MC9S08LG32, MC9S08LG16 - Reference Manual

MC9S08LG32
MC9S08LG16
Reference Manual
THIS DOCUMENT CONTAINS INFORMATION ON A NEW PRODUCT UNDER DEVELOPMENT. FREESCALE RESERVES THE RIGHT TO CHANGE OR
DISCONTINUE THIS PRODUCT WITHOUT NOTICE.
HCS08
Microcontrollers
MC9S08LG32RM
Rev. 5
8/2009
freescale.com
MC9S08LG32 Series Features
8-Bit HCS08 Central Processor Unit (CPU)
• Up to 40 MHz CPU at 5.5 V to 2.7 V across temperature
range of –40 °C to 85 °C and –40 °C to 105 °C
• HCS08 instruction set with added BGND instruction
• Support for up to 32 interrupt/reset sources
On-Chip Memory
• 32 KB or 18 KB dual array flash; read/program/erase
over full operating voltage and temperature
• 1984 byte random access memory (RAM)
• Security circuitry to prevent unauthorized access to
RAM and flash contents
Power-Saving Modes
• Two low-power stop modes (stop2 and stop3)
• Reduced-power wait mode
• Peripheral clock gating register can disable clocks to
unused modules, thereby reducing currents
• Low power on-chip crystal oscillator (XOSC) that can be
used in low-power modes to provide accurate clock
source to real time counter and LCD controller
• 100 μs typical wakeup time from stop3 mode
Clock Source Options
• Oscillator (XOSC) — Loop-control Pierce oscillator;
crystal or ceramic resonator range of 31.25 kHz to
38.4 kHz or 1 MHz to 16 MHz
• Internal Clock Source (ICS) — Internal clock source
module containing a frequency-locked-loop (FLL)
controlled by internal or external reference; precision
trimming of internal reference allows 0.2% resolution
and 2% deviation over temperature and voltage; supports
bus frequencies from 1 MHz to 20 MHz
System Protection
• COP reset with option to run from dedicated 1 kHz
internal clock or bus clock
• Low-voltage warning with interrupt
• Low-voltage detection with reset
• Illegal opcode detection with reset
• Illegal address detection with reset
• Flash and RAM protection
Development Support
• Single-wire background debug interface
• Breakpoint capability to allow single breakpoint setting
during in-circuit debugging (plus two more breakpoints
in on-chip debug module)
• On-chip in-circuit emulator (ICE) debug module
containing three comparators and nine trigger modes;
eight deep FIFO for storing change-of-flow addresses
and event-only data; debug module supports both tag and
force breakpoints
Peripherals
• LCD — Up to 4 x 41 or 8 x 37 LCD driver with internal
charge pump
• ADC — Up to 16-channel, 12-bit resolution; 2.5 μs
conversion time; automatic compare function;
temperature sensor; internal bandgap reference channel;
runs in stop3 and can wake up the system; fully
functional from 5.5 V to 2.7 V
• SCI — Full duplex non-return to zero (NRZ); LIN
master extended break generation; LIN slave extended
break detection; wakeup on active edge
• SPI— Full-duplex or single-wire bidirectional;
double-buffered transmit and receive; master or slave
mode; MSB-first or LSB-first shifting
• IIC — With up to 100 kbps with maximum bus loading;
multi-master operation; programmable slave address;
interrupt driven byte-by-byte data transfer; supports
broadcast mode and 10-bit addressing
• TPMx — One 6 channel and one 2 channel; selectable
input capture, output compare, or buffered edge or
center-aligned PWM on each channel
• MTIM — 8-bit counter with match register; four clock
sources with prescaler dividers; can be used for periodic
wakeup
• RTC — 8-bit modulus counter with binary or decimal
based prescaler; three clock sources including one
external source; can be used for time base, calendar, or
task scheduling functions
• KBI — One keyboard control module capable of
supporting 8x8 keyboard matrix
• IRQ — External pin for wakeup from low-power modes
Input/Output
• 39, 53, or 69 GPIOs
• 8 KBI and 1 IRQ interrupt with selectable polarity
• Hysteresis and configurable pullup device on all input
pins; configurable slew rate and drive strength on all
output pins
Package Options
• 48-pin LQFP, 64-pin LQFP, and 80-pin LQFP
MC9S08LG32 Reference Manual
Covers MC9S08LG32
MC9S08LG16
THIS DOCUMENT CONTAINS INFORMATION ON A NEW PRODUCT UNDER DEVELOPMENT. FREESCALE RESERVES THE RIGHT TO CHANGE OR
DISCONTINUE THIS PRODUCT WITHOUT NOTICE.
Related Documentation:
• MC9S08LG32PB (Product Brief)
Contains descriptive feature set, example application
information, and developer environment details
• MC9S08LG32 Data Sheet
Contains package information, pinouts,
electricals/characterization data, and mechanical
drawings
Find the most current versions of all documents at:
http://www.freescale.com
Freescale™ and the Freescale logo are trademarks of Freescale Semiconductor, Inc.
© Freescale Semiconductor, Inc., 2009. All rights reserved.
MC9S08LG32RM
Rev. 5
8/2009
Revision History
To provide the most up-to-date information, the revision of our documents on the World Wide Web will be
the most current. Your printed copy may be an earlier revision. To verify you have the latest information
available, refer to:
http://www.freescale.com
The following revision history table summarizes changes contained in this document.
Revision
Number
Revision
Date
Rev. 1
9/2008
First Initial Release.
Rev. 2
9/2008
Second Initial Release.
Rev. 3
11/2008
Alpha Customer Release.
Rev. 4
2/2009
Launch Release.
Rev. 5
8/2009
Description of Changes
• In Chapter 3, “Modes of Operation,” added On-Chip Peripheral Modules in
Stop Modes section in Chapter 3.
• In Table 5-2, corrected addresses for vector number from 23 to 18.
• In Table 7-1, updated KBI pins order as per PINPS1 register.
• Changed TCLK, T1CH0, T1CH1, T2CH0, T2CH1, T2CH2, T2CH3, T2CH4,
T2CH5 to TPMCLK, TPM1CH0, TPM1CH1, TPM2CH0, TPM2CH1,
TPM2CH2, TPM2CH3, TPM2CH4, TPM2CH5.
• Changed ‘LCDCPEN” to “LCDPEN” and “LCDFWF” to “LCDWF.”
• In Chapter 12, “Inter-Integrated Circuit (S08IICV2),” a note is added in the
introduction mentioning that MC9S08LG32 series of MCUs include only one
IIC module.
Freescale™ and the Freescale logo are trademarks of Freescale Semiconductor, Inc.
© Freescale Semiconductor, Inc., 2009. All rights reserved.
MC9S08LG32 MCU Series, Rev. 5
6
Freescale Semiconductor
List of Chapters
Chapter
Title
Page
Chapter 1 Device Overview ....................................................................................... 21
Chapter 2 Pins and Connections .............................................................................. 27
Chapter 3 Modes of Operation .................................................................................. 41
Chapter 4 Memory ...................................................................................................... 49
Chapter 5 Resets, Interrupts, and General System Control ................................... 73
Chapter 6 Parallel Input/Output Control................................................................... 97
Chapter 7 Keyboard Interrupt (S08KBIV2) ............................................................. 128
Chapter 8 Central Processor Unit (S08CPUV5) ..................................................... 135
Chapter 9 LCD Module (S08LCDLPV1)................................................................... 158
Chapter 10 Analog-to-Digital Converter (S08ADC12V1) ....................................... 200
Chapter 11 Internal Clock Source (S08ICSV3)....................................................... 226
Chapter 12 Inter-Integrated Circuit (S08IICV2) ...................................................... 241
Chapter 13 Serial Communications Interface (S08SCIV4).................................... 259
Chapter 14 Serial Peripheral Interface (S08SPIV4)................................................ 278
Chapter 15 Real-Time Counter (S08RTCV1) .......................................................... 297
Chapter 16 Timer/Pulse-Width Modulator (S08TPMV3) ........................................ 306
Chapter 17 Modulo Timer (S08MTIMV1) ................................................................. 327
Chapter 18 Development Support........................................................................... 337
Chapter 19 Debug Module (DBG) (64K).................................................................. 350
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7
Contents
Section Number
Title
Page
Chapter 1
Device Overview
1.1
1.2
1.3
Devices in the MC9S08LG32 Series ...............................................................................................21
MCU Block Diagram .......................................................................................................................22
System Clock Distribution ...............................................................................................................24
Chapter 2
Pins and Connections
2.1
2.2
2.3
Introduction ......................................................................................................................................27
Device Pin Assignment ....................................................................................................................27
Recommended System Connections ................................................................................................31
2.3.1 Power ................................................................................................................................33
2.3.2 Oscillator ...........................................................................................................................33
2.3.3 RESET ..............................................................................................................................34
2.3.4 Background / Mode Select (BKGD/MS) ..........................................................................34
2.3.5 IRQ ....................................................................................................................................35
2.3.6 LCD Pins ...........................................................................................................................35
2.3.7 General-Purpose I/O (GPIO) and Peripheral Ports ...........................................................36
Chapter 3
Modes of Operation
3.1
3.2
3.3
3.4
3.5
3.6
3.7
Introduction ......................................................................................................................................41
Features ............................................................................................................................................41
Run Mode.........................................................................................................................................41
Active Background Mode ................................................................................................................41
Wait Mode ........................................................................................................................................42
Stop Modes.......................................................................................................................................43
3.6.1 Stop2 Mode .......................................................................................................................43
3.6.2 Stop3 Mode .......................................................................................................................44
3.6.3 Active BDM Enabled in Stop Mode .................................................................................45
3.6.4 LVD Enabled in Stop Mode ..............................................................................................45
Mode Selection.................................................................................................................................45
3.7.1 On-Chip Peripheral Modules in Stop Modes ....................................................................48
Chapter 4
Memory
4.1
Introduction ......................................................................................................................................49
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9
Section Number
4.2
4.3
4.4
4.5
4.6
4.7
4.8
Title
Page
MC9S08LG32 Series Memory Map ................................................................................................49
Reset and Interrupt Vector Assignments ..........................................................................................50
Register Addresses and Bit Assignments.........................................................................................52
4.4.1 Reserved Flash Locations .................................................................................................59
RAM.................................................................................................................................................60
Flash .................................................................................................................................................60
4.6.1 Features .............................................................................................................................61
4.6.2 Program and Erase Times .................................................................................................61
4.6.3 Program and Erase Command Execution .........................................................................62
4.6.4 Burst Program Execution ..................................................................................................63
4.6.5 Access Errors ....................................................................................................................65
4.6.6 Flash Block Protection ......................................................................................................65
4.6.7 Vector Redirection ............................................................................................................66
Security.............................................................................................................................................66
Flash Registers and Control Bits......................................................................................................67
4.8.1 Flash Clock Divider Register (FCDIV) ............................................................................68
4.8.2 Flash Options Register (FOPT and NVOPT) ....................................................................69
4.8.3 Flash Configuration Register (FCNFG) ...........................................................................70
4.8.4 Flash Protection Register (FPROT and NVPROT) ..........................................................70
4.8.5 Flash Status Register (FSTAT) ..........................................................................................71
4.8.6 Flash Command Register (FCMD) ...................................................................................72
Chapter 5
Resets, Interrupts, and General System Control
5.1
5.2
5.3
5.4
5.5
5.6
5.7
5.8
Introduction ......................................................................................................................................73
Features ............................................................................................................................................73
MCU Reset.......................................................................................................................................73
Computer Operating Properly (COP) Watchdog..............................................................................74
Interrupts ..........................................................................................................................................75
5.5.1 Interrupt Stack Frame .......................................................................................................76
5.5.2 External Interrupt Request (IRQ) Pin ...............................................................................76
5.5.3 Interrupt Vectors, Sources, and Local Masks ...................................................................77
Low-Voltage Detect (LVD) System .................................................................................................79
5.6.1 Power-On Reset Operation ...............................................................................................79
5.6.2 Low-Voltage Detection (LVD) Reset Operation ...............................................................79
5.6.3 Low-Voltage Warning (LVW) Interrupt Operation ...........................................................79
Peripheral Clock Gating ...................................................................................................................79
Reset, Interrupt, and System Control Registers and Control Bits....................................................80
5.8.1 Interrupt Pin Request Status and Control Register (IRQSC) ............................................80
5.8.2 System Reset Status Register (SRS) .................................................................................82
5.8.3 System Background Debug Force Reset Register (SBDFR) ............................................83
5.8.4 System Options Register 1 (SOPT1) ................................................................................84
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Section Number
5.8.5
5.8.6
5.8.7
5.8.8
5.8.9
5.8.10
5.8.11
5.8.12
5.8.13
5.8.14
Title
Page
System Options Register 2 (SOPT2) ................................................................................85
System Device Identification Register (SDIDH, SDIDL) ................................................86
System Power Management Status and Control 1 Register (SPMSC1) ...........................87
System Power Management Status and Control 2 Register (SPMSC2) ...........................88
System Clock Gating Control 1Register (SCGC1) ...........................................................90
System Clock Gating Control 2 Register (SCGC2) ..........................................................91
Pin Position Control Register (PINPS1) ...........................................................................92
Pin Position Control Register (PINPS2) ...........................................................................93
Pin Position Control Register (PINPS3) ...........................................................................94
Pin Position Control Register (PINPS4) ...........................................................................95
Chapter 6
Parallel Input/Output Control
6.1
6.2
6.3
6.4
6.5
6.6
6.7
Introduction ......................................................................................................................................97
Pins Shared with LCD......................................................................................................................97
Port Data and Data Direction ...........................................................................................................97
Pullup, Slew Rate, and Drive Strength.............................................................................................98
6.4.1 Port Internal Pullup Enable ...............................................................................................98
6.4.2 Port Slew Rate Enable ......................................................................................................99
6.4.3 Port Drive Strength Select ................................................................................................99
Open Drain Operation ......................................................................................................................99
Pin Behavior in Stop Modes.............................................................................................................99
Parallel I/O and Pin Control Registers ...........................................................................................100
6.7.1 Port A Registers ..............................................................................................................100
6.7.2 Port B Registers ..............................................................................................................104
6.7.3 Port C Registers ..............................................................................................................107
6.7.4 Port D Registers ..............................................................................................................110
6.7.5 Port E Registers ..............................................................................................................113
6.7.6 Port F Registers ...............................................................................................................116
6.7.7 Port G Registers ..............................................................................................................119
6.7.8 Port H Registers ..............................................................................................................122
6.7.9 Port I Registers ................................................................................................................125
Chapter 7
Keyboard Interrupt (S08KBIV2)
7.1
7.2
Introduction ....................................................................................................................................128
7.1.1 Module Configuration .....................................................................................................128
7.1.2 KBI Clock Gating ...........................................................................................................128
7.1.3 Features ...........................................................................................................................130
7.1.4 Modes of Operation ........................................................................................................130
7.1.5 Block Diagram ................................................................................................................130
External Signal Description ...........................................................................................................131
MC9S08LG32 MCU Series, Rev. 5
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11
Section Number
7.3
7.4
Title
Page
Register Definition .........................................................................................................................131
7.3.1 KBI Status and Control Register (KBISC) .....................................................................131
7.3.2 KBI Pin Enable Register (KBIPE) ..................................................................................132
7.3.3 KBI Edge Select Register (KBIES) ................................................................................132
Functional Description ...................................................................................................................133
7.4.1 Edge Only Sensitivity .....................................................................................................133
7.4.2 Edge and Level Sensitivity .............................................................................................133
7.4.3 KBI Pullup/Pulldown Resistors ......................................................................................134
7.4.4 KBI Initialization ............................................................................................................134
Chapter 8
Central Processor Unit (S08CPUV5)
8.1
8.2
8.3
8.4
8.5
Introduction ....................................................................................................................................135
8.1.1 Features ...........................................................................................................................135
Programmer’s Model and CPU Registers ......................................................................................136
8.2.1 Accumulator (A) .............................................................................................................136
8.2.2 Index Register (H:X) ......................................................................................................136
8.2.3 Stack Pointer (SP) ...........................................................................................................137
8.2.4 Program Counter (PC) ....................................................................................................137
8.2.5 Condition Code Register (CCR) .....................................................................................137
Addressing Modes..........................................................................................................................139
8.3.1 Inherent Addressing Mode (INH) ...................................................................................139
8.3.2 Relative Addressing Mode (REL) ..................................................................................139
8.3.3 Immediate Addressing Mode (IMM) ..............................................................................139
8.3.4 Direct Addressing Mode (DIR) ......................................................................................139
8.3.5 Extended Addressing Mode (EXT) ................................................................................140
8.3.6 Indexed Addressing Mode ..............................................................................................140
Special Operations..........................................................................................................................141
8.4.1 Reset Sequence ...............................................................................................................141
8.4.2 Interrupt Sequence ..........................................................................................................141
8.4.3 Wait Mode Operation ......................................................................................................142
8.4.4 Stop Mode Operation ......................................................................................................142
8.4.5 BGND Instruction ...........................................................................................................143
HCS08 Instruction Set Summary ...................................................................................................144
Chapter 9
LCD Module (S08LCDLPV1)
9.1
Introduction ....................................................................................................................................158
9.1.1 LCD Clock Sources ........................................................................................................158
9.1.2 LCD Modes of Operation ...............................................................................................158
9.1.3 LCD Status after Stop2 Wakeup .....................................................................................158
9.1.4 LCD Clock Gating ..........................................................................................................158
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Section Number
9.2
9.3
9.4
9.5
9.6
Title
Page
9.1.5 Features ...........................................................................................................................160
9.1.6 Modes of Operation ........................................................................................................161
9.1.7 Block Diagram ................................................................................................................161
External Signal Description ...........................................................................................................162
9.2.1 LCD[44:0] .......................................................................................................................163
9.2.2 VLL1, VLL2, VLL3 ...........................................................................................................163
9.2.3 Vcap1, Vcap2 .....................................................................................................................163
Register Definition .........................................................................................................................163
9.3.1 LCD Control Register 0 (LCDC0) ..................................................................................163
9.3.2 LCD Control Register 1 (LCDC1) ..................................................................................164
9.3.3 LCD Voltage Supply Register (LCDSUPPLY) ...............................................................165
9.3.4 LCD Regulated Voltage Control Register (LCDRVC) ...................................................166
9.3.5 LCD Blink Control Register (LCDBCTL) .....................................................................167
9.3.6 LCD Status Register (LCDS) ..........................................................................................168
9.3.7 LCD Pin Enable Registers 0–5 (LCDPEN0–LCDPEN5) ..............................................168
9.3.8 Backplane Enable Registers 0–5 (BPEN0–BPEN5) ......................................................169
9.3.9 LCD Waveform Registers (LCDWF[44:0]) ...................................................................170
Functional Description ...................................................................................................................174
9.4.1 LCD Driver Description .................................................................................................175
9.4.2 LCDWF Registers ...........................................................................................................183
9.4.3 LCD Display Modes .......................................................................................................183
9.4.4 LCD Charge Pump, Voltage Divider, and Power Supply Operation ..............................185
9.4.5 Resets ..............................................................................................................................188
9.4.6 Interrupts .........................................................................................................................189
Initialization Section ......................................................................................................................189
9.5.1 Initialization Sequence ....................................................................................................189
9.5.2 Initialization Examples ...................................................................................................190
Application Information.................................................................................................................194
9.6.1 LCD Seven Segment Example Description ....................................................................195
9.6.2 LCD Contrast Control .....................................................................................................198
9.6.3 Stop Mode Recovery .......................................................................................................199
Chapter 10
Analog-to-Digital Converter (S08ADC12V1)
10.1 Introduction ....................................................................................................................................200
10.1.1 ADC shared with LCD ...................................................................................................200
10.1.2 ADC Reference and Supply Voltage ...............................................................................200
10.1.3 ADC Clock Gating ..........................................................................................................200
10.1.4 Module Configurations ...................................................................................................201
10.1.5 Features ...........................................................................................................................204
10.1.6 ADC Module Block Diagram .........................................................................................204
10.2 External Signal Description ...........................................................................................................205
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Section Number
10.3
10.4
10.5
10.6
Title
Page
10.2.1 Analog Power (VDDA) ....................................................................................................206
10.2.2 Analog Ground (VSSA) ...................................................................................................206
10.2.3 Voltage Reference High (VREFH) ...................................................................................206
10.2.4 Voltage Reference Low (VREFL) ....................................................................................206
10.2.5 Analog Channel Inputs (ADx) ........................................................................................206
Register Definition .........................................................................................................................206
10.3.1 Status and Control Register 1 (ADCSC1) ......................................................................206
10.3.2 Status and Control Register 2 (ADCSC2) ......................................................................208
10.3.3 Data Result High Register (ADCRH) .............................................................................208
10.3.4 Data Result Low Register (ADCRL) ..............................................................................209
10.3.5 Compare Value High Register (ADCCVH) ....................................................................209
10.3.6 Compare Value Low Register (ADCCVL) .....................................................................210
10.3.7 Configuration Register (ADCCFG) ................................................................................210
10.3.8 Pin Control 1 Register (APCTL1) ..................................................................................211
10.3.9 Pin Control 2 Register (APCTL2) ..................................................................................212
10.3.10Pin Control 3 Register (APCTL3) ..................................................................................213
Functional Description ...................................................................................................................214
10.4.1 Clock Select and Divide Control ....................................................................................215
10.4.2 Input Select and Pin Control ...........................................................................................215
10.4.3 Hardware Trigger ............................................................................................................215
10.4.4 Conversion Control .........................................................................................................215
10.4.5 Automatic Compare Function .........................................................................................218
10.4.6 MCU Wait Mode Operation ............................................................................................218
10.4.7 MCU Stop3 Mode Operation ..........................................................................................219
10.4.8 MCU Stop2 Mode Operation ..........................................................................................219
Initialization Information ...............................................................................................................220
10.5.1 ADC Module Initialization Example ..............................................................................220
Application Information.................................................................................................................222
10.6.1 External Pins and Routing ..............................................................................................222
10.6.2 Sources of Error ..............................................................................................................223
Chapter 11
Internal Clock Source (S08ICSV3)
11.1 Introduction ....................................................................................................................................226
11.1.1 Features ...........................................................................................................................228
11.1.2 Block Diagram ................................................................................................................228
11.1.3 Modes of Operation ........................................................................................................229
11.2 External Signal Description ...........................................................................................................230
11.3 Register Definition .........................................................................................................................230
11.3.1 ICS Control Register 1 (ICSC1) .....................................................................................231
11.3.2 ICS Control Register 2 (ICSC2) .....................................................................................233
11.3.3 ICS Trim Register (ICSTRM) .........................................................................................233
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Title
Page
11.3.4 ICS Status and Control (ICSSC) .....................................................................................234
11.4 Functional Description ...................................................................................................................236
11.4.1 Operational Modes ..........................................................................................................236
11.4.2 Mode Switching ..............................................................................................................238
11.4.3 Bus Frequency Divider ...................................................................................................239
11.4.4 Low Power Bit Usage .....................................................................................................239
11.4.5 DCO Maximum Frequency with 32.768 kHz Oscillator ................................................239
11.4.6 Internal Reference Clock ................................................................................................239
11.4.7 External Reference Clock ...............................................................................................240
11.4.8 Fixed Frequency Clock ...................................................................................................240
11.4.9 Local Clock .....................................................................................................................240
Chapter 12
Inter-Integrated Circuit (S08IICV2)
12.1 Introduction ....................................................................................................................................241
12.1.1 Module Configuration .....................................................................................................241
12.1.2 IIC Clock Gating .............................................................................................................241
12.1.3 Features ...........................................................................................................................243
12.1.4 Modes of Operation ........................................................................................................243
12.1.5 Block Diagram ................................................................................................................243
12.2 External Signal Description ...........................................................................................................244
12.2.1 SCL — Serial Clock Line ...............................................................................................244
12.2.2 SDA — Serial Data Line ................................................................................................244
12.3 Register Definition .........................................................................................................................244
12.3.1 IIC Address Register (IICxA) .........................................................................................245
12.3.2 IIC Frequency Divider Register (IICxF) ........................................................................245
12.3.3 IIC Control Register (IICxC1) ........................................................................................248
12.3.4 IIC Status Register (IICxS) .............................................................................................248
12.3.5 IIC Data I/O Register (IICxD) ........................................................................................249
12.3.6 IIC Control Register 2 (IICxC2) .....................................................................................250
12.4 Functional Description ...................................................................................................................251
12.4.1 IIC Protocol .....................................................................................................................251
12.4.2 10-bit Address .................................................................................................................254
12.4.3 General Call Address ......................................................................................................255
12.5 Resets .............................................................................................................................................255
12.6 Interrupts ........................................................................................................................................255
12.6.1 Byte Transfer Interrupt ....................................................................................................255
12.6.2 Address Detect Interrupt .................................................................................................256
12.6.3 Arbitration Lost Interrupt ................................................................................................256
12.7 Initialization/Application Information ...........................................................................................257
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Section Number
Title
Page
Chapter 13
Serial Communications Interface (S08SCIV4)
13.1 Introduction ....................................................................................................................................259
13.1.1 Module Instances ............................................................................................................259
13.1.2 Module Configuration .....................................................................................................259
13.1.3 SCI Clock Gating ............................................................................................................259
13.1.4 Features ...........................................................................................................................261
13.1.5 Modes of Operation ........................................................................................................261
13.1.6 Block Diagram ................................................................................................................262
13.2 Register Definition .........................................................................................................................264
13.2.1 SCI Baud Rate Registers (SCIxBDH, SCIxBDL) ..........................................................264
13.2.2 SCI Control Register 1 (SCIxC1) ...................................................................................265
13.2.3 SCI Control Register 2 (SCIxC2) ...................................................................................266
13.2.4 SCI Status Register 1 (SCIxS1) ......................................................................................267
13.2.5 SCI Status Register 2 (SCIxS2) ......................................................................................269
13.2.6 SCI Control Register 3 (SCIxC3) ...................................................................................270
13.2.7 SCI Data Register (SCIxD) .............................................................................................271
13.3 Functional Description ...................................................................................................................271
13.3.1 Baud Rate Generation .....................................................................................................271
13.3.2 Transmitter Functional Description ................................................................................272
13.3.3 Receiver Functional Description ....................................................................................273
13.3.4 Interrupts and Status Flags ..............................................................................................275
13.3.5 Additional SCI Functions ...............................................................................................276
Chapter 14
Serial Peripheral Interface (S08SPIV4)
14.1 Introduction ....................................................................................................................................278
14.1.1 Module Configuration .....................................................................................................278
14.1.2 SPI Clock Gating ............................................................................................................278
14.1.3 Features ...........................................................................................................................280
14.1.4 Block Diagrams ..............................................................................................................280
14.1.5 SPI Baud Rate Generation ..............................................................................................282
14.2 External Signal Description ...........................................................................................................283
14.2.1 SPSCK — SPI Serial Clock ............................................................................................283
14.2.2 MOSI — Master Data Out, Slave Data In ......................................................................283
14.2.3 MISO — Master Data In, Slave Data Out ......................................................................283
14.2.4 SS — Slave Select ..........................................................................................................283
14.3 Modes of Operation........................................................................................................................284
14.3.1 SPI in Stop Modes ..........................................................................................................284
14.4 Register Definition .........................................................................................................................284
14.4.1 SPI Control Register 1 (SPIxC1) ....................................................................................284
14.4.2 SPI Control Register 2 (SPIxC2) ....................................................................................285
MC9S08LG32 MCU Series, Rev. 5
16
Freescale Semiconductor
Section Number
Title
Page
14.4.3 SPI Baud Rate Register (SPIxBR) ..................................................................................286
14.4.4 SPI Status Register (SPIxS) ............................................................................................287
14.4.5 SPI Data Register (SPIxD) .............................................................................................288
14.5 Functional Description ...................................................................................................................289
14.5.1 Master Mode ...................................................................................................................289
14.5.2 Slave Mode .....................................................................................................................290
14.5.3 SPI Clock Formats ..........................................................................................................291
14.5.4 Special Features ..............................................................................................................293
14.5.5 SPI Interrupts ..................................................................................................................295
14.5.6 Mode Fault Detection .....................................................................................................295
Chapter 15
Real-Time Counter (S08RTCV1)
15.1 Introduction ....................................................................................................................................297
15.1.1 RTC Clock Gating ..........................................................................................................297
15.1.2 Features ...........................................................................................................................299
15.1.3 Modes of Operation ........................................................................................................299
15.1.4 Block Diagram ................................................................................................................300
15.2 External Signal Description ...........................................................................................................300
15.3 Register Definition .........................................................................................................................300
15.3.1 RTC Status and Control Register (RTCSC) ....................................................................301
15.3.2 RTC Counter Register (RTCCNT) ..................................................................................302
15.3.3 RTC Modulo Register (RTCMOD) ................................................................................302
15.4 Functional Description ...................................................................................................................302
15.4.1 RTC Operation Example .................................................................................................303
15.5 Initialization/Application Information ...........................................................................................304
Chapter 16
Timer/Pulse-Width Modulator (S08TPMV3)
16.1 Introduction ....................................................................................................................................306
16.1.1 TPM External Clock .......................................................................................................306
16.1.2 Module Instances ............................................................................................................306
16.1.3 Module Configuration .....................................................................................................306
16.1.4 TPM Clock Gating ..........................................................................................................307
16.1.5 Features ...........................................................................................................................308
16.1.6 Modes of Operation ........................................................................................................308
16.1.7 Block Diagram ................................................................................................................309
16.2 Signal Description ..........................................................................................................................311
16.2.1 Detailed Signal Descriptions ..........................................................................................311
16.3 Register Definition .........................................................................................................................314
16.3.1 TPM Status and Control Register (TPMxSC) ................................................................314
16.3.2 TPM-Counter Registers (TPMxCNTH:TPMxCNTL) ....................................................315
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
17
Section Number
Title
Page
16.3.3 TPM Counter Modulo Registers (TPMxMODH:TPMxMODL) ....................................316
16.3.4 TPM Channel n Status and Control Register (TPMxCnSC) ..........................................317
16.3.5 TPM Channel Value Registers (TPMxCnVH:TPMxCnVL) ..........................................318
16.4 Functional Description ...................................................................................................................319
16.4.1 Counter ............................................................................................................................320
16.4.2 Channel Mode Selection .................................................................................................321
16.5 Reset Overview ..............................................................................................................................324
16.5.1 General ............................................................................................................................324
16.5.2 Description of Reset Operation .......................................................................................324
16.6 Interrupts ........................................................................................................................................324
16.6.1 General ............................................................................................................................324
16.6.2 Description of Interrupt Operation .................................................................................325
Chapter 17
Modulo Timer (S08MTIMV1)
17.1 Introduction ....................................................................................................................................327
17.1.1 MTIM Clock Gating .......................................................................................................327
17.1.2 Features ...........................................................................................................................329
17.1.3 Modes of Operation ........................................................................................................329
17.1.4 Block Diagram ................................................................................................................330
17.2 External Signal Description ...........................................................................................................330
17.3 Memory Map and Register Definition ...........................................................................................331
17.3.1 Memory Map (Register Summary) .................................................................................331
17.3.2 Register Descriptions ......................................................................................................331
17.4 Functional Description ...................................................................................................................335
17.4.1 MTIM Operation Example .............................................................................................336
Chapter 18
Development Support
18.1 Introduction ....................................................................................................................................337
18.1.1 Forcing Active Background ............................................................................................337
18.1.2 Module Configuration .....................................................................................................337
18.1.3 Features ...........................................................................................................................338
18.2 Background Debug Controller (BDC) ...........................................................................................338
18.2.1 BKGD Pin Description ...................................................................................................339
18.2.2 Communication Details ..................................................................................................339
18.2.3 BDC Commands .............................................................................................................343
18.2.4 BDC Hardware Breakpoint .............................................................................................345
18.3 Register Definition .........................................................................................................................345
18.3.1 BDC Registers and Control Bits .....................................................................................346
18.3.2 System Background Debug Force Reset Register (SBDFR) ..........................................348
MC9S08LG32 MCU Series, Rev. 5
18
Freescale Semiconductor
Section Number
Title
Page
Chapter 19
Debug Module (DBG) (64K)
19.1 Introduction ....................................................................................................................................350
19.1.1 Features ...........................................................................................................................350
19.1.2 Modes of Operation ........................................................................................................351
19.1.3 Block Diagram ................................................................................................................351
19.2 Signal Description ..........................................................................................................................352
19.3 Memory Map and Registers ...........................................................................................................352
19.3.1 Module Memory Map .....................................................................................................352
19.3.2 Register Descriptions ......................................................................................................354
19.4 Functional Description ...................................................................................................................365
19.4.1 Comparator .....................................................................................................................365
19.4.2 Breakpoints .....................................................................................................................365
19.4.3 Trigger Selection .............................................................................................................366
19.4.4 Trigger Break Control (TBC) .........................................................................................366
19.4.5 FIFO ................................................................................................................................370
19.4.6 Interrupt Priority .............................................................................................................371
19.5 Resets .............................................................................................................................................371
19.6 Interrupts ........................................................................................................................................371
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
19
Chapter 1
Device Overview
The MC9S08LG32 and MC9S08LG16 are the members of the low-cost, low-power, and
high-performance HCS08 family of 8-bit microcontroller units (MCUs). All MCUs in the family use the
enhanced HCS08 core and are available with a variety of memory sizes and package types.
The MC9S08LG32 series MCUs are targeted to serve automotive, consumer and industrial markets.
Please check the ordering part numbers for different qualification tier products in Ordering Information
section of MC9S08LG32 Data Sheet.
1.1
Devices in the MC9S08LG32 Series
Table 1-1 summarizes the feature set available in the MC9S08LG32 series of MCUs.
Table 1-1. MC9S08LG32 series Features by MCU and Package
Feature
Flash size (bytes)
MC9S08LG32
MC9S08LG16
32,768
18,432
RAM size (bytes)
Pin quantity
1984
80
64
48
64
48
ADC
16 ch
12 ch
9 ch
12 ch
9 ch
LCD
8 x 37
4 x 41
8 x 29
4 x 33
8 x 21
4 x 25
8 x 29
4 x 33
8 x 21
4 x 25
53
39
ICE + DBG
yes
ICS
yes
IIC
yes
IRQ
yes
KBI
8 pin
GPIOs
69
53
39
RTC
yes
MTIM
yes
SCI1
yes
SCI2
yes
SPI
yes
TPM1 channels
2
TPM2 channels
6
XOSC
yes
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
21
Chapter 1 Device Overview
1.2
MCU Block Diagram
The block diagram in Figure 1-1 shows the structure of the MC9S08LG32 series MCU.
