frequencies
If an interface is not used, its clock can be disabled and that cell is left blank. All frequencies are in MHz unless otherwise
stated.
• SP1 is an integer such that the SPI1 clock frequency is a multiple of the CPU frequency.
• SP2 is an integer such that the SPI2 clock frequency is a multiple of the CPU frequency.
• U is an integer such that the UART clock frequency is a multiple of the CPU frequency.
• Only one Smart Card can be in use at any time. Its frequency is a multiple of the CPU frequency.
• The Memory clock frequency must be 8 Mhz or higher if USB is used. The 48 MHz oscillator mode is required for
USB operation.
There are 3 examples clock generation shown in FIGURE 15-2: on page 163, FIGURE 15-3: on page 164, and FIGURE
15-4: on page 165.
TABLE 15-16: VALID CLOCK FREQUENCIES
INDEX REF MEM CPU SPI1 SPI2 UART USB
(SIE) SC1 SC2 COMMENT
1 48 4 MEM SP1 *
CPU
SP2 *
CPU
U * CPU - SC1 *
CPU (4)
SC2 *
CPU (4)
USB, a
multiple of
CPU 2 48 8 MEM SP1 *
CPU
SP2 *
CPU
U * CPU 12 SC1 *
CPU (4)
SC2 *
CPU (4)
4 48 4.8 MEM SP1 *
CPU
SP2 *
CPU
U * CPU - SC1 *
CPU
(4.8)
SC2 *
CPU
(4.8)
USB, not a
multiple of
CPU
5 48 9.6 MEM SP1 *
CPU
SP2 *
CPU
U * CPU 12 SC1 *
CPU
(4.8)
SC2 *
CPU
(4.8)
6 48 9.6 MEM/2 SP1 *
CPU
SP2 *
CPU
U * CPU 12 SC1 *
CPU
(4.8)
SC2 *
CPU
(4.8)
7 4 REF MEM CPU CPU CPU - Low Power
mode
TABLE 15-17: VALID CLOCK FREQUENCIES
INDEX REF MEM CPU SPI1 SPI2 UART
USB
(SIE) SC1 COMMENT
1 48 4 MEM SP1 *
CPU
SP2 *
CPU
U *
CPU
- SC1 *
CPU (4)
USB, a multiple
of CPU
2 48 8 MEM SP1 *
CPU
SP2 *
CPU
U *
CPU
12 SC1 *
CPU (4)
4 48 4.8 MEM SP1 *
CPU
SP2 *
CPU
U *
CPU
- SC1 *
CPU
(4.8)
USB, not a
multiple of CPU
5 48 9.6 MEM SP1 *
CPU
SP2 *
CPU
U *
CPU
12 SC1*
CPU
(4.8)
6 48 9.6 MEM/2 SP1 *
CPU
SP2 *
CPU
U *
CPU
12 SC1 *
CPU
(4.8)
7 4 REF MEM CPU CPU CPU - Low Power
modes
9 32.768
KHz
REF MEM CPU CPU CPU
2013 - 2016 Microchip Technology Inc. DS00001561C-page 163
SEC1110/SEC1210
FIGURE 15-2: CLOCK GENERATION EXAMPLE 1 Clock generation: example 1
OSC in: frequency input is 48 MHz/4 MHz(/32.768 kHz), 50% duty cycle.
Memory Clock:
period programmable mem_div 1 to 16 cycles of OSC in, 50% duty cycle.
Mem_clk = Osc / mem_div. e.g. Shown mem_div = 4
CPU clock out:
period programmable 1 to 4 cycles of mem_clk, 50% duty cycle.
Cpu_clk = Mem_clk / cpu_div
cpu2mem_phase is 0 during last memory clock before cpu_clk rising edge.
usb_clk1x
(12 MHz)
Memory clk
e.g. 12 MHz
clk2x
(24 MHz)
osc48
usb_clk4x
spi_clk
e.g. 12 MHz
cpu_clk
e.g. 4 MHz
cpu2mem_phase 0 1 2
CPU rd/wr request if present always serviced in 0
Reset Release
SPI rd/wr request if present always serviced in 3/2/1 within 4 clocks or if CPU rd/wr request absent in 0, then in 0
2 3 10 USB rd/wr request if present always serviced within 4 clocks
}
} SPI clock out:
spi_clk = osc * (S/(mem_div*cpu_div), where mem_div*cpu_div/S is an integer. i.e. spi_clk is
a multiple of cpu_clk.
cpu2spi2_phase=0 defines the spi_clk rising edge on which CPU writes/reads the SPI block.
spi request to memory serviced within 4 memory clocks.
USB clock out:
clk_4x: Always 48 MHz Used by DPLL of USB.
clk_1x: Always 12 MHz Used by USB SIE
If mem_clk is a multiple of 4 MHz, i.e. 8/12 etc., USB accesses to memory are optimal.
usb request to memory serviced within 4 clocks. In e.g. serviced within 3 clocks, in 2/1/0.
cpu2spi_phase 0 1 2
cpu2spi_phase 0
spi_clk
e.g. 4 MHz
SEC1110/SEC1210
DS00001561C-page 164 2013 - 2016 Microchip Technology Inc.
FIGURE 15-3: CLOCK GENERATION EXAMPLE 2 Clock generation : example 2
OSC in: frequency input is 48 MHz/ 4 MHhz(/32.768 kHz), 50% duty cycle.
Memory Clock:
period programmable mem_div 1 to 16 cycles of OSC in, 50% duty cycle.
Mem_clk = Osc / mem_div. e.g. Shown mem_div = 6
CPU clock out:
period programmable 1 to 4 cycles of mem_clk, 50% duty cycle.
Cpu_clk = Mem_clk / cpu_div
cpu2mem_phase is high during last memory clock before cpu_clk rising edge.
In above e.g. where cpu_clk=mem_clk=8Mhz, where cpu2mem_phase=0, cpu
is wait stated to service priority 1-USB, priority 2-SPI, priority 3-SPI.
usb_clk1x
(12 MHz)
Memory clk
e.g. 8 MHz
clk2x
(24 MHz)
osc48
usb_clk4x
cpu2mem_phase
cpu2uart_phase
uart_clk
e.g. 16 MHz
CPU rd/wr request if present always serviced in 0
SPI rd/wr request if present always serviced in 3/2/1 within 4 clocks or if CPU rd/wr request absent in 0, then in 0
Reset Release
2 3 10 USB rd/wr request if present always serviced within 4 clocks
UART clock out:
uart_clk = osc * (U/(mem_div*cpu_div), where mem_div*cpu_div/U is an integer. i.e.
uart_clk is a multiple of cpu_clk.
cpu2uart_phase defines the uart_clk rising edge on which CPU writes/reads the UART
block.
uart request to memory serviced within 4 memory clocks.
USB clock out:
clk_4x: Always 48 MHz Used by DPLL of USB.
clk_1x: Always 12 MHz Used by USB SIE
If mem_clk frequency is a multiple of 4Mhz (8/12/16 MHz etc), USB to memory access
are optimal.
}
}
uart_clk
e.g. 8 MHz
uart_clk
e.g. 8 MHz
0
cpu2uart_phase
2013 - 2016 Microchip Technology Inc. DS00001561C-page 165
SEC1110/SEC1210
FIGURE 15-4: CLOCK GENERATION EXAMPLE 3 Clock generation: example 3
OSC in: frequency input is 48 MHz/4 MHz (/32.768 kHz), 50% duty cycle.
Memory Clock:
period programmable mem_div 1 to 16 cycles of OSC in, 50% duty cycle.
Mem_clk = Osc / mem_div. e.g. Shown mem_div = 4
CPU clock out:
period programmable 1 to 4 cycles of mem_clk, 50% duty cycle.
Cpu_clk = Mem_clk / cpu_div
cpu2mem_phase is 0 during last memory clock before cpu_clk rising edge.
usb_clk1x
(12 MHz)
Memory clk
e.g. 9.6 MHz
clk2x
(24 MHz)
osc48
usb_clk4x
sc1_clk
e.g. 48
MHz
cpu_clk
e.g. 4.8 MHz
cpu2mem_phase 0 1
CPU rd/wr request if present always serviced in 0
Reset Release
2 3 10 USB rd/wr request if present always serviced within 4 clocks
}
SC1/SC2 clock out:
sc1_clk = osc * (SC1/(mem_div*cpu_div), where mem_div*cpu_div/SC1 is an integer.
i.e. sc1_clk is a multiple of cpu_clk.
cpu2sc1_phase=0 defines the sc1_clk rising edge on which CPU writes/reads the SC1
block.
USB clock out:
clk_4x: Always 48 MHz Used by DPLL of USB.
clk_1x: Always 12 MHz Used by USB SIE
If mem_clk is a multiple of 4Mhz (4/812/16 MHz etc.), then USB to memory access are
optimal.
usb request to memory serviced within 4 clocks. In e.g. serviced within 3 clocks, in 2/1/
0.
cpu2sc1_phase
SEC1110/SEC1210
DS00001561C-page 166 2013 - 2016 Microchip Technology Inc.
15.7 Power
FIGURE 15-5: SEC1110/SEC1210 POWER STATES
ALL_CC +
CLK_PWR_CB
+
GPIO + KB
+
DFT
USB +
DMA
ERAM IRAM
HALT3 Mode
Optional to power down
IRAM/ERAM/ USB
RUN1 Mode
HALT2 Mode
CPU Sleep
USB Resume/ GPIO
WOE
ALL_CC + ALL_CB +
CLK_PWR_CA
+
CPU + Timers 0/1/2 +
UART + SPI1 + SPI2 +
SC1 + OTP + ROM +
4/ 48 MHz OSC
ERAM IRAM
USB +
DMA
ALL_CC + ALL_CB +
CLK_PWR_CA
+
CPU + Timers 0/½ +
UART + SPI1 + SPI2 +
SC1/SC2 + OTP + ROM +
4Mhz/ PD OSC
ERAM IRAM
USB +
DMA
RUN2 (USB=on),
RUN3 (USB=off)
Modes
CC : Powered by Low Quiescent regulator
CB : Powered by Standby regulator
CA: Powered by Active regulator
RESET_N R=0
RESET_N=1
RESET_N=0
OSC_MODE=
000/001
PWR_CORE_DIS=
001,
OSC_MODE=
100/111/110
PWR_CORE_DIS=
000,
OSC_MODE=
100/111/110
GPIO WOE
STOP Mode
ALL_CC + ALL_CB +
CLK_PWR_CA
+
CPU + Timers 0/½ +
UART + SPI1 + SPI2 +
SC1/SC2 + OTP + ROM +
4/8 MHz
ERAM IRAM
GPIO WOE
USB
off
2013 - 2016 Microchip Technology Inc. DS00001561C-page 167
SEC1110/SEC1210
15.7.1 CPU SLEEP/POWER MANAGEMENT
The R8051XC2 has a power management control unit that generates clock enable signals for the main CPU and for
peripherals. This unit has two Power Down Modes: IDLE and STOP. It also generates an internal synchronous reset
signal (upon external reset, watchdog timer overflow, or software reset condition, OCDS). The IDLE Mode leaves the
clock of the internal peripherals running. Any interrupt will wake the CPU.
The CPU sleep modes may be entered in any of the RUN power states.
15.7.1.1 CPU_IDLE Mode
Setting the idle bit of the Power Control Register invokes the IDLE Mode. In the IDLE Mode, the clock for some peripherals
(Timer 0, Timer 1, WDT, interrupt controller, reset, and wake-up units) is running (the clkper_en=1 and clkcpu_en=0).
Dynamic power consumption drops because the CPU clock is stopped.
The CPU can exit the IDLE state with any interrupt or reset.
15.7.1.2 CPU_STOP Mode
The STOP Mode turns off both internal clocks: clk_cpu and clk_per. The CPU will exit this state when an External Interrupt
0 (reserved) or External Interrupt 1 (GPIO) occurs, or a reset occurs. Internally generated interrupts are disabled
since they require clock activity. Dynamic Power consumption drops further compared to IDLE Mode.
The CLK_PWR block is active, with oscillators up and running. Also, the peripherals such as SPI1, SPI2, SC1, SC2,
and UART may be running if they where enabled. The memory clock to the XDATA SRAM is also up.
The Wake-up from Power-Down Mode Control Unit services External Interrupt 0 (all interrupts except GPIOs) or External
Interrupt 1 (GPIO0,1, or 2 interrupts) during power-down modes. They can combinationally force the clock enable
outputs back to active state so that the clock generation can be resumed.
15.7.2 POWER STATES
15.7.2.1 STOP Mode
This mode is entered when the chip is powered, and the external signal RESET_N is low. Entering this mode disables
all the voltage regulators for the core and all IO rails. The amount of power consumed is at its least while in this state.
The IO pads, GPIO, USB and Smart Card pads are in high impedance mode (no power), but the pad inputs are 5 V
tolerant.
The typical use is RESET_N signal being asserted when a system is in low power mode The RESET_N is released only
when the Host requires an interface to the Smart Card.
When RESET_N is released, the chip powers up and enters RUN1 Mode (Section 15.7.2.3).
15.7.2.2 HALT Mode
The HALT modes are entered only from RUN2/ RUN3 modes.
In this Mode, the software disables the clock to all peripherals such as SPI1, SPI2, UART, SC1, and SC2. If this mode
was entered due to USB suspend, then the USB clock is disabled. The software must enable the Wake on Event Register
(USB/GPIO) before entering this mode.
The software enters this mode by setting the PWR_CORE_DIS bits and OSC_MODE[2] bit, which causes the oscillator
to be powered down. Now all main clocks in the core power domain are off, and the chip is in low power state.In order
to meet the 200uA USB suspend limit, there are two core power domains. In CoreB (Standby) domain the CLK_PWR,
UDC, XDATA ERAM, and IRAM are powered. All other core logic is powered down.
Only a wake-up event such as a USB Resume, GPIO event, or Reset event would cause the chip to exit this state to
RUN modes.
The 3.3 V core power to GPIOs and the USB transceiver is enabled.
SEC1110/SEC1210
DS00001561C-page 168 2013 - 2016 Microchip Technology Inc.
15.7.2.3 RUN1 Mode
This mode is entered after a power on reset event, or when the software operates the oscillator in Low Power Mode,
where the internal oscillator runs at 4 MHz. The dynamic power consumption is low, and it depends on which peripherals
are enabled, such as SPI1 (SPI2 in Debug Mode), or UART.
The peripherals such as USB, and SC1, and SC2 require accurate frequency generation, and must not be enabled in
the RUN1 Mode.
15.7.2.4 RUN2 Mode
This mode is entered when the software operates the oscillator in normal mode, where the internal oscillator runs at
48 MHz. The dynamic power consumption is high, and it depends on which peripherals are enabled, such as SPI1 (SPI2
in Debug Mode), UART, USB, SC1, and SC2. The USB is not configured and disabled.
The difference between RUN2 and RUN3 modes, is that in RUN2 mode, the USB is off. Hence if operating the Smart
Card blocks at lower baud rate, then 48 Mhz oscillator is not required, and reference clock could be at 4.
If Smart Card 1 (or Smart Card 2) is to be enabled, then the variable voltage regulators LDO2A, (or LDO2B) is enabled.
The software can enter lower power states such as RUN1, or HALT states, by changing the OSC_MODE[2:0] bits. The
software must turn off power supplies to SC1_VCC and SC2_VCC before going to low power modes.
The chip may enter this mode from RUN1 Mode by changing the OSC_MODE[2:0] bits to 010b and OSC48_SEL[1] to 0b.
15.7.2.5 RUN3 Mode
This mode is entered when the software operates the Oscillator in normal mode, where the internal oscillator runs at 4
or 48 Mhz. The dynamic power consumption is higher, and it depends on which peripherals are enabled, such as SPI1
(SPI2 in debug mode), UART, USB, SC1, SC2.
If Smart Card 1 (or Smart Card 2)is to be enabled, then Variable voltage regulators LDO2A (or LDO2B) is enabled.
The Software can enter lower power states such as RUN1, or HALT states, by changing the PWR_CORE_DIS[2:0] and
OSC_MODE[2:0] bits. The software must turn off power supplies to SC1_VCC and SC2_VCC before going to low power
modes.
The chip may enter this mode from RUN1 mode by changing the OSC_MODE[2:0] bits to ‘b010 and OSC48_SEL[1] to
‘b0.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 169
SEC1110/SEC1210
When RESET_N is low, all the regulators are in Power Down Mode. When RESET_N is released high, all the core voltage
and 3.3 V IO voltage rails are powered up.
FIGURE 15-6: POWER-ON SEQUENCING Reset deasserted 1.2V VDD_SOC domain up 1.2V Standby Power domain up 3.3V Power domain up
VDD5
RESET_N
PD_LOWIQ_LDO3_SOC
POWERGOOD_LDO3C
PD_STANDBY_LDO3_SOC
POWERGOOD_LDO3B_SOC
PD_LDO3_SOC
POWERGOOD_LDO3A_SOC
PD_LDO1_SOC
POWERGOOD_LDO1_SOC
PW_GD
(POR_5)
CORE_RESET_N
PD_LDO2A_SOC=1,
PD_LDO2B_SOC=1
1.2V Active Power domain up
PAD Outputs
(if enabled) Z
PAD (clamp0) Inputs
(if enabled) Clamp 0
SEC1110/SEC1210
DS00001561C-page 170 2013 - 2016 Microchip Technology Inc.
The power up state of internal voltage regulators is shown below.
15.7.3 POWER STATUS REGISTERS
If any bit changes in this register, then it causes a Power Status Event Interrupt.
TABLE 15-18: POWER STATUS1 REGISTER
POWER_STS1
(0X014 – RESET=001000XXB) POWER STATUS1 REGISTER
BYTE NAME R/W DESCRIPTION
7 POWERGOOD_LDO2A R If this bit is high, it indicates that SC2_VCC power is stable (100%).
It is low if the voltage drops below 85% of rated value.
If the SC2 smart card is in operation and this bit becomes low, it
indicates that SC2_VCC current limit has been reached, probably
due to a short circuit.
6 POWERGOOD_LDO2B R If this bit is high, it indicates that SC1_VCC power is stable (100%).
It is low if the voltage drops below 85% of rated value.
If the SC1 smart card is in operation and this bit becomes low, it
indicates that SC1_VCC current limit has been reached, probably
due to a short circuit.
5 POWERGOOD_LDO1 R If this bit is high, it indicates that LDO1 3.3 V power is stable (100%).
It is low if the voltage drops below 85% of rated value.
4 Reserved R Reserved
3 SC2_VCC_OCS R This bit is normally zero.
If this bit is set, it indicates that the short circuit current exceeded the
limits for SC2_VCC.
If the LDO2A regulator is powered on, and POWERGOOD_LDO2A
is never high because of excess short circuit current, then this bit is
set.This bit is reset when software reads this register.
2 SC1_VCC_OCS R This bit is normally zero.
If this bit is set, it indicates that the short circuit current excessed the
limits for SC1_VCC.
If the LDO2B regulator is powered on, and POWERGOOD_LDO2B
is never high because of excess short circuit current, then this bit is
set. This bit is reset when software reads this register.
1 VDD5_LOW RO This bit is set when the VDD5 power supply voltage drops below
4.8V, indicating the Smart Card cannot be operated as a Class A
terminal.
This bit is zero, when the VDD5 power is above 4.9V. The VDD5
comparator has a 100mV hysteresis.
T
0 Reserved R This bit is low when VDD5 is powered. This bit is always low in since
the only power source is VDD5.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 171
SEC1110/SEC1210
15.7.4 POWER CONTROL 1 REGISTER
These register bits control the power supply to the IO pads of the chip, except for the 3.3 V pads.
TABLE 15-19: POWER STATUS2 REGISTER
POWER_STS2
(0X017 – RESET=000XX11XB) POWER STATUS2 REGISTER
BYTE NAME R/W DESCRIPTION
7 SC2_VCC_PWR_OVRR R/W When this bit is set to 1, it allows powering up of the SC2 pads with
PWR_SC2_EN bits i.e., the SC register bit CARD2_VCC_CNTL need
not be configured to power the SC2 pads.
6:3 Reserved R Always read as 0
2 POWERGOOD_LDO3B R If this bit is high, it indicates that the Core 1.2 V standby power is
stable. It is low if the voltage drops below 85% of rated value.
1 POWERGOOD_LDO3A R If this bit is high, it indicates that the Core 1.2 V power is stable. It
is low if the voltage drops below 85% of rated value.
0 VDD5_LOW_3P5 R This bit if high indicates that the VDD5 power supply is less than
3.5V. This bit if low, indicates that the VDD5 power supply is more
than 3.5V.
TABLE 15-20: POWER CONTROL 1 REGISTER
POWER_CTL1
(0X015 – RESET=0X00) POWER CONTROL1 REGISTER
BYTE NAME R/W DESCRIPTION
7 SC2_CLK_SLEW_RATE R/W Always read as 0 in the SEC1110/SEC1210 version.
If this bit is set, it causes the Smart Card pads to operate normally,
i.e., the rise and fall times are within 8% of 4.8 MHz, even with large
capacitive loads (85 pF). If this bit is reset, it reduces the slew rate
of the SC2_CLK pad to 33% slew rate of normal operation.
This feature enables software to reduce the edge rate of the
SC2_CLK pad when the load capacitance is normal (around 30 pF),
by setting this bit.