PORT A
Real Time Counter
LCD[40:37]/PTB[7:4]
LCD[32:29]/PTB[3:0]
RESET/PTC6
BKGD/MS/PTC5
LCD[20:16]/PTC[4:0]
(RTC)
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
COP
8-BIT KEYBOARD
INTERRUPT (KBI)
RESET
IRQ
LVD
SERIAL PERIPHERAL
INTERFACE (SPI)
KBI[7:0]
SS
SPSCK
MISO
MOSI
SCL
IIC MODULE (IIC)
USER FLASH A
(LG32 = 16K BYTES)
(LG16 = 2K BYTES)
6-CHANNEL TIMER/PWM
(TPM2)
USER FLASH B
(LG32 = 16K BYTES)
(LG16 = 16K BYTES)
2-CHANNEL TIMER/PWM
(TPM1)
SERIAL COMMUNICATIONS
INTERFACE (SCI1)
USER RAM
SDA
TPM2CH[5:0]
TPMCLK
PORT D
TMRCLK
(MTIM)
LCD[7:0]/PTD[7:0]
PORT E
Modulo Timer
HCS08 SYSTEM CONTROL
IRQ
PORT B
BKGD/MS
LCD[15:8]/PTE[7:0]
TPM1CH[1:0]
PORT F
BKP
EXTAL/PTF7
XTAL/PTF6
TPM2CH3/KBI2/MOSI/PTF5
TPM2CH4/KBI1/MISO/PTF4
TPM2CH5/KBI0/SS/PTF3
ADC14/IRQ/TPM1CH1/SPSCK/PTF2
ADC13/TPM1CH0/RX1/PTF1
ADC12/TPM2CH2/KBI3/TX1/PTF0
PORT G
BKGD
LCD[44:41]/PTG[7:4]
LCD[36:33]/PTG[3:0]
PORT H
INT
ON-CHIP ICE (ICE) and
DEBUG MODULE (DBG)
TPM2CH4/KBI1/PTH7
ADC15/KBI0/TPM2CH5/PTH6
ADC11/TPM1CH0/KBI3/TX1/PTH5
ADC10/TPM1CH1/KBI2/RX1/PTH4
ADC[9:6]/KBI[7:4]/PTH[3:0]
PORT I
CPU
LCD28/ADC5/TPMCLK/PTA7
LCD27/ADC4/TPM2CH1/KBI7/PTA6
LCD26/ADC3/TPM2CH0/KBI6/PTA5
LCD25/ADC2/RX2/KBI5/PTA4
LCD24/ADC1/TX2/KBI4/PTA3
LCD23/ADC0/SDA/PTA2
LCD22/SCL/PTA1
LCD21/PTA0
PORT C
HCS08 CORE
SS/SCL/TPM2CH0/PTI5
SPSCK/SDA/TPM2CH1/PTI4
MOSI/TPM2CH2/PTI3
MISO/TPM2CH3/PTI2
TX2/TMRCLK/PTI1
RX2/PTI0
TPMCLK
TxD1
RxD1
1984 BYTES
SERIAL COMMUNICATIONS
INTERFACE (SCI2)
INTERNAL CLOCK
Source (ICS)
TxD2
RxD2
XTAL
LOW-POWER OSCILLATOR
12-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
VLL3_2
VLL3
VLL1
VLL2
VCAP1
EXTAL
AD[15:0]
LIQUID CRYSTAL
DISPLAY DRIVER
(LCD)
VCAP2
LCD[44:0]
VDD
VSS
VSS2
VDDA/VREFH
VSSA/VREFL
VOLTAGE
REGULATOR
Available only on 80-pin package
Available only on 64-pin and 80-pin package
*/Default function out of reset/*
Figure 1-1. MC9S08LG32 Series Block Diagram
MC9S08LG32 MCU Series, Rev. 5
22
Freescale Semiconductor
Chapter 1 Device Overview
Table 1-2 provides the functional version of the on-chip modules.
Table 1-2. Module Versions
Module
Version
Analog-to-Digital Converter
(ADC12)
1
Central Processor Unit
(CPU)
5
Inter-Integrated Circuit
(IIC)
2
Internal Clock Source
(ICS)
3
Keyboard Interrupt
(KBI)
2
Liquid Crystal Display Module
(LCD)
1
Low Power Oscillator
(XOSC)
1
Modulo Timer
(MTIM)
1
On-Chip In-Circuit Debug/Emulator
(DBG)
3
Real Time Counter
(RTC)
1
Serial Communications Interface
(SCI)
4
Serial Peripheral Interface
(SPI)
4
Timer Pulse Width Modulator
(TPM)
3
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
23
Chapter 1 Device Overview
1.3
System Clock Distribution
Figure 1-2 shows a simplified clock connection diagram of the ICS. Some modules in the MCU have
selectable clock inputs as shown. The clock inputs to the modules indicate the clock(s) that are used to
drive the module function. All memory-mapped registers associated with the modules are clocked with
BUSCLK. The ICS supplies the following clock sources:
• ICSOUT — This clock source is used as the CPU clock and is divided by 2 to generate the
peripheral bus clock, BUSCLK. Control bits in the ICS control registers determine which of the
three clock sources is connected:
— Internal reference clock
— External reference clock
— Frequency-locked loop (FLL) output
For more information on configuring the ICSOUT clock, see Chapter 11, “Internal Clock Source
(S08ICSV3).”
• ICSLCLK — This clock source is derived from the digitally controlled oscillator (DCO) of the ICS
when the ICS is configured to run off the internal or external reference clock. The development
tools can select this internal self-clocked source (~ 8 MHz) to speed up the BDC communications
in systems where the bus clock is slow.
• ICSERCLK — This is an external reference clock and can be selected as the alternate clock for
ADC. The “Optional External Reference Clock” section in Chapter 11, “Internal Clock Source
(S08ICSV3),” explains the ICSERCLK in more detail. For more information regarding the use of
ICSERCLK with this module, see Chapter 10, “Analog-to-Digital Converter (S08ADC12V1).”
• ICSIRCLK — This is an internal reference clock and can be selected as the RTC clock source, or
as ALTCLK source for the LCD. Chapter 11, “Internal Clock Source (S08ICSV3)” explains the
ICSIRCLK in more detail. For more information regarding use of ICSIRCLK with these modules,
see Chapter 15, “Real-Time Counter (S08RTCV1),” and Chapter 9, “LCD Module
(S08LCDLPV1).”
• ICSFFCLK — This fixed frequency clock (FFCLK) is generated after it is synchronized with the
bus clock. The frequency of the ICSFFCLK is determined by the settings of the ICS. For more
information, see the “Fixed Frequency Clock” section in Chapter 11, “Internal Clock Source
(S08ICSV3).” It can be selected as a clock source for the MTIM and TPM modules. For
information regarding use of ICSFFCLK with these modules, see Chapter 16, “Timer/Pulse-Width
Modulator (S08TPMV3),” and Chapter 17, “Modulo Timer (S08MTIMV1).”
• LPOCLK — This clock is generated from an internal low power oscillator (LPO) that is
completely independent of the ICS module. The LPOCLK can be selected as the clock source to
the COP and RTC module. See Section 5.4, “Computer Operating Properly (COP) Watchdog,” and
Chapter 15, “Real-Time Counter (S08RTCV1),” for details on using the LPOCLK with these
modules.
• OSCOUT — This is the output of the XOSC module and can be selected as the LCD and RTC
clock source. This clock source can be used for LCD and RTC in stop2 mode. For more information
regarding use of OSCOUT with these modules, see Chapter 15, “Real-Time Counter
(S08RTCV1),” and Chapter 9, “LCD Module (S08LCDLPV1).”
MC9S08LG32 MCU Series, Rev. 5
24
Freescale Semiconductor
Chapter 1 Device Overview
•
TPMCLK — The TPMCLK is an optional external clock source for the TPM modules. The
TPMCLK must be limited to 1/4th of the frequency of the bus clock for synchronization. For more
information, see the “External TPM Clock Sources” section in Chapter 16, “Timer/Pulse-Width
Modulator (S08TPMV3).”
TMRCLK — The TMRCLK is an optional external clock source for the MTIM module. For more
information, see Chapter 17, “Modulo Timer (S08MTIMV1).”
•
NOTE
ICSERCLK is a gated version of OSCOUT. ICSERCLK is not available in
STOP modes while OSCOUT is available if ERCLKEN and EREFSTEN
are set.
TPMCLK
1 kHz
LPO
LPOCLK
RTC
TMRCLK
TPM1
COP
TPM2
MTIM
SCI1
SCI2
SPI
ICSIRCLK
ICSERCLK
ICS
ICSFFCLK
÷2
ICSOUT
÷2
SYNC*
FFCLK*
BUSCLK
ICSLCLK
OSCOUT
XOSC
CPU
EXTAL
XTAL
BDC
DBG
IIC
* The fixed frequency clock (FFCLK) is internally
synchronized to the bus clock and must not
exceed one half of the bus clock frequency.
LCD
ADC
ADC has min and max
frequency requirements.
See the ADC chapter and
electricals appendix for
details.
FLASH
KBI
Flash has frequency
requirements for program
and erase operation. See the
electricals appendix for
details.
Figure 1-2. System Clock Distribution Diagram
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
25
Chapter 1 Device Overview
MC9S08LG32 MCU Series, Rev. 5
26
Freescale Semiconductor
Chapter 2
Pins and Connections
2.1
Introduction
This section describes signals that connect to the package pins. It includes pinout diagrams, recommended
system connections, and detailed discussions of signals.
2.2
Device Pin Assignment
This section shows the pin assignments for MC9S08LG32 series. The priority of functions on a pin is in
ascending order from left to right and bottom to top. Another view of pinouts and function priority is given
in Table 2-1.
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
27
80-Pin LQFP
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
PTC4/LCD20
PTA0/LCD21
PTG2/LCD35
PTG3/LCD36
PTA1/SCL/LCD22
PTA2/SDA/ADC0/LCD23
PTA3/KBI4/TX2/ADC1/LCD24
PTA4/KBI5/RX2/ADC2/LCD25
PTA5/KBI6/TPM2CH0/ADC3/LCD26
PTA6/KBI7/TPM2CH1/ADC4/LCD27
PTA7/TPMCLK/ADC5/LCD28
PTC5/BKGD/MS
PTC6/RESET
PTH0/KBI4/ADC6
PTH1/KBI5/ADC7
PTH2KBI6/ADC8
PTH3/KBI7/ADC9
PTH4/RX1/KBI2/TPM1CH1/ADC10
PTH5/TX1/KBI3/TPM1CH0/ADC11
PTF3/SS/KBI0/TPM2CH5
VLL3
PTF5/MOSI/KBI2/TPM2CH3
PTF4/MISO/KBI1/TPM2CH4
PTI5/TPM2CH0/SCL/SS
PTI4/TPM2CH1/SDA/SPSCK
PTI3/TPM2CH2/MOSI
PTI2/TPM2CH3/MISO
PTI1/TMRCLK/TX2
PTI0/RX2
PTH7/KBI1/TPM2CH4
VSS
VDD
PTF7/EXTAL
PTF6/XTAL
VDDA/VREFH
VSSA/VREFL
PTH6/TPM2CH5/KBI0/ADC15
PTF2/SPSCK/TPM1CH1/IRQ/ADC14
PTF1/RX1/TPM1CH0/ADC13
PTF0/TX1/KBI3/TPM2CH2/ADC12
PTD7/LCD7
PTD6/LCD6
PTD5/LCD5
PTD4/LCD4
PTD3/LCD3
PTD2/LCD2
PTB3/LCD32
PTB2/LCD31
PTB7/LCD40
PTB6/LCD39
PTB5/LCD38
PTB4/LCD37
PTB1/LCD30
PTB0/LCD29
PTD1/LCD1
PTD0/LCD0
VCAP1
VCAP2
VLL1
VLL2
80
79
78
77
76
75
74
73
72
71
70
69
68
67
66
65
64
63
62
61
PTE0/LCD8
PTE1/LCD9
PTE2/LCD10
PTE3/LCD11
PTE4/LCD12
PTE5/LCD13
PTG0/LCD33
PTG1/LCD34
PTG4/LCD41
PTG5/LCD42
PTG6/LCD43
PTG7/LCD44
VLL3_2
VSS2
PTE6/LCD14
PTE7/LCD15
PTC0/LCD16
PTC1/LCD17
PTC2/LCD18
PTC3/LCD19
Chapter 2 Pins and Connections
Figure 2-1. 80-Pin LDFP
NOTE
VREFH/VREFL are internally connected to VDDA/VSSA.
MC9S08LG32 MCU Series, Rev. 5
28
Freescale Semiconductor
64-Pin LQFP
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
PTC4/LCD20
PTA0/LCD21
PTG2/LCD35
PTG3/LCD36
PTA1/SCL/LCD22
PTA2/SDA/ADC0/LCD23
PTA3/KBI4/TX2/ADC1/LCD24
PTA4/KBI5/RX2/ADC2/LCD25
PTA5/KBI6/TPM2CH0/ADC3/LCD26
PTA6/KBI7/TPM2CH1/ADC4/LCD27
PTA7/TPMCLK/ADC5/LCD28
PTC5/BKGD/MS
PTC6/RESET
PTH4/RX1/KBI2/TPM1CH1/ADC10
PTH5/TX1/KBI3/TPM1CH0/ADC11
PTF3/SS/KBI0/TPM2CH5
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
VLL3
PTF5/MOSI/KBI2/TPM2CH3
PTF4/MISO/KBI1/TPM2CH4
PTI5/TPM2CH0/SCL/SS
PTI4/TPM2CH1/SDA/SPSCK
PTH7/KBI1/TPM2CH4
VSS
VDD
PTF7/EXTAL
PTF6/XTAL
VDDA/VREFH
VSSA/VREFL
PTH6/TPM2CH5/KBI0/ADC15
PTF2/SPSCK/TPM1CH1/IRQ/ADC14
PTF1/RX1/TPM1CH0/ADC13
PTF0/TX1/KBI3/TPM2CH2/ADC12
PTD7/LCD7
PTD6/LCD6
PTD5/LCD5
PTD4/LCD4
PTD3/LCD3
PTD2/LCD2
PTB3/LCD32
PTB2/LCD31
PTB1/LCD30
PTB0/LCD29
PTD1/LCD1
PTD0/LCD0
VCAP1
VCAP2
VLL1
VLL2
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
PTE0/LCD8
PTE1/LCD9
PTE2/LCD10
PTE3/LCD11
PTE4/LCD12
PTE5/LCD13
PTG0/LCD33
PTG1/LCD34
VLL3_2
VSS2
PTE6/LCD14
PTE7/LCD15
PTC0/LCD16
PTC1/LCD17
PTC2/LCD18
PTC3/LCD19
Chapter 2 Pins and Connections
Figure 2-2. 64-Pin LQFP
NOTE
VREFH/VREFL are internally connected to VDDA/VSSA.
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
29
37
48
PTD7/LCD7
47
1
PTC3/LCD19
PTC2/LCD18
PTC1/LCD17
PTC0/LCD16
PTE7/LCD15
PTE6/LCD14
PTE5/LCD13
PTE4/LCD12
PTE3/LCD11
PTE2/LCD10
PTE1/LCD9
PTE0/LCD8
Chapter 2 Pins and Connections
46
45
44
43
42
41
40
39
38
36 PTC4/LCD20
PTD6/LCD6
2
35
PTA0/LCD21
PTD5/LCD5
3
34
PTA1/SCL/LCD22
PTD4/LCD4
4
33
PTA2/SDA/ADC0/LCD23
PTD3/LCD3
5
32
PTA3/KBI4/TX2/ADC1/LCD24
PTD2/LCD2
6
31
PTA4/KBI5/RX2/ADC2/LCD25
PTD1/LCD1
7
30
PTA5/KBI6/TPM2CH0/ADC3/LCD26
PTD0/LCD0
8
29
PTA6/KBI7/TPM2CH1/ADC4/LCD27
9
28
PTA7/TPMCLK/ADC5/LCD28
VCAP2
10
27
PTC5/BKGD/MS
VLL1
11
26
PTC6/RESET
VCAP1
48-Pin LQFP
25 PTF3/SS/KBI0/TPM2CH5
VLL2 12
14
15
16
17
18
19
20
21
22
23
PTF1/RX1/TPM1CH0/ADC13
PTF2/SPSCKS/TPM1CH1/IRQ/ADC14
VSSA/VREFL
VDDA/VREFH
PTF6/XTAL
PTF7/EXTAL
VDD
VSS
PTF4/MISO/KBI1/TPM2CH4
PTF5/MOSI/KBI2/TPM2CH3
VLL3
PTF0/TX1/KBI3/TPM2CH2/ADC12
24
13
Figure 2-3. 48-Pin LQFP
NOTE
VREFH/VREFL are internally connected to VDDA/VSSA.
MC9S08LG32 MCU Series, Rev. 5
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Freescale Semiconductor
Chapter 2 Pins and Connections
2.3
Recommended System Connections
Figure 2-4 shows pin connections that are common to MC9S08LG32 series application systems.
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
31
Chapter 2 Pins and Connections
RESET
(NOTE 3)
OPTIONAL
MANUAL
RESET
RF
EXTAL
XTAL
0.1 μF
Available only on 80-pin package
Available only on 64-pin and 80-pin package
*/Default function out of reset/*
4
5
PORT A
PORT B
EXTAL/PTF7
XTAL/PTF6
TPM2CH3/KBI2/MOSI/PTF5
TPM2CH4/KBI1/MISO/PTF4
TPM2CH5/KBI0/SS/PTF3
ADC14/IRQ/TPM1CH1/SPSCK/PTF2
ADC13/TPM1CH0/RX1/PTF1
ADC12/TPM2CH2/KBI3/TX1/PTF0
LCD[44:41]/PTG[7:4]
LCD[36:33]/PTG[3:0]
TPM2CH4/KBI1/PTH7
ADC15/KBI0/TPM2CH5/PTH6
ADC11/TPM1CH0/KBI3/TX1/PTH5
ADC10/TPM1CH1/KBI2/RX1/PTH4
ADC[9:6]/KBI[7:4]/PTH[3:0]
VLL1
VLL2
LCD
Module
VLL3
3
LCD[15:8]/PTE[7:0]
0.1 μF
VCAP1
SS/SCL/TPM2CH0/PTI5
SPSCK/SDA/TPM2CH1/PTI4
MOSI/TPM2CH2/PTI3
MISO/TPM2CH3/PTI2
TX2/TMRCLK/PTI1
RX2/PTI0
PORT I
0.1 μF
2
LCD[7:0]/PTD[7:0]
C2
RS
1
PORT C
BKGD/MS
(NOTE 4)
VDD
X1
PORT D
BACKGROUND HEADER
C1
RESET_B/PTC6
BKGD/MS/PTC5
LCD[20:16]/PTC[4:0]
PORT F
VSS
PORT G
VDD
CBY
0.1 μF
PORT H
VSSA/VREFL
CBLK +
10 μF
LCD[40:37]/PTB[7:4]
LCD[32:29]/PTB[3:0]
VDDA/VREFH
CBYAD
0.1 μF
+
SYSTEM
POWER 5 V
LCD28/ADC5/TPMCLK/PTA7
LCD27/ADC4/TPM2CH1/KBI7/PTA6
LCD26/ADC3/TPM2CH0/KBI6/PTA5
LCD25/ADC2/RX2/KBI5/PTA4
LCD24/ADC1/TX2/KBI4/PTA3
LCD23/ADC0/SDA/PTA2
LCD22/SCL/PTA1
LCD21/PTA0
PORT E
MC9S08LG32
VCAP2
LCD[44:0]
LCD Glass
0.1μF
NOTES:
RESET pin can only be used to reset into user mode, you can not enter BDM using RESET pin. To enter BDM, hold MS low
during POR or write a 1 to BDFR in SBDFR with MS low after issuing BDM command.
RC filter on RESET pin recommended for noisy environments.
When PTC6 is configured as RESET, pin becomes bi-directional with output being open-drain drive containing an internal
pullup device.
When PTC5 is configured as BKGD, pin becomes bi-directional.
LCD mode shown is for Charge pump enabled, other configurations are necessary for different LCD modes.
Figure 2-4. Basic System Connections
MC9S08LG32 MCU Series, Rev. 5
32
Freescale Semiconductor
Chapter 2 Pins and Connections
2.3.1
Power
VDD and VSS are primary power supply pins for the MCU. This voltage source supplies power to all I/O
buffer circuitry and to an internal voltage regulator. The internal voltage regulator provides a regulated
lower-voltage source for the CPU and other internal circuitry of the MCU.
The LCD/GPIO can be powered differently. For additional information, see Chapter 6, “Parallel
Input/Output Control.”
Typically, application systems have two separate capacitors across the power pins. In this case, there must
be a bulk electrolytic capacitor, such as a 10-μF tantalum capacitor, to provide bulk charge storage for the
overall system, and a 0.1-μF ceramic bypass capacitor located as near to the MCU power pins as practical
to suppress high-frequency noise.
VDDA and VSSA are the analog power supply pins for the MCU. This voltage source supplies power to the
ADC modules.
VREFH and VREFL pins are the voltage reference high and the voltage reference low inputs, respectively,
for the ADC module. For this MCU, VDDA shares the VREFH pin and VSSA shares the VREFL pin.
2.3.2
Oscillator
Immediately after reset, the MCU uses an internally generated clock provided by the internal clock source
(ICS) module. The ICS can be configured to run off the on-chip oscillator (ICSERCLK). The output of the
oscillator (OSCOUT) is used to run the RTC and LCD bypassing the ICS. The oscillator can be configured
to run in stop2 or stop3 modes. For more information, see Section 1.3, “System Clock Distribution,” and
Chapter 11, “Internal Clock Source (S08ICSV3).”
The oscillator (XOSC) in this MCU is a Pierce oscillator that can accommodate a crystal or ceramic
resonator. An external clock source can optionally be connected to the EXTAL input pin.
Refer to Figure 2-4 for the following discussion. RS (when used) and RF must be low-inductance resistors,
such as carbon composition resistors. Wire-wound resistors and some metal film resistors have too much
inductance. C1 and C2 normally must be high-quality ceramic capacitors that are specifically designed for
high-frequency applications.
RF provides a bias path to keep the EXTAL input in its linear range during crystal startup; its value is not
generally critical. Typical systems use 1 MΩ to 10 MΩ. Higher values are sensitive to humidity and lower
values reduce gain and (in extreme cases) could prevent startup.
C1 and C2 are typically in the 5 pF to 25 pF range and are chosen to match the requirements of a specific
crystal or resonator. Be sure to consider the printed circuit board (PCB) capacitance and the MCU pin
capacitance when selecting C1 and C2. The crystal manufacturer typically specifies a load capacitance,
which is the series combination of C1 and C2 (which are usually of the same size). As a first-order
approximation, use 10 pF as an estimate of combined pin and PCB capacitance for each oscillator pin
(EXTAL and XTAL).
MC9S08LG32 MCU Series, Rev. 5
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Chapter 2 Pins and Connections
2.3.3
RESET
After a power-on reset (POR), the PTC6/RESET pin defaults to RESET. Clearing RSTPE in SOPT1
configures the pin to be an output-only pin with an open-drain drive and an internal pullup device. RSTPE
is a write-once bit; so once written, it becomes read-only until the next reset. This bit is sticky and is reset
only at POR or LVD; it retains its value across other resets. When enabled, the RESET pin can be used to
reset the MCU from an external source when the pin is driven low.
Internal POR and low-voltage reset circuitry typically make external reset circuitry unnecessary. This pin
is normally connected to the standard 6-pin background debug connector, so a development system can
directly reset the MCU system. A manual external reset can be added by supplying a simple switch to
ground (pull reset pin low to force a reset).
Whenever any non-POR reset is initiated (whether from an external signal or from an internal system), the
enabled RESET pin is driven low for about 34 bus cycles. The reset circuitry decodes the cause of reset
and records it by setting a corresponding bit in the system reset status register (SRS).
NOTE
This pin does not contain a clamp diode to VDD and must not be driven
above VDD.
The voltage on the internally pulled up RESET pin, when measured, is
below VDD. The internal gates connected to this pin are pulled to VDD. If
the RESET pin is required to drive to a VDD level, an external pullup must
be used.
In EMC-sensitive applications, an external RC filter is recommended on the
RESET pin, if enabled.
2.3.4
Background / Mode Select (BKGD/MS)
During POR or background debug force reset (for more information, see Section 5.8.3, “System
Background Debug Force Reset Register (SBDFR)”), the PTC5/BKGD/MS pin functions as a mode select
pin. Immediately after any reset, the pin functions as the background pin and can be used for background
debug communication. When BKGD/MS function is enabled with BKGDPE = 1, an internal pullup device
automatically becomes active. Clearing BKGDPE in SOPT1 configures the pin to be an output-only pin.
The background debug communication function is enabled when BKGDPE in SOPT1 is set. BKGDPE is
set following any reset of the MCU and must be cleared to use the PTC5/BKGD/MS pin’s alternative pin
functions.
After any reset, if nothing is connected to this pin, the MCU enters normal operating mode. If a debug
system is connected to the 6-pin standard background debug header, it can hold BKGD/MS low. It can do
this during a POR or after issuing a background debug force reset. This forces the MCU to active
background mode.
The BKGD/MS pin is used primarily with BDC communications, and features a custom protocol that uses
16 clock cycles of the target MCU’s BDC clock per bit time. The target MCU’s BDC clock can run as fast
MC9S08LG32 MCU Series, Rev. 5
34
Freescale Semiconductor
Chapter 2 Pins and Connections
as the bus clock, so no significant capacitance must be connected to the BKGD/MS pin that could interfere
with background serial communications.
Although the BKGD/MS pin is a pseudo open-drain pin, the background debug communication protocol
provides brief, actively driven, high speedup pulses to ensure fast rise times. Small capacitances from
cables and the absolute value of the internal pullup device play a minimal role in determining rise and fall
times on the BKGD/MS pin.
NOTE
Ensure this pin is not low when the part is coming out of POR or BDFR
reset. Exit from stop2 causes POR, therefore POR includes the exit from
stop2. Because the pin defaults to BKGD/MS function out of reset, a low
value on this pin while coming out of POR or BDFR causes the part to boot
into BDM mode. If this pin is not being used at all, it must be tied high. A
pullup is recommended when using this pin as GPIO.
2.3.5
IRQ
The PTF2/IRQ pin can be used as a wakeup source for the MCU. For stop2 wakeup, this pin has an analog
path which is enabled based on the input buffer enable for this pin, irrespective of whether or not this pin
is configured as IRQ.
NOTE
Care needs to be taken that if this pin is configured as input, it is not low
during stop2 mode, otherwise the part exits stop2 mode irrespective of
whether this pin is configured as IRQ or not. This pin can be disabled as a
wakeup source if it is configured as an output.
2.3.6
2.3.6.1
LCD Pins
LCD Power Pins
The VLL1, VLL2, VLL3, Vcap1, and Vcap2 pins are dedicated to providing power to the LCD module. On
64-pin and 80-pin packages the VLL3_2 pin must be tied to VLL3 on board. For more information about
LCD pins, see Chapter 9, “LCD Module (S08LCDLPV1).”
2.3.6.2
LCD Driver Pins
The MC9S08LG32 series of MCUs provide 45 LCD driver pins for the 80-pin packages, 37 pins for the
64-pin packages, and 29 pins for the 48-pin packages. Each LCD pin has pin enable control, so you can
choose to use any LCD pin as either LCD driver or GPIO. If the LCD module is disabled, the LCD driver
pins become high-impedance and the LCD/GPIO pins are configured as GPIO. The LCD pins are
open-drain after resets except for stop2 wakeup. For more information about LCD driver pins, see
Chapter 9, “LCD Module (S08LCDLPV1).”
Pins that have shared function with the LCD have special behavior based on the state of the VSUPPLY
bits in the LCDSUPPLY register. These pins can operate as full complementary drive or open drain drive
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
35
Chapter 2 Pins and Connections
depending on the VSUPPLY bits. When VLL3 is connected to VDD externally, VSUPPLY = 11,
FCDEN = 1, and RVEN = 0, the pins operate as full complementary drive. For all other VSUPPLY modes,
the LCD/GPIO operates as open drain.
NOTE
For GPIO muxed with LCD pins, full complimentary or open drain drive is
controlled by the LCD controller. When LCD pins are configured as open
drain GPIOs, then the internal pullup is not disabled in output mode and is
controlled by the GPIO pull control register. This can cause some leakage
from the pads if a pullup is enabled and a zero is being driven.
2.3.7
General-Purpose I/O (GPIO) and Peripheral Ports
The MC9S08LG32 series of MCUs support up to 69 GPIO pins including 2 output-only pins that are
shared with on-chip peripheral functions (timers, serial I/O, LCD, ADC, etc.). The GPIO output-only pins
(PTC5/BKGD/MS and PTC6/RESET) are bi-directional when configured as BKGD and RESET,
respectively.
GPIO that is muxed with LCD pins can be configured to reference VDD or VLL3. See Section 2.3.6.2,
“LCD Driver Pins,” for more details.
When a port pin is configured as a general-purpose output or a peripheral uses the port pin as an output,
the software can select one of the two drive strengths and can enable or disable the slew rate control. When
a port pin is configured as a general-purpose input or a peripheral uses the port pin as an input, the software
can enable a pullup device.
When an on-chip peripheral system is controlling a pin, the data direction control bits still determine what
is read from port data registers even though the peripheral module controls the pin direction by controlling
an enable for the pin’s output buffer. For information about controlling these pins as general-purpose I/O
pins, see Chapter 6, “Parallel Input/Output Control.”
•
•
NOTE
To avoid extra current drain from floating input pins, the reset
initialization routine in the application program must either enable
on-chip pullup devices or change the direction of unused or non-bonded
pins to outputs so they do not float.
When using RESET pin as bi-directional reset and LCD pins as
open-drain GPIO, the internal pullups are not disabled when these pins
are used in output mode. This can cause some current leakage through
the pads if zero is driven. This is also true for stop2 mode.
Table 2-1. Pin Availability by Package Pin-Count
Packages
<-- Lowest
Priority
--> Highest
80
64
48
Port Pin
Alt 1
Alt 2
Alt 3
Alt 4
1
1
1
PTD7
LCD7
—
—
—
2
2
2
PTD6
LCD6
—
—
—
MC9S08LG32 MCU Series, Rev. 5
36
Freescale Semiconductor
Chapter 2 Pins and Connections
Table 2-1. Pin Availability by Package Pin-Count (continued)
Packages
<-- Lowest
Priority
--> Highest
80
64
48
Port Pin
Alt 1
Alt 2
Alt 3
Alt 4
3
3
3
PTD5
LCD5
—
—
—
4
4
4
PTD4
LCD4
—
—
—
5
5
5
PTD3
LCD3
—
—
—
6
6
6
PTD2
LCD2
—
—
—
7
7
—
PTB3
LCD32
—
—
—
8
8
—
PTB2
LCD31
—
—
—
9
—
—
PTB7
LCD40
—
—
—
10
—
—
PTB6
LCD39
—
—
—
11
—
—
PTB5
LCD38
—
—
—
12
—
—
PTB4
LCD37
—
—
—
13
9
—
PTB1
LCD30
—
—
—
14
10
—
PTB0
LCD29
—
—
—
15
11
7
PTD1
LCD1
—
—
—
16
12
8
PTD0
LCD0
—
—
—
17
13
9
VCAP1
—
—
—
—
18
14
10
VCAP2
—
—
—
—
19
15
11
VLL1
—
—
—
—
20
16
12
VLL2
—
—
—
—
21
17
13
VLL3
—
—
—
—
22
18
14
PTF5
MOSI
KBI2
TPM2CH3
—
23
19
15
PTF4
MISO
KBI1
TPM2CH4
—
24
20
—
PTI5
TPM2CH0
SCL
SS
—
25
21
—
PTI4
TPM2CH1
SDA
SPSCK
—
26
—
—
PTI3
TPM2CH2
MOSI
—
—
27
—
—
PTI2
TPM2CH3
MISO
—
—
28
—
—
PTI1
TMRCLK
TX2
—
—
29
—
—
PTI0
RX2
—
—
—
30
22
—
PTH7
KBI1
TPM2CH4
—
—
31
23
16
VSS
—
—
—
—
32
24
17
VDD
—
—
—
—
33
25
18
PTF7
EXTAL
—
—
—
34
26
19
PTF6
XTAL
—
—
—
35
27
20
VDDA
VREFH
—
—
—
36
28
21
VSSA
VREFL
—
—
—
37
29
—
PTH6
TPM2CH5
KBI0
ADC15
—
38
30
22
PTF2
SPSCK
TPM1CH1
IRQ
ADC14
39
31
23
PTF1
RX1
TPM1CH0
ADC13
—
40
32
24
PTF0
TX1
KBI3
TPM2CH2
ADC12
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
37
Chapter 2 Pins and Connections
Table 2-1. Pin Availability by Package Pin-Count (continued)
Packages
<-- Lowest
Priority
--> Highest
80
64
48
Port Pin
Alt 1
Alt 2
Alt 3
Alt 4
41
33
25
PTF3
SS
KBI0
TPM2CH5
—
42
34
—
PTH5
TX1
KBI3
TPM1CH0
ADC11
43
35
—
PTH4
RX1
KBI2
TPM1CH1
ADC10
44
—
—
PTH3
KBI7
ADC9
—
—
45
—
—
PTH2
KBI6
ADC8
—
—
46
—
—
PTH1
KBI5
ADC7
—
—
47
—
—
PTH0
KBI4
ADC6
—
—
48
36
26
PTC6
RESET
—
—
—
49
37
27
PTC5
BKGD/MS
—
—
—
50
38
28
PTA7
TPMCLK
ADC5
LCD28
—
51
39
29
PTA6
KBI7
TPM2CH1
ADC4
LCD27
52
40
30
PTA5
KBI6
TPM2CH0
ADC3
LCD26
53
41
31
PTA4
KBI5
RX2
ADC2
LCD25
54
42
32
PTA3
KBI4
TX2
ADC1
LCD24
55
43
33
PTA2
SDA
ADC0
LCD23
—
56
44
34
PTA1
SCL
LCD22
—
—
57
45
—
PTG3
LCD36
—
—
—
58
46
—
PTG2
LCD35
—
—
—
59
47
35
PTA0
LCD21
—
—
—
60
48
36
PTC4
LCD20
—
—
—
61
49
37
PTC3
LCD19
—
—
—
62
50
38
PTC2
LCD18
—
—
—
63
51
39
PTC1
LCD17
—
—
—
64
52
40
PTC0
LCD16
—
—
—
65
53
41
PTE7
LCD15
—
—
—
66
54
42
PTE6
LCD14
—
—
—
67
55
—
VSS2
—
—
—
—
68
56
—
VLL3_2
—
—
—
—
69
—
—
PTG7
LCD44
—
—
—
70
—
—
PTG6
LCD43
—
—
—
71
—
—
PTG5
LCD42
—
—
—
72
—
—
PTG4
LCD41
—
—
—
73
57
—
PTG1
LCD34
—
—
—
74
58
—
PTG0
LCD33
—
—
—
75
59
43
PTE5
LCD13
—
—
—
76
60
44
PTE4
LCD12
—
—
—
77
61
45
PTE3
LCD11
—
—
—
78
62
46
PTE2
LCD10
—
—
—
MC9S08LG32 MCU Series, Rev. 5
38
Freescale Semiconductor
Chapter 2 Pins and Connections
Table 2-1. Pin Availability by Package Pin-Count (continued)
Packages
<-- Lowest
Priority
--> Highest
80
64
48
Port Pin
Alt 1
Alt 2
Alt 3
Alt 4
79
63
47
PTE1
LCD9
—
—
—
80
64
48
PTE0
LCD8
—
—
—
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
39
Chapter 2 Pins and Connections
MC9S08LG32 MCU Series, Rev. 5
40
Freescale Semiconductor
Chapter 3
Modes of Operation
3.1
Introduction
This chapter describes the operating modes of the MC9S08LG32 series. It also describes entry, exit, and
the functionality of each mode.