6 Reserved R Always read as 0
5 Reserved R Always read as 0
4 SC1_CLK_SLEW_RATE R/W Always read as 0 in the SEC1110/SEC1210 version.
If this bit is set, it causes the Smart Card pads to operate normally,
i.e., the rise and fall times are within 8% of 4.8 MHz, even with large
capacitive loads (85 pF). If this bit is reset, it reduces the slew rate
of the SC1_CLK pad to 33% slew rate of normal operation.
This feature enables software to reduce the edge rate of the
SC1_CLK pad when load capacitance is normal (around 30 pF), by
setting this bit.
3:2 PWR_SC2_EN R/W This register controls the voltage regulator for the Smart Card 2
pads, if the PWR_SC2_EN33 bit is zero. This is applicable only to the
SEC1210. Otherwise this field is read only.
00 : SC2_VCC is powered down.
01 : SC2_VCC supplies 5.0 V (Class A)
10 : SC2_VCC supplies 3.0 V (Class B)
11 : SC2_VCC supplies 1.8 V (Class C).
The VCC_CNTL bit in the Smart Card 2 SC_Sync_ALL Register must
be set to enable the PWR_SC2_EN values to control the voltage
regulator. If VCC_CNTL is reset, then it is equivalent to 00b setting.
SEC1110/SEC1210
DS00001561C-page 172 2013 - 2016 Microchip Technology Inc.
The PWR_SC1_EN bit controls the power to all the Smart Card 1 pins, namely SC1_CLK, SC1_IO, SC1_RST_N, SC1_C4,
and SC1_C8.
The Power Control 2 Register controls the power supply to the core logic of the chip, and the power to the 3.3 V pads.
1:0 PWR_SC1_EN R/W This register controls the voltage regulator for the Smart Card 1
pads, if PWR_SC1_EN33 bit is zero.
00 : SC1_VCC is powered down.
01 : SC1_VCC supplies 5.0 V (Class A)
10 : SC1_VCC supplies 3.0 V (Class B)
11 : SC1_VCC supplies 1.8 V (Class C).
The VCC_CNTL bit in the Smart Card 1 SC_Sync_ALL Register must
be set to enable PWR_SC1_EN values to control the voltage
regulator. If VCC_CNTL is reset, then it is equivalent to 00b setting.
TABLE 15-21: POWER CONTROL 2 REGISTER
POWER_CTL2
(0X016 – RESET=0X00) POWER CONTROL2 REGISTER
BYTE NAME R/W DESCRIPTION
7 PWR_SC1_EN33 R/W If this bit is high, it indicates that the SC1_VCC supplies 3.3 V. If this
bit is low, it allows the PWR_SC1_EN bit to control SC1_VCC power.
6 PWR_SC2_EN33 R/W If this bit is high, it indicates that SC2_VCC supplies 3.3 V. This bit
if low, allows PWR_SC2_EN bit to control SC2_VCC power.
5 PWR_VDD33_DIS R/W This field indicates whether the power to the pads using VDD33 is
disabled in low power modes.
0 : Power to VDD3 pads is enabled.
1 : Power to VDD3 pads is disabled. Note that PWR_CORE_DIS[1]
also must also be 1 for 3.3 V pads to be disabled.
4 SC1_VCC_PWR_OVRRD R/W Always read as 0 in SEC1110/SEC1210 version.
If this bit is set, the LDO2B regulator can be controlled directly by
the PWR_SC1_EN register bits. If this bit is cleared, the Smart Card
controller bits control the LDO2B regulator.
3 PWR_RAMS_DIS R/W This field indicates whether the power to the RAMs in the core logic
is disabled in low power modes.
0 : Power to all RAM blocks is enabled.
1 : Power to the IRAM, ERAM blocks is disabled.
A write to this field only takes affect after a consecutive write to the
OSC48_CTL register.
2:0 PWR_CORE_DIS[2:0] R/W This field indicates whether the power to the core logic is disabled
in low power modes.
000 : Power to all core blocks is enabled.
Bit 0 : Controls power disable to voltage regulator LDO3A which
supplies power to most of the core logic except the USB core, and
some parts of CLK_PWR block.
Bit 1 : Reserved.
Bit 2 : Reserved.
A write to this field only takes effect after a consecutive write to the
OSC48_CTL register.
TABLE 15-20: POWER CONTROL 1 REGISTER
POWER_CTL1
(0X015 – RESET=0X00) POWER CONTROL1 REGISTER
BYTE NAME R/W DESCRIPTION
2013 - 2016 Microchip Technology Inc. DS00001561C-page 173
SEC1110/SEC1210
The PWR_SC2_EN bit controls the power to the Smart Card 2 pins, namely SC2_CLK, SC2_IO, and SC2_RST_N.
To enter low power modes, a write to PWR_STOP_MODE bit in PWR_CNTL1 register or a write to
PWR_CORE_DIS[2:0], PWR_RAMS_DIS and PWR_VDD33_DIS bits in PWR_CNTL2 register should be followed by
a write to OSC48_CTL register to take effect. Any writes to other bits of PWR_CNTL1 and PWR_CNTL2 registers are
ignored for this "two consecutive writes" rule. The hardware needs approximately 300 CPU clocks to enter the low power
states.
15.8 One Time Programmable ROM Configuration
This OTP Configuration Register is read only and is updated every time before reset release to the 8051 CPU. It captures
the first byte of Table 15-22, “One Time Programmable Configuration Register,” on page 173. Since the initial
unprogrammed state of the OTP special registers is all zeroes, this register powers up as zero.
15.9 Clock Power Test Registers
These registers at address offsets 0x20 to 0x23 are for Microchip Internal use only, and changing the default values may
cause faulty operation of the device.
TABLE 15-22: ONE TIME PROGRAMMABLE CONFIGURATION REGISTER
OTP_CFG
(0X18 - RESET=0X00) OTP CONFIG REGISTER
BYTE NAME R/W DESCRIPTION
7 FORCE_OTP_ROM R 1 : Forces execution out of the OTP ROM irrespective of the BOND2
value.
0 : Execute out of ROM or OTP_ROM, or external SPI2 depending
on Table 7-1, “Code Execution Truth Table,” on page 21.
6 OTP_ROM_EN R 1 : Forces execution out of the OTP ROM if BOND2 (i.e.,
EXT_SPI2_EN) is zero.
0 : Execute out of ROM, or external SPI2 depending on BOND2
5 JTAG_DIS R If this bit is programmed, then JTAG_CLK cannot be configured in
JTAG Mode. OCDS debug access to 8051 CPU is disabled. LVJTAG
access is also disabled.
4:3 Reserved R Reserved
2:1 LOCK[1:0] R Active high. Locks VPP switch in individual sectors 1 and 0.
0 MLOCK R Active high. Locks VPP switch to all sectors.
TABLE 15-23: CLKPWR TEST1 REGISTER
CLKPWR_TEST1
(0X020 – RESET=0X00) CLKPWR REGISTER
BIT NAME R/W DESCRIPTION
7:6 TEMPCOMPPRG_48MOS
C[1:0]
RO The default value is 00. The effect of changing these values is not
documented. This field is tied to 00.
5:3 IBIASPRG_48MOSC[2:0] RW The default value is 000. The effect of changing these values is not
documented.
2:0 STARTUP_48MOSC[2:0] RW The default value is 000. The effect of changing these values is not
documented.
SEC1110/SEC1210
DS00001561C-page 174 2013 - 2016 Microchip Technology Inc.
TABLE 15-24: CLKPWR TEST2 REGISTER
CLKPWR_TEST2
(0X021 – RESET=0X00) CLKPWR TEST2 REGISTER
BIT NAME R/W DESCRIPTION
7 TF_PG_LDO3A RW The default value is 0.
6 TF_PG_SEL_LDO3A RW The default value is 0. A value of 1 bypasses the power good
detector for LDO3A, and the value written in TF_PG_LDO3A is
observed in POWERGOOD_LDO3A field.
This field is defined for scan purposes.
5 TF_PG_LDO1 RW The default value is 0.
4 TF_PG_SEL_LDO1 RW The default value is 0. A value of 1 bypasses the power good
detector for LDO1, and the value written in TF_PG_LDO1 is
observed in POWERGOOD_LDO1 field.
These two fields can be tested in functional mode.
3 TF_PG_LDO2A RW The default value is 0, since Smart Card 2 is disabled by default.
2 TF_PG_SEL_LDO2A RW The default value is 0. A value of 1 bypasses the power good
detector for LDO2A, and the value written in TF_PG_LDO2A is
observed in POWERGOOD_LDO2A field.
1 TF_PG_LDO2B RW The default value is 0 since Smart Card 1 is disabled by default.
0 TF_PG_SEL_LDO2B RW The default value is 0. A value of 1 bypasses the power good
detector for LDO2B, and the value written in TF_PG_LDO2B is
observed in POWERGOOD_LDO2B field.
TABLE 15-25: CLKPWR TEST3 REGISTER
CLKPWR_TEST3
(0X022 – RESET=0X00) CLKPWR TEST3 REGISTER
BIT NAME R/W DESCRIPTION
7 TF_SFST_LDO3A RW The default value is 0. A value of 1 disables the soft start feature of
LDO3A.
6 TF_SFST_LDO1 RW The default value is 0. A value of 1 disables the soft start feature of
LDO1.
5 TF_SFST_LDO2A RW The default value is 0. A value of 1 disables the soft start feature of
LDO2A.
4 TF_SFST_LDO2B RW The default value is 0. A value of 1 disables the soft start feature of
LDO2B.
3 TF_CL_LDO3A RW The default value is 0. A value of 1 doubles the current limit of
LDO3A.
2 TF_CL_LDO1 RW The default value is 0. A value of 1 doubles the current limit of LDO1.
1 TF_CL_LDO2A RW The default value is 0. A value of 1 doubles the current limit of
LDO2A.
0 TF_CL_LDO2B RW The default value is 0. A value of 1 doubles the current limit of
LDO2B.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 175
SEC1110/SEC1210
In functional mode, if EXT_OSC48_PRESENT bit is one, then JTAG_TDI_LAT bit is used by boot ROM firmware to indicate
the external clock frequency as 48 Mhz (JTAG_TDI_LAT=1), or 12 Mhz (JTAG_TDI_LAT=0). The firmware changes
the MEM_CLK_DIV factor as 12 (external 48 Mhz clock), or 1 (external 12 Mhz clock). This test feature is used in ATE
mode.
TABLE 15-26: CLKPWR TEST4 REGISTER
CLKPWR_TEST4
(0X023 – RESET=0X00) CLKPWR TEST4 REGISTER
BIT NAME R/W DESCRIPTION
7 Reserved RO This bit is always zero.
6 RESET_SRC_SRST RO This bit if set indicates that the reset of the chip was due to ssrstreq
bit in SRST register.
5 RESET_SRC_WDOG RO This bit if set indicates that the reset of the chip was due to
Watchdog reset.
4 FAKE_TF_PG_2A_REG R/W Always read as zero in SEC1110/SEC1210.
This bit if set disables powergood faking through the regulator
interface. Instead it enables PWR_GD pin of SC2 PADS to be
powergood faked directly. For the direct powergood faking, this bit
should be set along with both "TF_PG_LDO2A and
TF_PG_SEL_LDO2A" bits. When this bit is cleared, LDO2A
regulator interface will be used to powergood faking.
3 FAKE_TF_PG_2B_REG R/W Always read as zero in SEC1110/SEC1210.
This bit if set disables powergood faking through the regulator
interface. Instead it enables PWR_GD pin of SC1 PADS to be
powergood faked directly. For the direct powergood faking, this bit
should be set along with both "TF_PG_LDO2B and
TF_PG_SEL_LDO2B" bits. When this bit is cleared, LDO2B
regulator interface will be used to powergood faking.
2 JTAG_TDI_LAT RO This bit indicates the value of JTAG_TDI pin at internal reset release
time (3.3V pads are powered up).
1 JTAG_CLK_LAT RO This bit indicates the value of JTAG_CLK pin at internal reset release
time (3.3V pads are powered up).
0 TEST_LAT RO This bit indicates the value of TEST pin at internal reset release time
(3.3V pads are powered up).
TABLE 15-27: CLKPWR VERSION REGISTER
CLKPWR_VERSION
(0X01B – RESET=0X01) VERSION REGISTER
BIT NAME R/W DESCRIPTION
7:4 Reserved R Always read as zero.
3:0 VERSION[3:0] R The field indicates the mask revision of silicon. The default value is
0001 : indicating A0
SEC1110/SEC1210
DS00001561C-page 176 2013 - 2016 Microchip Technology Inc.
16.0 OTP ROM TEST INTERFACE
The One Time Programmable (OTP) ROM is 128 kbits in size, organized as 16 kB during Read Mode.
• Up to 4 bits may be programmed at a time
By default, the OTP ROM is read in Single-Ended Mode utilizing a single memory cell per logical bit of information. Two
additional read modes are provided to enhance margins and secure data in highly reliable, field programmable systems:
Differential Mode and Redundant Mode. The Read Mode is controlled by the Mode Register and can be dynamically
changed for different sections of the address space.
• In Single-Ended Read Mode, the memory cell is compared to a reference to determine its state. The main memory
is addressed by A[9:0] in Single-Ended Mode. The ROM memory size is 16 kB.
• In Differential Read Mode, two memory cells are compared to each other, one programmed and one not, without a
need for a reference. The main memory is addressed by A[9:1] in Differential Mode. The address bit A0 selects
between the two physical cells constituting one logical bit and is used during program and verification operations.
The ROM memory size is 8 kB.
• In Redundant Read Mode, two memory cells are accessed in parallel (wired-OR manner) and compared to a
higher reference, which results in increased signal margins. Redundant Mode offers improvement for defective
programmed cells only; there is no improvement for defective unprogrammed cells (leaky cells). In Redundant
Mode, the memory is addressed by A[9:2,0]. Bit A1 is ignored during read, but is used during program and verify
operations. The ROM memory size is 8 kB.
• The memory can also operate in Differential-Redundant Mode utilizing four cells per logical bit of information. In
Differential-Redundant Read Mode both address bits A[1:0] are ignored, but they are used for program and verification.
The ROM memory size is 4 kB.
• The 8051 CPU can access the OTP in two ways. One is through the parallel interface, where the OTP looks like a
regular ROM, with 8051 issuing program or data address, and data being accessed parallelly. The processor also
has access to the OTP through a Serial Test Port interface for programming.
16.1 OTP ROM Test Registers Summary
The register addresses indicated below are offset address to XDATA base memory address A400h.
16.2 OTP_ROM Description
The OTP ROM Non-Voltaile Memory (NVM) is organized into a regular structure of rows and columns of memory cells.
The memory array is further organized into two sectors and four banks. A sector has 512 words and occupies the A[8:0]
address space. The address bit A9 selects the sectors.
To reduce programming time, all banks are programmed simultaneously (i.e., in parallel).
TABLE 16-1: OTP TEST REGISTERS MAP
REGISTER NAME XDATA ADDRESS EC TYPE
OTP_SPECIAL 0x00 ~ 0x0F R/W
OTP_REDUNDANCY_REG 0x20 ~ 0x2F R/W
OTP_MODE_MRL 0x30 R/W
OTP_MODE_MRH 0x31 R/W
OTP_MODE_MRAL 0x32 R/W
OTP_MODE_MRAH 0x33 R/W
OTP_MODE_MRBL 0x34 R/W
OTP_MODE_MRBH 0x35 R/W
CPU_TCMD_REG 0x36 R/W
CPU_TCTL_REG 0x37 R/W
CPU_SHIFT_REG 0x38 ~ 0x3B R/W
Reserved 0x3C ~ 0x3F R
CPU_TDATA_REG 0x40 ~ 0x4F R/W
2013 - 2016 Microchip Technology Inc. DS00001561C-page 177
SEC1110/SEC1210
When all the bits are in un-programmed state, a read of all even address (A0=0) is 0, and a read of all odd address
(A0=1) is 1.
16.2.1 BOOT ROWS
In addition to the regular memory array, every sector includes 16 additional rows, called boot rows, for testing and memory
bookkeeping purposes. The boot rows form non-continuous address spaces and are accessible when A10 is HIGH.
The A10 pin selects between the two address spaces: the main memory address space and the boot address space. A
typical boot space map is shown in Table 16-2 on page 177. The lowest boot address of sector 0 and sector 1 are
reserved for the power-up reset sequence with their content respectively loaded into the Special Register (sector 0) and
the Redundancy Register (sector 1). The user should program these locations with the desired content for the Special
and Redundancy registers.
The even locations in the boot rows other than location 0 and 2 can be used by the application either for testing or any
specific purpose such as a scratch pad or memory book-keeping. The odd location in the boot row memory are readonly
locations used as examples of Mask ROM. Locations 1,3,5,7, 9, and 11 are unprogrammed and read as all 1s,
while locations 13 and 15 are programmed and read as all 0s.
All boot row reads are done in Single-Ended Mode even when the main NVM array is configured in Differential or Redundant
Mode.
Note: In SEC1110/SEC1210 Silicon Anomaly 8: when running code from OTP that updates the CPU and memory
clock dividers, it must not be aligned to a 16 byte boundary. This is because 16 bytes of OTP is fetched at
a 16-byte address boundary, and cached for subsequent code fetches. Hence, in SEC1110/SEC1210 chip,
use the provided API function in ROM to perform the clock divider update. This function is 16-byte aligned,
and ensures that when the write to the CPU and memory clock dividers occurs, an OTP fetch is from the
cache and not the OTP ROM.
TABLE 16-2: BOOT BLOCK ADDRESS MAP FOR A10:=1
WORD#
SECTO
R
ADDRE
SS
A9
A[8:4] A[3:2] A[1:0] CONTENTS
PGM
ACCES
S
DATA ON ALL
OUTPUTS
0 0/1 xxxxx 00 00 For Testing or User Application yes 0 or PGM.
1 0/1 xxxxx 00 01 Read Only, Unprogrammed no 1
2 0/1 xxxxx 00 10 For Testing or User Application yes 0 or PGM.
3 0/1 xxxxx 00 11 Read Only, Unprogrammed no 1
4 0/1 xxxxx 01 00 For Testing or User Application yes 0 or PGM.
5 0/1 xxxxx 01 01 Read Only, Unprogrammed no 1
6 0/1 xxxxx 01 10 For Testing or User Application yes 0 or PGM.
7 0/1 xxxxx 01 11 Read Only, Unprogrammed no 1
8 0/1 xxxxx 10 00 For Testing or User Application yes 0 or PGM.
9 0/1 xxxxx 10 01 Read Only, Unprogrammed no 1
10 0/1 xxxxx 10 10 For Testing or User Application yes 0 or PGM.
11 0/1 xxxxx 10 11 Read Only, Unprogrammed no 1
12 0/1 xxxxx 11 00 For Testing or User Application yes 0 or PGM.
13 0/1 xxxxx 11 01 Read Only, Unprogrammed no 0
14 0/1 xxxxx 11 10 For Testing or User Application yes 0 or PGM.
15 0/1 xxxxx 11 11 Read Only, Unprogrammed no 0
SEC1110/SEC1210
DS00001561C-page 178 2013 - 2016 Microchip Technology Inc.
16.2.2 REDUNDANT MODE
Redundant Mode (enabled by MR4) can be used in applications where the certainty of being able to program any information
bit is required
The two words that store the information are located at A1=1 and A1=0. During a redundant mode read, the A1 address
is ignored; however, A1 is needed during program and program-verify to access the 2 words individually. Program-verify
is a programming step where the application sets up the macrocell to read in Single-Ended Mode using aggressive read
voltage and timing to verify proper data storage. To ensure that the data will be read back reliably during operation, the
same information should be stored into both A1 addresses, regardless of whether any cell is defective.
16.2.3 ROW REDUNDANCY
Redundant Mode can also be used with differential read, as Differential-Redundant Mode, in which case 4 cells would
be used to store one information bit. The 4 cells reside in the A[1:0] address space 00b to 11b.
Row redundancy is a word-oriented repair mechanism. It can repair both defective programmed and unprogrammed
cells, and can be used with all read modes: single-ended, differential, redundant, and differential-redundant.
Row redundancy can also be used to replace already programmed words in situations such as firmware update if the
application does not use row redundancy for repairs.
The Redundancy Register (RR) is used to achieve row redundancy and defective word repairs in the NVM memory.
16.2.3.1 Redundant words
In each memory sector there are 16 redundant words (spare entries). To repair a defective word in a sector, the entire
16-word segment containing the defective word is replaced with the 16 redundant words (spare entries) in the same
sector. The 16-word segments that can be replaced in the NVM memory are aligned on a 4-bit boundary (lowest 4 bits
of address from 0x0 to 0xF). The Redundancy Register stores the addresses of defective 16-word segments in the different
sectors.
Only one replacement of 16 words as a group can be made per sector. All 16 redundant words must be programmed
with the data that would otherwise go to the normal words.
Typically, to program the redundant words the Mode register ‘row redundancy access’ bit (MR9) should be enabled. The
normal words are disabled, and memory operations (program, program-verify, read) are performed only on the redundant
words. In this case, the redundant words are addressed as follows: A10=0, A9 selects the sector, A[3:0] selects
one of the 16 words, A[8:4] is ignored. Once redundant word programming has finished, disable the row redundancy
access bit.
16.2.3.2 Redundancy Register (RR)
Each byte in the RR stores the address of a 16-word segment containing one or multiple defective words. A bit in each
byte indicates when the stored address is valid. The addresses stored in the RR are used by the address comparator
to detect defective rows to be replaced by the redundant words (spare entries). The number of bytes in the RR are 16.