3.2
•
•
•
•
3.3
Features
Active background mode for code development.
Run mode — CPU clocks can be run at full speed and the internal supply is fully regulated.
Wait mode — CPU shuts down to conserve power; system clocks are running and full regulation
is maintained.
Stop modes — System clocks are stopped and voltage regulator is in standby.
— Stop3 — All internal circuits are powered for fast recovery.
— Stop2 — Partial power down of internal circuits, RAM content is retained, and the I/O states
are held.
Run Mode
This is the normal operating mode for the MC9S08LG32 series. In this mode, the CPU executes code from
internal memory with execution beginning at the address fetched from memory at 0xFFFE–0xFFFF after
reset.
3.4
Active Background Mode
The active background mode functions are managed through the BDC in the HCS08 core. The BDC and
the on-chip debug module (DBG), provide the means for analyzing MCU operation during software
development.
Active background mode is entered by any of six methods:
• When the BKGD/MS pin is low during POR
• When the BKGD/MS pin is low immediately after issuing a background debug force reset (for
more information, see Section 5.8.3, “System Background Debug Force Reset Register (SBDFR)”)
• When a BACKGROUND command is received through the BKGD/MS pin
• When a BGND instruction is executed
• When encountering a BDC breakpoint
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
41
Chapter 3 Modes of Operation
•
When encountering a DBG breakpoint
NOTE
The MCU needs to be unsecure for the last four methods.
After entering active background mode, the CPU is held in a suspended state while it waits for serial
background commands instead of executing instructions from the user application program.
The background commands are of two types:
• Non-intrusive commands — These commands are defined as commands that can be issued while
the user program is running. Non-intrusive commands can be issued through the BKGD pin while
the MCU is in run mode. Non-intrusive commands can also be executed when the MCU is in active
background mode. Non-intrusive commands include:
— Memory access commands
— Memory-access-with-status commands
— BDC register access commands
— The BACKGROUND command
• Active background commands— These commands can only be executed while the MCU is in
active background mode. Active background commands include commands to:
— Read or write CPU registers
— Trace one user program instruction at a time
— Leave active background mode to return to the user application program (GO)
Active background mode is used to program a bootloader or user application program into the flash
program memory before the MCU is operated in run mode for the first time. When the MC9S08LG32
series is shipped from the Freescale Semiconductor factory, the flash program memory is erased by default,
unless specifically noted. As a result, no program can be executed in run mode until the flash memory is
initially programmed. Active background mode can also be used to erase and reprogram the flash memory
after it has been previously programmed.
For additional information about the active background mode, refer to the Chapter 18, “Development
Support.”
3.5
Wait Mode
Wait mode is entered by executing a WAIT instruction. Upon execution of the WAIT instruction, the CPU
enters a low-power state in which it is not clocked. The I bit in CCR is cleared when the CPU enters wait
mode, enabling interrupts. When an interrupt request occurs, the CPU exits the wait mode and resumes
processing beginning with the stacking operations that lead to the interrupt service routine.
While the MCU is in wait mode, there are some restrictions on which background debug commands can
be used. Only the BACKGROUND command and memory-access-with-status commands are available
when the MCU is in wait mode. The memory-access-with-status commands do not allow memory access,
but they report an error indicating that the MCU is either in stop or wait mode. The BACKGROUND
command can be used to wake the MCU from the wait mode and enter active background mode.
MC9S08LG32 MCU Series, Rev. 5
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Freescale Semiconductor
Chapter 3 Modes of Operation
The clocks to the peripherals are controlled by SCGC registers in this mode. For lowest possible current
in WAIT mode, all peripherals which are not required must be clock gated before entering in this mode.
3.6
Stop Modes
One of the two stop modes (stop2 or stop3) is entered upon execution of a STOP instruction when the
STOPE bit in the system option 1 register (SOPT1) is set. In both the stop modes, the bus and the CPU
clocks are halted.
• In stop3, the voltage regulator is in standby and ICS module can be configured to leave the
reference clocks running.
• In stop2, the voltage regulator is in partial powerdown.
See Chapter 11, “Internal Clock Source (S08ICSV3),” for more information.
If the STOPE bit is not set when the CPU executes a STOP instruction, the MCU does not enter either of
the stop modes and an illegal opcode reset is forced. Stop modes are selected by setting the appropriate
bits in the System Power Management Status and Control Registers, SPMSC1 and SPMSC2.
Table 3-1 shows all control bits that affect the stop mode selection and the modes selected under various
conditions. The selected mode is entered following the execution of a STOP instruction.
Table 3-1. Stop Mode Selection
Register
SOPT1
BDCSCR
SPMSC1
SPMSC2
Bit name
STOPE
ENBDM 1
0
x
x
x
Stop modes disabled; illegal opcode reset if STOP
instruction executed
1
1
x
x
Stop3 with BDM enabled 2
1
0
Both bits must be 1
x
Stop3 with voltage regulator active
1
0
Either bit a 0
0
Stop3 (with Voltage regulator in Standby)
1
0
Either bit a 0
1
Stop2
Stop Mode
LVDE
LVDSE
PPDC
1
ENBDM is located in the BDCSCR that is only accessible through BDC commands, see Chapter 18, “Development
Support.”
2
When in stop3 mode with BDM enabled, the SIDD is near the RIDD levels because internal clocks are enabled.
3.6.1
Stop2 Mode
To enter stop2, execute a STOP instruction under the conditions as shown in Table 3-1. Most of an internal
circuitry of the MCU is powered off in stop2 mode with an exception of the RAM, the low power
oscillator, RTC and the LCD module. Upon entering stop2 mode, all I/O pin control signals are latched so
that the pins retain their states during stop2. The LCD driver pins continue to drive the signals necessary
to display the LCD data.
To exit from stop2 mode, assert the wakeup pins (PTC6/RESET or PTF2/IRQ) or through RTC interrupt
or POR.
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
43
Chapter 3 Modes of Operation
NOTE
When PTC6/RESET or PTF2/IRQ is used as an active low wakeup source
it must be configured as an input prior to executing a STOP instruction.
PTC6/RESET and PTF2/IRQ can be disabled as a wakeup if it is configured
as output port. For lowest power consumption in stop2, these pins must not
be left open if configured as input (enable the internal pullup or tie an
external pullup device).
Upon wakeup from stop2 mode, the MCU starts up as from a POR with the following sequence:
• All module control and status registers are reset, except for SPMSC1-SPMSC2, RTCSC,
RTCCNT, RTCMOD, LCDPENx, LCDBPENx, and LCDWFRx.
• The LVD reset function is enabled and the MCU remains in the reset state if VDD is below the LVD
trip point.
• The CPU takes the reset vector
In addition to the above, upon waking up from stop2 mode, the PPDF bit in SPMSC2 is set. This flag is
used to direct user code to go to a stop2 recovery routine. PPDF remains set and the I/O pin states remain
latched until a 1 is written to PPDACK in SPMSC2.
If using the low-power oscillator during stop2 mode, you reconfigure the ICSC2 register that contains
oscillator control bits before PPDACK is written.
To maintain I/O states for pins that were configured as GPIO before entering stop2, you restore the
contents of the I/O port registers to the port registers before writing to the PPDACK bit. If the port registers
are not restored from RAM before writing to PPDACK, then the pins are switched to their reset states when
PPDACK is written.
For pins that were configured as peripheral I/O, you reconfigure the peripheral module that interfaces to
the pin before writing to the PPDACK bit. If the peripheral module is not enabled before writing to
PPDACK, the pins are controlled by their associated port control registers when the I/O latches are opened.
If enabled, LCD functionality continues in stop2 mode and upon stop2 recovery the LCD control registers
(LCDC0, LCDC1, LCDSUPPLY, LCDRVC, LCDBCTL, and LCDS) must be re-initialized before writing
the PPDACK.
3.6.2
Stop3 Mode
To enter stop3 mode, execute a STOP instruction under the conditions shown in Table 3-1. The states of
all the internal registers and logic, RAM contents, and I/O pin states are maintained.
Stop3 mode can be exited by asserting RESET, or by an interrupt from one of the following sources: LVW,
RTC, ADC, IRQ, SCI1, SCI2, LCD, or KBI.
If stop3 is exited by means of the RESET pin, the MCU is reset and operation resumes after taking the
reset vector. Using an internal interrupt sources to exit, results in the MCU taking an appropriate interrupt
vector.
MC9S08LG32 MCU Series, Rev. 5
44
Freescale Semiconductor
Chapter 3 Modes of Operation
3.6.3
Active BDM Enabled in Stop Mode
Entry into active background mode from run mode is enabled if the ENBDM bit in BDCSCR is set. This
register is described in Chapter 18, “Development Support.” If ENBDM is set when the CPU executes a
STOP instruction, the system clocks to the background debug logic remain active when the MCU enters
the stop mode. Because of this, background debug communication remains possible. In addition, the
voltage regulator does not enter its low-power standby state, but maintains full internal regulation. If you
attempt to enter the stop2 mode with ENBDM set, the MCU enters the stop3 mode instead.
Most background commands are not available in the stop mode. The memory-access-with-status
commands do not allow memory access, but they report an error indicating that the MCU is in either stop
or wait mode. The BACKGROUND command can be used to wake the MCU from the stop mode and enter
the active background mode if the ENBDM bit is set. After entering the background debug mode, all
background commands are available.
3.6.4
LVD Enabled in Stop Mode
The LVD system can generate a reset or an interrupt when the supply voltage drops below the LVD or
LVW threshold respectively. If the LVD is enabled in stop (LVDE and LVDSE bits in SPMSC1 both set),
the voltage regulator remains active during stop mode. If you attempt to enter the stop2 mode with LVD
enabled for stop, the MCU enters the stop3 mode instead.
3.7
Mode Selection
Several control signals are used to determine the current operating mode of the device. Table 3-2 shows
the conditions for each of the device’s operating modes.
Table 3-2. Power Mode Selections
BDCSCR
BDM
SPMSC1
PMC
SPMSC2
PMC
Mode of Operation
CPU & Periph CLKs
ENBDM 1 LVDE LVDSE
RUN mode
Affects on
Sub-System
0
x
x
PPDC
x
On. ICS in any mode.
1
WAIT mode—(Assumes
WAIT instruction executed.)
Stop3—(Assumes STOPE
bit is set and STOP
instruction executed.) Note
that stop3 is used in place of
stop2 if the BDM or LVD is
enabled.
0
BDM
Clock
Voltage
Regulator
off
on
on
x
x
x
1
0
0
x
0
0
1
0
0
0
1
1
x
1
x
x
x
CPU clock is off;
peripheral clocks on. ICS
state is same as RUN
mode.
off
ICS in STOP. OSCOUT
optionally on.2
off
standby
off
off
ICSLCLK still active.
on
on
on
on—stop
currents
are
increased.
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
45
Chapter 3 Modes of Operation
Table 3-2. Power Mode Selections (continued)
BDCSCR
BDM
SPMSC1
PMC
SPMSC2
PMC
Mode of Operation
Affects on
Sub-System
CPU & Periph CLKs
ENBDM
Stop2—(Assumes STOPE
bit is set and STOP
instruction executed.) If BDM
or LVD is enabled, stop3 is
invoked rather than stop2.
0
1
LVDE LVDSE
0
x
1
0
PPDC
1
OSCOUT optionally on.2,3
BDM
Clock
Voltage
Regulator
off
partial
powerdown
1
ENBDM is located in the BDC status and control register (BDCSCR) which is write-accessible only through BDC
commands.
2
Configured within the ICS module based on the settings of IREFSTEN, EREFSTEN, IRCLKEN and ERCLKEN.
3
In stop2, the CPU, flash, ICS and all peripheral modules are powered down except for the RTC and LCD.
Wait
Mode
1
Run
3
2
Stop3
Regulator State
Run
Full on
Wait
Full on
Stop3
Standby
Stop2
Partial powerdown
Stop2
Figure 3-1. Allowable Power Mode Transitions for the MC9S08LG32 Series
Figure 3-1 illustrates mode state transitions allowed between the legal states shown in Table 3-1.
Table 3-3 defines triggers for the various state transitions shown in Figure 3-1.
Table 3-3. Triggers for Transitions Shown in Figure 3-1.
Transition #
From
To
1
Run
Wait
WAIT instruction
Wait
Run
Interrupt or reset
Run
Stop3
Stop3
Run
2
Trigger
Pre-configure settings shown in Table 3-1, issue
STOP instruction
Interrupt or reset
MC9S08LG32 MCU Series, Rev. 5
46
Freescale Semiconductor
Chapter 3 Modes of Operation
Table 3-3. Triggers for Transitions Shown in Figure 3-1. (continued)
1
Transition #
From
To
Trigger
3
Run
Stop2
Pre-configure settings shown in Table 3-1, issue
STOP instruction
Stop2
Run
assert zero on wakup pins (PTC6/RESET or
PTF2/IRQ)1 or RTC interrupt or POR
An analog connection from these pins to the on-chip regulator wakes up the regulator, which initiates a power-on-reset
sequence.
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
47
Chapter 3 Modes of Operation
3.7.1
On-Chip Peripheral Modules in Stop Modes
When the MCU enters any stop mode, system clocks to the internal peripheral modules are stopped. Even
in the exception case (ENBDM = 1), where clocks to the background debug logic continue to operate,
clocks to the peripheral systems are halted to reduce power consumption. Refer to Section 3.6.1, “Stop2
Mode,” and Section 3.6.2, “Stop3 Mode,” for specific information on system behavior in stop modes.
Table 3-4. Stop and Low Power Mode Behavior
Mode
Peripheral
Stop2
Stop3
CPU
Off
Standby
RAM
Standby
Standby
FLASH
Off
Standby
Port I/O Registers
Off
Standby
ADC
Off
Optionally On1
BDM
Off2
Optionally On
COP
Off
Off
ICS
Off
Optionally On3
IIC
Off
Standby
IRQ
Wake Up
Optionally On
KBI
Off
Optionally On
4
Optionally On
LVD/LVW
Optionally On
Optionally On
MTIM
Off
Optionally On
SCIx
Off
Standby
SPI
Off
Standby
RTC
Optionally On
Optionally On
TPMx
Off
Standby
Partial Powerdown
Optionally On5
Optionally On6
Optionally On6
States Held
Peripheral Control
Voltage Regulator
XOSC
I/O Pins
1
2
3
4
5
6
Off
LCD
Requires the asynchronous ADC clock. For stop3, LVD must be enabled to
run in stop if converting the bandgap channel.
If ENBDM is set when entering stop2, the MCU will actually enter stop3.
IRCLKEN and IREFSTEN set in ICSC1, else in standby.
If LVDSE is set when entering stop2, the MCU will actually enter stop3.
Requires the LVD to be enabled, else in standby. See Section 3.6.4, “LVD
Enabled in Stop Mode”.
ERCLKEN and EREFSTEN set in ICSC2, else in standby.
MC9S08LG32 MCU Series, Rev. 5
48
Freescale Semiconductor
Chapter 4
Memory
4.1
Introduction
This chapter describes the on-chip memory in the MC9S08LG32 series of MCUs. It details the memory
map, vector and bit assignments, registers and control bits, and other RAM and flash features.
4.2
MC9S08LG32 Series Memory Map
As shown in Figure 4-1, on-chip memory in the MC9S08LG32 series of MCUs consists of RAM, flash
memory for nonvolatile data storage, and I/O and control/status registers. The registers are divided into
four groups:
• Direct-page registers (0x0000 through 0x005F)
• LCD data registers (0x0820 through 0x085C)
• High-page registers (0x1800 through 0x187A)
• Nonvolatile registers (0xFFB0 through 0xFFBF)
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
49
Chapter 4 Memory
0x0000
0x0000
DIRECT PAGE REGISTERS
0x005F
0x0060
0x005F
0x0060
RAM
1984 BYTES
0x081F
0x0820
0x085C
0x0860
UNIMPLEMENTED
4000 BYTES
0x17FF
0x1800
RAM
1984 BYTES
0x081F
0x0820
LCD Registers
0x085C
0x0860
DIRECT PAGE REGISTERS
0x17FF
0x1800
HIGH PAGE REGISTERS
LCD Registers
UNIMPLEMENTED
4000 BYTES
HIGH PAGE REGISTERS
0x187A
0x187B
0x187A
0x187B
UNIMPLEMENTED
UNIMPLEMENTED
0x7FFF
0x8000
16,384 BYTES
FLASH A
0xB7FF
0xB800
FLASH A
2048 BYTES
0xC000
0xC000
16,384 BYTES
FLASHB
Flash B
16,384 BYTES
0xFFFF
0xFFFF
MC9S08LG16
MC9S08LG32
Note:
0x085C-0x085F is reserved. Unlike un-implemented spaces, access to these locations would not cause illegal address
reset.
Figure 4-1. MC9S08LG32 Series Memory Maps
4.3
Reset and Interrupt Vector Assignments
Table 4-1 shows the address assignments for reset and interrupt vectors. The vector names shown in this
table are labels used in the Freescale Semiconductor equate file for the MC9S08LG32 series.
Table 4-1. Reset and Interrupt Vectors (Sheet 1 of 2)
Address
(High/Low)
0xFF80:FF81
Vector
Vector Name
Unused Vector Space
(available for user program)
0xFFC8:FFC9
MC9S08LG32 MCU Series, Rev. 5
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Freescale Semiconductor
Chapter 4 Memory
Table 4-1. Reset and Interrupt Vectors (Sheet 2 of 2) (continued)
Address
(High/Low)
Vector
Vector Name
0xFFCA:0xFFCB
RTC
Vrtc
0xFFCC:0xFFCD
Modulo Timer
Vmtim
0xFFCE:0xFFCF
TPM2 Overflow
Vtpm2ovf
0xFFD0:0xFFD1
TPM2 Channel 5
Vtpm2ch5
0xFFD2:0xFFD3
TPM2 Channel 4
Vtpm2ch4
0xFFD4:0xFFD5
TPM2 Channel 3
Vtpm2ch3
0xFFD6:0xFFD7
TPM2 Channel 2
Vtpm2ch2
0xFFD8:0xFFD9
TPM2 Channel 1
Vtpm2ch1
0xFFDA:0xFFDB
TPM2 Channel 0
Vtpm2ch0
0xFFDC:0xFFDD
ADC Conversion
Vadc
0xFFDE:0xFFDF
KBI Interrupt
Vkeyboard
0xFFE0:0xFFE1
IIC
Viic
0xFFE2:0xFFE3
SCI2 Transmit
Vsci2tx
0xFFE4:0xFFE5
SCI2 Receive
Vsci2rx
0xFFE6:0xFFE7
SCI2 Error
Vsci2err
0xFFE8:0xFFE9
SPI
Vspi
0xFFEA:0xFFEB
LCD Frame
Vlcd
0xFFEC:0xFFED
SCI1 Transmit
Vsci1tx
0xFFEE:0xFFEF
SCI1 Receive
Vsci1rx
0xFFF0:0xFFF1
SCI1 Error
Vsci1err
0xFFF2:0xFFF3
TPM1 Overflow
Vtpm1ovf
0xFFF4:0xFFF5
TPM1 Channel 1
Vtpm1ch1
0xFFF6:0xFFF7
TPM1 Channel 0
Vtpm1ch0
0xFFF8:0xFFF9
Low Voltage Warning
Vlvw
0xFFFA:0xFFFB
IRQ
Virq
0xFFFC:0xFFFD
SWI
Vswi
0xFFFE:0xFFFF
Reset
Vreset
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
51
Chapter 4 Memory
4.4
Register Addresses and Bit Assignments
The register groups in the MC9S08LG32 series consist of the following locations in the memory map:
• Direct-page registers are located at the first 96 locations. Access these locations with efficient
direct addressing mode instructions.
• LCD Registers, LCDPENx, LCDBPENx, LCDWFx are located at the end of the RAM module.
• High-page registers are used much less often, so they are located above 0x1800 in the memory
map. This leaves more room in the direct page registers for more frequently used registers and
RAM.
• The nonvolatile register area consists of a block of 16 locations in flash memory at
0xFFB0–0xFFBF. Nonvolatile register locations include:
— NVPROT and NVOPT are loaded into working registers at reset
— An 8-byte backdoor comparison key that optionally allows controlled access to secure memory
Because the nonvolatile register locations are flash memory, they must be erased and programmed
like other flash memory locations.
Direct-page registers can be accessed with efficient direct addressing mode instructions. Bit manipulation
instructions can be used to access any bit in any direct-page register. Table 4-2 is a summary of all
user-accessible direct-page registers and control bits.
The direct page registers in Table 4-2 can use the more efficient direct addressing mode, which requires
only the lower byte of the address. Because of this, the lower byte of the address in column one is shown
in bold text. In Table 4-4 and Table 4-5, the whole address in column one is shown in bold. In Table 4-2,
Table 4-4, and Table 4-5, the register names in column two are shown in bold to set them apart from the
bit names to the right. Cells that are not associated with named bits are shaded. A shaded cell with a 0
indicates this unused bit always reads as a 0. Shaded cells with dashes indicate unused or reserved bit
locations that could read as 1s or 0s. When writing to these bits, write a 0 unless otherwise specified.
MC9S08LG32 MCU Series, Rev. 5
52
Freescale Semiconductor
Chapter 4 Memory
Table 4-2. Direct-Page Register Summary (Sheet 1 of 3)
Address
Register
Name
Bit 7
6
5
4
3
2
1
Bit 0
0x0000
PTAD
PTAD7
PTAD6
PTAD5
PTAD4
PTAD3
PTAD2
PTAD1
PTAD0
0x0001
PTADD
PTADD7
PTADD6
PTADD5
PTADD4
PTADD3
PTADD2
PTADD1
PTADD0
0x0002
PTBD
PTBD7
PTBD6
PTBD5
PTBD4
PTBD3
PTBD2
PTBD1
PTBD0
0x0003
PTBDD
PTBDD7
PTBDD6
PTBDD5
PTBDD4
PTBDD3
PTBDD2
PTBDD1
PTBDD0
0x0004
PTCD
0
PTCD6
PTCD5
PTCD4
PTCD3
PTCD2
PTCD1
PTCD0
0x0005
PTCDD
0
PTCDD6
PTCDD5
PTCDD4
PTCDD3
PTCDD2
PTCDD1
PTCDD0
0x0006
PTDD
PTDD7
PTDD6
PTDD5
PTDD4
PTDD3
PTDD2
PTDD1
PTDD0
0x0007
PTDDD
PTDDD7
PTDDD6
PTDDD5
PTDDD4
PTDDD3
PTDDD2
PTDDD1
PTDDD0
0x0008
IICA
AD7
AD6
AD5
AD4
AD3
AD2
AD1
0
0x0009
IICF
0x000A
IICC1
IICEN
IICIE
MST
TX
TXAK
RSTA
0
0
0x000B
IICS
TCF
IAAS
BUSY
ARBL
0
SRW
IICIF
RXAK
GCAEN
ADEXT
0
0
0
AD10
AD9
AD8
0x000C
IICD
0x000D
IICC2
MULT
ICR
DATA
0x000E
PTED
PTED7
PTED6
PTED5
PTED4
PTED3
PTED2
PTED1
PTED0
0x000F
PTEDD
PTEDD7
PTEDD6
PTEDD5
PTEDD4
PTEDD3
PTEDD2
PTEDD1
PTEDD0
0x0010
SCI1BDH
LBKDIE
RXEDGIE
0
SBR12
SBR11
SBR10
SBR9
SBR8
0x0011
SCI1BDL
SBR7
SBR6
SBR5
SBR4
SBR3
SBR2
SBR1
SBR0
0x0012
SCI1C1
LOOPS
SCISWAI
RSRC
M
WAKE
ILT
PE
PT
0x0013
SCI1C2
TIE
TCIE
RIE
ILIE
TE
RE
RWU
SBK
0x0014
SCI1S1
TDRE
TC
RDRF
IDLE
OR
NF
FE
PF
0x0015
SCI1S2
LBKDIF
RXEDGIF
0
RXINV
RWUID
BRK13
LBKDE
RAF
0x0016
SCI1C3
R8
T8
TXDIR
TXINV
ORIE
NEIE
FEIE
PEIE
0x0017
SCI1D
Bit 7
6
5
4
3
2
1
Bit 0
0x0018
SCI2BDH
LBKDIE
RXEDGIE
0
SBR12
SBR11
SBR10
SBR9
SBR8
0x0019
SCI2BDL
SBR7
SBR6
SBR5
SBR4
SBR3
SBR2
SBR1
SBR0
0x001A
SCI2C1
LOOPS
SCISWAI
RSRC
M
WAKE
ILT
PE
PT
0x001B
SCI2C2
TIE
TCIE
RIE
ILIE
TE
RE
RWU
SBK
0x001C
SCI2S1
TDRE
TC
RDRF
IDLE
OR
NF
FE
PF
0x001D
SCI2S2
LBKDIF
RXEDGIF
0
RXINV
RWUID
BRK13
LBKDE
RAF
0x001E
SCI2C3
R8
T8
TXDIR
TXINV
ORIE
NEIE
FEIE
PEIE
0x001F
SCI2D
Bit 7
6
5
4
3
2
1
Bit 0
0x0020
TPM2SC
TOF
TOIE
CPWMS
CLKSB
CLKSA
PS2
PS1
PS0
0x0021
TPM2CNTH
Bit 15
14
13
12
11
10
9
Bit 8
0x0022
TPM2CNTL
Bit 7
6
5
4
3
2
1
Bit 0
0x0023 TPM2MODH
Bit 15
14
13
12
11
10
9
Bit 8
0x0024 TPM2MODL
Bit 7
6
5
4
3
2
1
Bit 0
0x0025
TPM2C0SC
CH0F
CH0IE
MS0B
MS0A
ELS0B
ELS0A
0
0
0x0026
TPM2C0VH
Bit 15
14
13
12
11
10
9
Bit 8
0x0027
TPM2C0VL
Bit 7
6
5
4
3
2
1
Bit 0
0x0028
TPM2C1SC
CH1F
CH1IE
MS1B
MS1A
ELS1B
ELS1A
0
0
0x0029
TPM2C1VH
Bit 15
14
13
12
11
10
9
Bit 8
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
53
Chapter 4 Memory
Table 4-2. Direct-Page Register Summary (Sheet 2 of 3)
Address
Register
Name
Bit 7
6
5
4
3
2
1
Bit 0
0x002A
TPM2C1VL
Bit 7
6
5
4
3
2
1
Bit 0
0x002B
TPM2C2SC
CH2F
CH2IE
MS2B
MS2A
ELS2B
ELS2A
0
0
0x002C
TPM2C2VH
Bit 15
14
13
12
11
10
9
Bit 8
0x002D
TPM2C2VL
Bit 7
6
5
4
3
2
1
Bit 0
0x002E
TPM2C3SC
CH3F
CH3IE
MS3B
MS3A
ELS3B
ELS3A
0
0
0x002F
TPM2C3VH
Bit 15
14
13
12
11
10
9
Bit 8
0x0030
TPM2C3VL
Bit 7
6
5
4
3
2
1
Bit 0
0x0031
TPM2C4SC
CH4F
CH4IE
MS4B
MS4A
ELS4B
ELS4A
0
0
0x0032
TPM2C4VH
Bit 15
14
13
12
11
10
9
Bit 8
0x0033
TPM2C4VL
Bit 7
6
5
4
3
2
1
Bit 0
0x0034
TPM2C5SC
CH5F
CH5IE
MS5B
MS5A
ELS5B
ELS5A
0
0
0x0035
TPM2C5VH
Bit 15
14
13
12
11
10
9
Bit 8
0x0036
TPM2C5VL
Bit 7
6
5
4
3
2
1
Bit 0
0x0037
IRQSC
0
IRQPDD
IRQEDG
IRQPE
IRQF
IRQACK
IRQIE
IRQMOD
0x0038
LCDC0
LCDEN
SOURCE
LCLK2
LCLK1
LCLK0
DUTY2
DUTY1
DUTY0
0x0039
LCDC1
LCDIEN
0
0
0
0
FCDEN
LCDWAI
LCDSTP
0x003A LCDSUPPLY
CPSEL
HREFSEL
LADJ1
LADJ0
0
0x003B
LCDRVC
RVEN
0
0
0
RVTRIM3
RVTRIM2
RVTRIM1
RVTRIM0
0x003C
LCDBCTL
BLINK
ALT
BLANK
0
BMODE
BRATE2
BRATE1
BRATE0
0x003D
LCDS
LCDIF
0
0
0
0
0
0
0
BBYPASS VSUPPLY1 VSUPPLY0
0x003E
PTFD
PTFD7
PTFD6
PTFD5
PTFD4
PTFD3
PTFD2
PTFD1
PTFD0
0x003F
PTFDD
PTFDD7
PTFDD6
PTFDD5
PTFDD4
PTFDD3
PTFDD2
PTFDD1
PTFDD0
0x0040
TPM1SC
TOF
TOIE
CPWMS
CLKSB
CLKSA
PS2
PS1
PS0
0x0041
TPM1CNTH
Bit 15
14
13
12
11
10
9
Bit 8
0x0042
TPM1CNTL
Bit 7
6
5
4
3
2
1
Bit 0
0x0043 TPM1MODH
Bit 15
14
13
12
11
10
9
Bit 8
Bit 7
6
5
4
3
2
1
Bit 0
0x0045
0x0044 TPM1MODL
TPM1C0SC
CH0F
CH0IE
MS0B
MS0A
ELS0B
ELS0A
0
0
0x0046
TPM1C0VH
Bit 15
14
13
12
11
10
9
Bit 8
0x0047
TPM1C0VL
Bit 7
6
5
4
3
2
1
Bit 0
0x0048
TPM1C1SC
CH1F
CH1IE
MS1B
MS1A
ELS1B
ELS1A
0
0
0x0049
TPM1C1VH
Bit 15
14
13
12
11
10
9
Bit 8
4
3
2
1
Bit 0
0x004A
TPM1C1VL
Bit 7
6
5
0x004B
ADCSC1
COCO
AIEN
ADCO
0x004C
ADCSC2
ADACT
ADTRG
ACFE
ACFGT
0
0
—
—
0x004D
ADCRH
0
0
0
0
ADR11
ADR10
ADR9
ADR8
0x004E
ADCRL
ADR7
ADR6
ADR5
ADR4
ADR3
ADR2
ADR1
ADR0
0x004F
ADCCVH
0
0
0
0
ADCV11
ADCV10
ADCV9
ADCV8
0x0050
ADCCVL
ADCV7
ADCV6
ADCV4
ADCV3
ADCV2
ADCV1
ADCV0
0x0051
ADCCFG
ADLPC
0x0052
APCTL1
ADPC7
ADPC6
ADPC5
ADPC4
ADPC3
ADPC2
ADPC1
ADPC0
0x0053
APCTL2
ADPC15
ADPC14
ADPC13
ADPC12
ADPC11
ADPC10
ADPC9
ADPC8
ADCV5
ADIV
ADCH
ADLSMP
MODE
ADICLK
MC9S08LG32 MCU Series, Rev. 5
54
Freescale Semiconductor
Chapter 4 Memory
Table 4-2. Direct-Page Register Summary (Sheet 3 of 3)
Address
Register
Name
Bit 7
6
5
4
3
2
1
Bit 0
0x0054
PTGD
PTGD7
PTGD6
PTGD5
PTGD4
PTGD3
PTGD2
PTGD1
PTGD0
0x0055
PTGDD
PTGDD7
PTGDD6
PTGDD5
PTGDD4
PTGDD3
PTGDD2
PTGDD1
PTGDD0
0x0056
PTHD
PTHD7
PTHD6
PTHD5
PTHD4
PTHD3
PTHD2
PTHD1
PTHD0
0x0057
PTHDD
PTHDD7
PTHDD6
PTHDD5
PTHDD4
PTHDD3
PTHDD2
PTHDD1
PTHDD0
0x0058
SPIC1
SPIE
SPE
SPTIE
MSTR
CPOL
CPHA
SSOE
LSBFE
0x0059
SPIC2
0
0
0
MODFEN
BIDIROE
0
SPISWAI
SPC0
0x005A
SPIBR
0
SPPR2
SPPR1
SPPR0
SPR3
SPR2
SPR1
SPR0
0x005B
SPIS
SPRF
0
SPTEF
MODF
0
0
0
0
0x005C
Reserved
0
0
0
0
0
0
0
0
0x005D
SPID
Bit 7
6
5
4
3
2
1
Bit 0
0x005E
PTID
0
0
PTID5
PTID4
PTID3
PTID2
PTID1
PTID0
0x005F
PTIDD
0
0
PTIDD5
PTIDD4
PTIDD3
PTIDD2
PTIDD1
PTIDD0
Use the LCD registers shown in table below to enable LCD functionality and display the LCD data.
Table 4-3. LCD Registers (Sheet 1 of 2)
Address
Register
Name
0x0820
LCDPEN0
PEN7
PEN6
PEN5
PEN4
0x0821
LCDPEN1
PEN15
PEN14
PEN13
PEN12
0x0822
LCDPEN2
PEN23
PEN22
PEN21
PEN20
0x0823
LCDPEN3
PEN31
PEN30
PEN29
PEN28
0x0824
LCDPEN4
PEN39
PEN38
PEN37
0x0825
LCDPEN5
—
—
—
0x0826
0x0827
Reserved
—
—
—
—
—
—
Bit 7
6
5
4
3
2
1
Bit 0
PEN3
PEN2
PEN1
PEN0
PEN11
PEN10
PEN9
PEN8
PEN19
PEN18
PEN17
PEN16
PEN27
PEN26
PEN25
PEN24
PEN36
PEN35
PEN34
PEN33
PEN32
PEN44
PEN43
PEN42
PEN41
PEN40
—
—
—
—
—
—
—
—
—
—
0x0828 LCDBPEN0
BPEN7
BPEN6
BPEN5
BPEN4
BPEN3
BPEN2
BPEN1
BPEN0
0x0829 LCDBPEN1
BPEN15
BPEN14
BPEN13
BPEN12
BPEN11
BPEN10
BPEN9
BPEN8
0x082A LCDBPEN2
BPEN23
BPEN22
BPEN21
BPEN20
BPEN19
BPEN18
BPEN17
BPEN16
0x082B LCDBPEN3
BPEN31
BPEN30
BPEN29
BPEN28
BPEN27
BPEN26
BPEN25
BPEN24
0x082C LCDBPEN4
BPEN39
BPEN38
BPEN37
BPEN36
BPEN35
BPEN34
BPEN33
BPEN32
0x082D LCDBPEN5
—
—
—
BPEN44
BPEN43
BPEN42
BPEN41
BPEN40
0x082E
0x082F
Reserved
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
0x0830
LCDWF0
BPHLCD0
BPGLCD0
BPFLCD0
BPELCD0
BPDLCD0
BPCLCD0
BPBLCD0
BPALCD0
0x0831
LCDWF1
BPHLCD1
BPGLCD1
BPFLCD1
BPELCD1
BPDLCD1
BPCLCD1
BPBLCD1
BPALCD1
0x0832
LCDWF2
BPHLCD2
BPGLCD2
BPFLCD2
BPELCD2
BPDLCD2
BPCLCD2
BPBLCD2
BPALCD2
0x0833
LCDWF3
BPHLCD3
BPGLCD3
BPFLCD3
BPELCD3
BPDLCD3
BPCLCD3
BPBLCD3
BPALCD3
0x0834
LCDWF4
BPHLCD4
BPGLCD4
BPFLCD4
BPELCD4
BPDLCD4
BPCLCD4
BPBLCD4
BPALCD4
0x0835
LCDWF5
BPHLCD5
BPGLCD5
BPFLCD5
BPELCD5
BPDLCD5
BPCLCD5
BPBLCD5
BPALCD5
0x0836
LCDWF6
BPHLCD6
BPGLCD6
BPFLCD6
BPELCD6
BPDLCD6
BPCLCD6
BPBLCD6
BPALCD6
0x0837
LCDWF7
BPHLCD7
BPGLCD7
BPFLCD7
BPELCD7
BPDLCD7
BPCLCD7
BPBLCD7
BPALCD7
0x0838
LCDWF8
BPHLCD8
BPGLCD8
BPFLCD8
BPELCD8
BPDLCD8
BPCLCD8
BPBLCD8
BPALCD8
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
55
Chapter 4 Memory
Table 4-3. LCD Registers (Sheet 2 of 2)
Address
Register
Name
Bit 7
6
5
4
3
2
1
Bit 0
BPHLCD9
BPGLCD9
BPFLCD9
BPELCD9
BPDLCD9
BPCLCD9
BPBLCD9
BPALCD9
0x0839
LCDWF9
0x083A
LCDWF10 BPHLCD10 BPGLCD10 BPFLCD10 BPELCD10 BPDLCD10 BPCLCD10 BPBLCD10 BPALCD10
0x083B
LCDWF11 BPHLCD11 BPGLCD11 BPFLCD11 BPELCD11 BPDLCD11 BPCLCD11 BPBLCD11 BPALCD11
0x083C
LCDWF12 BPHLCD12 BPGLCD12 BPFLCD12 BPELCD12 BPDLCD12 BPCLCD12 BPBLCD12 BPALCD12
0x083D
LCDWF13 BPHLCD13 BPGLCD13 BPFLCD13 BPELCD13 BPDLCD13 BPCLCD13 BPBLCD13 BPALCD13
0x083E
LCDWF14 BPHLCD14 BPGLCD14 BPFLCD14 BPELCD14 BPDLCD14 BPCLCD14 BPBLCD14 BPALCD14
0x083F
LCDWF15 BPHLCD15 BPGLCD15 BPFLCD15 BPELCD15 BPDLCD15 BPCLCD15 BPBLCD15 BPALCD15
0x0840
LCDWF16 BPHLCD16 BPGLCD16 BPFLCD16 BPELCD16 BPDLCD16 BPCLCD16 BPBLCD16 BPALCD16
0x0841
LCDWF17 BPHLCD17 BPGLCD17 BPFLCD17 BPELCD17 BPDLCD17 BPCLCD17 BPBLCD17 BPALCD17
0x0842
LCDWF18 BPHLCD18 BPGLCD18 BPFLCD18 BPELCD18 BPDLCD18 BPCLCD18 BPBLCD18 BPALCD18
0x0843
LCDWF19 BPHLCD19 BPGLCD19 BPFLCD19 BPELCD19 BPDLCD19 BPCLCD19 BPBLCD19 BPALCD19
0x0844
LCDWF20 BPHLCD20 BPGLCD20 BPFLCD20 BPELCD20 BPDLCD20 BPCLCD20 BPBLCD20 BPALCD20
0x0845
LCDWF21 BPHLCD21 BPGLCD21 BPFLCD21 BPELCD21 BPDLCD21 BPCLCD21 BPBLCD21 BPALCD21
0x0846
LCDWF22 BPHLCD22 BPGLCD22 BPFLCD22 BPELCD22 BPDLCD22 BPCLCD22 BPBLCD22 BPALCD22
0x0847
LCDWF23 BPHLCD23 BPGLCD23 BPFLCD23 BPELCD23 BPDLCD23 BPCLCD23 BPBLCD23 BPALCD23
0x0848
LCDWF24 BPHLCD24 BPGLCD24 BPFLCD24 BPELCD24 BPDLCD24 BPCLCD24 BPBLCD24 BPALCD24
0x0849
LCDWF25 BPHLCD25 BPGLCD25 BPFLCD25 BPELCD25 BPDLCD25 BPCLCD25 BPBLCD25 BPALCD25
0x084A
LCDWF26 BPHLCD26 BPGLCD26 BPFLCD26 BPELCD26 BPDLCD26 BPCLCD26 BPBLCD26 BPALCD26
0x084B
LCDWF27 BPHLCD27 BPGLCD27 BPFLCD27 BPELCD27 BPDLCD27 BPCLCD27 BPBLCD27 BPALCD27
0x084C
LCDWF28 BPHLCD28 BPGLCD28 BPFLCD28 BPELCD28 BPDLCD28 BPCLCD28 BPBLCD28 BPALCD28
0x084D
LCDWF29 BPHLCD29 BPGLCD29 BPFLCD29 BPELCD29 BPDLCD29 BPCLCD29 BPBLCD29 BPALCD29
0x084E
LCDWF30 BPHLCD30 BPGLCD30 BPFLCD30 BPELCD30 BPDLCD30 BPCLCD30 BPBLCD30 BPALCD30
0x084F
LCDWF31 BPHLCD31 BPGLCD31 BPFLCD31 BPELCD31 BPDLCD31 BPCLCD31 BPBLCD31 BPALCD31
0x0850
LCDWF32 BPHLCD32 BPGLCD32 BPFLCD32 BPELCD32 BPDLCD32 BPCLCD32 BPBLCD32 BPALCD32
0x0851
LCDWF33 BPHLCD33 BPGLCD33 BPFLCD33 BPELCD33 BPDLCD33 BPCLCD33 BPBLCD33 BPALCD33
0x0852
LCDWF34 BPHLCD34 BPGLCD34 BPFLCD34 BPELCD34 BPDLCD34 BPCLCD34 BPBLCD34 BPALCD34
0x0853
LCDWF35 BPHLCD35 BPGLCD35 BPFLCD35 BPELCD35 BPDLCD35 BPCLCD35 BPBLCD35 BPALCD35
0x0854
LCDWF36 BPHLCD36 BPGLCD36 BPFLCD36 BPELCD36 BPDLCD36 BPCLCD36 BPBLCD36 BPALCD36
0x0855
LCDWF37 BPHLCD37 BPGLCD37 BPFLCD37 BPELCD37 BPDLCD37 BPCLCD37 BPBLCD37 BPALCD37
0x0856
LCDWF38 BPHLCD38 BPGLCD38 BPFLCD38 BPELCD38 BPDLCD38 BPCLCD38 BPBLCD38 BPALCD38
0x0857
LCDWF39 BPHLCD39 BPGLCD39 BPFLCD39 BPELCD39 BPDLCD39 BPCLCD39 BPBLCD39 BPALCD39
0x0858
LCDWF40 BPHLCD40 BPGLCD40 BPFLCD40 BPELCD40 BPDLCD40 BPCLCD40 BPBLCD40 BPALCD40
0x0859
LCDWF41 BPHLCD41 BPGLCD41 BPFLCD41 BPELCD41 BPDLCD41 BPCLCD41 BPBLCD41 BPALCD41
0x085A
LCDWF42 BPHLCD42 BPGLCD42 BPFLCD42 BPELCD42 BPDLCD42 BPCLCD42 BPBLCD42 BPALCD42
0x085B
LCDWF43 BPHLCD43 BPGLCD43 BPFLCD43 BPELCD43 BPDLCD43 BPCLCD43 BPBLCD43 BPALCD43
0x085C
LCDWF44 BPHLCD44 BPGLCD44 BPFLCD44 BPELCD44 BPDLCD44 BPCLCD44 BPBLCD44 BPALCD44
High-page registers, shown in Table 4-4, are accessed much less often than other I/O and control registers
so they have been located outside the direct addressable memory space, starting at 0x1800.
MC9S08LG32 MCU Series, Rev. 5
56
Freescale Semiconductor
Chapter 4 Memory
Table 4-4. High-Page Register Summary (Sheet 1 of 3)
Address Register Name
Bit 7
6
5
4
3
2
1
Bit 0
POR
PIN
COP
ILOP
ILAD
0
LVD
0
0x1800
SRS
0x1801
SBDFR
0
0
0
0
0
0
0
BDFR
0x1802
SOPT1
COPE
COPT
STOPE
0
0
0
BKGDPE
RSTPE
0x1803
SOPT2
COPCLKS
0
0
0
0
0
0
SPIFE
0x1804 0x1805
Reserved
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
0x1806
SDIDH
—
—
—
—
ID11
ID10
ID9
ID8
0x1807
SDIDL
ID7
ID6
ID5
ID4
ID3
ID2
ID1
ID0
0x1808
Reserved
—
—
—
—
—
—
—
—
0x1809
SPMSC1
LVWF
LVWACK
LVWIE
LVDRE
LVDSE
LVDE
—
BGBE
0x180A
SPMSC2
—
—
LVDV
LVWV
PPDF
PPDACK
—
PPDC
0x180B 0x180D
Reserved
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
0x180E
SCGC1
RTC
TPM2
TPM1
ADC
MTIM
IIC
SCI2
SCI1
0x180F
SCGC2
DBG
FLS
IRQ
KBI
0
0
LCD
SPI
0x1810
DBGCAH
Bit 15
14
13
12
11
10
9
Bit 8
0x1811
DBGCAL
Bit 7
6
5
4
3
2
1
Bit 0
0x1812
DBGCBH
Bit 15
14
13
12
11
10
9
Bit 8
0x1813
DBGCBL
Bit 7
6
5
4
3
2
1
Bit 0
0x1814
DBGCCH
Bit 15
14
13
12
11
10
9
Bit 8
0x1815
DBGCCL
Bit 7
6
5
4
3
2
1
Bit 0
0x1816
DBGFH
Bit 15
14
13
12
11
10
9
Bit 8
0x1817
DBGFL
Bit 7
6
5
4
3
2
1
Bit 0
0x1818
DBGCAX
RWAEN
RWA
0
0
0
0
0
0
0x1819
DBGCBX
RWBEN
RWB
0
0
0
0
0
0
0x181A
DBGCCX
RWCEN
RWC
0
0
0
0
0
0
0x181B
Reserved
—
—
—
—
—
—
—
—
0x181C
DBGC
DBGEN
ARM
TAG
BRKEN
0
0
0
LOOP1
0x181D
DBGT
TRGSEL
BEGIN
0
0
0x181E
DBGS
AF
BF
CF
0
0
0
0
ARMF
0x181F
DBGCNT
0
0
0
0
0x1820
FCDIV
DIVLD
PRDIV8
0x1821
FOPT
KEYEN
FNORED
0
0
0
0
0x1822
Reserved
—
—
—
—
—
—
—
0
0
KEYACC
0
0
0
0
TRG
CNT
DIV
0x1823
FCNFG
0x1824
FPROT
0x1825
FSTAT
0x1826
FCMD
0x1827 0x182F
Reserved
—
—
—
—
—
—
0x1830
PINPS1
KBI7
KBI6
0x1831
PINPS2
TPM2[5]
0x1832
PINPS3
TX2
SEC
FPS
FCBEF
FCCF
FPVIOL
—
0
FPDIS
FACCERR
0
FBLANK
0
0
—
—
—
—
—
—
—
—
—
—
KBI5
KBI4
KBI3
KBI2
KBI1
KBI0
TPM2[4]
TPM2[3]
TPM2[2]
TPM2[1]
TPM2[0]
TPM1[1]
TPM1[0]
RX2
SCL
SDA
MISO
MOSI
SCK
SS
FCMD
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
57
Chapter 4 Memory
Table 4-4. High-Page Register Summary (Sheet 2 of 3)
Address Register Name
Bit 7
6
5
4
3
2
1
Bit 0
0x1833
PINPS4
0
0
0
0
0
0
TX1
RX1
0x1834 0x183B
Reserved
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
0x183C
RTCSC
RTIF
0x183D
RTCCNT
0x183E
RTCMOD
0x183F
Reserved
—
—
—
—
—
—
—
—
0x1840
PTAPE
PTAPE7
PTAPE6
PTAPE5
PTAPE4
PTAPE3
PTAPE2
PTAPE1
PTAPE0
0x1841
PTASE
PTASE7
PTASE6
PTASE5
PTASE4
PTASE3
PTASE2
PTASE1
PTASE0
0x1842
PTADS
PTADS7
PTADS6
PTADS5
PTADS4
PTADS3
PTADS2
PTADS1
PTADS0
0x1843
Reserved
—
—
—
—
—
—
—
—
0x1844
PTBPE
PTBPE7
PTBPE6
PTBPE5
PTBPE4
PTBPE3
PTBPE2
PTBPE1
PTBPE0
0x1845
PTBSE
PTBSE7
PTBSE6
PTBSE5
PTBSE4
PTBSE3
PTBSE2
PTBSE1
PTBSE0
0x1846
PTBDS
PTBDS7
PTBDS6
PTBDS5
PTBDS4
PTBDS3
PTBDS2
PTBDS1
PTBDS0
0x1847
Reserved
—
—
—
—
—
—
—
—
0x1848
PTCPE
—
PTCPE6
PTCPE5
PTCPE4
PTCPE3
PTCPE2
PTCPE1
PTCPE0
0x1849
PTCSE
—
PTCSE6
PTCSE5
PTCSE4
PTCSE3
PTCSE2
PTCSE1
PTCSE0
0x184A
PTCDS
—
PTCDS6
PTCDS5
PTCDS4
PTCDS3
PTCDS2
PTCDS1
PTCDS0
0x184B
Reserved
—
—
—
—
—
—
—
—
0x184C
PTDPE
PTDPE7
PTDPE6
PTDPE5
PTDPE4
PTDPE3
PTDPE2
PTDPE1
PTDPE0
0x184D
PTDSE
PTDSE7
PTDSE6
PTDSE5
PTDSE4
PTDSE3
PTDSE2
PTDSE1
PTDSE0
0x184E
PTDDS
PTDDS7
PTDDS6
PTDDS5
PTDDS4
PTDDS3
PTDDS2
PTDDS1
PTDDS0
0x184F
Reserved
—
—
—
—
—
—
—
—
0x1850
PTEPE
PTEPE7
PTEPE6
PTEPE5
PTEPE4
PTEPE3
PTEPE2
PTEPE1
PTEPE0
0x1851
PTESE
PTESE7
PTESE6
PTESE5
PTESE4
PTESE3
PTESE2
PTESE1
PTESE0
0x1852
PTEDS
PTEDS7
PTEDS6
PTEDS5
PTEDS4
PTEDS3
PTEDS2
PTEDS1
PTEDS0
0x1853
Reserved
—
—
—
—
—
—
—
—
RTCLKS
RTIE
RTCPS
RTCCNT
RTCMOD
0x1854
PTFPE
PTFPE7
PTFPE6
PTFPE5
PTFPE4
PTFPE3
PTFPE2
PTFPE1
PTFPE0
0x1855
PTFSE
PTFSE7
PTFSE6
PTFSE5
PTFSE4
PTFSE3
PTFSE2
PTFSE1
PTFSE0
0x1856
PTFDS
PTFDS7
PTFDS6
PTFDS5
PTFDS4
PTFDS3
PTFDS2
PTFDS1
PTFDS0
0x1857 0x185F
Reserved
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
0x1860
ICSC1
CLKS
IREFS
IRCLKEN
IREFSTEN
0x1861
ICSC2
BDIV
EREFS
ERCLKEN EREFSTEN
0x1862
ICSTRM
RDIV
RANGE
HGO
LP
TRIM
0x1863
ICSSC
0x1864 0x1867
Reserved
DRST
Reserved
—
—
—
—
—
—
—
—
0x1868
PTGPE
PTGPE7
PTGPE6
PTGPE5
PTGPE4
PTGPE3
PTGPE2
PTGPE1
PTGPE0
—
—
DMX32
IREFST
—
—
CLKST
—
—
OSCINIT
FTRIM
—
—
0x1869
PTGSE
PTGSE7
PTGSE6
PTGSE5
PTGSE4
PTGSE3
PTGSE2
PTGSE1
PTGSE0
0x186A
PTGDS
PTGDS7
PTGDS6
PTGDS5
PTGDS4
PTGDS3
PTGDS2
PTGDS1
PTGDS0
0x186B
Reserved
—
—
—
—
—
—
—
—
0x186C
PTHPE
PTHPE7
PTHPE6
PTHPE5
PTHPE4
PTHPE3
PTHPE2
PTHPE1
PTHPE0
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Table 4-4. High-Page Register Summary (Sheet 3 of 3)
Address Register Name
Bit 7
6
5
4
3
2
1
Bit 0
0x186D
PTHSE
PTHSE7
PTHSE6
PTHSE5
PTHSE4
PTHSE3
PTHSE2
PTHSE1
PTHSE0
0x186E
PTHDS
PTHDS7
PTHDS6
PTHDS5
PTHDS4
PTHDS3
PTHDS2
PTHDS1
PTHDS0
0x186F
Reserved
—
—
—
—
—
—
—
—
0x1870
MTIMSC
TOF
TOIE
TRST
TSTP
0
0
0
0
0x1871
MTIMCLK
0
0
0x1872
MTIMCNT
0x1873
MTIMMOD
0x1874
PTIPE
—
—
PTIPE1
PTIPE0
0x1875
PTISE
—
—
PTISE5
PTISE4
PTISE3
PTISE2
PTISE1
PTISE0
0x1876
PTIDS
—
—
PTIDS5
PTIDS4
PTIDS3
PTIDS2
PTIDS1
PTIDS0
0x1877
Reserved
—
—
—
—
—
—
—
—
0x1878
KBISC
0
0
0
0
KBF
KBACK
KBIE
KBMOD
0x1879
KBIPE
KBIPE7
KBIPE6
KBIPE5
KBIPE4
KBIPE3
KBIPE2
KBIPE1
KBIPE0
0x187A
KBIES
KBEDG7
KBEDG6
KBEDG5
KBEDG4
KBEDG3
KBEDG2
KBEDG1
KBEDG0
4.4.1
CLKS
PS
COUNT
MOD
PTIPE5
PTIPE4
PTIPE3
PTIPE2
Reserved Flash Locations
Several reserved flash memory locations, shown in Table 4-5, are used for storing values used by several
registers. These registers include an 8-byte backdoor key, NVBACKKEY, which can be used to gain
access to secure memory resources. During reset events, the contents of NVPROT and NVOPT in the
reserved flash memory are transferred into corresponding FPROT and FOPT registers in the high-page
registers area to control security and block protection options.
Locations 0xFFAE and 0xFFAF are reserved for ICS FTRIM and ICS TRIM values respectively. These
locations are left blank at the factory. Third party tools can program these locations with the trim values.
User can copy these values to corresponding ICS registers to get ICS trimmed clock frequency
Table 4-5. Reserved Flash Memory Addresses
Address
Register Name
0xFFB0 –
0xFFB7
NVBACKKEY
0xFFB8 –
0xFFBC
Reserved
Bit 7
6
5
4
3
2
1
Bit 0
—
—
—
—
—
—
—
—
—
8-Byte Comparison Key
—
—
—
—
—
—
—
—
0xFFBD
NVPROT
0xFFBE
Reserved
—
—
—
—
—
—
0xFFBF
NVOPT
KEYEN
FNORED
0
0
0
0
FPS
FPDIS
—
SEC
Provided the key enable (KEYEN) bit is 1, the 8-byte comparison key can be used to temporarily
disengage memory security. This key mechanism can be accessed only through user code running in secure
memory. (A security key cannot be entered directly through background debug commands.) This security
key can be disabled completely by programming the KEYEN bit to 0. If the security key is disabled, the
only way to disengage security is by mass erasing the flash if needed (normally through the background
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debug interface) and verifying that flash is blank. To avoid returning to secure mode after the next reset,
program the security bits (SEC) to the unsecured state (1:0).
4.5
RAM
The MC9S08LG32 series includes static RAM. The locations in RAM below 0x0100 can be accessed
using the more efficient direct addressing mode, and any single bit in this area can be accessed with the bit
manipulation instructions (BCLR, BSET, BRCLR, and BRSET). Locating the most frequently accessed
program variables in this area of RAM is preferred.
At power-on, the contents of RAM are uninitialized. RAM data is unaffected by any reset provided that
the supply voltage does not drop below the minimum value for RAM retention (VRAM).
For compatibility with M68HC05 MCUs, the HCS08 resets the stack pointer to 0x00FF. In the
MC9S08LG32 series, it is usually best to reinitialize the stack pointer to the top of the RAM so the direct
page RAM can be used for frequently accessed RAM variables and bit-addressable program variables.
Include the following 2-instruction sequence in your reset initialization routine (where RamLast is equated
to the highest address of the RAM in the Freescale Semiconductor-provided equate file).
LDHX
TXS
#RamLast+1
;point one past RAM
;SP<-(H:X-1)
When security is enabled, the RAM is considered a secure memory resource and is not accessible through
background debug mode (BDM) or through code executing from non-secure memory. See Section 4.7,
“Security,” for a detailed description of the security feature.
4.6
Flash
The flash memory is intended primarily for program storage. In-circuit programming allows the operating
program to be loaded into the flash memory after final assembly of the application product. It is possible
to program the entire array through the single-wire background debug interface. Because no special
voltages are needed for flash erase and programming operations, in-application programming is also
possible through other software-controlled communication paths. For a more detailed discussion of
in-circuit and in-application programming, refer to the HCS08 Family Reference Manual, Volume I,
Freescale Semiconductor document order number HCS08RMv1/D.
Because the MC9S08LG32 series contains two flash arrays, program and erase operations can be
conducted on one array while executing code from the other. The security and protection features treat the
two arrays as a single memory entity. Programming and erasing of each flash array is conducted through
the same command interface detailed in the following sections.
It is not possible to page erase or program both arrays at the same time. The mass erase command erases
both arrays, and the blank check command checks both arrays.
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4.6.1
Features
Features of the flash memory include:
• Flash size
— MC9S08LG32: 32,768 bytes (16,384 bytes in Flash A, 16,384 bytes in Flash B)
— MC9S08LG16: 18,432 bytes (2,048 bytes in Flash A, 16,384 in Flash B)
• Single power supply program and erase
• Command interface for fast program and erase operation
• Up to 100,000 program/erase cycles at typical voltage and temperature
• Flexible block protection
• Security feature for flash and RAM
• Auto power-down for low-frequency read accesses
4.6.2
Program and Erase Times
Before any program or erase command can be accepted, the flash clock divider register (FCDIV) must be
written to set the internal clock for the flash module to a frequency (fFCLK) between 150 kHz and 200 kHz
(see Section 4.8.1, “Flash Clock Divider Register (FCDIV)”). This register can be written only once, so
normally this write is performed during reset initialization. FCDIV cannot be written if the access error
flag, FACCERR in FSTAT, is set. Ensure that FACCERR is not set before writing to the FCDIV register.
The command processor uses one period of the resulting clock (1/fFCLK) to time program and erase pulses.
An integer number of these timing pulses is used by the command processor to complete a program or
erase command.
Table 4-6 shows program and erase times. The bus clock frequency and FCDIV determine the frequency
of FCLK (fFCLK). The time for one cycle of FCLK is tFCLK = 1/fFCLK. The times are shown as a number
of cycles of FCLK and as an absolute time for the case where tFCLK = 5 μs. Program and erase times
shown include overhead for the command state machine and enabling and disabling of program and erase
voltages.
Table 4-6. Program and Erase Times
Parameter
1
Cycles of FCLK
Time if FCLK = 200 kHz
Byte program
9
45 μs
Byte program (burst)
4
20 μs1
Page erase
4000
20 ms
Mass erase
20,000
100 ms
Excluding start/end overhead
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4.6.3
Program and Erase Command Execution
The FCDIV register must be initialized and any error flag is cleared before beginning command execution.
The command execution steps are:
1. Write a data value to an address in the flash array. The address and data information from this write
is latched into the flash interface. This write is a required first step in any command sequence. For
erase and blank check commands, the value of the data is not important. For page erase commands,
the address may be any address in the 512-byte page of flash to be erased. For mass erase and blank
check commands, the address can be any address in the flash memory. Whole pages of 512 bytes
are the smallest block of flash that may be erased.
NOTE
Do not program any byte in the flash more than once after a successful erase
operation. Reprogramming bits to a byte that is already programmed is not
allowed without first erasing the page in which the byte resides or mass
erasing the entire flash memory. Programming without first erasing may
disturb data stored in the flash.
2. Write the command code for the desired command to FCMD. The five valid commands are blank
check (0x05), byte program (0x20), burst program (0x25), page erase (0x40), and mass erase
(0x41). The command code is latched into the command buffer.
3. Write a 1 to the FCBEF bit in FSTAT to clear FCBEF and launch the command (including its
address and data information).
A partial command sequence can be aborted manually by writing a 0 to FCBEF any time after the
write to the memory array and before writing the 1 that clears FCBEF and launches the complete
command. Aborting a command in this way sets the FACCERR access error flag, which must be
cleared before starting a new command.
A strictly monitored procedure must be obeyed or the command will not be accepted. This
minimizes the possibility of any unintended changes to the flash memory contents. The command
complete flag (FCCF) indicates when a command is complete. The command sequence must be
completed by clearing FCBEF to launch the command. Figure 4-2 is a flowchart for executing all
of the commands except for burst programming. The FCDIV register must be initialized before
using any flash commands. This must be done only once following a reset.
4. Wait until the FCCF bit in FSTAT is set. As soon as FCCF= 1, the operation has completed
successfully.
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(1)
WRITE TO FCDIV (1)
FLASH PROGRAM AND
ERASE FLOW
Required only once after reset.
START
FACCERR?
0
1
CLEAR ERROR
WRITE TO FLASH
TO BUFFER ADDRESS AND DATA
WRITE COMMAND TO FCMD
(2)
WRITE 1 TO FCBEF
TO LAUNCH COMMAND
AND CLEAR FCBEF (2)
FPVIOL OR
FACCERR?
Wait at least four bus cycles
before checking FCBEF or FCCF.
YES
ERROR EXIT
NO
0
FCCF?
1
DONE
Figure 4-2. Flash Program and Erase Flowchart
4.6.4
Burst Program Execution
The burst program command is used to program sequential bytes of data in less time than would be
required using the standard program command. This is possible because the high voltage to the flash array
does not need to be disabled between program operations. Ordinarily, when a program or erase command
is issued, an internal charge pump associated with the flash memory must be enabled to supply high
voltage to the array. Upon completion of the command, the charge pump is turned off. When a burst
program command is issued, the charge pump is enabled and then remains enabled after completion of the
burst program operation if these two conditions are met:
• The next burst program command has been queued before the current program operation has
completed.
• The next sequential address selects a byte on the same physical row as the current byte being
programmed. A row of flash memory consists of 64 bytes. A byte within a row is selected by
addresses A5 through A0. A new row begins when addresses A5 through A0 are all zero.
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The first byte of a series of sequential bytes being programmed in burst mode takes the same amount of
time to program as a byte programmed in standard mode. The subsequent bytes program in the burst
program time provided that the conditions above are met. In the case where the next sequential address is
the beginning of a new row, the program time for that byte is the standard time instead of the burst time.
This is because the high voltage to the array must be disabled and then enabled again. If a new burst
command has not been queued before the current command completes, then the charge pump is disabled
and the high voltage removed from the array.
(1)
WRITE TO FCDIV (1)
FLASH BURST
PROGRAM FLOW
Required only once after reset.
START
FACCERR?
1
0
CLEAR ERROR
FCBEF?
1
0
WRITE TO FLASH
TO BUFFER ADDRESS AND DATA
WRITE COMMAND (0x25) TO FCMD
WRITE 1 TO FCBEF
TO LAUNCH COMMAND
AND CLEAR FCBEF (2)
FPVIO OR
FACCERR?
NO
YES
(2)
YES
Wait at least four bus cycles before
checking FCBEF or FCCF.
ERROR EXIT
NEW BURST COMMAND?
NO
0
FCCF?
1
DONE
Figure 4-3. Flash Burst Program Flowchart
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4.6.5
Access Errors
An access error occurs whenever the command execution protocol is violated.
Any of the following actions causes the access error flag (FACCERR) in FSTAT to be set. Before any
command can be processed, FACERR must be cleared. To clear FACCERR, write a 1 to FACCERR in
FSTAT.
• Writing to a flash address before the internal flash clock frequency has been set by writing to the
FCDIV register
• Writing to a flash address while FCBEF is not set (A new command cannot start until the command
buffer is empty.)
• Writing a second time to a flash address before launching the previous command (There is only
one write to flash for every command.)
• Writing a second time to FCMD before launching the previous command (There is only one write
to FCMD for every command.)
• Writing to any flash control register other than FCMD after writing to a flash address
• Writing any command code to FCMD other than the five allowed codes (0x05, 0x20, 0x25, 0x40,
or 0x41)
• Writing any flash control register other than the write to FSTAT (to clear FCBEF and launch the
command) after writing the command to FCMD
• The MCU enters stop mode while a program or erase command is in progress (The command is
aborted.)
• Writing the byte program, burst program, or page erase command code (0x20, 0x25, or 0x40) with
a background debug command while the MCU is secured (The background debug controller can
only do blank check and mass erase commands when the MCU is secure.)
• Writing 0 to FCBEF to cancel a partial command
4.6.6
Flash Block Protection
The block protection feature prevents the protected region of flash from program or erase changes. Block
protection is controlled through the flash protection register (FPROT). When enabled, block protection
begins at any 512 byte boundary below the last address of flash, 0xFFFF. (See Section 4.8.4, “Flash
Protection Register (FPROT and NVPROT)”).
After exit from reset, FPROT is loaded with the contents of the NVPROT location, which is in the
nonvolatile register block of the flash memory. FPROT cannot be changed directly from application
software to prevent runaway programs from altering the block protection settings. Because NVPROT is
within the last 512 bytes of flash, if any amount of memory is protected, NVPROT is itself protected and
cannot be altered (intentionally or unintentionally) by the application software. FPROT can be written
through background debug commands, which allows a protected flash memory to be erased and
reprogrammed.
The block protection mechanism is illustrated in Figure 4-4. The FPS bits are used as the upper bits of the
last address of unprotected memory. This address is formed by concatenating FPS7:FPS1 with logic 1 bits
as shown. For example, to protect the last 1536 bytes of memory (addresses 0xFA00 through 0xFFFF), the
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FPS bits must be set to 1111 100, which results in the value 0xF9FF as the last address of unprotected
memory. In addition to programming the FPS bits to the appropriate value, FPDIS (bit 0 of NVPROT)
must be programmed to logic 0 to enable block protection. Therefore the value 0xF8 must be programmed
into NVPROT to protect addresses 0xFA00 through 0xFFFF.
FPS7 FPS6 FPS5 FPS4 FPS3
A15
A14
A13
A12
A11
FPS2
FPS1
A10
A9
1
1
1
1
1
1
1
1
1
A8 A7 A6 A5 A4 A3 A2 A1 A0
Figure 4-4. Block Protection Mechanism
One use of block protection is to block protect an area of flash memory for a bootloader program. This
bootloader program then can be used to erase the rest of the flash memory and reprogram it. Because the
bootloader is protected, it remains intact even if MCU power is lost in the middle of an erase and
reprogram operation.
4.6.7
Vector Redirection
Whenever any block protection is enabled, the reset and interrupt vectors are protected. Vector redirection
allows users to modify interrupt vector information without unprotecting bootloader and reset vector
space. Vector redirection is enabled by programming the FNORED bit in the NVOPT register located at
address 0xFFBF to zero. For redirection to occur, at least some portion but not all of the flash memory
must be block protected by programming the NVPROT register located at address 0xFFBD. All of the
interrupt vectors (memory locations 0xFFC0–0xFFFD) are redirected, though the reset vector
(0xFFFE:FFFF) is not.
For example, if 512 bytes of flash are protected, the protected address region is from 0xFE00 through
0xFFFF. The interrupt vectors (0xFFC0–0xFFFD) are redirected to the locations 0xFDC0–0xFDFD. For
instance, if an SPI interrupt is taken, the values in the locations 0xFDE8:FDE9 are used for the vector
instead of the values in the locations 0xFFE8:FFE9. This allows you to reprogram the unprotected portion
of the flash with new program code including new interrupt vector values while leaving the protected area,
which includes the default vector locations, unchanged.
4.7
Security
The MC9S08LG32 series includes circuitry to prevent unauthorized access to the contents of flash and
RAM memory. When security is engaged, flash and RAM are considered secure resources. Direct-page
registers, high-page registers, and the background debug controller are considered unsecured resources.
Programs executing within secure memory have normal access to any MCU memory locations and
resources. Attempts to access a secure memory location with a program executing from an unsecured
memory space or through the background debug interface are blocked (writes are ignored and reads return
all 0s).
Security is engaged or disengaged based on the state of two nonvolatile register bits (SEC01:SEC00) in
the FOPT register. During reset, the contents of the nonvolatile location NVOPT are copied from flash into
the working FOPT register in high-page register space. To engage security, program the NVOPT location.
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You can do this at the same time the flash memory is programmed. The 1:0 state disengages security and
the other three combinations engage security. Notice the erased state (1:1) makes the MCU secure. During
development, whenever the flash is erased, you must immediately program the SEC00 bit to 0 in NVOPT
so SEC01:SEC00 = 1:0. This allows the MCU to remain unsecured after a subsequent reset.
The on-chip debug module cannot be enabled while the MCU is secure. The separate background debug
controller can still be used for background memory access commands of unsecured resources.