TABLE 16-3: OTP REDUNDANCY REGISTER
OTP_REDUNDANCY_REG
(0X20 ~ 0X2F - RESET = 0XXX) OTP REDUNDANCY REGISTER
BIT NAME R/W DESCRIPTION
7 OTP_RR_S2 R/W Set to 0
6 OTP_RR_A8 R/W A8 bit of defective word in sector
5 OTP_RR_A7 R/W A7 bit of defective word in sector
4 OTP_RR_A6 R/W A6 bit of defective word in sector
3 OTP_RR_BEMF R/W Byte Enable Master Fuse, when set to 1, indicates that the OTP_RR
byte contains a valid address to be detected. When no detection is
required, to prevent the RR byte from producing a match this bit
should be set to 0.
2 OTP_RR_A5 R/W A5 bit of defective word in sector
1 OTP_RR_A4 R/W A4 bit of defective word in sector.
0 Not used R/W Not used.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 179
SEC1110/SEC1210
Each byte in the RR corresponds to a memory sector. At power-up or macrocell reset, the RR is automatically loaded
from boot rows 0 and 2 of sector 1 (A9=1, A[8:4]=xxxxx, A[3:0]=0/2) in Redundant Mode. Thus the addresses to be
detected (defective 16-word segment addresses) must be programmed in boot rows 0 and 2 of sector 1 with the same
data.
The RR byte at 0x20 must be used for repairs in sector 0, and RR at 0x21 must be used for repairs in sector 1.
The other redundant words (spare entries) RR bytes 0x22 ~ 0x2F can be used for other purposes such as extra storage,
incremental memory updates/replacements, as long as bit 3 of these bytes are not programmed.
When boot rows 0 and 2 of sector 1 have never been programmed, such as during initial macrocell programming, the
boot read sequence will load all zeros into RR. Thus bit 3 of all RR bytes will be zero and the address detector will not
produce any matches even if the RED_EN port is high.
The RR bytes would be programmed at test time, if a defective bit is detected during cell stress test. If the OTP has no
defects and the RR bytes are unprogrammed, repairs may be done by the customer for other purposes such as code
patching.
16.2.3.3 Address detector
Row redundancy is enabled by setting the RED_EN pin HIGH. This pin enables the address comparator. The redundant
addresses may be accessed by setting MR9 HIGH for programming or read operations.
The address comparator compares the input addresses against the defective 16-word segment addresses stored in the
RR. When a match is found, the word at address A[3:0] in the spare 16-word segment is accessed instead of the normal
memory array word.
For 128 Kbits OTP ROM, the sector bits S0=A9, S[2:0]=00.
16.2.4 SPECIAL REGISTERS
The OTP Special Register powers up in an all HIGH state and is loaded with the content of boot rows 0 and 2, sector 0
after a power-up or a RESET command. The SR may be used to control security lock, multiple-time programmability,
encryption keys and other customer-defined functions.
The assignment of the Special Register bytes are shown in Table 16-5, “OTP SR Byte Assignment,” on page 180. The
byte 0 location is registered in the OTP_CFG Register when the OTP is powered up the first time. Similarly bytes 1, and
2 are registered by the OSC_TEST_REGS, when the OTP is powered up the first time.
TABLE 16-4: OTP SPECIAL REGISTER
OTP_SPECIAL
(0X00 ~ 0X0F - RESET = 0XXX) OTP SPECIAL REGISTERS
BIT NAME R/W DESCRIPTION
7:0 OTP_SPECIAL[7:0] R Special registers
SEC1110/SEC1210
DS00001561C-page 180 2013 - 2016 Microchip Technology Inc.
16.2.5 SERIAL TEST PORT INTERFACE
The test port is controlled by the following bits:
• TSCK, TSI, TSO (serial interface)
• TCMD[2:0] (test port instruction)
• TRSTN (asynchronous reset)
• TCLRN (asynchronous command clear)
TABLE 16-5: OTP SR BYTE ASSIGNMENT
BYTE BITS NAME DESCRIPTION
0 7 FORCE_OTP_ROM 1 : Forces execution out of the OTP ROM irrespective of BOND2
value.
0 : Execute out of ROM or OTP_ROM, or external SPI2 depending on
Table 7-1, “Code Execution Truth Table,” on page 21.
6 OTP_ROM_EN 1 : Forces execution out of the OTP ROM if BOND2 (i.e.,
EXT_SPI2_EN) is zero.
0 :Execute out of OTP ROM, or external SPI depending on BOND2
5 JTAG_DIS If this bit is programmed, then JTAG_CLK pin cannot be configured
in JTAG Mode. OCDS debug access to 8051 CPU is disabled.
LVJTAG access is also disabled.
4:3 Reserved Reserved
2:1 LOCK[1:0] Active high. Locks VPP switch in individual sectors 1 and 0.
0 MLOCK Active high. Locks VPP switch to all sectors.
1 7:0 Reserved Reserved field for test.
This field is used for 48 MHz oscillator trim.
2 7:4 Reserved Reserved field for test.
This field is used for Band Gap trimming.
3:2 Reserved Reserved field for test
1:0 Reserved Reserved field for test.
This field is used for 48 MHz oscillator trim.
3 7:0 Reserved Reserved field for test
4 7:0 Reserved Reserved field for test
5 7:0 Reserved Reserved field for test.
6 7:0 Reserved
7 7:0 Reserved Reserved field for test.
8 7:0 Reserved
9 7:0 Reserved Reserved field for test
10 7:0 Reserved
11 7:0 Reserved Reserved field for test.
12
13
14
15
7:0 Reserved
UNIQUE_SNO
Reserved field for test.
This field is a Unique Serial number to make each die unique.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 181
SEC1110/SEC1210
The key objective for the test port design is to provide random access to the memory through a set of shift registers for
testing and programming purposes. This is achieved by shifting in and out data, address and command synchronously
with a serial clock. The length of all the registers is optimized for fastest test execution.
In addition, a burst mode is provided that allows the user to quickly scan, shift or compare all or selected memory
addresses under control of the internal address counter. An example of a READ CLEAN ARRAY test program using the
burst mode is provided later.
16.2.5.1 Serial Test Port Operations
The test port consists of an instruction decoder decoding the state of the test control pins TCMD[2:0], a 6-bit command
register (CMD), a 24-bit mode register (TMODE), a 24-bit shift register (SHIFT) and a variable length address register
(ADDRESS). SERIAL CONTROL logic is used to provide serial data input and serial data output connection.
The following instructions are decoded from pins TCMD[2:0]: IDLE, DIRECT, SHIFT, UPDATE_MODE,
UPDATE_ADDR, ROTATE, UPDATE_CMD, INC_ADDR. Table 16-6, “TCMD[2:0] Instruction Decoder,” on page 181
lists all valid instruction codes.
The shift register is controlled by the serial clock TSCK (through JTAG_CLK) while the SHIFT instruction is decoded.
The MSB is shifted first. The CMD, ADDRESS and TMODE registers are updated with the contents of the SHIFT register
synchronously with TSCK upon decoding the UPDATE_CMD, UPDATE_ADDR and UPDATE_MODE instructions
respectively. The mapping of the shift register bits to CMD, ADDRESS, TMODE bits is shown in Table 16-7, “TEST PORT
Registers Mapping,” on page 182. The 8051 CPU has parallel access to the shift register through CPU_SHIFT_REG
Register.
The CMD Register controls the macrocell commands: READ, WRITE, PGM, PCH, COMP and RESET. The state of the
CMD Register is synchronously with TSCK cleared by the IDLE instruction and asynchronously cleared by the TCLRN
pin LOW. The 8051 CPU has parallel access to the command register through CPU_TCMD_REG Register.
The TMODE Register controls macrocell control inputs. In addition, it controls the output TSO (to JTAG_TDO) multiplexer
and a special burst/increment access mode.
The DIRECT, ROTATE instructions provide control asynchronously for the macrocell SEN pin. DIRECT instruction connects
the TSCK and TSI to macrocell serial port pins SCK and SI, which allows for direct serial access to the macrocell
DATA REGISTER and macrocell MODE REGISTER. The ROTATE instruction connects the SO macrocell output to SI
macrocell input and connects the TSCK to macrocell SCK input.
The IDLE command clears the macrocell command register at the positive edge of the TSCK clock. The INC_ADDR
command acts like the IDLE command but increments the address by 1 or 2 depending on the INC2 bit in the Test Mode
Register.
If INC2 = 0, addr = addr + 1
If INC2 = 1, addr = addr + 2
The tables below provides detail description for instruction set, registers mapping, burst and output TSO mux operation.
TABLE 16-6: TCMD[2:0] INSTRUCTION DECODER
TCMD[2:0] DECODED STATE DESCRIPTION
000 IDLE Reset CMD Register, increment ADDR if BURST0 and
READ are active
001 DIRECT Macro SEN=HIGH, SCK=TSCK, SI=TSI
010 SHIFT Shift data in SHIFT Register by positive edge of TSCK
011 UPDATE_TMODE Update TMODE Register by positive edge of TSCK
100 UPDATE_ADDR Update ADDR Register by positive edge of TSCK
101 ROTATE Macro SEN=HIGH, SCK=TSCK, SI=SO
110 UPDATE_CMD Update CMD Register by positive edge of TSCK
111 INC_ADDR Reset CMD Register, increment ADDR
SEC1110/SEC1210
DS00001561C-page 182 2013 - 2016 Microchip Technology Inc.
TABLE 16-7: TEST PORT REGISTERS MAPPING
SHIFT TMODE REGISTER CMD REGISTER ADDRESS REGISTER
SR0 TSO_SEL0 COMP A0
SR1 TSO_SEL1 PCH A1
SR2 TSO_SEL2 PGM A2
SR3 BURST0 READ A3
SR4 BURST1 WRITE A4
SR5 INC2 RESET A5
SR6 MODE_SEL A6
SR7 RESET_M A7
SR8 AUX_UPDATE A8
SR9 MACRO_SEL A9
SR10 PWR_DOWN A10
SR11 MLOCK
SR12 BIT_LOCK0
SR13 BIT_LOCK1
SR14 BIT_LOCK2
SR15 RED_EN
SR16 PWRUP_ENB
SR17 LOAD_QR
SR18 QS_TEST
SR19 PUP_DIS
SR20 P_START
SR21 ALL_BANKS
SR22 MRB
SR23 MRA
SR24 AB0
SR25 AB1
SR[26 AB2
SR27 Reserved
SR28 Reserved
SR29 Reserved
SR30 Reserved
SR31 Reserved
TABLE 16-8: TSO OUTPUT MULTIPLEXER DESCRIPTION BURST CONTROL TABLE
TSO_SEL[2:0] TSO FUNCTION TSO_SEL[2:0] TSO FUNCTION
000 STATUS 100 PWR_UP
001 SO 101 VPP_MON
010 A10 110 STATUS
011 STATUS 111 STATUS
2013 - 2016 Microchip Technology Inc. DS00001561C-page 183
SEC1110/SEC1210
16.2.6 PARALLEL ACCESS TO TEST PORT INTERFACE
Parallel access for the 8051 CPU. This enables parallel writes to the OTP Data and Mode registers.