You can choose to allow or disallow a security unlocking mechanism through an 8-byte backdoor security
key. If the nonvolatile KEYEN bit in NVOPT/FOPT is 0, the backdoor key is disabled and there is no way
to disengage security without completely erasing all flash locations. If KEYEN is 1, a secure user program
can temporarily disengage security by:
1. Writing 1 to KEYACC in the FCNFG register. This makes the flash module interpret writes to the
backdoor comparison key locations (NVBACKKEY through NVBACKKEY+7) as values to be
compared against the key rather than as the first step in a flash program or erase command.
2. Writing the user-entered key values to the NVBACKKEY through NVBACKKEY+7 locations.
These writes must be done in order starting with the value for NVBACKKEY and ending with
NVBACKKEY+7. STHX must not be used for these writes because these writes cannot be done
on adjacent bus cycles. User software normally would get the key codes from outside the MCU
system through a communication interface such as a serial I/O.
3. Writing 0 to KEYACC in the FCNFG register. If the 8-byte key that was just written matches the
key stored in the flash locations, SEC01:SEC00 are automatically changed to 1:0 and security
disengages until the next reset.
The security key can be written only from secure memory (either RAM or flash), so it cannot be entered
through background commands without the cooperation of a secure user program.
The backdoor comparison key (NVBACKKEY through NVBACKKEY+7) is located in flash memory
locations in the nonvolatile register space so users can program these locations exactly as they would
program any other flash memory location. The nonvolatile registers are in the same 512-byte block of flash
as the reset and interrupt vectors, so block protecting that space also block protects the backdoor
comparison key. Block protects cannot be changed from user application programs, so if the vector space
is block protected, the backdoor security key mechanism cannot permanently change the block protect,
security settings, or the backdoor key.
Security can always be disengaged through the background debug interface by taking these steps:
1. Disable any block protections by writing FPROT. FPROT can be written only with background
debug commands, not from application software.
2. Mass erase flash if necessary.
3. Blank check flash. Provided flash is completely erased, security is disengaged until the next reset.
To avoid returning to secure mode after the next reset, program NVOPT so SEC01:SEC00 = 1:0.
4.8
Flash Registers and Control Bits
The flash module has six 8-bit registers in the high-page register space. Two locations (NVOPT,
NVPROT) in the nonvolatile register space in flash memory are copied into corresponding high-page
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control registers (FOPT, FPROT) at reset. There is also an 8-byte comparison key in flash memory. Refer
to Table 4-4 and Table 4-5 for the absolute address assignments for all flash registers. This section refers
to registers and control bits only by their names. A Freescale Semiconductor-provided equate or header
file is normally used to translate these names into the appropriate absolute addresses.
4.8.1
Flash Clock Divider Register (FCDIV)
Bit 7 of this register is a read-only flag. DIV Bits 6:0 may be read at any time, but can be written only one
time. Before any erase or programming operations are possible, write to this register to set the frequency
of the clock for the nonvolatile memory system within acceptable limits.Table 4-8 shows the appropriate
values for PRDIV8 and DIV for selected bus frequencies.
7
R
6
5
4
3
2
1
0
0
0
0
DIVLD
PRDIV8
DIV
W
Reset
0
0
0
0
0
= Unimplemented or Reserved
Figure 4-5. Flash Clock Divider Register (FCDIV)
Table 4-7. FCDIV Register Field Descriptions
Field
Description
7
DIVLD
Divisor Loaded Status Flag — When set, this read-only status flag indicates that the FCDIV register has been
written since reset. Reset clears this bit and the first write to this register causes this bit to become set regardless
of the data written.
0 FCDIV has not been written since reset; erase and program operations disabled for flash.
1 FCDIV has been written since reset; erase and program operations enabled for flash.
6
PRDIV8
5:0
DIV
Prescale (Divide) Flash Clock by 8
0 Clock input to the flash clock divider is the bus rate clock.
1 Clock input to the flash clock divider is the bus rate clock divided by 8.
Divisor for Flash Clock Divider — The flash clock divider divides the bus rate clock (or the bus rate clock
divided by 8 if PRDIV8 = 1) by the value in the 6-bit DIV field plus one. The resulting frequency of the internal
flash clock must fall within the range of 200 kHz to 150 kHz for proper flash operations. Program/Erase timing
pulses are one cycle of this internal flash clock which corresponds to a range of 5 μs to 6.7 μs. The automated
programming logic uses an integer number of these pulses to complete an erase or program operation. See
Equation 4-1 and Equation 4-2.
if PRDIV8 = 0 — fFCLK = fBus ÷ (DIV + 1)
Eqn. 4-1
if PRDIV8 = 1 — fFCLK = fBus ÷ (8 × (DIV + 1))
Eqn. 4-2
Table 4-8 shows the appropriate values for PRDIV8 and DIV for selected bus frequencies.
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Table 4-8. Flash Clock Divider Settings
4.8.2
fBus
PRDIV8
(Binary)
DIV
(Decimal)
fFCLK
Program/Erase Timing Pulse
(5 μs Min, 6.7 μs Max)
20 MHz
1
12
192.3 kHz
5.2 μs
10 MHz
0
49
200 kHz
5 μs
8 MHz
0
39
200 kHz
5 μs
4 MHz
0
19
200 kHz
5 μs
2 MHz
0
9
200 kHz
5 μs
1 MHz
0
4
200 kHz
5 μs
200 kHz
0
0
200 kHz
5 μs
150 kHz
0
0
150 kHz
6.7 μs
Flash Options Register (FOPT and NVOPT)
During reset, the contents of the nonvolatile location NVOPT are copied from flash into FOPT. To change
the value in this register, erase and reprogram the NVOPT location in flash memory as usual and then issue
a new MCU reset.
R
7
6
5
4
3
2
1
0
KEYEN
FNORED
0
0
0
0
SEC01
SEC00
W
Reset
This register is loaded from nonvolatile location NVOPT during reset.
= Unimplemented or Reserved
Figure 4-6. Flash Options Register (FOPT)
Table 4-9. FOPT Register Field Descriptions
Field
Description
7
KEYEN
Backdoor Key Mechanism Enable — When this bit is 0, the backdoor key mechanism cannot be used to
disengage security. The backdoor key mechanism is accessible only from the user (secured) firmware. BDM
commands cannot be used to write key comparison values that would unlock the backdoor key. For more detailed
information about the backdoor key mechanism, refer to Section 4.7, “Security.”
0 No backdoor key access allowed.
1 If user firmware writes an 8-byte value that matches the nonvolatile backdoor key (NVBACKKEY through
NVBACKKEY+7 in that order), security is temporarily disengaged until the next MCU reset.
6
FNORED
Vector Redirection Disable — When this bit is 1, then vector redirection is disabled.
0 Vector redirection enabled.
1 Vector redirection disabled.
1:0
SEC0[1:0]
Security State Code — This 2-bit field determines the security state of the MCU as shown in Table 4-10. When
the MCU is secure, the contents of RAM and flash memory cannot be accessed by instructions from any
unsecured source including the background debug interface. SEC01:SEC00 changes to 1:0 after successful
backdoor key entry or a successful blank check of flash.
For more detailed information about security, refer to Section 4.7, “Security.”
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Table 4-10. Security States1
1
4.8.3
R
SEC01:SEC00
Description
0:0
secure
0:1
secure
1:0
unsecured
1:1
secure
SEC01:SEC00 changes to 1:0 after successful backdoor
key entry or a successful blank check of flash.
Flash Configuration Register (FCNFG)
7
6
0
0
5
4
3
2
1
0
0
0
0
0
0
0
0
0
0
0
KEYACC
W
Reset
0
0
0
= Unimplemented or Reserved
Figure 4-7. Flash Configuration Register (FCNFG)
Table 4-11. FCNFG Register Field Descriptions
Field
Description
5
KEYACC
Enable Writing of Access Key — This bit enables writing of the backdoor comparison key. For more detailed
information about the backdoor key mechanism, refer to Section 4.7, “Security.”
0 Writes to flash are interpreted as the start of a flash programming or erase command.
1 Writes to NVBACKKEY (0xFFB0–0xFFB7) are interpreted as comparison key writes while writes to rest of the
flash are ignored.
4.8.4
Flash Protection Register (FPROT and NVPROT)
During reset, the contents of the nonvolatile location NVPROT is copied from flash into FPROT. FPROT
can be read at any time. With FPDIS set, all bits are writable, but with FPDIS clear the FPS bits are writable
as long as the size of the protected region is being increased. Any FPROT write that attempts to decrease
the size of the protected region is ignored.
7
R
6
5
4
3
2
1
FPS(1)
0
FPDIS(1)
W
Reset
1
This register is loaded from nonvolatile location NVPROT during reset.
Background commands can be used to change the contents of these bits in FPROT.
Figure 4-8. Flash Protection Register (FPROT)
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Table 4-12. FPROT Register Field Descriptions
Field
Description
7:1
FPS
Flash Protect Select Bits — When FPDIS = 0, this 7-bit field determines the ending address of unprotected
flash locations at the high address end of the flash. Protected flash locations cannot be erased or programmed.
0
FPDIS
4.8.5
Flash Protection Disable
0 Flash block specified by FPS7:FPS1 is block protected (program and erase not allowed).
1 No flash block is protected.
Flash Status Register (FSTAT)
7
6
R
5
4
FPVIOL
FACCERR
0
0
FCCF
FCBEF
3
2
1
0
0
FBLANK
0
0
0
0
0
0
W
Reset
1
1
= Unimplemented or Reserved
Figure 4-9. Flash Status Register (FSTAT)
Table 4-13. FSTAT Register Field Descriptions
Field
Description
7
FCBEF
Flash Command Buffer Empty Flag — The FCBEF bit is used to launch commands. It also indicates that the
command buffer is empty so that a new command sequence can be executed when performing burst
programming. The FCBEF bit is cleared by writing a 1 to it or when a burst program command is transferred to
the array for programming. Only burst program commands can be buffered.
0 Command buffer is full (not ready for additional commands).
1 A new burst program command can be written to the command buffer.
6
FCCF
Flash Command Complete Flag — FCCF is set automatically when the command buffer is empty and no
command is being processed. FCCF is cleared automatically when a new command is started (by writing 1 to
FCBEF to register a command). Writing to FCCF has no meaning or effect.
0 Command in progress
1 All commands complete
5
FPVIOL
Protection Violation Flag — FPVIOL is set automatically when a command is written that attempts to erase or
program a location in a protected block (the erroneous command is ignored). FPVIOL is cleared by writing a 1 to
FPVIOL.
0 No protection violation.
1 An attempt was made to erase or program a protected location.
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Table 4-13. FSTAT Register Field Descriptions (continued)
Field
Description
4
FACCERR
Access Error Flag — FACCERR is set automatically when the proper command sequence is not obeyed exactly
(the erroneous command is ignored), if a program or erase operation is attempted before the FCDIV register has
been initialized, or if the MCU enters stop while a command was in progress. For a more detailed discussion of
the exact actions that are considered access errors, see Section 4.6.5, “Access Errors.” FACCERR is cleared by
writing a 1 to FACCERR. Writing a 0 to FACCERR has no meaning or effect.
0 No access error.
1 An access error has occurred.
2
FBLANK
Flash Verified as All Blank (erased) Flag — FBLANK is set automatically at the conclusion of a blank check
command if the entire flash array was verified to be erased. FBLANK is cleared by clearing FCBEF to write a new
valid command. Writing to FBLANK has no meaning or effect.
0 After a blank check command is completed and FCCF = 1, FBLANK = 0 indicates the flash array is not
completely erased.
1 After a blank check command is completed and FCCF = 1, FBLANK = 1 indicates the flash array is completely
erased (all 0xFF).
4.8.6
Flash Command Register (FCMD)
Only five command codes are recognized in normal user modes as shown in Table 4-14. Refer to Section
4.6.3, “Program and Erase Command Execution,” for a detailed discussion of flash programming and erase
operations.
R
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
0
0
0
0
W
Reset
FCMD
0
0
0
0
Figure 4-10. Flash Command Register (FCMD)
Table 4-14. Flash Commands
Command
FCMD
Equate File Label
Blank check
0x05
mBlank
Byte program
0x20
mByteProg
Byte program — burst mode
0x25
mBurstProg
Page erase (512 bytes/page)
0x40
mPageErase
Mass erase (all flash)
0x41
mMassErase
All other command codes are illegal and generate an access error.
It is not necessary to perform a blank check command after a mass erase operation. Only blank check is
required as part of the security unlocking mechanism.
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Chapter 5
Resets, Interrupts, and General System Control
5.1
Introduction
This section discusses basic reset and interrupt mechanisms and the various sources of reset and interrupt
in the MC9S08LG32 series. Some interrupt sources from peripheral modules are discussed in greater
detail in other sections of this document. This section gathers basic information about all reset and interrupt
sources in one place for easy reference.
5.2
Features
Reset and interrupt features include:
• Multiple sources of reset for flexible system configuration and reliable operation
• Reset status register (SRS) to indicate source of most recent reset
• Separate interrupt vector for all modules (reduces polling overhead) (see Table 5-2)
5.3
MCU Reset
Resetting the MCU provides a way to start processing from a known set of initial conditions. During reset,
most control and status registers are forced to initial values and the program counter is loaded from the
reset vector (0xFFFE:0xFFFF). On-chip peripheral modules are disabled and I/O pins are initially
configured as general-purpose high-impedance inputs with pullup devices disabled. The I bit in the
condition code register (CCR) is set to block maskable interrupts so the user program has a chance to
initialize the stack pointer (SP) and system control settings. SP is forced to 0x00FF at reset.
The MC9S08LG32 series has the following sources for reset:
• Power-on reset (POR)
• External pin reset (PIN)
• Computer operating properly (COP) timer
• Illegal opcode detect (ILOP)
• Illegal address detect (ILAD)
• Low-voltage detect (LVD)
• Background debug forced reset
Each of these sources, with the exception of the background debug forced reset, has an associated bit in
the system reset status register (SRS). The background debug forced reset causes all the bits in the SRS
register to clear, and can be detected by all zeros in SRS.
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5.4
Computer Operating Properly (COP) Watchdog
The COP watchdog is intended to force a system reset when the application software fails to execute as
expected. To prevent a system reset from the COP timer (when it is enabled), application software must
reset the COP counter periodically. If the application program gets lost and fails to reset the COP counter
before it times out, a system reset is generated to force the system back to a known starting point.
After any reset, the COPE becomes set in SOPT1 enabling the COP watchdog (see Section 5.8.4, “System
Options Register 1 (SOPT1),” for additional information). If the COP watchdog is not used in an
application, it can be disabled by clearing COPE. The COP counter is reset by writing any value to the
address of SRS. This write does not affect the data in the read-only SRS. Instead, the act of writing to this
address is decoded and sends a reset signal to the COP counter.
The COPCLKS bit in SOPT2 (see Section 5.8.5, “System Options Register 2 (SOPT2),” for additional
information) selects the clock source used for the COP timer. The clock source options are either the bus
clock or an internal 1 kHz clock source. With each clock source, there is an associated short and long
time-out controlled by COPT in SOPT1. Table 5-1 summaries the control functions of the COPCLKS and
COPT bits. The COP watchdog defaults to operation from the 1 kHz clock source and the associated long
time-out (28 cycles).
Table 5-1. COP Configuration Options
Control Bits
1
Clock Source
COP Overflow Count
0
~1 kHz
25 cycles (32 ms)1
0
1
~1 kHz
28 cycles (256 ms)1
1
0
Bus
213 cycles
1
1
Bus
218 cycles
COPCLKS
COPT
0
Values are shown in this column based on tLPO = 1 ms. See tLPO in the data sheet for the
tolerance of this value.
Even if your application uses the reset default settings of COPE, COPCLKS, and COPT; you must write
to the write-once SOPT1 and SOPT2 registers, during reset initialization, to lock in the settings. That way,
the settings cannot be changed accidentally if the application program gets lost. The initial writes to SOPT1
and SOPT2 reset the COP counter.
The write to SRS that services (clears) the COP counter must not be placed in an interrupt service routine
(ISR) because the ISR could continue to be executed periodically even if the main application program
fails.
In background debug mode, the COP counter does not increment.
When the bus clock source is selected, the COP counter does not increment while the system is in stop
mode. The COP counter resumes as soon as the MCU exits stop mode.
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When the 1 kHz clock source is selected, the COP counter is re-initialized to zero upon entry to stop mode.
The COP counter begins from zero after the MCU exits stop mode.
5.5
Interrupts
Interrupts provide a way to save the current CPU status and registers, execute an interrupt service routine
(ISR), and then restore the CPU status so processing can resume where it left off before the interrupt. Other
than the software interrupt (SWI), which is a program instruction, interrupts are caused by hardware events
such as an edge on the IRQ pin or a timer-overflow event. The debug module can also generate an SWI
under certain circumstances.
If an event occurs in an enabled interrupt source, an associated read-only status flag is set. The CPU does
not respond unless the local interrupt enable is a 1 (enabled) and the I bit in the CCR is 0 to allow interrupts.
The global interrupt mask (I bit) in the CCR is initially set after reset which prevents all maskable interrupt
sources. The user program initializes the stack pointer and performs other system setup before clearing the
I bit to allow the CPU to respond to interrupts.
When the CPU receives a qualified interrupt request, it completes the current instruction before responding
to the interrupt. The interrupt sequence obeys the same cycle-by-cycle sequence as the SWI instruction
and consists of:
• Saving the CPU registers on the stack
• Setting the I bit in the CCR to mask further interrupts
• Fetching the interrupt vector for the highest-priority interrupt that is currently pending
• Filling the instruction queue with the first three bytes of program information starting from the
address fetched from the interrupt vector locations
While the CPU is responding to the interrupt, the I bit is automatically set to avoid the possibility of
another interrupt interrupting the ISR itself (this is called nesting of interrupts). Normally, the I bit is
restored to 0 when the CCR is restored from the value stacked on entry to the ISR. In rare cases, the I bit
can be cleared inside an ISR (after clearing the status flag that generated the interrupt) so that other
interrupts can be serviced without waiting for the first service routine to finish. This practice is not
recommended for anyone other than the most experienced programmers because it can lead to subtle
program errors that are difficult to debug.
The interrupt service routine ends with a return-from-interrupt (RTI) instruction which restores the CCR,
A, X, and PC registers to their pre-interrupt values by reading the previously saved information from the
stack.
NOTE
For compatibility with M68HC08 devices, the H register is not
automatically saved and restored. It is good programming practice to push
H onto the stack at the start of the interrupt service routine (ISR) and restore
it immediately before the RTI that is used to return from the ISR.
If more than one interrupt is pending when the I bit is cleared, the highest priority source is serviced first
(see Table 5-2).
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5.5.1
Interrupt Stack Frame
Figure 5-1 shows the contents and organization of a stack frame. Before the interrupt, the stack pointer
(SP) points at the next available byte location on the stack. The current values of CPU registers are stored
on the stack starting with the low-order byte of the program counter (PCL) and ending with the CCR. After
stacking, the SP points at the next available location on the stack. This address is one less than the address
where the CCR was saved. The PC value that is stacked is the address of the instruction in the main
program that would have executed next if the interrupt had not occurred.
UNSTACKING
ORDER
TOWARD LOWER ADDRESSES
²
7
0
5
1
4
2
ACCUMULATOR
3
3
INDEX REGISTER (LOW BYTE X)*
2
4
PROGRAM COUNTER HIGH
1
5
PROGRAM COUNTER LOW
CONDITION CODE REGISTER
SP AFTER
INTERRUPT STACKING
SP BEFORE
THE INTERRUPT
²
²
STACKING
ORDER
²
TOWARD HIGHER ADDRESSES
* High byte (H) of index register is not automatically stacked.
Figure 5-1. Interrupt Stack Frame
When an RTI instruction is executed, these values are recovered from the stack in reverse order. As part
of the RTI sequence, the CPU fills the instruction pipeline by reading three bytes of program information,
starting from the PC address recovered from the stack.
The status flag corresponding to the interrupt source must be acknowledged (cleared) before returning
from the ISR. Typically, the flag is cleared at the beginning of the ISR so that if another interrupt is
generated by this same source it is registered so it can be serviced after completion of the current ISR.
5.5.2
External Interrupt Request (IRQ) Pin
External interrupts are managed by the IRQ status and control register (IRQSC). When the IRQ function
is enabled, synchronous logic monitors the pin for edge-only or edge-and-level events. When the MCU is
in stop mode and system clocks are shut down, a separate asynchronous path is used so the IRQ pin can
wake the MCU.
5.5.2.1
Pin Configuration Options
The IRQ pin enable (IRQPE) control bit in IRQSC must be 1 in order for the IRQ pin to act as the interrupt
request (IRQ) input. As an IRQ input, you can choose the polarity of edges or levels detected (IRQEDG),
whether the pin detects edges-only or edges and levels (IRQMOD) and whether an event causes an
interrupt or only sets the IRQF flag which can be polled by software (IRQIE).
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The IRQ pin, when enabled, defaults to use an internal pull device (IRQPDD = 0), configured as a pullup
or pulldown depending on the polarity chosen. If the user desires to use an external pullup or pulldown,
the IRQPDD can be written to a 1 to turn off the internal device.
BIH and BIL instructions may be used to detect the level on the IRQ pin when the pin is configured to act
as the IRQ input.
5.5.2.2
Edge and Level Sensitivity
The IRQMOD control bit reconfigures the detection logic so it detects edge events and pin levels. In the
edge and level detection mode, the IRQF status flag becomes set when an edge is detected (when the IRQ
pin changes from the deasserted to the asserted level), but the flag is continuously set (and cannot be
cleared) as long as the IRQ pin remains at the asserted level.
5.5.2.3
IRQ Initialization
When IRQ is first enabled it is possible to get a false IRQ interrupt flag. To prevent a false interrupt request
during IRQ initialization, you must do the following:
1. Mask IRQ interrupt by clearing IRQIE in IRQSC.
2. Select the IRQ mode by writing to the IRQEDG, IRQMOD and IRQPDD bits in IRQSC.
3. Enable the IRQ pin by setting the IRQPE bit in IRQSC.
4. Write to IRQACK in IRQSC to clear any false interrupts.
5. Set IRQIE in IRQSC to enable interrupts.
5.5.3
Interrupt Vectors, Sources, and Local Masks
Table 5-2 provides a summary of all interrupt sources. Higher-priority sources are located toward the
bottom of the table. The high-order byte of the address for the interrupt service routine is located at the
first address in the vector address column, and the low-order byte of the address for the interrupt service
routine is located at the next higher address.
When an interrupt condition occurs, an associated flag bit becomes set. If the associated local interrupt
enable is 1, an interrupt request is sent to the CPU. Within the CPU, if the global interrupt mask (I bit in
the CCR) is 0, the CPU finishes the current instruction; stack the PCL, PCH, X, A, and CCR CPU registers;
set the I bit; and then fetch the interrupt vector for the highest priority pending interrupt. Processing then
continues in the interrupt service routine.
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Table 5-2. Vector Summary
Vector
Vector
Priority Number
Lowest
Highest
Address
(High/Low)
Vector
Name
31
0xFFC0:FFC1
through
through
27
0xFFC8:FFC9
26
0xFFCA:0xFFCB
Vrtc
25
0xFFCC:0xFFCD
Vmtim
24
0xFFCE:0xFFCF Vtpm2ovf
23
0xFFD0/0xFFD1 Vtpm2ch5
22
0xFFD2/0xFFD3 Vtpm2ch4
21
0xFFD4/0xFFD5 Vtpm2ch3
20
0xFFD6/0xFFD7 Vtpm2ch2
19
0xFFD8/0xFFD9 Vtpm2ch1
18
0xFFDA/0xFFDB Vtpm2ch0
17
0xFFDC/0xFFDD
Vadc
16
0xFFDE/0xFFDF Vkeyboard
15
0xFFE0/0xFFE1
Viic
14
0xFFE2/0xFFE3
Vsci2tx
13
0xFFE4/0xFFE5
Vsci2rx
Module
Source
Enable
Description
Unused Vector Space
(available for user program)
RTC
MTIM
TPM2
TPM2
TPM2
TPM2
TPM2
TPM2
TPM2
ADC
KBI
IIC
SCI2
SCI2
12
0xFFE6/0xFFE7
Vsci2err
SCI2
11
0xFFE8/0xFFE9
Vspi
SPI
10
9
8
0xFFEA/0xFFEB
0xFFEC/0xFFED
0xFFEE/0xFFEF
Vlcd
Vsci1tx
Vsci1rx
LCD
SCI1
SCI1
7
0xFFF0/0xFFF1
Vsci1err
SCI1
6
5
4
3
0xFFF2/0xFFF3
0xFFF4/0xFFF5
0xFFF6/0xFFF7
0xFFF8/0xFFF9
Vtpm1ovf
Vtpm1ch1
Vtpm1ch0
Vlvw
2
1
0
0xFFFA/0xFFFB
0xFFFC/0xFFFD
0xFFFE/0xFFFF
Virq
Vswi
Vreset
TPM1
TPM1
TPM1
System
control
IRQ
Core
System
control
RTIF
TOF
TOF
CH5F
CH4F
CH3F
CH2F
CH1F
CH0F
COCO
KBF
IICIS
TDRE, TC
IDLE, RDRF,
LBKDIF,
RXEDGIF
OR, NF,
FE, PF
SPIF, MODF,
SPTEF
LCDF
TDRE, TC
IDLE, RDRF,
LBKDIF,
RXEDGIF
OR, NF,
FE, PF
TOF
CH1F
CH0F
LVWF
RTIE
TOIE
TO2E
CH5IE
CH4IE
CH3IE
CH2IE
CH1IE
CH0IE
AIEN
KBIE
IICIE
TIE, TCIE
ILIE, RIE,
LBKDIE,
RXEDGIE
ORIE, NFIE,
FEIE, PFIE
SPIE, SPIE, SPTIE
Counter Match
Counter Match
TPM2 overflow
TPM2 channel 5
TPM2 channel 4
TPM2 channel 3
TPM2 channel 2
TPM2 channel 1
TPM2 channel 0
ADC
Keyboard pins
IIC control
SCI transmit
SCI receive
LCDIE
TIE, TCIE
ILIE, RIE,
LBKDIE,
RXEDGIE
ORIE, NFIE,
FEIE, PFIE
TOIE
CH1IE
CH0IE
LVWIE
LCD Frame Interrupt
SCI transmit
SCI receive
IRQF
SWI Instruction
COP
LVD
RESET pin
Illegal opcode
Illegal address
POR
IRQIE
—
COPE
LVDRE
RSTPE
—
—
IRQ pin
Software interrupt
Watchdog timer
Low-voltage detect
External pin
Illegal opcode
Illegal address
SCI error
SPI
SCI error
TPM1 overflow
TPM1 channel 1
TPM1 channel 0
Low-voltage warning
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5.6
Low-Voltage Detect (LVD) System
The MC9S08LG32 series includes a system to protect against low voltage conditions to protect memory
contents and control MCU system states during supply voltage variations. The system is comprised of a
power-on reset (POR) circuit and a LVD circuit. The LVD circuit is enabled when LVDE in SPMSC1. The
LVD is disabled upon entering either of the stop modes unless LVDSE is set in SPMSC1. If LVDSE and
LVDE are both set, then the MCU enters stop3 instead of stop2, and the current consumption in stop3 with
the LVD enabled is greater.
5.6.1
Power-On Reset Operation
When power is initially applied to the MCU, or when the supply voltage drops below the power-on reset
rearm voltage level, VPOR, the POR circuit causes a reset condition. As the supply voltage rises, the LVD
circuit holds the MCU in reset until the supply has risen above the low voltage detection low threshold,
VLVDL. Both the POR bit and the LVD bit in SRS are set following a POR.
5.6.2
Low-Voltage Detection (LVD) Reset Operation
The LVD can be configured to generate a reset upon detection of a low voltage condition by setting
LVDRE to 1. After an LVD reset has occurred, the LVD system holds the MCU in reset until the supply
voltage has risen above the low voltage detection threshold. The LVD bit in the SRS register is set
following either an LVD reset or POR.
5.6.3
Low-Voltage Warning (LVW) Interrupt Operation
The LVD system has a low voltage warning flag (LVWF) to indicate to you that the supply voltage is
approaching, but remains above, the LVD voltage. The LVW has an interrupt associated with it, enabled
by setting the LVWIE bit in the SPMSC1 register. If enabled, an LVW interrupt request occurs when the
LVWF is set. LVWF is cleared by writing a 1 to the LVWACK bit in SPMSC1 provided the LVW condition
no longer exists.
5.7
Peripheral Clock Gating
The MC9S08LG32 series includes a clock gating system to manage the bus clock sources to the individual
peripherals. Using this system, you can enable or disable the bus clock to each of the peripherals at the
clock source, eliminating unnecessary clocks to peripherals which are not in use and thereby reducing the
overall run and wait mode currents.
Out of reset, all peripheral clocks are disabled. For lowest possible run or wait currents, user software must
disable the clock source to any peripheral not in use. The actual clock is enabled or disabled immediately
following the write to the Clock Gating Control registers (SCGC1 and SCGC2). Any peripheral with a
gated clock cannot be used unless its clock is enabled. Writing to the registers of a peripheral with a
disabled clock has no effect.
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NOTE
User software must disable the peripheral before disabling the clocks to the
peripheral. When clocks are re-enabled to a peripheral, the peripheral
registers need to be re-initialized by user software.
In stop modes, the bus clock is disabled for all gated peripherals, regardless of the settings in SCGC1 and
SCGC2.
5.8
Reset, Interrupt, and System Control Registers and Control Bits
One 8-bit register in the direct page register space and fourteen 8-bit registers in the high-page register
space are related to reset and interrupt systems.
Refer to Table 4-2 and Table 4-4 in Chapter 4, “Memory,” for the absolute address assignments for all
registers. This section refers to registers and control bits only by their names. A Freescale-provided equate
or header file is used to translate these names into the appropriate absolute addresses.
Some control bits in the SOPT1 and SPMSC2 registers are related to modes of operation. Although brief
descriptions of these bits are provided here, the related functions are discussed in greater detail in
Chapter 3, “Modes of Operation.”
5.8.1
Interrupt Pin Request Status and Control Register (IRQSC)
This direct page register includes status and control bits which are used to configure the IRQ function,
report status, and acknowledge IRQ events.
7
R
6
5
4
IRQPDD
IRQEDG
IRQPE
0
3
2
IRQF
0
W
Reset
1
0
IRQIE
IRQMOD
0
0
IRQACK
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 5-2. Interrupt Request Status and Control Register (IRQSC)
Table 5-3. IRQSC Register Field Descriptions
Field
Description
6
IRQPDD
Interrupt Request (IRQ) Pull Device Disable — This read/write control bit is used to disable the internal
pullup/pulldown device when the IRQ pin is enabled (IRQPE = 1) allowing for an external device to be used.
0 IRQ pull device enabled if IRQPE = 1.
1 IRQ pull device disabled if IRQPE = 1.
5
IRQEDG
Interrupt Request (IRQ) Edge Select — This read/write control bit is used to select the polarity of edges or
levels on the IRQ pin that cause IRQF to be set. The IRQMOD control bit determines whether the IRQ pin is
sensitive to both edges and levels or only edges. When IRQEDG = 1 and the internal pull device is enabled, the
pullup device is reconfigured as an optional pulldown device.
0 IRQ is falling edge or falling edge/low-level sensitive.
1 IRQ is rising edge or rising edge/high-level sensitive.
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Chapter 5 Resets, Interrupts, and General System Control
Table 5-3. IRQSC Register Field Descriptions (continued)
Field
Description
4
IRQPE
IRQ Pin Enable — This read/write control bit enables the IRQ pin function. When this bit is set the IRQ pin can
be used as an interrupt request.
0 IRQ pin function is disabled.
1 IRQ pin function is enabled.
3
IRQF
2
IRQACK
1
IRQIE
0
IRQMOD
IRQ Flag — This read-only status bit indicates when an interrupt request event has occurred.
0 No IRQ request.
1 IRQ event detected.
IRQ Acknowledge — This write-only bit is used to acknowledge interrupt request events (write 1 to clear IRQF).
Writing 0 has no meaning or effect. Reads always return 0. If edge-and-level detection is selected (IRQMOD = 1),
IRQF cannot be cleared while the IRQ pin remains at its asserted level.
IRQ Interrupt Enable — This read/write control bit determines whether IRQ events generate an interrupt
request.
0 Interrupt request when IRQF set is disabled (use polling).
1 Interrupt requested whenever IRQF = 1.
IRQ Detection Mode — This read/write control bit selects either edge-only detection or edge-and-level
detection. The IRQEDG control bit determines the polarity of edges and levels that are detected as interrupt
request events. See Section 5.5.2.2, “Edge and Level Sensitivity,” for more details.
0 IRQ event on falling edges or rising edges only.
1 IRQ event on falling edges and low levels or on rising edges and high levels.
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Chapter 5 Resets, Interrupts, and General System Control
5.8.2
System Reset Status Register (SRS)
This high-page register includes read-only status flags to indicate the source of the most recent reset. When
a debug host forces reset by writing 1 to BDFR in the SBDFR register, none of the status bits in SRS is
set. Writing any value to this register address clears the COP watchdog timer without affecting the contents
of this register. The reset state of these bits depends on what caused the MCU to reset.
R
7
6
5
4
3
2
1
0
POR
PIN
COP
ILOP
ILAD
0
LVD
0
W
POR:
1
0
0
0
0
0
1
0
LVD:
u(1)
0
0
0
0
0
1
0
0
Note(2)
Note(2)
Note(2)
Note(2)
0
0
0
Any other
reset:
1
2
Writing any value to SRS address clears COP watchdog timer.
u = unaffected
Any of these reset sources that are active at the time of reset entry causes the corresponding bit(s) to be set; bits corresponding
to sources that are not active at the time of reset entry are cleared.
Figure 5-3. System Reset Status (SRS)
Table 5-4. SRS Register Field Descriptions
Field
Description
7
POR
Power-On Reset — Reset was caused by the power-on detection logic. Because the internal supply voltage was
ramping up at the time, the low-voltage reset (LVD) status bit is also set to indicate that the reset occurred while
the internal supply was below the LVD threshold.
0 Reset not caused by POR.
1 POR caused reset.
6
PIN
External Reset Pin — Reset was caused by an active-low level on the external reset pin.
0 Reset not caused by external reset pin.
1 Reset came from external reset pin.
5
COP
Computer Operating Properly (COP) Watchdog — Reset was caused by the COP watchdog timer timing out.
This reset source can be blocked by COPE = 0.
0 Reset not caused by COP timeout.
1 Reset caused by COP timeout.
4
ILOP
Illegal Opcode — Reset was caused by an attempt to execute an unimplemented or illegal opcode. The STOP
instruction is considered illegal if stop is disabled by STOPE = 0 in the SOPT register. The BGND instruction is
considered illegal if active background mode is disabled by ENBDM = 0 in the BDCSC register.
0 Reset not caused by an illegal opcode.
1 Reset caused by an illegal opcode.
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Table 5-4. SRS Register Field Descriptions (continued)
Field
Description
3
ILAD
Illegal Address — Reset was caused by an attempt to access either data or an instruction at an unimplemented
memory address.
0 Reset not caused by an illegal address
1 Reset caused by an illegal address
1
LVD
Low Voltage Detect — If the LVDRE bit is set and the supply drops below the LVD trip voltage, an LVD reset
occurs. This bit is also set by POR.
0 Reset not caused by LVD trip or POR.
1 Reset caused by LVD trip or POR.
5.8.3
System Background Debug Force Reset Register (SBDFR)
This high-page register contains a single write-only control bit. A serial background command such as
WRITE_BYTE must be used to write to SBDFR. Attempts to write this register from a user program are
ignored. Reads always return 0x00.
R
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
BDFR1
W
Reset:
0
0
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 5-4. System Background Debug Force Reset Register (SBDFR)
1
BDFR is writable only through serial background debug commands, not from user programs.
Table 5-5. SBDFR Register Field Descriptions
Field
Description
0
BDFR
Background Debug Force Reset — A serial background command such as WRITE_BYTE can be used to allow
an external debug host to force a target system reset. Writing 1 to this bit forces an MCU reset. This bit cannot
be written from a user program.To enter user mode, PTC5/BKGD/MS must be high immediately after issuing
WRITE_BYTE command. To enter BDM, PTC5/BKGD/MS must be low immediately after issuing WRITE_BYTE
command. See the data sheet for more information.
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5.8.4
System Options Register 1 (SOPT1)
This high-page register is a write-once register, so only the first write after reset is honored. It can be read
at any time. Any subsequent attempt to write to SOPT1 (intentionally or unintentionally) is ignored to
avoid accidental changes to these sensitive settings. SOPT1 must be written during the user’s reset
initialization program to set the desired controls even if the desired settings are the same as the reset
settings.
7
6
5
COPE
COPT
STOPE
Reset:
1
1
0
0
0
POR and
LVR:
1
1
0
0
0
R
4
3
2
1
0
0
0
0
BKGDPE
RSTPE
0
1
u(1)
0
1
1
W
= Unimplemented or Reserved
Figure 5-5. System Options Register 1 (SOPT1)
1
u = unaffected
Table 5-6. SOPT1 Register Field Descriptions
Field
Description
7
COPE
COP Watchdog Enable — This write-once bit selects whether the COP watchdog is enabled.
0 COP watchdog timer disabled.
1 COP watchdog timer enabled (force reset on timeout).
6
COPT
COP Watchdog Timeout — This write-once bit selects the timeout period of the COP. COPT along with
COPCLKS in SOPT2 defines the COP timeout period.
0 Short timeout period selected.
1 Long timeout period selected.
5
STOPE
Stop Mode Enable — This write-once bit is used to enable stop mode. If stop mode is disabled and a user
program attempts to execute a STOP instruction, an illegal opcode reset is forced.
0 Stop mode disabled.
1 Stop mode enabled.
1
BKGDPE
0
RSTPE
Background Debug Mode Pin Enable — This write-once bit when set enables the PTC5/BKGD/MS pin to
function as BKGD/MS. When clear, the pin functions as output only GPIO. This pin defaults to the BKGD/MS
function following any MCU reset.
0 PTC5/BKGD/MS pin functions as PTC5.
1 PTC5/BKGD/MS pin functions as BKGD/MS.
RESET Pin Enable — This write-once bit when set enables the PTC6/RESET pin to function as RESET. When
clear, the pin functions as open drain output only GPIO. This pin defaults to its RESET function following an MCU
POR or LVD. When RSTPE is set, an internal pullup device is enabled on RESET.
0 PTC6/RESET pin functions as PTC6.
1 PTC6/RESET pin functions as RESET.
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5.8.5
System Options Register 2 (SOPT2)
This high-page register contains bits to configure MCU specific features on the MC9S08LG32 series
devices.
7
R
COPCLKS1
6
5
4
3
2
1
0
0
0
0
0
0
0
SPIFE
W
Reset:
0
0
0
0
0
0
0
1
= Unimplemented or Reserved
Figure 5-6. System Options Register 2 (SOPT2)
1
This bit can be written only one time after reset. Additional writes are ignored.
Table 5-7. SOPT2 Register Field Descriptions
Field
7
COPCLKS
0
SPIFE
Description
COP Watchdog Clock Select — This write-once bit selects the clock source of the COP watchdog.
0 Internal 1 kHz clock is source to COP.
1 Bus clock is source to COP.
SPI Filter Enable— This bit selects the IFE control of the SPI pins.
0 IFE disabled
1 IFE enabled
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5.8.6
System Device Identification Register (SDIDH, SDIDL)
These high-page read-only registers are included so host development systems can identify the HCS08
derivative. This allows the development software to recognize where specific memory blocks, registers,
and control bits are located in a target MCU.
7
6
5
4
R
3
2
1
0
ID11
ID10
ID9
ID8
0
0
0
0
W
Reset:
—
—
—
—
= Unimplemented or Reserved
Figure 5-7. System Device Identification Register — High (SDIDH)
Table 5-8. SDIDH Register Field Descriptions
Field
7:4
Reserved
3:0
ID[11:8]
R
Description
Bits 7:4 are reserved. Reading these bits result in an indeterminate value; writes have no effect.
Part Identification Number — Each derivative in the HCS08 Family has a unique identification number. The
MC9S08LG32 is hard coded to the value 0x02A. See also ID bits in Table 5-9.
7
6
5
4
3
2
1
0
ID7
ID6
ID5
ID4
ID3
ID2
ID1
ID0
0
0
1
0
1
0
1
0
W
Reset:
= Unimplemented or Reserved
Figure 5-8. System Device Identification Register — Low (SDIDL)
Table 5-9. SDIDL Register Field Descriptions
Field
7:0
ID[7:0]
Description
Part Identification Number — Each derivative in the HCS08 Family has a unique identification number. The
MC9S08LG32 is hard coded to the value 0x02A. See also ID bits in Table 5-8.
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5.8.7
System Power Management Status and Control 1 Register
(SPMSC1)
This high-page register contains status and control bits to support the low voltage detect function, and to
enable the bandgap voltage reference for use by the ADC module. To configure the low voltage detect trip
voltage, see Table for the LVDV bit description in SPMSC2.
R
7
6
LVWF1
0
W
5
4
3
2
LVWIE
LVDRE2
LVDSE
LVDE2
1
0
03
BGBE
LVWACK
RESET:
0
0
0
1
1
1
0
0
POR and LVD:
0
0
0
1
1
1
0
0
= Unimplemented or Reserved
Figure 5-9. System Power Management Status and Control 1 Register (SPMSC1)
1
LVWF is set in the case when VSupply transitions below the trip point or after reset and VSupply is already below VLVW.
Write-once only after any system reset
3 Bit 1 is a reserved bit that must always be written to 0.
2
Table 5-10. SPMSC1 Register Field Descriptions
Field
7
LVWF
6
LVWACK
Description
Low-Voltage Warning Flag - The LVWF bit indicates the Low-Voltage Warning status.
0 Low voltage warning not present.
1 Low voltage warning is present or was present.
Low-Voltage Warning Acknowledge
The LVWACK bit indicates the Low-Voltage Warning Acknowledge status. Writing a logic 1 to LVWACK clears
LVWF to a logic 0 if a low voltage warning is not present.
5
LVWIE
Low-Voltage Warning Interrupt Enable
This bit enables hardware interrupt requests for LVWF..
0 Hardware interrupt disabled(use polling).
1 Request a hardware interrupt when LVWF=1.
4
VDRE
Low-Voltage Detect Reset Enable
This write-once bit enables LVD events to generate a hardware reset(provided LVDE=1). This bit has no effect if
the LVDE bit is a logic 0.
0 LVD events do not generate hardware resets.
1 Force an MCU reset when an enabled low-voltage detect event occurs.
3
LVDSE
Low-Voltage Detect Stop Enable
Provided LVDE = 1, this read/write bit determines whether the low-voltage detect function operates when the
MCU is in stop mode. This bit has no effect if the LVDE bit is a logic 0.
0 Low-Voltage detect disabled during stop mode.
1 Low-Voltage detect enabled during stop mode.
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Table 5-10. SPMSC1 Register Field Descriptions (continued)
Field
Description
2
LVDE
Low-Voltage Detect Enable
This write-once bit enables low-voltage detect logic and qualifies the operation of other bits in this register.
0 LVD logic disabled.
1 LVD logic enabled.
0
BGBE
Bandgap Buffer Enable
This bit enables an internal buffer for the bandgap voltage reference for use by the ADC module on one of its
internal channels.
0 Bandgap buffer disabled.
1 Bandgap buffer enabled.
5.8.8
System Power Management Status and Control 2 Register
(SPMSC2)
This register is used to report the status of the low voltage warning function, and to configure the stop
mode behavior of the MCU.
R
7
6
0
0
5
4
LVDV1
LVWV
3
2
1
PPDF
0
0
W
0
PPDC2
PPDACK
POR:
0
0
0
0
0
0
0
0
LVD:
0
0
U
U
0
0
0
0
Any other Reset:
0
0
U
U
0
0
0
0
= Unimplemented or Reserved
U = Unaffected by MCU Reset
Figure 5-10. System Power Management Status and Control 2 Register (SPMSC2)
1 This bit can be written only one time after power-on reset. Additional writes are ignored.
2 This bit can be written only one time after reset. Additional writes are ignore.
Table 5-11. SPMSC2 Register Field Descriptions
Field
Description
5
LVDV
Low-Voltage Detect Voltage Select
This write-once bit selects the low voltage detect(LVD) trip point setting. It also selects warning voltage
range.See Table 5-12 for definition of these voltages.
5
LVWV
Low-Voltage Warning Voltage Select
The bit selects the low voltage warning(LVW) trip point voltage. See Table 5-12 for definition of these voltages.
3
PPDF
Partial Power Down Flag
This read-only status bit indicates that the MCU has recovered from stop2 mode.
0 MCU has not recovered from stop2 mode.
1 MCU recovered from stop2 mode.
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Table 5-11. SPMSC2 Register Field Descriptions (continued)
Field
2
PPDACK
0
PPDC
Description
Partial Power Down Acknowledge
Writing a logic 1 to PPDACK clears the PPDF bit.
Partial Power Down Control
This write-once bit controls whether stop2 or stop3 mode is selected.
0 Stop3 mode enabled.
1 Stop2, partial power down mode enabled.
Table 5-12. LVD and LVW Trip Points
Num
1
2
Characteristic
1
High LVD trip point (VSUPPLY falling, LVDV = 1)1
2
High LVD trip point (VSUPPLY rising, LVDV = 1)
3
Low LVD trip point (VSUPPLY falling, LVDV = 0)
4
Low LVD trip point (VSUPPLY rising, LVDV = 0)
5
High LVW trip point (VSUPPLY falling, {LVDV,LVWV} = 00)
6
High LVW trip point (VSUPPLY rising, {LVDV,LVWV} = 00)
7
Low LVW trip point (VSUPPLY falling, {LVDV,LVWV} = 01)
8
Low LVW trip point (VSUPPLY rising, {LVDV,LVWV} = 01)
9
High LVW trip point (VSUPPLY falling, {LVDV,LVWV} = 10)
10
High LVW trip point (VSUPPLY rising, {LVDV,LVWV} = 10)
11
Low LVW trip point (VSUPPLY falling, {LVDV,LVWV} = 11)
12
Low LVW trip point (VSUPPLY rising, {LVDV,LVWV} = 11)
Symbol
Min
Max
Unit
VLVDXH
3.902
4.10
V
4.00
4.20
V
2.48
2.64
V
2.54
2.70
V
2.66
2.82
V
2.72
2.88
V
2.84
3.00
V
2.90
3.06
V
4.20
4.40
V
4.30
4.50
V
4.50
4.70
V
4.60
4.80
V
VLVDXL
VLVWXLL
VLVWXLH
VLVWXHL
VLVWXHH
All values measured with respect to VSUPPLY
All values with factory trim
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5.8.9
System Clock Gating Control 1Register (SCGC1)
This high-page register contains control bits to enable or disable the bus clock to the TPMx, ADC, IIC,
MTIM, RTC, and SCIx modules. Gating off the clocks to unused peripherals is used to reduce the MCU’s
run and wait currents. See Section 5.7, “Peripheral Clock Gating,” for more information.
NOTE
User software must disable the peripheral before disabling the clocks to the
peripheral. When clocks are re-enabled to a peripheral, the peripheral
registers need to be re-initialized by user software.
7
6
5
4
3
2
1
0
RTC
TPM2
TPM1
ADC
MTIM
IIC
SCI2
SCI1
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 5-11. System Clock Gating Control 1Register (SCGC1)
Table 5-13. SCGC1 Register Field Descriptions
Field
7
RTC
Description
RTC Clock Gate Control — This bit controls the clock gate to the RTC module.
0 Bus clock to the RTC module is disabled.
1 Bus clock to the RTC module is enabled.
6
TPM2
TPM2 Clock Gate Control — This bit controls the clock gate to the TPM2 module.
0 Bus clock to the TPM2 module is disabled.
1 Bus clock to the TPM2 module is enabled.
5
TPM1
TPM1 Clock Gate Control — This bit controls the clock gate to the TPM1 module.
0 Bus clock to the TPM1 module is disabled.
1 Bus clock to the TPM1 module is enabled.
4
ADC
ADC Clock Gate Control — This bit controls the clock gate to the ADC module.
0 Bus clock to the ADC module is disabled.
1 Bus clock to the ADC module is enabled.
3
MTIM
MTIM Clock Gate Control — This bit controls the clock gate to the MTIM module.
0 Bus clock to the MTIM module is disabled.
1 Bus clock to the MTIM module is enabled.
2
IIC
IIC Clock Gate Control — This bit controls the clock gate to the IIC module.
0 Bus clock to the IIC module is disabled.
1 Bus clock to the IIC module is enabled.
1
SCI2
SCI2 Clock Gate Control — This bit controls the clock gate to the SCI2 module.
0 Bus clock to the SCI2 module is disabled.
1 Bus clock to the SCI2 module is enabled.
0
SCI1
SCI1 Clock Gate Control — This bit controls the clock gate to the SCI1 module.
0 Bus clock to the SCI1 module is disabled.
1 Bus clock to the SCI1 module is enabled.
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5.8.10
System Clock Gating Control 2 Register (SCGC2)
This high-page register contains control bits to enable or disable the bus clock to the IRQ, KBI, LCD, and
SPI modules. Gating off the clocks to unused peripherals is used to reduce the MCU’s run and wait
currents. See Section 5.7, “Peripheral Clock Gating,” for more information.
NOTE
User software must disable the peripheral before disabling the clocks to the
peripheral. When clocks are re-enabled to a peripheral, the peripheral
registers need to be re-initialized by user software.
7
6
5
4
DBG
FLS
IRQ
KBI
R
W
Reset:
0
1
0
0
3
2
0
0
—
—
0
0
1
0
LCD
SPI
0
0
= Unimplemented or Reserved
Figure 5-12. System Clock Gating Control 2 Register (SCGC2)
Table 5-14. SCGC2 Register Field Descriptions
Field
Description
7
DBG
DBG Register Clock Gate Control — This bit controls the bus clock gate to the DBG module.
0 Bus clock to the DBG module is disabled.
1 Bus clock to the DBG module is enabled.
6
FLS
Flash Clock Gate Control — This bit controls the bus clock gate to the Flash module.
0 Bus clock to the Flash module is disabled.
1 Bus clock to the Flash module is enabled.
5
IRQ
IRQ Clock Gate Control — This bit controls the bus clock gate to the IRQ module.
0 Bus clock to the IRQ module is disabled.
1 Bus clock to the IRQ module is enabled.
4
KBI
KBI Clock Gate Control — This bit controls the clock gate to the KBI module.
0 Bus clock to the KBI module is disabled.
1 Bus clock to the KBI module is enabled.
1
LCD
LCD Clock Gate Control — This bit controls the bus clock gate to the LCD module. Only the bus clock is gated,
the OSCOUT, TODCLK and LPOCLK are still available to the LCD.
0 Bus clock to the LCD module is disabled.
1 Bus clock to the LCD module is enabled.
0
SPI
SPI Clock Gate Control — This bit controls the clock gate to the SPI module.
0 Bus clock to the SPI module is disabled.
1 Bus clock to the SPI module is enabled.
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5.8.11
Pin Position Control Register (PINPS1)
This high-page register contains the control bits that determine which of the two possible pins is used as
the source for the indicated KBIx pin function. The default source is the pin available on the 48-pin
package.
7
6
5
4
3
2
1
0
KBI7
KBI6
KBI5
KBI4
KBI3
KBI2
KBI1
KBI0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 5-13. Pin Position Control Register (PINPS1)
Table 5-15. PINPS1 Register Field Descriptions
Field
Description
8
KBI7
KBI7 Pin Position — This bit controls the pin position of KBI7.
0 KBI7 sourced from PTA6
1 KBI7 sourced from PTH3
7
KBI6
KBI6 Pin Position — This bit controls the pin position of KBI6.
0 KBI6 sourced from PTA5
1 KBI6 sourced from PTH2
6
KBI5
KBI5 Pin Position — This bit controls the pin position of KBI5.
0 KBI5 sourced from PTA4
1 KBI5 sourced from PTH1
5
KBI4
KBI4 Pin Position — This bit controls the pin position of KBI4.
0 KBI4 sourced from PTA3
1 KBI4 sourced from PTH0
4
KBI3
KBI3 Pin Position — This bit controls the pin position of KBI3.
0 KBI3 sourced from PTF0
1 KBI3 sourced from PTH5
3
KBI2
KBI2 Pin Position — This bit controls the pin position of KBI2.
0 KBI2 sourced from PTF5
1 KBI2 sourced from PTH4
2
KBI1
KBI1 Pin Position — This bit controls the pin position of KBI1.
0 KBI1 sourced from PTF4
1 KBI1 sourced from PTH7
1
KBI0
KBI0 Pin Position — This bit controls the pin position of KBI0.
0 KBI0 sourced from PTF3
1 KBI0 sourced from PTH6
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5.8.12
Pin Position Control Register (PINPS2)
This high-page register contains the control bits that determine which of the two potential pins is used as
the source for the TPMx pin function. The default source is the pin available on the 48-pin package.
7
6
5
4
3
2
1
0
TPM2[5]
TPM2[4]
TPM2[3]
TPM2[2]
TPM2[1]
TPM2[0]
TPM1[1]
TPM1[0]
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 5-14. Pin Position Control Register (PINPS2)
Table 5-16. PINPS2 Register Field Descriptions
Field
Description
7
TPM2[5]
TPM2[5] Pin Position — This bit controls the pin position of TPM2[5].
0 TPM2[5] sourced from PTF3
1 TPM2[5] sourced from PTH6
6
TPM2[4]
TPM2[4] Pin Position — This bit controls the pin position of TPM2[4].
0 TPM2[4] sourced from PTF4
1 TPM2[4] sourced from PTH7
5
TPM2[3]
TPM2[3] Pin Position — This bit controls the pin position of TPM2[3].
0 TPM2[3] sourced from PTF5
1 TPM2[3] sourced from PTI2
4
TPM2[2]
TPM2[2] Pin Position — This bit controls the pin position of TPM2[2].
0 TPM2[2] sourced from PTF0
1 TPM2[2] sourced from PTI3
3
TPM2[1]
TPM2[1] Pin Position — This bit controls the pin position of TPM2[1].
0 TPM2[1] sourced from PTA6
1 TPM2[1] sourced from PTI4
2
TPM2[0]
TPM2[0] Pin Position — This bit controls the pin position of TPM2[0].
0 TPM2[0] sourced from PTA5
1 TPM2[0] sourced from PTI5
1
TPM1[1]
TPM1[1] Pin Position — This bit controls the pin position of TPM1[1].
0 TPM1[1] sourced from PTF2
1 TPM1[1] sourced from PTH4
0
TPM1[0]
TPM1[0] Pin Position — This bit controls the pin position of TPM1[0].
0 TPM1[0] sourced from PTF1
1 TPM1[0] sourced from PTH5
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5.8.13
Pin Position Control Register (PINPS3)
This high-page register contains control bits that determine which of the two potential pins is used as the
source for the function. The default source is the pin available on the 48-pin package.
7
6
5
4
3
2
1
0
TX2
RX2
SCL
SDA
MISO
MOSI
SCK
SS
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 5-15. Pin Position Control Register (PINPS3)
Table 5-17. PINPS3 Register Field Descriptions
Field
Description
7
TX2
TX2 Pin Position — This bit controls the pin position of TX2.
0 TX2 sourced from PTA3.
1 TX2 sourced from PTI1.
6
RX2
RX2 Pin Position — This bit controls the pin position of RX2.
0 RX2 sourced from PTA4.
1 RX2 sourced from PTI0.
5
SCL
SCL Pin Position — This bit controls the pin position of SCL.
0 SCL sourced from PTA1.
1 SCL sourced from PTI5.
4
SDA
SDA Pin Position — This bit controls the pin position of SDA.
0 SDA sourced from PTA2.
1 SDA sourced from PTI4.
3
MISO
MISO Pin Position — This bit controls the pin position of MISO.
0 MISO sourced from PTF4.
1 MISO sourced from PTI2.
2
MOSI
MOSI Pin Position — This bit controls the pin position of MOSI.
0 MOSI sourced from PTF5.
1 MOSI sourced from PTI3.
1
SCK
SCK Pin Position — This bit controls the pin position of SCK.
0 SCK sourced from PTF2.
1 SCK sourced from PTI4.
0
SS
SS Pin Position — This bit controls the pin position of SS.
0 SS sourced from PTF3.
1 SS sourced from PTI5.
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5.8.14
Pin Position Control Register (PINPS4)
This high-page register contains control bits that determine which of the two potential pins is used as the
source for the function. The default source is the pin available on 48-pin package.
7
6
5
4
3
2
1
0
0
0
0
0
0
0
TX1
RX1
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 5-16. Pin Position Control Register (PINPS4)
Table 5-18. PINPS4 Register Field Descriptions
Field
Description
1
TX1
TX1 Pin Position — This bit controls the pin position of TX1.
0 TX1 sourced from PTF0.
1 TX1 sourced from PTH5.
0
RX1
RX1 Pin Position — This bit controls the pin position of RX1.
0 RX1 sourced from PTF1.
1 RX1 sourced from PTH4.
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Chapter 6
Parallel Input/Output Control
6.1
Introduction
This section explains software controls related to parallel input/output (I/O) and pin control. The
MC9S08LG32 has nine parallel I/O ports (PTA-PTI) which include a total of 69 I/O pins, including two
output-only pins. See Chapter 2, “Pins and Connections,” for more information about pin assignments and
external hardware considerations of these pins.
Many of these pins are shared with on-chip peripherals such as timer systems, communication systems, or
keyboard interrupts, as shown in Table 2-1. The peripheral modules have priority over the general-purpose
I/O functions so that when a peripheral is enabled, the I/O functions associated with the shared pins may
be disabled.
After reset, the shared peripheral functions are disabled and the pins are configured as inputs
(PTxDDn = 0). The pin control functions for each pin are configured as follows: slew rate control enabled
(PTxSEn = 1), low drive strength selected (PTxDSn = 0), and internal pullups disabled (PTxPEn = 0).
NOTE
All general-purpose I/O pins are not available on all packages. To avoid
extra current drain from floating input pins, your reset initialization routine
in the application program must either enable on-chip pullup devices or
change the direction of unconnected pins to outputs so the pins do not float.
6.2
Pins Shared with LCD
Pins that have shared function with the LCD have special behavior based on the state of the VSUPPLY
bits in the LCDSUPPLY register. These pins (PTA, PTB, PTC[4:0], PTD, PTE and PTG) can operate as
full complementary drive or open drain drive depending on the VSUPPLY bits. When VLL3 is connected
to VDD externally, VSUPPLY = 11, FCDEN = 1, and RVEN = 0; the pins operate as full complementary
drive. For all other VSUPPLY modes, the GPIO shared with LCD operates as open drain.
6.3
Port Data and Data Direction
Reading and writing of parallel I/Os are performed through the port data registers (PTxDn). The direction,
either input or output, is controlled through the port data direction registers (PTxDDn). The parallel I/O
port function for an individual pin is illustrated in the block diagram shown in Figure 6-1.
The data direction control bit (PTxDDn) determines whether the output buffer or the input buffer for the
associated pin is enabled. When a shared digital function is enabled for a pin, the output buffer is controlled
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by the shared function. However, the data direction register bit continues to control the source for reads of
the port data register.
When a shared analog function is enabled for a pin, both the input and output buffers are disabled. A value
of 0 is read for any port data bit where the bit is an input (PTxDDn = 0) and the input buffer is disabled. In
general, whenever a pin is shared with both an alternate digital function and an analog function, the analog
function has priority such that if both the digital and analog functions are enabled, the analog function
controls the pin.
It is good programming practice to write to the port data register before changing the direction of a port
pin so it becomes an output. This ensures that the pin is not driven momentarily with an old data value that
happen to be in the port data register.
PTxDDn
D
Output Enable
Q
Input Enable
PTxDn
D
Q
Output Data
1
Port Read
Data
0
Synchronizer
Input Data
BUSCLK
Figure 6-1. Parallel I/O Block Diagram
6.4
Pullup, Slew Rate, and Drive Strength
Associated with the parallel I/O ports is a set of registers located in the high-page register space that
operates independently of the parallel I/O registers. These registers are used to control pullups, slew rate,
and drive strength for the pins and can be used in conjunction with the peripheral functions on these pins.
6.4.1
Port Internal Pullup Enable
For all GPIOs, set the corresponding bit in the pullup enable register (PTxPEn) to enable an internal pullup
resistor for each port pin. Typically, GPIO internal pullups are disabled when in output mode. However,
for GPIO that are muxed with LCD pins, the internal pullup is not disabled when in open drain, output
mode. Similarly the internal pullup for GPIO muxed with open drain RESET pin is not disabled in the
output mode.
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The pullup device is disabled if the pin is controlled by an analog function regardless of the state of the
corresponding pullup enable register bit.
6.4.2
Port Slew Rate Enable
Slew rate control can be enabled for each port pin by setting the corresponding bit in the slew rate control
register (PTxSEn). When enabled, slew control limits the rate at which an output can transition to reduce
EMC emissions. Slew rate control has no effect on pins that are configured as inputs.
6.4.3
Port Drive Strength Select
An output pin can be configured for high-output drive strength by setting the corresponding bit in the drive
strength select register (PTxDSn). When high drive is selected, a pin is capable of sourcing and sinking
greater current. Even though every I/O pin can be selected as high drive, you must ensure that the total
current source and sink limits for the MCU are not exceeded. Drive strength selection is intended to affect
the DC behavior of I/O pins. However, the AC behavior is also affected. High drive allows a pin to drive
a greater load with the same switching speed as a low drive enabled pin into a smaller load. Because of
this, the EMC emissions may be affected by enabling pins as high drive.
6.5
Open Drain Operation
For most cases, port pins that share functions with the LCD operate as open drain outputs. As an open drain
output, the output high of the pin is dependent upon the pullup resistor. The pullup resistor can be an
internal resistor enabled by the PTxPEx bit or an external resistor.
• The value of the internal resistor can be in the range of 17.5 to 52.5 kΩ
• The value of an external resistor must be carefully selected to ensure it supports the output loads
that are being driven.
6.6
Pin Behavior in Stop Modes
Pin behavior following execution of a STOP instruction depends on the stop mode that is entered. An
explanation of pin behavior for the various stop modes follows:
• Stop2 mode is a partial power-down mode, whereby I/O latches are maintained in their pre-STOP
instruction state. CPU register status and the state of I/O registers must be saved in RAM before
the STOP instruction is executed to place the MCU in stop2 mode. Upon recovery from stop2
mode, before accessing any I/O, you must examine the state of the PPDF bit in the SPMSC2
register. If the PPDF bit is 0, I/O must be initialized as if a power-on reset had occurred. If the PPDF
bit is 1, I/O register states must be restored from the values saved in RAM before the STOP
instruction was executed. Peripherals may require initialization or restoration to their pre-stop
condition. You must then write a 1 to the PPDACK bit in the SPMSC2 register. Access to I/O is
again permitted in the user application program.
• If the LCD module is configured to operate in Stop modes, the drive mode of the GPIO shared with
LCD is retained upon stop recovery.
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•
6.7
In stop3 mode, all I/O is maintained because internal logic circuitry stays powered up. Upon
recovery, normal I/O function is available to the user.
Parallel I/O and Pin Control Registers
This section provides information about the registers associated with the parallel I/O ports. The data and
data direction registers are located in page zero of the memory map. The pullup, slew rate, and drive
strength control registers are located in the high-page section of the memory map.
Refer to tables in Chapter 4, “Memory,” for the absolute address assignments for all parallel I/O and their
pin control registers. This section refers to registers and control bits only by their names. A Freescale
Semiconductor-provided equate or header file is normally to translate these names into the appropriate
absolute addresses.
6.7.1
Port A Registers
Port A is controlled by the registers listed below. All the pins of port A are shared with LCD. These pins
have special behavior as explained in Section 6.2.
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6.7.1.1
Port A Data Register (PTAD)
7
6
5
4
3
2
1
0
PTAD7
PTAD6
PTAD5
PTAD4
PTAD3
PTAD2
PTAD1
PTAD0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-2. Port A Data Register (PTAD)
Table 6-1. PTAD Register Field Descriptions
Field
Description
7:0
PTAD[7:0]
Port A Data Register Bits — For port A pins that are inputs, reads return the logic level on the pin. For port A
pins that are configured as outputs, reads return the last value written to this register.
Writes are latched into all bits of this register. For port A pins that are configured as outputs, the logic level is
driven out the corresponding MCU pin.
Reset forces PTAD to all 0s, but these 0s are not driven out the corresponding pins because reset also configures
all port pins as high-impedance inputs with pullups disabled.
6.7.1.2
Port A Data Direction Register (PTADD)
7
6
5
4
3
2
1
0
PTADD7
PTADD6
PTADD5
PTADD4
PTADD3
PTADD2
PTADD1
PTADD0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-3. Port A Data Direction Register (PTADD)
Table 6-2. PTADD Register Field Descriptions
Field
Description
7:0
Data Direction for Port A Bits — These read/write bits control the direction of port A pins and what is read for
PTADD[7:0] PTAD reads.
0 Input (output driver disabled) and reads return the pin value.
1 Output driver enabled for port A bit n and PTAD reads return the contents of PTADn.
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6.7.1.3
Port A Pull Enable Register (PTAPE)
7
6
5
4
3
2
1
0
PTAPE7
PTAPE6
PTAPE5
PTAPE4
PTAPE3
PTAPE2
PTAPE1
PTAPE0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-4. Internal Pull Enable for Port A Register (PTAPE)
Table 6-3. PTAPE Register Field Descriptions
Field
Description
7:0
Internal Pull Enable for Port A Bits — Each of these control bits determines if the internal pullup or pulldown
PTAPE[7:0] device is enabled for the associated PTA pin. For port A pins that are configured as outputs, these bits have no
effect and the internal pull devices are disabled.
0 Internal pullup device disabled for port A bit n.
1 Internal pullup device enabled for port A bit n.
6.7.1.4
Port A Slew Rate Enable Register (PTASE)
7
6
5
4
3
2
1
0
PTASE7
PTASE6
PTASE5
PTASE4
PTASE3
PTASE2
PTASE1
PTASE0
1
1
1
1
1
1
1
1
R
W
Reset:
Figure 6-5. Slew Rate Enable for Port A Register (PTASE)
Table 6-4. PTASE Register Field Descriptions
Field
Description
7:0
Output Slew Rate Enable for Port A Bits — Each of these control bits determines if the output slew rate control
PTASE[7:0] is enabled for the associated PTA pin. For port A pins that are configured as inputs, these bits have no effect.
0 Output slew rate control disabled for port A bit n.
1 Output slew rate control enabled for port A bit n.
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6.7.1.5
Port A Drive Strength Selection Register (PTADS)
7
6
5
4
3
2
1
0
PTADS7
PTADS6
PTADS5
PTADS4
PTADS3
PTADS2
PTADS1
PTADS0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-6. Drive Strength Selection for Port A Register (PTADS)
Table 6-5. PTADS Register Field Descriptions
Field
Description
7:0
Output Drive Strength Selection for Port A Bits — Each of these control bits selects between low and high
PTADS[7:0] output drive for the associated PTA pin. For port A pins that are configured as inputs, these bits have no effect.
0 Low output drive strength selected for port A bit n.
1 High output drive strength selected for port A bit n.
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6.7.2
Port B Registers
Port B is controlled by the registers listed below. All the pins of Port B are shared with LCD. These pins
have special behavior as explained in Section 6.2.
6.7.2.1
Port B Data Register (PTBD)
7
6
5
4
3
2
1
0
PTBD7
PTBD6
PTBD5
PTBD4
PTBD3
PTBD2
PTBD1
PTBD0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-7. Port B Data Register (PTBD)
Table 6-6. PTBD Register Field Descriptions
Field
Description
7:0
PTBD[7:0]
Port B Data Register Bits — For Port B pins that are inputs, reads return the logic level on the pin. For Port B
pins that are configured as outputs, reads return the last value written to this register.
Writes are latched into all bits of this register. For Port B pins that are configured as outputs, the logic level is
driven out the corresponding MCU pin.
Reset forces PTBD to all 0s, but these 0s are not driven out the corresponding pins because reset also configures
all port pins as high-impedance inputs with pullups disabled.
6.7.2.2
Port B Data Direction Register (PTBDD)
7
6
5
4
3
2
1
0
PTBDD7
PTBDD6
PTBDD5
PTBDD4
PTBDD3
PTBDD2
PTBDD1
PTBDD0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-8. Port B Data Direction Register (PTBDD)
Table 6-7. PTBDD Register Field Descriptions
Field
Description
7:0
Data Direction for Port B Bits — These read/write bits control the direction of Port B pins and what is read for
PTBDD[7:0] PTBD reads.
0 Input (output driver disabled) and reads return the pin value.
1 Output driver enabled for Port B bit n and PTBD reads return the contents of PTBDn.
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6.7.2.3
Port B Pull Enable Register (PTBPE)
7
6
5
4
3
2
1
0
PTBPE7
PTBPE6
PTBPE5
PTBPE4
PTBPE3
PTBPE2
PTBPE1
PTBPE0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-9. Internal Pull Enable for Port B Register (PTBPE)
Table 6-8. PTBPE Register Field Descriptions
Field
Description
7:0
Internal Pull Enable for Port B Bits — Each of these control bits determines if the internal pullup or pulldown
PTBPE[7:0] device is enabled for the associated PTB pin. For Port B pins that are configured as outputs, these bits have no
effect and the internal pull devices are disabled.