16.2.6.1 OTP CPU Test Port Command Instruction Register
16.2.6.2 OTP CPU Test Port Control Register
16.2.6.3 OTP CPU Test Port Shift Register
BURST[1:0] FUNCTION
00 no
01 READ
10 no
11 READ/COMP
TABLE 16-9: CPU TEST PORT COMMAND INSTRUCTION REGISTER
CPU_TCMD_REG
(0X36 - RESET = 0X10) OTP TEST PORT COMMAND REGISTER
BIT NAME R/W DESCRIPTION
7:5 Reserved R Always read as 0
4 TRSTN R/W OTP Test Port reset of TMODE, CMD, SHIFT registers.
3 TCLRN R/W OTP Test Port clear of the command register.
2:0 TCMD[2:0] R/W OTP Test Port Command instruction
TABLE 16-10: CPU TEST PORT CONTROL REGISTER
CPU_TCTL_REG
(0X37 - RESET = 0X00) OTP TEST PORT CONTROL REGISTER
BIT NAME R/W DESCRIPTION
7 COUNT_EN R/W Generate clocks in TSCK, COUNT times. If this bit is set, TSCK is
generated every CPU clock and COUNT field is decrement by one;
until COUNT field becomes zero.
6:0 COUNT[5:0] R/W Indicated number of TSCK clocks to generate
TABLE 16-11: CPU TEST PORT SHIFT REGISTER
CPU_SHIFT_REG
(0X38 ~ 0X3B- RESET = 0X00) OTP TEST PORT SHIFT REGISTER
BYTE NAME R/W DESCRIPTION
0 SHIFT[7:0] R/W OTP Test Port Shift register. The mapping of shift register bits to
TMODE, CMD, ADDRESS registers of OTP is shown in Table 16-
7, “TEST PORT Registers Mapping,” on page 182. 1 SHIFT[15:8] R/W
2 SHIFT[23:16] R/W
3 SHIFT[31:24] R/W
SEC1110/SEC1210
DS00001561C-page 184 2013 - 2016 Microchip Technology Inc.
16.2.6.4 OTP CPU Test Port Status Register
The writes to OTP_TDATA_REG[7:0] at 0x40 offset (OTP_TDATA_REG at 0x41 to 0x4F must have been written earlier),
cause this data to be input to OTP, and the WRITE command to be pulsed (a single ref_clk).
The bits in TMODE register must have been updated by the firmware by writing to the CPU_SHIFT register and
UPDATE_MODE command before any of the Mode register writes.
The reads to any register in OTP_TDATA_REG causes the current internal OTP data register values to be provided to
the CPU.
16.2.6.5 Mode Register (MR)
The Mode Register controls all internal references needed for read, program, verify and test operations. The RESET_M
command resets the Mode Register to its default settings. The MODE_SEL pin selects between the Data Register and
the Mode Register for serial shift and parallel write access. Both registers have common serial input and output (SI,SO)
pins, but they have separate parallel data input and output buses.
The hardware asserts RESET for a clock (clk48) to the OTPROM to reset the MR, MRA, MRB registers, to be ready for
Functional Mode.
TABLE 16-12: CPU TEST PORT STATUS REGISTER
CPU_TP_STATUS_REG
(0X3C ~ 0X3C- RESET = 0X00) OTP TEST PORT STATUS REGISTER
BIT NAME R/W DESCRIPTION
7:5 Reserved R Always read as 0
4 OTP_TSO R Indicates the Test Port TSO value.
3 OTP_SO R Serial data output from DATA/MODE REGISTER
2 OTP_STATUS R Active high. Comparator output.
1 OTP_VPP_MON R Active high. If enabled (HIGH), indicates that VPP is applied.
0 OTP_PWR_UP R Active high Power-up reset output. HIGH when power detected.
Status bit, used by ROM firmware to ensure OTP is working.
TABLE 16-13: OTP MODE REGISTER LSB
OTP_MODE_MRL
(0X30 - RESET = 0X00) OTP MODE REGISTER LSB
BIT NAME R/W DESCRIPTION
7:0 MR[7:0] R/W Microchip use only.
TABLE 16-14: OTP MODE REGISTER MSB
OTP_MODE_MRH
(0X31 - RESET = 0X00) OTP MODE REGISTER MSB
BIT NAME R/W DESCRIPTION
7:0 MR[15:8] R/W Microchip use only.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 185
SEC1110/SEC1210
16.2.6.6 Auxiliary Mode Register (MRA and MRB)
In addition to the main Mode Register (MR), OTP macrocells are equipped with Auxiliary Mode Registers (MRA and
MRB) controlling internal voltage regulators and charge pumps. These registers are accessed using AUX_UPDATE
command and the MRA and MRB settings.
The writes to OTP_MODE_MRL (OTP_MODE_MRH must have been written earlier), cause this data to be input to OTP,
and the WRITE command to be pulsed (a single ref_clk).
Similarly, the writes to OTP_MODE_MRAL (OTP_MODE_MRAH must have been written earlier), cause this data to be
input to OTP, and the WRITE command to be pulsed (a single ref_clk).
The writes to OTP_MODE_MRBL (OTP_MODE_MRBH must have been written earlier), cause this data to be input to
OTP, and the WRITE command to be pulsed (a single ref_clk).
The bits in TMODE register must have been updated by the firmware by writing to the CPU_SHIFT register and
UPDATE_MODE command before any of the Mode register writes.
The reads to OTP_MODE_MRH or OTP_MODE_MRL causes the current internal OTP Mode Register values to be
updated to these registers, and provided to the CPU.
The reads to OTP_MODE_MRAH or OTP_MODE_MRAL causes the current internal OTP Mode Register A values to
be updated to these registers, and provided to the CPU.
The reads to OTP_MODE_MRBH or OTP_MODE_MRBL causes the current internal OTP Mode Register B values to
be updated to these registers, and provided to the CPU.
TABLE 16-15: OTP MODE A REGISTER LSB
OTP_MODE_MRAL
(0X32 - RESET = 0X00) OTP MODE A REGISTER LSB
BIT NAME R/W DESCRIPTION
7:0 MRA[7:0] R/W Microchip use only.
TABLE 16-16: OTP MODE A REGISTER MSB
OTP_MODE_MRAH
(0X33 - RESET = 0X00) OTP MODE A REGISTER MSB
BIT NAME R/W DESCRIPTION
7:0 MRA[15:8] R/W Microchip use only.
TABLE 16-17: OTP MODE B REGISTER LSB
OTP_MODE_MRBL
(0X34 - RESET = 0X00) OTP MODE B REGISTER LSB
BIT NAME R/W DESCRIPTION
7:0 MRB[7:0] R/W Microchip use only.
TABLE 16-18: OTP MODE B REGISTER MSB
OTP_MODE_MRBH
(0X35 - RESET = 0X00) OTP MODE B REGISTER MSB
BIT NAME R/W DESCRIPTION
15:0 MRB15:0 R/W Microchip use only.
SEC1110/SEC1210
DS00001561C-page 186 2013 - 2016 Microchip Technology Inc.
16.2.7 MEMORY COMMANDS
16.2.7.1 WRITE Command
The user has full access to the Data and Mode registers through the parallel input/output ports using SHIFT and WRITE
commands. The WRITE command loads asynchronously data into the Data Register (or Mode Register). The selection
between the Data and Mode registers is done with the MODE_SEL bit. During programming, the SHIFT or WRITE commands
are used to write data into the Data Register, which is then programmed into the NVM memory array using the
PROGRAM command. The commands are also used to setup the different registers (MR, MRA, MRB) of the SiPROM
macrocell.
16.2.7.2 SHIFT Command
The OTP ROM macrocell interface is implemented as a serial/parallel input/output interface to the shift registers
(Data/Mode registers). The SHIFT command interface includes the Shift Clock (SCK), the Shift Enable (SEN), the Shift
Input (SI) and the Shift Output (SO) pins. Bits are shifted serially through the SI pin into the Most Significant Bit (MSB)
of the Data/Mode Register. All bits inside the Data/Mode Register are shifted by one position lower at each SCK period
when SEN is held high. The Least Significant Bit (LSB) of the Data/Mode Register is output on the SO pin. All bits are
shifted synchronously with the SCK clock.
The selection between the Data and Mode registers is done with the MODE_SEL signal.
16.2.7.3 READ Command
The READ command asynchronously transfers data from the memory location addressed by the A[10:0] pins to the
Data Register output latch, without overriding the input latch set by the WRITE or SHIFT commands. Once retrieved,
the data is available on the parallel outputs Q[127:0] or can be shifted out through the SO pin using the serial clock SCK
and SHIFT command.
The READ command is externally controlled by the READ pulse width.
2013 - 2016 Microchip Technology Inc. DS00001561C-page 187
SEC1110/SEC1210
17.0 TEST MODES, JTAG, AND XNOR
There are two JTAG controllers in parallel, one for 8051 CPU Functional Mode and one for test modes. Only one of the
them is active at any time, depending on the mode of operation.
17.1 Functional 8051 JTAG Capabilities
• Fully compliant with IEEE1149.1 standard
• 4-bit Instruction Register
• Standard 1-bit BYPASS register
• Standard 32-bit IDCODE register
• Four JTAG registers give access to on-chip memory and register resources
• Boundary Scan for the chip
FIGURE 17-1: JTAG TEST BLOCK DIAGRAM
TEST JTAG 8051 JTAG (O C D S) JTAG_TDI JTAG_CLK JTAG_TMS JTAG_TDO
T est M odes F unctional M ode
SEC1110/SEC1210
DS00001561C-page 188 2013 - 2016 Microchip Technology Inc.
18.0 DC PARAMETERS
18.1 Maximum Ratings
Note 18-1 Stresses above the specified parameters may cause permanent damage to the device. This is a
stress rating only. Functional operation of the device at any condition above those indicated in the
operation sections of this specification is not implied.
Note 18-2 When powering this device from laboratory or system power supplies the Absolute Maximum Ratings
must not be exceeded or device failure can result. Some power supplies exhibit voltage spikes on
their outputs when the AC power is switched on or off. In addition, voltage transients on the AC power
line may appear on the DC output. When this possibility exists, a clamp circuit should be used.
Note 18-3 RESET_N should not be set HIGH (e.g., 5.5 V) if VDD5 is 0 as the circuit will not be reliable.
PARAMETER SYMBOL MIN MAX UNITS COMMENTS
Storage
Temperature
TSTOR -55 150 °C
Lead
Temperature
°C Refer to JEDEC
Specification J-STD-020D
VDD5 supply
voltage
VDD5 -0.3 5.5 V
Voltage on
USB_DP and
USB_DM pins
-0.3 3.6 V 3.3 V 10%.