0 Internal pullup device disabled for Port B bit n.
1 Internal pullup device enabled for Port B bit n.
6.7.2.4
Port B Slew Rate Enable Register (PTBSE)
7
6
5
4
3
2
1
0
PTBSE7
PTBSE6
PTBSE5
PTBSE4
PTBSE3
PTBSE2
PTBSE1
PTBSE0
1
1
1
1
1
1
1
1
R
W
Reset:
Figure 6-10. Slew Rate Enable for Port B Register (PTBSE)
Table 6-9. PTBSE Register Field Descriptions
Field
Description
7:0
Output Slew Rate Enable for Port B Bits — Each of these control bits determines if the output slew rate control
PTBSE[7:0] is enabled for the associated PTB pin. For Port B pins that are configured as inputs, these bits have no effect.
0 Output slew rate control disabled for Port B bit n.
1 Output slew rate control enabled for Port B bit n.
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6.7.2.5
Port B Drive Strength Selection Register (PTBDS)
7
6
5
4
3
2
1
0
PTBDS7
PTBDS6
PTBDS5
PTBDS4
PTBDS3
PTBDS2
PTBDS1
PTBDS0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-11. Drive Strength Selection for Port B Register (PTBDS)
Table 6-10. PTBDS Register Field Descriptions
Field
Description
7:0
Output Drive Strength Selection for Port B Bits — Each of these control bits selects between low and high
PTBDS[7:0] output drive for the associated PTB pin. For Port B pins that are configured as inputs, these bits have no effect.
0 Low output drive strength selected for Port B bit n.
1 High output drive strength selected for Port B bit n.
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6.7.3
Port C Registers
Port C is controlled by the registers listed below. PTC[4:0] are shared with LCD. These pins have special
behavior as explained in Section 6.2. PTC[5] is a output only pin. PTC[6] is a output only pin with open
drain drive and internal pull up.
6.7.3.1
Port C Data Register (PTCD)
7
R
6
5
4
3
2
1
0
PTCD6
PTCD5
PTCD4
PTCD3
PTCD2
PTCD1
PTCD0
0
0
0
0
0
0
0
0
W
Reset:
0
Figure 6-12. Port C Data Register (PTCD)
Table 6-11. PTCD Register Field Descriptions
Field
Description
6:0
PTCD[6:0]
Port C Data Register Bits — For Port C pins that are inputs, reads return the logic level on the pin. For Port C
pins that are configured as outputs, reads return the last value written to this register.
Writes are latched into all bits of this register. For Port C pins that are configured as outputs, the logic level is
driven out the corresponding MCU pin.
Reset forces PTCD to all 0s, but these 0s are not driven out the corresponding pins because reset also configures
all port pins as high-impedance inputs with pullups disabled.
6.7.3.2
Port C Data Direction Register (PTCDD)
7
R
6
5
4
3
2
1
0
PTCDD6
PTCDD5
PTCDD4
PTCDD3
PTCDD2
PTCDD1
PTCDD0
0
0
0
0
0
0
0
0
W
Reset:
0
Figure 6-13. Port C Data Direction Register (PTCDD)
Table 6-12. PTCDD Register Field Descriptions
Field
Description
6:0
Data Direction for Port C Bits — These read/write bits control the direction of Port C pins and what is read for
PTCDD[6:0] PTCD reads.
0 Input (output driver disabled) and reads return the pin value.
1 Output driver enabled for Port C bit n and PTCD reads return the contents of PTCDn.
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6.7.3.3
Port C Pull Enable Register (PTCPE)
7
R
6
5
4
3
2
1
0
PTCPE6
PTCPE5
PTCPE4
PTCPE3
PTCPE2
PTCPE1
PTCPE0
0
0
0
0
0
0
0
0
W
Reset:
0
Figure 6-14. Internal Pull Enable for Port C Register (PTCPE)
Table 6-13. PTCPE Register Field Descriptions
Field
Description
6:0
Internal Pull Enable for Port C Bits — Each of these control bits determines if the internal pullup or pulldown
PTCPE[6:0] device is enabled for the associated PTC pin. For Port C pins that are configured as outputs, these bits have no
effect and the internal pull devices are disabled.
0 Internal pullup device disabled for Port C bit n.
1 Internal pullup device enabled for Port C bit n.
6.7.3.4
Port C Slew Rate Enable Register (PTCSE)
7
R
6
5
4
3
2
1
0
PTCSE6
PTCSE5
PTCSE4
PTCSE3
PTCSE2
PTCSE1
PTCSE0
1
1
1
1
1
1
1
0
W
Reset:
0
Figure 6-15. Slew Rate Enable for Port C Register (PTCSE)
Table 6-14. PTCSE Register Field Descriptions
Field
Description
6:0
Output Slew Rate Enable for Port C Bits — Each of these control bits determines if the output slew rate control
PTCSE[6:0] is enabled for the associated PTC pin. For Port C pins that are configured as inputs, these bits have no effect.
0 Output slew rate control disabled for Port C bit n.
1 Output slew rate control enabled for Port C bit n.
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6.7.3.5
Port C Drive Strength Selection Register (PTCDS)
7
R
6
5
4
3
2
1
0
PTCDS6
PTCDS5
PTCDS4
PTCDS3
PTCDS2
PTCDS1
PTCDS0
0
0
0
0
0
0
0
0
W
Reset:
0
Figure 6-16. Drive Strength Selection for Port C Register (PTCDS)
Table 6-15. PTCDS Register Field Descriptions
Field
Description
6:0
Output Drive Strength Selection for Port C Bits — Each of these control bits selects between low and high
PTCDS[6:0] output drive for the associated PTC pin. For Port C pins that are configured as inputs, these bits have no effect.
0 Low output drive strength selected for Port C bit n.
1 High output drive strength selected for Port C bit n.
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6.7.4
Port D Registers
Port D is controlled by the registers listed below. All port D pins are shared with LCD. These pins have
special behavior as explained in Section 6.2.
6.7.4.1
Port D Data Register (PTDD)
7
6
5
4
3
2
1
0
PTDD7
PTDD6
PTDD5
PTDD4
PTDD3
PTDD2
PTDD1
PTDD0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-17. Port D Data Register (PTDD)
Table 6-16. PTDD Register Field Descriptions
Field
Description
7:0
PTDD[7:0]
Port D Data Register Bits — For Port D pins that are inputs, reads return the logic level on the pin. For Port D
pins that are configured as outputs, reads return the last value written to this register.
Writes are latched into all bits of this register. For Port D pins that are configured as outputs, the logic level is
driven out the corresponding MCU pin.
Reset forces PTDD to all 0s, but these 0s are not driven out the corresponding pins because reset also configures
all port pins as high-impedance inputs with pullups disabled.
6.7.4.2
Port D Data Direction Register (PTDDD)
7
6
5
4
3
2
1
0
PTDDD7
PTDDD6
PTDDD5
PTDDD4
PTDDD3
PTDDD2
PTDDD1
PTDDD0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-18. Port D Data Direction Register (PTDDD)
Table 6-17. PTDDD Register Field Descriptions
Field
Description
7:0
Data Direction for Port D Bits — These read/write bits control the direction of Port D pins and what is read for
PTDDD[7:0] PTDD reads.
0 Input (output driver disabled) and reads return the pin value.
1 Output driver enabled for Port D bit n and PTDD reads return the contents of PTDDn.
MC9S08LG32 MCU Series, Rev. 5
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Freescale Semiconductor
Chapter 6 Parallel Input/Output Control
6.7.4.3
Port D Pull Enable Register (PTDPE)
7
6
5
4
3
2
1
0
PTDPE7
PTDPE6
PTDPE5
PTDPE4
PTDPE3
PTDPE2
PTDPE1
PTDPE0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-19. Internal Pull Enable for Port D Register (PTDPE)
Table 6-18. PTDPE Register Field Descriptions
Field
Description
7:0
Internal Pull Enable for Port D Bits — Each of these control bits determines if the internal pullup or pulldown
PTDPE[7:0] device is enabled for the associated PTD pin. For Port D pins that are configured as outputs, these bits have no
effect and the internal pull devices are disabled.
0 Internal pullup device disabled for Port D bit n.
1 Internal pullup device enabled for Port D bit n.
6.7.4.4
Port D Slew Rate Enable Register (PTDSE)
7
6
5
4
3
2
1
0
PTDSE7
PTDSE6
PTDSE5
PTDSE4
PTDSE3
PTDSE2
PTDSE1
PTDSE0
1
1
1
1
1
1
1
1
R
W
Reset:
Figure 6-20. Slew Rate Enable for Port D Register (PTDSE)
Table 6-19. PTDSE Register Field Descriptions
Field
Description
7:0
Output Slew Rate Enable for Port D Bits — Each of these control bits determines if the output slew rate control
PTDSE[7:0] is enabled for the associated PTD pin. For Port D pins that are configured as inputs, these bits have no effect.
0 Output slew rate control disabled for Port D bit n.
1 Output slew rate control enabled for Port D bit n.
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
111
Chapter 6 Parallel Input/Output Control
6.7.4.5
Port D Drive Strength Selection Register (PTDDS)
7
6
5
4
3
2
1
0
PTDDS7
PTDDS6
PTDDS5
PTDDS4
PTDDS3
PTDDS2
PTDDS1
PTDDS0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-21. Drive Strength Selection for Port D Register (PTDDS)
Table 6-20. PTDDS Register Field Descriptions
Field
Description
7:0
Output Drive Strength Selection for Port D Bits — Each of these control bits selects between low and high
PTDDS[7:0] output drive for the associated PTD pin. For Port D pins that are configured as inputs, these bits have no effect.
0 Low output drive strength selected for Port D bit n.
1 High output drive strength selected for Port D bit n.
MC9S08LG32 MCU Series, Rev. 5
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Chapter 6 Parallel Input/Output Control
6.7.5
Port E Registers
Port E is controlled by the registers listed below. All Port E pins are shared with LCD. These pins have
special behavior as explained in Section 6.2.
6.7.5.1
Port E Data Register (PTED)
7
6
5
4
3
2
1
0
PTED7
PTED6
PTED5
PTED4
PTED3
PTED2
PTED1
PTED0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-22. Port E Data Register (PTED)
Table 6-21. PTED Register Field Descriptions
Field
Description
7:0
PTED[7:0]
Port E Data Register Bits — For Port E pins that are inputs, reads return the logic level on the pin. For Port E
pins that are configured as outputs, reads return the last value written to this register.
Writes are latched into all bits of this register. For Port E pins that are configured as outputs, the logic level is
driven out the corresponding MCU pin.
Reset forces PTED to all 0s, but these 0s are not driven out the corresponding pins because reset also configures
all port pins as high-impedance inputs with pullups disabled.
6.7.5.2
Port E Data Direction Register (PTEDD)
7
6
5
4
3
2
1
0
PTEDD7
PTEDD6
PTEDD5
PTEDD4
PTEDD3
PTEDD2
PTEDD1
PTEDD0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-23. Port E Data Direction Register (PTEDD)
Table 6-22. PTEDD Register Field Descriptions
Field
Description
7:0
Data Direction for Port E Bits — These read/write bits control the direction of Port E pins and what is read for
PTEDD[7:0] PTED reads.
0 Input (output driver disabled) and reads return the pin value.
1 Output driver enabled for Port E bit n and PTED reads return the contents of PTEDn.
MC9S08LG32 MCU Series, Rev. 5
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113
Chapter 6 Parallel Input/Output Control
6.7.5.3
Port E Pull Enable Register (PTEPE)
7
6
5
4
3
2
1
0
PTEPE7
PTEPE6
PTEPE5
PTEPE4
PTEPE3
PTEPE2
PTEPE1
PTEPE0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-24. Internal Pull Enable for Port E Register (PTEPE)
Table 6-23. PTEPE Register Field Descriptions
Field
Description
7:0
Internal Pull Enable for Port E Bits — Each of these control bits determines if the internal pullup or pulldown
PTEPE[7:0] device is enabled for the associated PTE pin. For Port E pins that are configured as outputs, these bits have no
effect and the internal pull devices are disabled.
0 Internal pullup device disabled for Port E bit n.
1 Internal pullup device enabled for Port E bit n.
6.7.5.4
Port E Slew Rate Enable Register (PTESE)
7
6
5
4
3
2
1
0
PTESE7
PTESE6
PTESE5
PTESE4
PTESE3
PTESE2
PTESE1
PTESE0
1
1
1
1
1
1
1
1
R
W
Reset:
Figure 6-25. Slew Rate Enable for Port E Register (PTESE)
Table 6-24. PTESE Register Field Descriptions
Field
Description
7:0
Output Slew Rate Enable for Port E Bits — Each of these control bits determines if the output slew rate control
PTESE[7:0] is enabled for the associated PTE pin. For Port E pins that are configured as inputs, these bits have no effect.
0 Output slew rate control disabled for Port E bit n.
1 Output slew rate control enabled for Port E bit n.
MC9S08LG32 MCU Series, Rev. 5
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Chapter 6 Parallel Input/Output Control
6.7.5.5
Port E Drive Strength Selection Register (PTEDS)
7
6
5
4
3
2
1
0
PTEDS7
PTEDS6
PTEDS5
PTEDS4
PTEDS3
PTEDS2
PTEDS1
PTEDS0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-26. Drive Strength Selection for Port E Register (PTEDS)
Table 6-25. PTEDS Register Field Descriptions
Field
Description
7:0
Output Drive Strength Selection for Port E Bits — Each of these control bits selects between low and high
PTEDS[7:0] output drive for the associated PTE pin. For Port E pins that are configured as inputs, these bits have no effect.
0 Low output drive strength selected for Port E bit n.
1 High output drive strength selected for Port E bit n.
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
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Chapter 6 Parallel Input/Output Control
6.7.6
Port F Registers
Port F is controlled by the registers listed below.
6.7.6.1
Port F Data Register (PTFD)
7
6
5
4
3
2
1
0
PTFD7
PTFD6
PTFD5
PTFD4
PTFD3
PTFD2
PTFD1
PTFD0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-27. Port F Data Register (PTFD)
Table 6-26. PTFD Register Field Descriptions
Field
Description
7:0
PTFD[7:0]
Port F Data Register Bits — For Port F pins that are inputs, reads return the logic level on the pin. For Port F
pins that are configured as outputs, reads return the last value written to this register.
Writes are latched into all bits of this register. For Port F pins that are configured as outputs, the logic level is
driven out the corresponding MCU pin.
Reset forces PTFD to all 0s, but these 0s are not driven out the corresponding pins because reset also configures
all port pins as high-impedance inputs with pullups disabled.
6.7.6.2
Port F Data Direction Register (PTFDD)
7
6
5
4
3
2
1
0
PTFDD7
PTFDD6
PTFDD5
PTFDD4
PTFDD3
PTFDD2
PTFDD1
PTFDD0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-28. Port F Data Direction Register (PTFDD)
Table 6-27. PTFDD Register Field Descriptions
Field
Description
7:0
Data Direction for Port F Bits — These read/write bits control the direction of Port F pins and what is read for
PTFDD[7:0] PTFD reads.
0 Input (output driver disabled) and reads return the pin value.
1 Output driver enabled for Port F bit n and PTFD reads return the contents of PTFDn.
MC9S08LG32 MCU Series, Rev. 5
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Chapter 6 Parallel Input/Output Control
6.7.6.3
Port F Pull Enable Register (PTFPE)
7
6
5
4
3
2
1
0
PTFPE7
PTFPE6
PTFPE5
PTFPE4
PTFPE3
PTFPE2
PTFPE1
PTFPE0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-29. Internal Pull Enable for Port F Register (PTFPE)
Table 6-28. PTFPE Register Field Descriptions
Field
Description
7:0
Internal Pull Enable for Port F Bits — Each of these control bits determines if the internal pullup or pulldown
PTFPE[7:0] device is enabled for the associated PTF pin. For Port F pins that are configured as outputs, these bits have no
effect and the internal pull devices are disabled.
0 Internal pullup device disabled for Port F bit n.
1 Internal pullup device enabled for Port F bit n.
6.7.6.4
Port F Slew Rate Enable Register (PTFSE)
7
6
5
4
3
2
1
0
PTFSE7
PTFSE6
PTFSE5
PTFSE4
PTFSE3
PTFSE2
PTFSE1
PTFSE0
1
1
1
1
1
1
1
1
R
W
Reset:
Figure 6-30. Slew Rate Enable for Port F Register (PTFSE)
Table 6-29. PTFSE Register Field Descriptions
Field
Description
7:0
Output Slew Rate Enable for Port F Bits — Each of these control bits determines if the output slew rate control
PTFSE[7:0] is enabled for the associated PTF pin. For Port F pins that are configured as inputs, these bits have no effect.
0 Output slew rate control disabled for Port F bit n.
1 Output slew rate control enabled for Port F bit n.
MC9S08LG32 MCU Series, Rev. 5
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117
Chapter 6 Parallel Input/Output Control
6.7.6.5
Port F Drive Strength Selection Register (PTFDS)
7
6
5
4
3
2
1
0
PTFDS7
PTFDS6
PTFDS5
PTFDS4
PTFDS3
PTFDS2
PTFDS1
PTFDS0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-31. Drive Strength Selection for Port F Register (PTFDS)
Table 6-30. PTFDS Register Field Descriptions
Field
Description
7:0
Output Drive Strength Selection for Port F Bits — Each of these control bits selects between low and high
PTFDS[7:0] output drive for the associated PTF pin. For Port F pins that are configured as inputs, these bits have no effect.
0 Low output drive strength selected for Port F bit n.
1 High output drive strength selected for Port F bit n.
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Chapter 6 Parallel Input/Output Control
6.7.7
Port G Registers
Port G is controlled by the registers listed below. All Port G pins are shared with LCD. These pins have
special behavior as explained in Section 6.2.
6.7.7.1
Port G Data Register (PTGD)
7
6
5
4
3
2
1
0
PTGD7
PTGD6
PTGD5
PTGD4
PTGD3
PTGD2
PTGD1
PTGD0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-32. Port G Data Register (PTGD)
Table 6-31. PTGD Register Field Descriptions
Field
Description
7:0
PTGD[7:0]
Port G Data Register Bits — For Port G pins that are inputs, reads return the logic level on the pin. For Port G
pins that are configured as outputs, reads return the last value written to this register.
Writes are latched into all bits of this register. For Port G pins that are configured as outputs, the logic level is
driven out the corresponding MCU pin.
Reset forces PTGD to all 0s, but these 0s are not driven out the corresponding pins because reset also
configures all port pins as high-impedance inputs with pullups disabled.
6.7.7.2
Port G Data Direction Register (PTGDD)
7
6
5
4
3
2
1
0
PTGDD7
PTGDD6
PTGDD5
PTGDD4
PTGDD3
PTGDD2
PTGDD1
PTGDD0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-33. Port G Data Direction Register (PTGDD)
Table 6-32. PTGDD Register Field Descriptions
Field
Description
7:0
Data Direction for Port G Bits — These read/write bits control the direction of Port G pins and what is read for
PTGDD[7:0] PTGD reads.
0 Input (output driver disabled) and reads return the pin value.
1 Output driver enabled for Port G bit n and PTGD reads return the contents of PTGDn.
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
119
Chapter 6 Parallel Input/Output Control
6.7.7.3
Port G Pull Enable Register (PTGPE)
7
6
5
4
3
2
1
0
PTGPE7
PTGPE6
PTGPE5
PTGPE4
PTGPE3
PTGPE2
PTGPE1
PTGPE0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-34. Internal Pull Enable for Port G Register (PTGPE)
Table 6-33. PTGPE Register Field Descriptions
Field
Description
7:0
Internal Pull Enable for Port G Bits — Each of these control bits determines if the internal pullup or pulldown
PTGPE[7:0] device is enabled for the associated PTG pin. For Port G pins that are configured as outputs, these bits have no
effect and the internal pull devices are disabled.
0 Internal pullup device disabled for Port G bit n.
1 Internal pullup device enabled for Port G bit n.
6.7.7.4
Port G Slew Rate Enable Register (PTGSE)
7
6
5
4
3
2
1
0
PTGSE7
PTGSE6
PTGSE5
PTGSE4
PTGSE3
PTGSE2
PTGSE1
PTGSE0
1
1
1
1
1
1
1
1
R
W
Reset:
Figure 6-35. Slew Rate Enable for Port G Register (PTGSE)
Table 6-34. PTGSE Register Field Descriptions
Field
Description
7:0
Output Slew Rate Enable for Port G Bits — Each of these control bits determines if the output slew rate control
PTGSE[7:0] is enabled for the associated PTG pin. For Port G pins that are configured as inputs, these bits have no effect.
0 Output slew rate control disabled for Port G bit n.
1 Output slew rate control enabled for Port G bit n.
MC9S08LG32 MCU Series, Rev. 5
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Chapter 6 Parallel Input/Output Control
6.7.7.5
Port G Drive Strength Selection Register (PTGDS)
7
6
5
4
3
2
1
0
PTGDS7
PTGDS6
PTGDS5
PTGDS4
PTGDS3
PTGDS2
PTGDS1
PTGDS0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-36. Drive Strength Selection for Port G Register (PTGDS)
Table 6-35. PTGDS Register Field Descriptions
Field
Description
7:0
Output Drive Strength Selection for Port G Bits — Each of these control bits selects between low and high
PTGDS[7:0] output drive for the associated PTG pin. For Port G pins that are configured as inputs, these bits have no effect.
0 Low output drive strength selected for Port G bit n.
1 High output drive strength selected for Port G bit n.
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
121
Chapter 6 Parallel Input/Output Control
6.7.8
Port H Registers
Port H is controlled by the registers listed below.
6.7.8.1
Port H Data Register (PTHD)
7
6
5
4
3
2
1
0
PTHD7
PTHD6
PTHD5
PTHD4
PTHD3
PTHD2
PTHD1
PTHD0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-37. Port H Data Register (PTHD)
Table 6-36. PTHD Register Field Descriptions
Field
Description
7:0
PTHD[7:0]
Port H Data Register Bits — For Port H pins that are inputs, reads return the logic level on the pin. For Port H
pins that are configured as outputs, reads return the last value written to this register.
Writes are latched into all bits of this register. For Port H pins that are configured as outputs, the logic level is
driven out the corresponding MCU pin.
Reset forces PTHD to all 0s, but these 0s are not driven out the corresponding pins because reset also configures
all port pins as high-impedance inputs with pullups disabled.
6.7.8.2
Port H Data Direction Register (PTHDD)
7
6
5
4
3
2
1
0
PTHDD7
PTHDD6
PTHDD5
PTHDD4
PTHDD3
PTHDD2
PTHDD1
PTHDD0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-38. Port H Data Direction Register (PTHDD)
Table 6-37. PTHDD Register Field Descriptions
Field
Description
7:0
Data Direction for Port H Bits — These read/write bits control the direction of Port H pins and what is read for
PTHDD[7:0] PTHD reads.
0 Input (output driver disabled) and reads return the pin value.
1 Output driver enabled for Port H bit n and PTHD reads return the contents of PTHDn.
MC9S08LG32 MCU Series, Rev. 5
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Chapter 6 Parallel Input/Output Control
6.7.8.3
Port H Pull Enable Register (PTHPE)
7
6
5
4
3
2
1
0
PTHPE7
PTHPE6
PTHPE5
PTHPE4
PTHPE3
PTHPE2
PTHPE1
PTHPE0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-39. Internal Pull Enable for Port H Register (PTHPE)
Table 6-38. PTHPE Register Field Descriptions
Field
Description
7:0
Internal Pull Enable for Port H Bits — Each of these control bits determines if the internal pullup or pulldown
PTHPE[7:0] device is enabled for the associated PTH pin. For Port H pins that are configured as outputs, these bits have no
effect and the internal pull devices are disabled.
0 Internal pullup device disabled for Port H bit n.
1 Internal pullup device enabled for Port H bit n.
6.7.8.4
Port H Slew Rate Enable Register (PTHSE)
7
6
5
4
3
2
1
0
PTHSE7
PTHSE6
PTHSE5
PTHSE4
PTHSE3
PTHSE2
PTHSE1
PTHSE0
1
1
1
1
1
1
1
1
R
W
Reset:
Figure 6-40. Slew Rate Enable for Port H Register (PTHSE)
Table 6-39. PTHSE Register Field Descriptions
Field
Description
7:0
Output Slew Rate Enable for Port H Bits — Each of these control bits determines if the output slew rate control
PTHSE[7:0] is enabled for the associated PTH pin. For Port H pins that are configured as inputs, these bits have no effect.
0 Output slew rate control disabled for Port H bit n.
1 Output slew rate control enabled for Port H bit n.
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
123
Chapter 6 Parallel Input/Output Control
6.7.8.5
Port H Drive Strength Selection Register (PTHDS)
7
6
5
4
3
2
1
0
PTHDS7
PTHDS6
PTHDS5
PTHDS4
PTHDS3
PTHDS2
PTHDS1
PTHDS0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 6-41. Drive Strength Selection for Port H Register (PTHDS)
Table 6-40. PTHDS Register Field Descriptions
Field
Description
7:0
Output Drive Strength Selection for Port H Bits — Each of these control bits selects between low and high
PTHDS[7:0] output drive for the associated PTH pin. For Port H pins that are configured as inputs, these bits have no effect.
0 Low output drive strength selected for Port H bit n.
1 High output drive strength selected for Port H bit n.
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Chapter 6 Parallel Input/Output Control
6.7.9
Port I Registers
The following registers control the Port 1.
6.7.9.1
R
Port I Data Register (PTID)
7
6
0
0
5
4
3
2
1
0
PTID5
PTID4
PTID3
PTID2
PTID1
PTID0
0
0
0
0
0
0
W
Reset:
0
0
Figure 6-42. Port I Data Register (PTID)
Table 6-41. PTID Register Field Descriptions
Field
Description
5:0
PTID[5:0]
Port I Data Register Bits — For Port I pins that are inputs, reads return the logic level on the pin. For Port I pins
that are configured as outputs, reads return the last value written to this register.
Writes are latched into all bits of this register. For Port I pins that are configured as outputs, the logic level is driven
out the corresponding MCU pin.
Reset forces PTID to all 0s, but these 0s are not driven out the corresponding pins because reset also configures
all port pins as high-impedance inputs with pullups disabled.
6.7.9.2
R
Port I Data Direction Register (PTIDD)
7
6
0
0
5
4
3
2
1
0
PTIDD5
PTIDD4
PTIDD3
PTIDD2
PTIDD1
PTIDD0
0
0
0
0
0
0
W
Reset:
0
0
Figure 6-43. Port I Data Direction Register (PTIDD)
Table 6-42. PTIDD Register Field Descriptions
Field
5:0
PTIDD[5:0]
Description
Data Direction for Port I Bits — These read/write bits control the direction of Port I pins and what is read for
PTID reads.
0 Input (output driver disabled) and reads return the pin value.
1 Output driver enabled for Port I bit n and PTID reads return the contents of PTIDn.
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
125
Chapter 6 Parallel Input/Output Control
6.7.9.3
R
Port I Pull Enable Register (PTIPE)
7
6
0
0
5
4
3
2
1
0
PTIPE5
PTIPE4
PTIPE3
PTIPE2
PTIPE1
PTIPE0
0
0
0
0
0
0
W
Reset:
0
0
Figure 6-44. Internal Pull Enable for Port I Register (PTIPE)
Table 6-43. PTIPE Register Field Descriptions
Field
5:0
PTIPE[5:0]
6.7.9.4
R
Description
Internal Pull Enable for Port I Bits — Each of these control bits determines if the internal pullup or pulldown
device is enabled for the associated PTI pin. For Port I pins that are configured as outputs, these bits have no
effect and the internal pull devices are disabled.
0 Internal pullup device disabled for Port I bit n.
1 Internal pullup device enabled for Port I bit n.
Port I Slew Rate Enable Register (PTISE)
7
6
0
0
5
4
3
2
1
0
PTISE5
PTISE4
PTISE3
PTISE2
PTISE1
PTISE0
1
1
1
1
1
1
W
Reset:
0
0
Figure 6-45. Slew Rate Enable for Port I Register (PTISE)
Table 6-44. PTISE Register Field Descriptions
Field
Description
5:0
PTISE[6:0]
Output Slew Rate Enable for Port I Bits — Each of these control bits determines if the output slew rate control
is enabled for the associated PTI pin. For Port I pins that are configured as inputs, these bits have no effect.
0 Output slew rate control disabled for Port I bit n.
1 Output slew rate control enabled for Port I bit n.
MC9S08LG32 MCU Series, Rev. 5
126
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Chapter 6 Parallel Input/Output Control
6.7.9.5
R
Port I Drive Strength Selection Register (PTIDS)
7
6
0
0
5
4
3
2
1
0
PTIDS5
PTIDS4
PTIDS3
PTIDS2
PTIDS1
PTIDS0
0
0
0
0
0
0
W
Reset:
0
0
Figure 6-46. Drive Strength Selection for Port I Register (PTIDS)
Table 6-45. PTIDS Register Field Descriptions
Field
7:0
PTIDS[7:0]
Description
Output Drive Strength Selection for Port I Bits — Each of these control bits selects between low and high
output drive for the associated PTI pin. For Port I pins that are configured as inputs, these bits have no effect.
0 Low output drive strength selected for Port I bit n.
1 High output drive strength selected for Port I bit n.
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Chapter 7
Keyboard Interrupt (S08KBIV2)
7.1
Introduction
The keyboard interrupt KBI module provides up to eight independently-enabled, external interrupt
sources.
7.1.1
Module Configuration
The KBI module pins, KBIn can be repositioned under software control using KBI0, KBI1, KBI2, KBI3,
KBI4, KBI5, KBI6, and KBI7 bits in PINPS1 register as shown in Table 7-1. KBI0, KBI1, KBI2, KBI3,
KBI4, KBI5, KBI6, and KBI7 bits in PINPS1 register selects which general-purpose I/O ports are
associated with KBI operation.
Table 7-1. KBI Position Options
KBIn in PINPS1
Port Pin for KBI7
Port Pin for KBI6
Port Pin for KBI5
Port Pin for KBI4
0 (default)
PTA6
PTA5
PTA4
PTA3
1
PTH3
PTH2
PTH1
PTH0
KBIn in PINPS1
Port Pin for KBI3
Port Pin for KBI2
Port Pin for KBI1
Port Pin for KBI0
0 (default)
PTF0
PTF5
PTF4
PTF3
1
PTH5
PTH4
PTH7
PTH6
7.1.2
KBI Clock Gating
The bus clock to the KBI can be gated on and off using the KBI bit in SCGC2. This bit is clear after any
reset, which disables the bus clock to this module. To conserve power, this bit can be cleared to disable the
clock to this module when not in use. For more details, see Section 5.7, “Peripheral Clock Gating.”
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Chapter 7 Keyboard Interrupt (S08KBIV2)
8-BIT KEYBOARD
INTERRUPT (KBI)
RESET
IRQ
SERIAL PERIPHERAL
INTERFACE (SPI)
KBI[7:0]
SS
SPSCK
MISO
RESET/PTC6
BKGD/MS/PTC5
LCD[20:16]/PTC[4:0]
MOSI
SCL
IIC MODULE (IIC)
USER FLASH A
(LG32 = 16K BYTES)
(LG16 = 2K BYTES)
6-CHANNEL TIMER/PWM
(TPM2)
USER FLASH B
(LG32 = 16K BYTES)
(LG16 = 16K BYTES)
2-CHANNEL TIMER/PWM
(TPM1)
SERIAL COMMUNICATIONS
INTERFACE (SCI1)
USER RAM
SDA
TPM2CH[5:0]
TPMCLK
PORT D
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
LVD
LCD[40:37]/PTB[7:4]
LCD[32:29]/PTB[3:0]
TMRCLK
LCD[7:0]/PTD[7:0]
PORT E
Modulo Timer
(MTIM)
IRQ
PORT A
Real Time Counter
(RTC)
HCS08 SYSTEM CONTROL
COP
PORT B
BKGD/MS
LCD[15:8]/PTE[7:0]
TPM1CH[1:0]
PORT F
BKP
EXTAL/PTF7
XTAL/PTF6
TPM2CH3/KBI2/MOSI/PTF5
TPM2CH4/KBI1/MISO/PTF4
TPM2CH5/KBI0/SS/PTF3
ADC14/IRQ/TPM1CH1/SPSCK/PTF2
ADC13/TPM1CH0/RX1/PTF1
ADC12/TPM2CH2/KBI3/TX1/PTF0
PORT G
BKGD
LCD[44:41]/PTG[7:4]
LCD[36:33]/PTG[3:0]
PORT H
INT
ON-CHIP ICE (ICE) and
DEBUG MODULE (DBG)
TPM2CH4/KBI1/PTH7
ADC15/KBI0/TPM2CH5/PTH6
ADC11/TPM1CH0/KBI3/TX1/PTH5
ADC10/TPM1CH1/KBI2/RX1/PTH4
ADC[9:6]/KBI[7:4]/PTH[3:0]
PORT I
CPU
LCD28/ADC5/TPMCLK/PTA7
LCD27/ADC4/TPM2CH1/KBI7/PTA6
LCD26/ADC3/TPM2CH0/KBI6/PTA5
LCD25/ADC2/RX2/KBI5/PTA4
LCD24/ADC1/TX2/KBI4/PTA3
LCD23/ADC0/SDA/PTA2
LCD22/SCL/PTA1
LCD21/PTA0
PORT C
HCS08 CORE
SS/SCL/TPM2CH0/PTI5
SPSCK/SDA/TPM2CH1/PTI4
MOSI/TPM2CH2/PTI3
MISO/TPM2CH3/PTI2
TX2/TMRCLK/PTI1
RX2/PTI0
TPMCLK
TxD1
RxD1
1984 BYTES
SERIAL COMMUNICATIONS
INTERFACE (SCI2)
INTERNAL CLOCK
Source (ICS)
TxD2
RxD2
XTAL
LOW-POWER OSCILLATOR
12-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
VLL3_2
VLL3
VLL1
VLL2
VCAP1
EXTAL
AD[15:0]
LIQUID CRYSTAL
DISPLAY DRIVER
(LCD)
VCAP2
LCD[44:0]
VDD
VSS
VSS2
VDDA/VREFH
VSSA/VREFL
VOLTAGE
REGULATOR
Available only on 80-pin package
Available only on 64-pin and 80-pin package
*/Default function out of reset/*
Figure 7-1. MC9S08LG32 Series Block Diagram Highlighting KBI Block and Pins
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Chapter 7 Keyboard Interrupt (S08KBIV2)
7.1.3
Features
The KBI features include:
• Up to eight keyboard interrupt pins with individual pin enable bits.