Voltage on
RESET_N
0 VDD5 (Note 18-3) V This pin may be connected
to VDD5 externally
(optionally to a RC circuit), or
is between 3.0 to VDD5.
indefinitely, without damage
to the device as long as
VDD5 are less than 5.5 V and
TA is less than 70oC.
Voltage on any
signal pin
-0.3 5.5 V • Positive Voltage on any
signal pin, with respect
to Ground 5.5 V
• Negative Voltage on any
pin, with respect to
Ground-0.3 V
• Maximum VDD5, +5.5 V
FIGURE 18-1: SUPPLY RISE TIME MODELS
t10%
10%
90%
Voltage tR T
t90% Tim e
100%
VSS
VDD5 3.0V to 5.5V
2013 - 2016 Microchip Technology Inc. DS00001561C-page 189
SEC1110/SEC1210
18.2 Operating Conditions
Note 18-1 0°C for commercial, -40°C for industrial.
Note 18-2 +70°C for commercial, +85°C for industrial.
18.3 DC Electrical Characteristics
(TA = 0°C - 70°C, VDD5 = +3.6 V to +5.5 V, unless otherwise noted)
PARAMETER SYMBOL MIN MAX UNITS COMMENTS
Operating Temperature TA Note 18-1 Note 18-2 °C Ambient temperature in air.
5.0 V supply voltage VDD5 3.6 5.5 V This pin may be connected to
VBUS of USB. To support Class A
Smart Card a 4.8 V minimum is
required which may not be met by
VBUS.
VDD5 supply rise time tRT 400 ns (Figure 18-1)
Voltage on
USB_DP and USB_DM
pins
3.0 3.6 V If VDD5 drops below 3.6 V, then
the MAX becomes VDD5
Voltage on RESET_N 0 VDD5
(Note 18-3)
V This pin may be connected to
VDD5 externally (optionally to a
RC circuit), or is between 3.0 to
VDD5.
indefinitely, without damage to the
device as long as VDD5 are less
than 5.5 V and TA is less than
70oC.
Voltage on any signal
pin
-0.3 5.5 V Other than USB_DP, USB_DM,
Smart Card pins, RESET_N
PARAMETER SYMBOL MIN TYP MAX UNITS COMMENTS
I/O8PUD Type Bidir Pad
Low Output Level VOL - - 0.4 V IOL = -8 mA
High Output Level VOH VDD33
- 0.4
- - VIOH = 8 mA
8 mA I/O sinking current IOL8 8.3 12.6 18.4 mA VOUT = 0.4 V
8 mA I/O sinking output impedance ROL8 21.7 31.6 48.3 VOUT = 0.4 V
8 mA I/O sourcing current IOH8 8.1 11.6 16 mA VOUT = VDD33 - 0.4 V
8 mA I/O sourcing output
impedance
ROH8 25 34.6 50 VOUT = VDD33 - 0.4 V
Output Leakage IIH5 1 µA VIN= 0 to VDD33,27°C
1.4 8 12 µA VIN = 0 to 5.5 V, 27°C
20 µA VIN = 0 to 5.5 V, 85°C
80 µA VIN=0 to 5.5 V,125°C
(Note 18-3)
Low Input Level VIL -0.3 - 0.8 V
High Input Level VIH5 2.0 - 5.5 V
Hysteresis VHYSI 336 399 459 mV
Pull-Down RDPD 46 65 90 k Condition Vpad =
VDD33 IDPD 33 50 79 A
Pull-Up RDPU 53 66 80 k Condition Vpad = 0 V
(Note 18-8) IDPU 38 50 68 A
SEC1110/SEC1210
DS00001561C-page 190 2013 - 2016 Microchip Technology Inc.
Note 18-3 Output leakage is measured with the current pins in high impedance.
Note 18-4 See Chapter 7, USB Specification Revision 2.0 for USB DC electrical characteristics.
Note 18-5 See the USB 2.0 Specification, Chapter 7, for USB DC electrical characteristics.
Note 18-6 The minimum VDD5 voltage necessary for proper operation of USB is 3.6 V.
Note 18-7 The USB suspend mode current ICSBY includes the current drawn through the USB_DP pin, which is
mandatory to indicate it is connected as a 12 Mbps device.
Note 18-8 Pull-up and pull-down impedances change with pad output voltage due to 5 V protection circuitry, the
voltage measured on a 5 V tolerant I/O pad during pull-up is a volt tolerant below VDD33.
Note 18-9 See the ISO/IEC7816-3 Third Edition 2006-11-01, Section 5.2 for Smart Card electrical
characteristics.
Note 18-10 See the EMV 4.3 Specification for Smart Card Test and compliance setup.
Note 18-11 See the GSM Specification for Smart Card Test and compliance setup.
Note 18-12 All signal pins are 5 V tolerant
IO-U
(Note 18-5)
USB
(Note 18-5)
(Note 18-6)
RESET_N Rise Time Trst_r 100 ns RESET_N pad
(Note 18-3) RESET_N Fall Time Trst_f 100 ns
RESET_N Low Input level VILRST 0.1 V RESET_N low causes
STOP mode entry
Oscillator 48/8/4 MHz accuracy
-40 < T < 125 °C
3.6 < VDD5 < 6.8 V
F48acc 0.1 0.2 % Internal oscillator @
48 MHz with USB
Dynamic Trim enabled
F48accd 0.82 1.5 % Internal oscillator @
48 MHz without USB
Dynamic Trim enabled
F8acc 0.78 1.83 % Internal oscillator @ 8
MHz
F4acc 0.78 1.83 % Internal oscillator @ 4
MHz
PARAMETER SYMBOL MIN TYP MAX UNITS COMMENTS
Smart Card SC1_VCC, SC2_VCC Regulator Output (IEC7816-3 Class A/B/C)
Smart Card Power Supply Voltage VSC1_VCC,
VSC2_VCC
4.6 VDD5-
0.2
min
((VDD5-
0.285),
5.25)
V Class A mode,
ISC1_VCC = 0 to 55 mA
Note 18-13
2.76 3.0 3.24 V Class B mode
1.66 1.8 1.94 V Class C mode
Smart Card Power Supply current ISC1, ISC2 55 mA Class A/B/C
Smart Card Over Current Sense
(OCS) Detection
IOCS1, IOCS2 110 mA
Detection Time on OCS tOSCDET 1 s
SC1_VCC/SC2_VCC Turn Off Time tSCOFF 5 ms SEC1110/SEC1210 A1
version
Note 18-14
500 s All Later versions
SC1_VCC/SC2_VCC Turn On Time tSCON 1 ms 1.0 F load
Note 18-14
PARAMETER SYMBOL MIN TYP MAX UNITS COMMENTS
2013 - 2016 Microchip Technology Inc. DS00001561C-page 191
SEC1110/SEC1210
Smart Card SC1_CLK/SC2_CLK Pin
SC1_CLK, SC2_CLK Low Output
Level at VSC1_VCC/VSC2_VCC=min
@ CL=30pF
Note 18-15
VOL 0 0.4 V Class A:
SEC1110/SEC1210 A1
version:
100µA < IOL < 0,
All Later versions:
IOLmax = -1 mA @125
°C
0 0.4 V Class B:
SEC1110/SEC1210 A1
version:
100µA < IOL < 0,
Later versions:
IOLmax = -1 mA @125
°C
0 0.15
VSCx_VC
C
V Class C:
SEC1110/SEC1210 A1
version:
100µA < IOL < 0,
Later versions:
IOLmax = -1 mA @125
°C
SC1_CLK, SC2_CLK High Output
Level at VSC1_VCC/VSC2_VCC=min
@ CL=30pF
Note 18-16
VOH VSCx_VC
C
- 0.5V
VSCx_VC
C
V Class A
0
2012-2015 Microchip Technology Inc. DS00001476B-page 1
INTRODUCTION
Although many applications can function with PWM
resolutions of less than eight bits, there is a range of
applications, such as dimming of lamps, where higher
resolution is required due to the sensitivity of the
human eye.
BACKGROUND
A conventional PWM uses a timer to produce a regular
switching frequency (TPWM), and then uses a ripple
counter to determine how many clocks the output is
held high before the pulse ends.
The output pulse width is adjusted as indicated in
Figure 1 to produce, in this case, a PWM with five
possible duty cycle settings (0%, 25%, 50%, 75% or
100%).
FIGURE 1: CONVENTIONAL PWM
The effective resolution (measured in bits) of a PWM
can be calculated by taking the base-2 logarithm of the
number of pulse width settings (N) possible.
EQUATION 1: PWM RESOLUTION
For a device running at 16 MHz, the smallest duty cycle
adjustment increment would be 62.5 ns (one system
clock). If the PWM is configured to run at a switching
frequency of 200 kHz (switching period of 5 us), 100%
duty cycle will be achieved when the duty cycle register
is set to 80 clocks (80 x 62.5 ns = 5 us). This would
make the effective PWM resolution only slightly more
than six bits, as there are 80 steps to choose from. This
is because one system clock divides into one period 80
times.
Knowing that there are 80 possible duty cycle steps, a
precise value for the resolution of the PWM can be
calculated as follows (Equation 2):
EQUATION 2: PWM RESOLUTION
EXAMPLE
A PWM running from a 16 MHz clock, which has a
10-bit duty cycle register, will start losing resolution due
to this limitation at a 15.6 kHz switching frequency. For
higher PWM switching frequencies, the duty cycle will
reach 100% before all of the steps in the 10-bit duty
cycle register have been used, and for all the remaining
values the output will simply remain at 100% duty
cycle.
The frequency at which this point is reached can be
calculated as follows (Equation 5):
EQUATION 3: SWITCHING FREQUENCY
LIMITATION
Author: Cobus Van Eeden
Microchip Technology Inc.
Resolution log = 2 N
log280 6.32 bits =
Fosc
#Steps --------------- 16MHz
2
10 ------------------ 16 000 000
1024 == = ----------------------------- 15.6 kHz
Combining the CLC and NCO to Implement
a High-Resolution PWM
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AN1476
DS00001476B-page 2 2012-2015 Microchip Technology Inc.
In most PWM applications, the PWM is switched at a
much higher frequency than the output can ever
change. By filtering this PWM signal using a low-pass
filter, the desired output is obtained. The filter removes
the high-frequency switching components of the PWM
by essentially calculating the average value of the
PWM signal, and presents this as the output. For
example, in a switching power supply, the output voltage
will be directly proportional to the duty cycle. The
consequence of this relationship is that the smaller the
adjustment to the PWM duty cycle, the smaller the
resulting change to the output will be resulting in more
precise control of the output.
From a control systems point of view, being able to
make small adjustments to the output effectively lowers
the quantization gain introduced by the PWM. In control
systems, this lowering of the gain is important to ensure
stability of the system.
DESIGN
PWM Construction
In principal, a PWM is created by the combination of the
two parameters. The first being a repeating trigger,
which determines how often the switching period or
switching frequency are pulsed, and the second being
a single-pulse generator, which determines how wide
the pulse is (the duty cycle). This is illustrated in
Figure 2.
FIGURE 2: PWM CONSTRUCTION
In order to achieve an increase in the effective PWM
resolution, the NCO peripheral on the PIC® device will
be used to create a monostable circuit (a circuit that
gives a single pulse of fixed duration when triggered).
The NCO will generate a signal that varies between two
values in a defined proportion, creating an average
pulse width, which is somewhere in between two
system clocks, as illustrated in Figure 3. The PWM
signal pulse width will vary (jitter/dither) by one clock
period, with the proportion/ratio of the variation
precisely determined by the NCO configuration.
FIGURE 3: NCO BASED PWM OPERATION
Switching Period Source
Pulse Generator
Repeating Pulses = PWM
Trigger
2012-2015 Microchip Technology Inc. DS00001476B-page 3
AN1476
In any application where the output is producing an
average value (e.g., average power transfer to the load
in SMPS or lighting applications), the variation in pulse
width will be perfectly acceptable, because the average
pulse width is accurately controlled.
By itself, the NCO peripheral cannot produce a PWM
signal, but its behavior can be changed by adding
some logic using the CLC to produce a PWM output.
This can be achieved by using the conventional PWM
as a clock source to trigger the PWM period, and use
the NCO to determine the pulse width. Any number of
clock sources could be used (e.g., Timers or even
external signals), and in some applications an external
trigger can be used to start the pulses, such as a
zero-current detection circuit for power supplies. A
simplified block diagram of how this will work is shown
in Figure 4.
FIGURE 4: NCO-BASED PWM PRINCIPLE OF OPERATION
The control logic in the CLC is used to set an output
when the switching clock indicates that it is time for the
next pulse, and clear this output to complete the pulse
once the NCO overflows.
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DS00001476B-page 4 2012-2015 Microchip Technology Inc.
IMPLEMENTATION USING CLC AND NCO
An implementation of this design using the NCO and
CLC is shown in Figure 5. For this design, the NCO is
placed in Pulse Frequency mode. In this mode of
operation, a short pulse is produced when the NCO
overflows.
The operation of the circuit can be described as
follows:
1. When the system begins, the NCO output is low
because it is waiting for enough clocks to count
until it overflows and produces a pulse. This low
output signal is inverted so that the PWM output
becomes high and is fed into U2. This will supply
a high-speed clock back into the NCO clock pin
via U3.
2. The PWM output will remain high until the
accumulator overflows and the NCO output
changes. This will cause U2 to stop producing
the clock needed to run the NCO. At this point,
the NCO is stuck high until it can get the clocks
needed to finish its pulse. The PWM output is
now low.
3. The timing source will then pulse high through
U1 when the next period begins, feeding the
high-speed clock back to the NCO via U3.
4. The NCO uses these few clocks to finish the
pulse, and then the output toggles back to the
low position where it starts the process over
from step 1 above. The amount of time it takes
the NCO to overflow will depend on the remainder
left in the accumulator after the last overflow,
as well as the increment register. Due to the
accumulation of remainders the pulse will sometimes
be one system clock shorter than usual.
By controlling how often this happens (setting
the increment register), the exact average pulse
width can be controlled.
FIGURE 5: PWM IMPLEMENTATION USING CLC AND NCO
CALCULATIONS
The calculation of the pulse width will be according to
the NCO overflow frequency calculation, as listed in the
data sheet.
EQUATION 4: OUTPUT FREQUENCY
The average overflow frequency of the NCO will
determine the average output pulse width (TPULSE)
produced.
EQUATION 5: AVERAGE PULSE WIDTH
Table 1 below shows the pulse width, which this circuit
will produce using a 16 MHz clock connected directly to
the NCO clock input (FNCO), given various increment
register values. Note that, for high increment values, a
single increment of the register will change the pulse
width by a mere 15 ps.
CLK
NCO
OUT PWM Output
Fosc
Timing Source
Duty Cycle Control
Time Base Examples
Timer Overflow
PWM
External Trigger (ZC/ZV)
Clock/Oscillator
Switching Frequency Control
FOUT FNCO
Increment
2
n = --------------------------
TPULSE
1
FOUT
= -------------
2012-2015 Microchip Technology Inc. DS00001476B-page 5
AN1476
CHARACTERISTICS
It is important to note that the NCO is designed to give
linear control over frequency. The control over pulse
width is subsequently not linear. As can be seen from
the equation for calculating TPULSE above (Equation 5),
the pulse width will vary with the inverse of the
frequency (1/x).
The result is that the effective resolution of the PWM is
not constant over the entire range from 0% to 100%
duty cycle.
For every duty cycle setting, the effective resolution at
this particular point can be calculated and then plotted
on a graph. This curve will look different depending on
what the switching frequency is, the pulse width being
adjusted independently from the switching frequency.
For a FSW = 3 kHz and a 16 MHz clock, the graphic will
look as follows (Figure 6).
FIGURE 6: HIGH RES PWM RESOLUTION PLOTTED AGAINST DUTY CYCLE
(CLOCK = 16 MHz, FSW = 3 kHz)
Although there is an equivalent of 21 bits of resolution
close to 0% duty cycle, this deteriorates to only 7.5 bits
of resolution at 100% duty cycle, at which point the
conventional PWM would outperform our
high-resolution implementation.
Interestingly, and perhaps counter-intuitively, the
resolution can be improved by decreasing the NCO
input clock frequency. Reducing this clock to 1 MHz will
have the result shown below (Figure 7).
TABLE 1: CALCULATED PWM PULSE WIDTH FOR DIFFERENT INCREMENT REGISTER
VALUES
Increment Value NCO FOUT (Hz) Average Pulse Width (ns)
65000 991,821 1,008.246
65001 991,837 1,008.231
20000 305,176 3,276.800
20001 305,191 3,276.636
100 1,526 655,360.000
101 1,541 648,871.287
23
21
19
17
15
13
11
9
7
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DS00001476B-page 6 2012-2015 Microchip Technology Inc.
FIGURE 7: HIGH RES PWM RESOLUTION PLOTTED AGAINST DUTY CYCLE
(CLOCK = 1 MHz, FSW = 3 kHz)
There is, of course, a limitation, as can be seen, close
to 0% duty cycle, where the increment register
maximum value is reached and smaller pulses cannot
be generated any more, but the resolution now never
reduces to less than 11 bits.
One way to improve the performance would be to invert
the PWM signal when it exceeds 50% duty cycle. Doing
this can effectively mirror the performance under 50%
duty cycle to the region above it, with the higher resolution.
There is still the option to use the original curve
where the limits of the increment are reached. This
results in the following graphic (Figure 8) for the same
conditions as the graphic above.
FIGURE 8: RESOLUTION VS DUTY CYCLE WITH SIGNAL INVERSION AT 50% DUTY CYCLE
(CLOCK = 1 MHz, FSW = 3 kHz)
19
21
17
15
13
11
9
7
22
20
18
16
14
12
10
8
2012-2015 Microchip Technology Inc. DS00001476B-page 7
AN1476
When the intention is to achieve both the highest
possible switching frequency and the highest
resolution using this technique, the configuration
shown below can be used (Figure 9). This graphic
shows the achievable resolution when using a 16 MHz
clock at a switching frequency of 500 kHz.
FIGURE 9: HIGH RES PWM RESOLUTION PLOTTED AGAINST DUTY CYCLE WITH
INVERSION AT 50% (CLOCK = 16 MHz, FSW = 500 kHz)
SUMMARY
Conventional PWMs start losing effective resolution at
relatively low-switching frequencies. For applications
where the switching frequencies have to be fairly high,
and having as much PWM resolution as possible at
these frequencies is necessary, the NCO can be used
in conjunction with the CLC to create a very
high-resolution PWM output.
The smallest incremental change in pulse width
achievable by a conventional PWM with a 16 MHz
system clock speed would be 62.5 ns. If the fastest
available PWM clock is FOSC/4, then this increases to
250 ns.
On the same device, a PWM with an incremental pulse
width change of as little as 15 ps can be constructed
using the technique described in this application note.
Even if the requirement is not primarily high resolution,
this solution may still be attractive for a number of
applications, adding an additional PWM to the
capability of the device, or having a constant
on/off-time variable frequency PWM, where the pulse is
triggered externally as required, when doing zero
current switching in high-efficiency power converters.
18
17
16
15
14
13
12
11
10
9
8
DS00001476B-page 8 2012-2015 Microchip Technology Inc.
Information contained in this publication regarding device
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and may be superseded by updates. It is your responsibility to
ensure that your application meets with your specifications.
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conveyed, implicitly or otherwise, under any Microchip
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Serial Programming, ICSP, Inter-Chip Connectivity, KleerNet,
KleerNet logo, MiWi, MPASM, MPF, MPLAB Certified logo,
MPLIB, MPLINK, MultiTRAK, NetDetach, Omniscient Code
Generation, PICDEM, PICDEM.net, PICkit, PICtail,
RightTouch logo, REAL ICE, SQI, Serial Quad I/O, Total
Endurance, TSHARC, USBCheck, VariSense, ViewSpan,
WiperLock, Wireless DNA, and ZENA are trademarks of
Microchip Technology Incorporated in the U.S.A. and other
countries.
SQTP is a service mark of Microchip Technology Incorporated
in the U.S.A.
Silicon Storage Technology is a registered trademark of
Microchip Technology Inc. in other countries.
GestIC is a registered trademark of Microchip Technology
Germany II GmbH & Co. KG, a subsidiary of Microchip
Technology Inc., in other countries.
All other trademarks mentioned herein are property of their
respective companies.
© 2012-2015, Microchip Technology Incorporated, Printed in
the U.S.A., All Rights Reserved.
ISBN: 978-1-63277-695-2
Note the following details of the code protection feature on Microchip devices:
• Microchip products meet the specification contained in their particular Microchip Data Sheet.
• Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the
intended manner and under normal conditions.
• There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our
knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data
Sheets. Most likely, the person doing so is engaged in theft of intellectual property.
• Microchip is willing to work with the customer who is concerned about the integrity of their code.
• Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not
mean that we are guaranteeing the product as “unbreakable.”
Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our
products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts
allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.
Microchip received ISO/TS-16949:2009 certification for its worldwide
headquarters, design and wafer fabrication facilities in Chandler and
Tempe, Arizona; Gresham, Oregon and design centers in California
and India. The Company’s quality system processes and procedures
are for its PIC® MCUs and dsPIC® DSCs, KEELOQ® code hopping
devices, Serial EEPROMs, microperipherals, nonvolatile memory and
analog products. In addition, Microchip’s quality system for the design
and manufacture of development systems is ISO 9001:2000 certified.
QUALITY MANAGEMENT SYSTEM
CERTIFIED BY DNV
== ISO/TS 16949 ==
2012-2015 Microchip Technology Inc. DS00001476B-page 9
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01/27/15