• Each keyboard interrupt pin is programmable as falling edge (or rising edge) only, or both falling
edge and low level (or both rising edge and high level) interrupt sensitivity.
• One software enabled keyboard interrupt.
• Exit from low-power modes.
7.1.4
Modes of Operation
This section defines the KBI operation in wait, stop, and background debug modes.
7.1.4.1
KBI in Wait Mode
The KBI continues to operate in wait mode if enabled before executing the WAIT instruction. Therefore,
an enabled KBI pin (KBPEx = 1) can be used to bring the MCU out of wait mode if the KBI interrupt is
enabled (KBIE = 1).
7.1.4.2
KBI in Stop Modes
The KBI operates asynchronously in stop3 mode if enabled before executing the STOP instruction.
Therefore, an enabled KBI pin (KBPEx = 1) can be used to bring the MCU out of stop3 mode if the KBI
interrupt is enabled (KBIE = 1).
During stop2 mode, the KBI is disabled. In some systems, the pins associated with the KBI may be sources
of wakeup from stop2, see the stop modes section in the Chapter 3, “Modes of Operation.” Upon wakeup
from stop2 mode, the KBI module will be in the reset state.
7.1.4.3
KBI in Active Background Mode
When the microcontroller is in active background mode, the KBI will continue to operate normally.
7.1.5
Block Diagram
The block diagram for the keyboard interrupt module is shown Figure 7-2.
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Chapter 7 Keyboard Interrupt (S08KBIV2)
BUSCLK
KBACK
VDD
1
KBIP0
0
S
RESET
KBF
D CLR Q
KBIPE0
SYNCHRONIZER
CK
KBEDG0
KEYBOARD
INTERRUPT FF
1
KBIPn
0
S
STOP
STOP BYPASS
KBI
INTERRUPT
REQUEST
KBMOD
KBIPEn
KBIE
KBEDGn
Figure 7-2. KBI Block Diagram
7.2
External Signal Description
The KBI input pins can be used to detect either falling edges, or both falling edge and low level interrupt
requests. The KBI input pins can also be used to detect either rising edges, or both rising edge and high
level interrupt requests.
The signal properties of KBI are shown in Table 7-2.
Table 7-2. Signal Properties
Signal
KBIPn
7.3
Function
Keyboard interrupt pins
I/O
I
Register Definition
The KBI includes three registers:
• An 8-bit pin status and control register.
• An 8-bit pin enable register.
• An 8-bit edge select register.
Refer to the direct-page register summary in Chapter 4, “Memory,” for the absolute address assignments
for all KBI registers. This section refers to registers and control bits only by their names.
Some MCUs may have more than one KBI, so register names include placeholder characters to identify
which KBI is being referenced.
7.3.1
KBI Status and Control Register (KBISC)
KBISC contains the status flag and control bits, which are used to configure the KBI.
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Chapter 7 Keyboard Interrupt (S08KBIV2)
R
7
6
5
4
3
2
0
0
0
0
KBF
0
W
Reset:
1
0
KBIE
KBMOD
0
0
KBACK
0
0
0
0
0
0
= Unimplemented
Figure 7-3. KBI Status and Control Register
Table 7-3. KBISC Register Field Descriptions
Field
Description
7:4
Unused register bits, always read 0.
3
KBF
Keyboard Interrupt Flag — KBF indicates when a keyboard interrupt is detected. Writes have no effect on KBF.
0 No keyboard interrupt detected.
1 Keyboard interrupt detected.
2
KBACK
Keyboard Acknowledge — Writing a 1 to KBACK is part of the flag clearing mechanism. KBACK always reads
as 0.
1
KBIE
Keyboard Interrupt Enable — KBIE determines whether a keyboard interrupt is requested.
0 Keyboard interrupt request not enabled.
1 Keyboard interrupt request enabled.
0
KBMOD
7.3.2
Keyboard Detection Mode — KBMOD (along with the KBEDG bits) controls the detection mode of the keyboard
interrupt pins.
0 Keyboard detects edges only.
1 Keyboard detects both edges and levels.
KBI Pin Enable Register (KBIPE)
KBIPE contains the pin enable control bits.
7
6
5
4
3
2
1
0
KBIPE7
KBIPE6
KBIPE5
KBIPE4
KBIPE3
KBIPE2
KBIPE1
KBIPE0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 7-4. KBI Pin Enable Register
Table 7-4. KBIPE Register Field Descriptions
Field
7:0
KBIPEn
7.3.3
Description
Keyboard Pin Enables — Each of the KBIPEn bits enable the corresponding keyboard interrupt pin.
0 Pin not enabled as keyboard interrupt.
1 Pin enabled as keyboard interrupt.
KBI Edge Select Register (KBIES)
KBIES contains the edge select control bits.
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Chapter 7 Keyboard Interrupt (S08KBIV2)
7
6
5
4
3
2
1
0
KBEDG7
KBEDG6
KBEDG5
KBEDG4
KBEDG3
KBEDG2
KBEDG1
KBEDG0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 7-5. KBI Edge Select Register
Table 7-5. KBIES Register Field Descriptions
Field
7:0
KBEDGn
7.4
Description
Keyboard Edge Selects — Each of the KBEDGn bits selects the falling edge/low level or rising edge/high level
function of the corresponding pin).
0 Falling edge/low level.
1 Rising edge/high level.
Functional Description
This on-chip peripheral module is called a keyboard interrupt (KBI) module because originally it was
designed to simplify the connection and use of row-column matrices of keyboard switches. However, these
inputs are also useful as extra external interrupt inputs and as an external means of waking the MCU from
stop or wait low-power modes.
The KBI module allows up to eight pins to act as additional interrupt sources. Writing to the KBIPEn bits
in the keyboard interrupt pin enable register (KBIPE) independently enables or disables each KBI pin.
Each KBI pin can be configured as edge sensitive or edge and level sensitive based on the KBMOD bit in
the keyboard interrupt status and control register (KBISC). Edge sensitive can be software programmed to
be either falling or rising; the level can be either low or high. The polarity of the edge or edge and level
sensitivity is selected using the KBEDGn bits in the keyboard interrupt edge select register (KBIES).
Synchronous logic is used to detect edges. Prior to detecting an edge, enabled keyboard inputs must be at
the deasserted logic level. A falling edge is detected when an enabled keyboard input signal is seen as a
logic 1 (the deasserted level) during one bus cycle and then a logic 0 (the asserted level) during the next
cycle. A rising edge is detected when the input signal is seen as a logic 0 during one bus cycle and then a
logic 1 during the next cycle.
7.4.1
Edge Only Sensitivity
A valid edge on an enabled KBI pin will set KBF in KBISC. If KBIE in KBISC is set, an interrupt request
will be presented to the CPU. Clearing of KBF is accomplished by writing a 1 to KBACK in KBISC.
7.4.2
Edge and Level Sensitivity
A valid edge or level on an enabled KBI pin will set KBF in KBISC. If KBIE in KBISC is set, an interrupt
request will be presented to the CPU. Clearing of KBF is accomplished by writing a 1 to KBACK in
KBISC provided all enabled keyboard inputs are at their deasserted levels. KBF will remain set if any
enabled KBI pin is asserted while attempting to clear by writing a 1 to KBACK.
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Chapter 7 Keyboard Interrupt (S08KBIV2)
7.4.3
KBI Pullup/Pulldown Resistors
The KBI pins can be configured to use an internal pullup/pulldown resistor using the associated I/O port
pullup enable register. If an internal resistor is enabled, the KBIES register is used to select whether the
resistor is a pullup (KBEDGn = 0) or a pulldown (KBEDGn = 1).
7.4.4
KBI Initialization
When a keyboard interrupt pin is first enabled it is possible to get a false keyboard interrupt flag. To
prevent a false interrupt request during keyboard initialization, the user must do the following:
1. Mask keyboard interrupts by clearing KBIE in KBISC.
2. Enable the KBI polarity by setting the appropriate KBEDGn bits in KBIES.
3. If using internal pullup/pulldown device, configure the associated pullup enable bits in PTxPE.
4. Enable the KBI pins by setting the appropriate KBIPEn bits in KBIPE.
5. Write to KBACK in KBISC to clear any false interrupts.
6. Set KBIE in KBISC to enable interrupts.
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Chapter 8
Central Processor Unit (S08CPUV5)
8.1
Introduction
This section provides summary information about the registers, addressing modes, and instruction set of
the CPU of the HCS08 Family. For a more detailed discussion, refer to the HCS08 Family Reference
Manual, volume 1, Freescale Semiconductor document order number HCS08RMV1/D.
The HCS08 CPU is fully source- and object-code-compatible with the M68HC08 CPU. Several
instructions and enhanced addressing modes were added to improve C compiler efficiency and to support
a new background debug system which replaces the monitor mode of earlier M68HC08 microcontrollers
(MCU).
8.1.1
Features
Features of the HCS08 CPU include:
• Object code fully upward-compatible with M68HC05 and M68HC08 Families
• All registers and memory are mapped to a single 64 KB address space
• 16-bit stack pointer (any size stack anywhere in 64 KB CPU address space)
• 16-bit index register (H:X) with powerful indexed addressing modes
• 8-bit accumulator (A)
• Many instructions treat X as a second general-purpose 8-bit register
• Seven addressing modes:
— Inherent — Operands in internal registers
— Relative — 8-bit signed offset to branch destination
— Immediate — Operand in next object code byte(s)
— Direct — Operand in memory at 0x0000–0x00FF
— Extended — Operand anywhere in 64 KB address space
— Indexed relative to H:X — Five submodes including auto increment
— Indexed relative to SP — Improves C efficiency dramatically
• Memory-to-memory data move instructions with four address mode combinations
• Overflow, half-carry, negative, zero, and carry condition codes support conditional branching on
the results of signed, unsigned, and binary-coded decimal (BCD) operations
• Efficient bit manipulation instructions
• Fast 8-bit by 8-bit multiply and 16-bit by 8-bit divide instructions
• Stop and Wait instructions to invoke low-power operating modes
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8.2
Programmer’s Model and CPU Registers
Figure 8-1 shows the five CPU registers. CPU registers are not part of the memory map.
7
0
ACCUMULATOR
A
16-BIT INDEX REGISTER H:X
H INDEX REGISTER (HIGH)
8
15
INDEX REGISTER (LOW)
7
X
0
SP
STACK POINTER
0
15
PROGRAM COUNTER
7
0
CONDITION CODE REGISTER V 1 1 H I N Z C
PC
CCR
CARRY
ZERO
NEGATIVE
INTERRUPT MASK
HALF-CARRY (FROM BIT 3)
TWO’S COMPLEMENT OVERFLOW
Figure 8-1. CPU Registers
8.2.1
Accumulator (A)
The A accumulator is a general-purpose 8-bit register. One operand input to the arithmetic logic unit
(ALU) is connected to the accumulator and the ALU results are often stored into the A accumulator after
arithmetic and logical operations. The accumulator can be loaded from memory using various addressing
modes to specify the address where the loaded data comes from, or the contents of A can be stored to
memory using various addressing modes to specify the address where data from A will be stored.
Reset has no effect on the contents of the A accumulator.
8.2.2
Index Register (H:X)
This 16-bit register is actually two separate 8-bit registers (H and X), which often work together as a 16-bit
address pointer where H holds the upper byte of an address and X holds the lower byte of the address. All
indexed addressing mode instructions use the full 16-bit value in H:X as an index reference pointer;
however, for compatibility with the earlier M68HC05 Family, some instructions operate only on the
low-order 8-bit half (X).
Many instructions treat X as a second general-purpose 8-bit register that can be used to hold 8-bit data
values. X can be cleared, incremented, decremented, complemented, negated, shifted, or rotated. Transfer
instructions allow data to be transferred from A or transferred to A where arithmetic and logical operations
can then be performed.
For compatibility with the earlier M68HC05 Family, H is forced to 0x00 during reset. Reset has no effect
on the contents of X.
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Chapter 8 Central Processor Unit (S08CPUV5)
8.2.3
Stack Pointer (SP)
This 16-bit address pointer register points at the next available location on the automatic last-in-first-out
(LIFO) stack. The stack may be located anywhere in the 64 KB address space that has RAM and can be
any size up to the amount of available RAM. The stack is used to automatically save the return address for
subroutine calls, the return address and CPU registers during interrupts, and for local variables. The AIS
(add immediate to stack pointer) instruction adds an 8-bit signed immediate value to SP. This is most often
used to allocate or deallocate space for local variables on the stack.
SP is forced to 0x00FF at reset for compatibility with the earlier M68HC05 Family. HCS08 programs
normally change the value in SP to the address of the last location (highest address) in on-chip RAM
during reset initialization to free up direct page RAM (from the end of the on-chip registers to 0x00FF).
The RSP (reset stack pointer) instruction was included for compatibility with the M68HC05 Family and
is seldom used in new HCS08 programs because it only affects the low-order half of the stack pointer.
8.2.4
Program Counter (PC)
The program counter is a 16-bit register that contains the address of the next instruction or operand to be
fetched.
During normal program execution, the program counter automatically increments to the next sequential
memory location every time an instruction or operand is fetched. Jump, branch, interrupt, and return
operations load the program counter with an address other than that of the next sequential location. This
is called a change-of-flow.
During reset, the program counter is loaded with the reset vector that is located at 0xFFFE and 0xFFFF.
The vector stored there is the address of the first instruction that will be executed after exiting the reset
state.
8.2.5
Condition Code Register (CCR)
The 8-bit condition code register contains the interrupt mask (I) and five flags that indicate the results of
the instruction just executed. Bits 6 and 5 are set permanently to 1. The following paragraphs describe the
functions of the condition code bits in general terms. For a more detailed explanation of how each
instruction sets the CCR bits, refer to the HCS08 Family Reference Manual, volume 1, Freescale
Semiconductor document order number HCS08RMv1.
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Chapter 8 Central Processor Unit (S08CPUV5)
7
0
CONDITION CODE REGISTER V 1 1 H I N Z C
CCR
CARRY
ZERO
NEGATIVE
INTERRUPT MASK
HALF-CARRY (FROM BIT 3)
TWO’S COMPLEMENT OVERFLOW
Figure 8-2. Condition Code Register
Table 8-1. CCR Register Field Descriptions
Field
Description
7
V
Two’s Complement Overflow Flag — The CPU sets the overflow flag when a two’s complement overflow occurs.
The signed branch instructions BGT, BGE, BLE, and BLT use the overflow flag.
0 No overflow
1 Overflow
4
H
Half-Carry Flag — The CPU sets the half-carry flag when a carry occurs between accumulator bits 3 and 4 during
an add-without-carry (ADD) or add-with-carry (ADC) operation. The half-carry flag is required for binary-coded
decimal (BCD) arithmetic operations. The DAA instruction uses the states of the H and C condition code bits to
automatically add a correction value to the result from a previous ADD or ADC on BCD operands to correct the
result to a valid BCD value.
0 No carry between bits 3 and 4
1 Carry between bits 3 and 4
3
I
Interrupt Mask Bit — When the interrupt mask is set, all maskable CPU interrupts are disabled. CPU interrupts
are enabled when the interrupt mask is cleared. When a CPU interrupt occurs, the interrupt mask is set
automatically after the CPU registers are saved on the stack, but before the first instruction of the interrupt service
routine is executed.
Interrupts are not recognized at the instruction boundary after any instruction that clears I (CLI or TAP). This
ensures that the next instruction after a CLI or TAP will always be executed without the possibility of an intervening
interrupt, provided I was set.
0 Interrupts enabled
1 Interrupts disabled
2
N
Negative Flag — The CPU sets the negative flag when an arithmetic operation, logic operation, or data
manipulation produces a negative result, setting bit 7 of the result. Simply loading or storing an 8-bit or 16-bit value
causes N to be set if the most significant bit of the loaded or stored value was 1.
0 Non-negative result
1 Negative result
1
Z
Zero Flag — The CPU sets the zero flag when an arithmetic operation, logic operation, or data manipulation
produces a result of 0x00 or 0x0000. Simply loading or storing an 8-bit or 16-bit value causes Z to be set if the
loaded or stored value was all 0s.
0 Non-zero result
1 Zero result
0
C
Carry/Borrow Flag — The CPU sets the carry/borrow flag when an addition operation produces a carry out of bit
7 of the accumulator or when a subtraction operation requires a borrow. Some instructions — such as bit test and
branch, shift, and rotate — also clear or set the carry/borrow flag.
0 No carry out of bit 7
1 Carry out of bit 7
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Chapter 8 Central Processor Unit (S08CPUV5)
8.3
Addressing Modes
Addressing modes define the way the CPU accesses operands and data. In the HCS08, memory, status and
control registers, and input/output (I/O) ports share a single 64 KB CPU address space. This arrangement
means that the same instructions that access variables in RAM can also be used to access I/O and control
registers or nonvolatile program space.
Some instructions use more than one addressing mode. For instance, move instructions use one addressing
mode to specify the source operand and a second addressing mode to specify the destination address.
Instructions such as BRCLR, BRSET, CBEQ, and DBNZ use one addressing mode to specify the location
of an operand for a test and then use relative addressing mode to specify the branch destination address
when the tested condition is true. For BRCLR, BRSET, CBEQ, and DBNZ, the addressing mode listed in
the instruction set tables is the addressing mode needed to access the operand to be tested, and relative
addressing mode is implied for the branch destination.
8.3.1
Inherent Addressing Mode (INH)
In this addressing mode, operands needed to complete the instruction (if any) are located within CPU
registers so the CPU does not need to access memory to get any operands.
8.3.2
Relative Addressing Mode (REL)
Relative addressing mode is used to specify the destination location for branch instructions. A signed 8-bit
offset value is located in the memory location immediately following the opcode. During execution, if the
branch condition is true, the signed offset is sign-extended to a 16-bit value and is added to the current
contents of the program counter, which causes program execution to continue at the branch destination
address.
8.3.3
Immediate Addressing Mode (IMM)
In immediate addressing mode, the operand needed to complete the instruction is included in the object
code immediately following the instruction opcode in memory. In the case of a 16-bit immediate operand,
the high-order byte is located in the next memory location after the opcode, and the low-order byte is
located in the next memory location after that.
8.3.4
Direct Addressing Mode (DIR)
In direct addressing mode, the instruction includes the low-order eight bits of an address in the direct page
(0x0000–0x00FF). During execution a 16-bit address is formed by concatenating an implied 0x00 for the
high-order half of the address and the direct address from the instruction to get the 16-bit address where
the desired operand is located. This is faster and more memory efficient than specifying a complete 16-bit
address for the operand.
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8.3.5
Extended Addressing Mode (EXT)
In extended addressing mode, the full 16-bit address of the operand is located in the next two bytes of
program memory after the opcode (high byte first).
8.3.6
Indexed Addressing Mode
Indexed addressing mode has seven variations including five that use the 16-bit H:X index register pair
and two that use the stack pointer as the base reference.
8.3.6.1
Indexed, No Offset (IX)
This variation of indexed addressing uses the 16-bit value in the H:X index register pair as the address of
the operand needed to complete the instruction.
8.3.6.2
Indexed, No Offset with Post Increment (IX+)
This variation of indexed addressing uses the 16-bit value in the H:X index register pair as the address of
the operand needed to complete the instruction. The index register pair is then incremented
(H:X = H:X + 0x0001) after the operand has been fetched. This addressing mode is only used for MOV
and CBEQ instructions.
8.3.6.3
Indexed, 8-Bit Offset (IX1)
This variation of indexed addressing uses the 16-bit value in the H:X index register pair plus an unsigned
8-bit offset included in the instruction as the address of the operand needed to complete the instruction.
8.3.6.4
Indexed, 8-Bit Offset with Post Increment (IX1+)
This variation of indexed addressing uses the 16-bit value in the H:X index register pair plus an unsigned
8-bit offset included in the instruction as the address of the operand needed to complete the instruction.
The index register pair is then incremented (H:X = H:X + 0x0001) after the operand has been fetched. This
addressing mode is used only for the CBEQ instruction.
8.3.6.5
Indexed, 16-Bit Offset (IX2)
This variation of indexed addressing uses the 16-bit value in the H:X index register pair plus a 16-bit offset
included in the instruction as the address of the operand needed to complete the instruction.
8.3.6.6
SP-Relative, 8-Bit Offset (SP1)
This variation of indexed addressing uses the 16-bit value in the stack pointer (SP) plus an unsigned 8-bit
offset included in the instruction as the address of the operand needed to complete the instruction.
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8.3.6.7
SP-Relative, 16-Bit Offset (SP2)
This variation of indexed addressing uses the 16-bit value in the stack pointer (SP) plus a 16-bit offset
included in the instruction as the address of the operand needed to complete the instruction.
8.4
Special Operations
The CPU performs a few special operations that are similar to instructions but do not have opcodes like
other CPU instructions. In addition, a few instructions such as STOP and WAIT directly affect other MCU
circuitry. This section provides additional information about these operations.
8.4.1
Reset Sequence
Reset can be caused by a power-on-reset (POR) event, internal conditions such as the COP (computer
operating properly) watchdog, or by assertion of an external active-low reset pin. When a reset event
occurs, the CPU immediately stops whatever it is doing (the MCU does not wait for an instruction
boundary before responding to a reset event). For a more detailed discussion about how the MCU
recognizes resets and determines the source, refer to Chapter 5, “Resets, Interrupts, and General System
Control.”
The reset event is considered concluded when the sequence to determine whether the reset came from an
internal source is done and when the reset pin is no longer asserted. At the conclusion of a reset event, the
CPU performs a 6-cycle sequence to fetch the reset vector from 0xFFFE and 0xFFFF and to fill the
instruction queue in preparation for execution of the first program instruction.
8.4.2
Interrupt Sequence
When an interrupt is requested, the CPU completes the current instruction before responding to the
interrupt. At this point, the program counter is pointing at the start of the next instruction, which is where
the CPU should return after servicing the interrupt. The CPU responds to an interrupt by performing the
same sequence of operations as for a software interrupt (SWI) instruction, except the address used for the
vector fetch is determined by the highest priority interrupt that is pending when the interrupt sequence
started.
The CPU sequence for an interrupt is:
1. Store the contents of PCL, PCH, X, A, and CCR on the stack, in that order.
2. Set the I bit in the CCR.
3. Fetch the high-order half of the interrupt vector.
4. Fetch the low-order half of the interrupt vector.
5. Delay for one free bus cycle.
6. Fetch three bytes of program information starting at the address indicated by the interrupt vector
to fill the instruction queue in preparation for execution of the first instruction in the interrupt
service routine.
After the CCR contents are pushed onto the stack, the I bit in the CCR is set to prevent other interrupts
while in the interrupt service routine. Although it is possible to clear the I bit with an instruction in the
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interrupt service routine, this would allow nesting of interrupts (which is not recommended because it
leads to programs that are difficult to debug and maintain).
For compatibility with the earlier M68HC05 MCUs, the high-order half of the H:X index register pair (H)
is not saved on the stack as part of the interrupt sequence. The user must use a PSHH instruction at the
beginning of the service routine to save H and then use a PULH instruction just before the RTI that ends
the interrupt service routine. It is not necessary to save H if you are certain that the interrupt service routine
does not use any instructions or auto-increment addressing modes that might change the value of H.
The software interrupt (SWI) instruction is like a hardware interrupt except that it is not masked by the
global I bit in the CCR and it is associated with an instruction opcode within the program so it is not
asynchronous to program execution.
8.4.3
Wait Mode Operation
The WAIT instruction enables interrupts by clearing the I bit in the CCR. It then halts the clocks to the
CPU to reduce overall power consumption while the CPU is waiting for the interrupt or reset event that
will wake the CPU from wait mode. When an interrupt or reset event occurs, the CPU clocks will resume
and the interrupt or reset event will be processed normally.
If a serial BACKGROUND command is issued to the MCU through the background debug interface while
the CPU is in wait mode, CPU clocks will resume and the CPU will enter active background mode where
other serial background commands can be processed. This ensures that a host development system can still
gain access to a target MCU even if it is in wait mode.
8.4.4
Stop Mode Operation
Usually, all system clocks, including the crystal oscillator (when used), are halted during stop mode to
minimize power consumption. In such systems, external circuitry is needed to control the time spent in
stop mode and to issue a signal to wake up the target MCU when it is time to resume processing. Unlike
the earlier M68HC05 and M68HC08 MCUs, the HCS08 can be configured to keep a minimum set of
clocks running in stop mode. This optionally allows an internal periodic signal to wake the target MCU
from stop mode.
When a host debug system is connected to the background debug pin (BKGD) and the ENBDM control
bit has been set by a serial command through the background interface (or because the MCU was reset into
active background mode), the oscillator is forced to remain active when the MCU enters stop mode. In this
case, if a serial BACKGROUND command is issued to the MCU through the background debug interface
while the CPU is in stop mode, CPU clocks will resume and the CPU will enter active background mode
where other serial background commands can be processed. This ensures that a host development system
can still gain access to a target MCU even if it is in stop mode.
Recovery from stop mode depends on the particular HCS08 and whether the oscillator was stopped in stop
mode. Refer to Chapter 3, “Modes of Operation,” for more details.
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8.4.5
BGND Instruction
The BGND instruction is new to the HCS08 compared to the M68HC08. BGND would not be used in
normal user programs because it forces the CPU to stop processing user instructions and enter the active
background mode. The only way to resume execution of the user program is through reset or by a host
debug system issuing a GO, TRACE1, or TAGGO serial command through the background debug
interface.
Software-based breakpoints can be set by replacing an opcode at the desired breakpoint address with the
BGND opcode. When the program reaches this breakpoint address, the CPU is forced to active
background mode rather than continuing the user program.
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8.5
HCS08 Instruction Set Summary
Instruction Set Summary Nomenclature
The nomenclature listed here is used in the instruction descriptions in Figure 8-2.
Operators
( ) = Contents of register or memory location shown inside parentheses
← = Is loaded with (read: “gets”)
& = Boolean AND
| = Boolean OR
⊕ = Boolean exclusive-OR
× = Multiply
÷ = Divide
: = Concatenate
+ = Add
– = Negate (two’s complement)
CPU registers
A = Accumulator
CCR = Condition code register
H = Index register, higher order (most significant) 8 bits
X = Index register, lower order (least significant) 8 bits
PC = Program counter
PCH = Program counter, higher order (most significant) 8 bits
PCL = Program counter, lower order (least significant) 8 bits
SP = Stack pointer
Memory and addressing
M = A memory location or absolute data, depending on addressing mode
M:M + 0x0001= A 16-bit value in two consecutive memory locations. The higher-order (most
significant) 8 bits are located at the address of M, and the lower-order (least
significant) 8 bits are located at the next higher sequential address.
Condition code register (CCR) bits
V = Two’s complement overflow indicator, bit 7
H = Half carry, bit 4
I = Interrupt mask, bit 3
N = Negative indicator, bit 2
Z = Zero indicator, bit 1
C = Carry/borrow, bit 0 (carry out of bit 7)
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CCR activity notation
– = Bit not affected
0 = Bit forced to 0
1 = Bit forced to 1
= Bit set or cleared according to results of operation
U = Undefined after the operation
Machine coding notation
dd = Low-order 8 bits of a direct address 0x0000–0x00FF (high byte assumed to be 0x00)
ee = Upper 8 bits of 16-bit offset
ff = Lower 8 bits of 16-bit offset or 8-bit offset
ii = One byte of immediate data
jj = High-order byte of a 16-bit immediate data value
kk = Low-order byte of a 16-bit immediate data value
hh = High-order byte of 16-bit extended address
ll = Low-order byte of 16-bit extended address
rr = Relative offset
Source form
Everything in the source forms columns, except expressions in italic characters, is literal information that
must appear in the assembly source file exactly as shown. The initial 3- to 5-letter mnemonic is always a
literal expression. All commas, pound signs (#), parentheses, and plus signs (+) are literal characters.
n — Any label or expression that evaluates to a single integer in the range 0–7
opr8i — Any label or expression that evaluates to an 8-bit immediate value
opr16i — Any label or expression that evaluates to a 16-bit immediate value
opr8a — Any label or expression that evaluates to an 8-bit value. The instruction treats this 8-bit
value as the low order 8 bits of an address in the direct page of the 64 KB address space (0x00xx).
opr16a — Any label or expression that evaluates to a 16-bit value. The instruction treats this
value as an address in the 64 KB address space.
oprx8 — Any label or expression that evaluates to an unsigned 8-bit value, used for indexed
addressing
oprx16 — Any label or expression that evaluates to a 16-bit value. Because the HCS08 has a
16-bit address bus, this can be either a signed or an unsigned value.
rel — Any label or expression that refers to an address that is within –128 to +127 locations
from the next address after the last byte of object code for the current instruction. The
assembler will calculate the 8-bit signed offset and include it in the object code for this
instruction.
Address modes
INH = Inherent (no operands)
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IMM = 8-bit or 16-bit immediate
DIR = 8-bit direct
EXT = 16-bit extended
IX = 16-bit indexed no offset
IX+ = 16-bit indexed no offset, post increment (CBEQ and MOV only)
IX1 = 16-bit indexed with 8-bit offset from H:X
IX1+ = 16-bit indexed with 8-bit offset, post increment (CBEQ only)
IX2 = 16-bit indexed with 16-bit offset from H:X
REL = 8-bit relative offset
SP1 = Stack pointer with 8-bit offset
SP2 = Stack pointer with 16-bit offset
Table 8-2 provides a summary of the HCS08 instruction set in all possible addressing modes. The table
shows operand construction, execution time in internal bus clock cycles, and cycle-by-cycle details for
each addressing mode variation of each instruction.
ADC
ADC
ADC
ADC
ADC
ADC
ADC
ADC
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
ADD
ADD
ADD
ADD
ADD
ADD
ADD
ADD
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
Operation
Add with Carry
A ← (A) + (M) + (C)
Add without Carry
A ← (A) + (M)
Object Code
IMM
DIR
EXT
IX2
IX1
IX
SP2
SP1
A9
B9
C9
D9
E9
F9
9E D9
9E E9
ii
dd
hh ll
ee ff
ff
IMM
DIR
EXT
IX2
IX1
IX
SP2
SP1
AB
BB
CB
DB
EB
FB
9E DB
9E EB
ii
dd
hh ll
ee ff
ff
ee ff
ff
ee ff
ff
Cycles
Source
Form
Address
Mode
Table 8-2. Instruction Set Summary (Sheet 1 of 10)
Cyc-by-Cyc
Details
Affect
on CCR
V11H
INZC
2
3
4
4
3
3
5
4
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
Þ 1 1 Þ
– Þ Þ Þ
2
3
4
4
3
3
5
4
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
Þ 1 1 Þ
– Þ Þ Þ
AIS #opr8i
Add Immediate Value (Signed) to
Stack Pointer
SP ← (SP) + (M)
IMM
A7 ii
2
pp
– 1 1 –
– – – –
AIX #opr8i
Add Immediate Value (Signed) to
Index Register (H:X)
H:X ← (H:X) + (M)
IMM
AF ii
2
pp
– 1 1 –
– – – –
Logical AND
A ← (A) & (M)
IMM
DIR
EXT
IX2
IX1
IX
SP2
SP1
2
3
4
4
3
3
5
4
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
0 1 1 –
– Þ Þ –
AND
AND
AND
AND
AND
AND
AND
AND
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
A4
B4
C4
D4
E4
F4
9E D4
9E E4
ii
dd
hh ll
ee ff
ff
ee ff
ff
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Operation
Arithmetic Shift Left
Object Code
Cycles
Source
Form
Address
Mode
Table 8-2. Instruction Set Summary (Sheet 2 of 10)
Cyc-by-Cyc
Details
Affect
on CCR
V11H
INZC
DIR
INH
INH
IX1
IX
SP1
38 dd
48
58
68 ff
78
9E 68 ff
5
1
1
5
4
6
rfwpp
p
p
rfwpp
rfwp
prfwpp
Þ 1 1 –
– Þ Þ Þ
DIR
INH
INH
IX1
IX
SP1
37 dd
47
57
67 ff
77
9E 67 ff
5
1
1
5
4
6
rfwpp
p
p
rfwpp
rfwp
prfwpp
Þ 1 1 –
– Þ Þ Þ
Branch if Carry Bit Clear
(if C = 0)
REL
24 rr
3
ppp
– 1 1 –
– – – –
BCLR n,opr8a
Clear Bit n in Memory
(Mn ← 0)
DIR (b0)
DIR (b1)
DIR (b2)
DIR (b3)
DIR (b4)
DIR (b5)
DIR (b6)
DIR (b7)
11
13
15
17
19
1B
1D
1F
dd
dd
dd
dd
dd
dd
dd
dd
5
5
5
5
5
5
5
5
rfwpp
rfwpp
rfwpp
rfwpp
rfwpp
rfwpp
rfwpp
rfwpp
– 1 1 –
– – – –
BCS rel
Branch if Carry Bit Set (if C = 1)
(Same as BLO)
REL
25 rr
3
ppp
– 1 1 –
– – – –
BEQ rel
Branch if Equal (if Z = 1)
REL
27 rr
3
ppp
– 1 1 –
– – – –
BGE rel
Branch if Greater Than or Equal To
(if N ⊕ V = 0) (Signed)
REL
90 rr
3
ppp
– 1 1 –
– – – –
BGND
Enter active background if ENBDM=1
Waits for and processes BDM
commands until GO, TRACE1, or
TAGGO
INH
82
5+
fp...ppp
– 1 1 –
– – – –
BGT rel
Branch if Greater Than (if Z | (N ⊕ V) = 0)
REL
(Signed)
92 rr
3
ppp
– 1 1 –
– – – –
BHCC rel
Branch if Half Carry Bit Clear (if H = 0)
REL
28 rr
3
ppp
– 1 1 –
– – – –
BHCS rel
Branch if Half Carry Bit Set (if H = 1)
REL
29 rr
3
ppp
– 1 1 –
– – – –
BHI rel
Branch if Higher (if C | Z = 0)
REL
22 rr
3
ppp
– 1 1 –
– – – –
BHS rel
Branch if Higher or Same (if C = 0)
(Same as BCC)
REL
24 rr
3
ppp
– 1 1 –
– – – –
BIH rel
Branch if IRQ Pin High (if IRQ pin = 1)
REL
2F rr
3
ppp
– 1 1 –
– – – –
BIL rel
Branch if IRQ Pin Low (if IRQ pin = 0)
REL
2E rr
3
ppp
– 1 1 –
– – – –
ASL opr8a
ASLA
ASLX
ASL oprx8,X
ASL ,X
ASL oprx8,SP
ASR opr8a
ASRA
ASRX
ASR oprx8,X
ASR ,X
ASR oprx8,SP
BCC rel
C
0
b7
b0
(Same as LSL)
Arithmetic Shift Right
C
b7
b0
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BIT
BIT
BIT
BIT
BIT
BIT
BIT
BIT
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
Operation
Bit Test
(A) & (M)
(CCR Updated but Operands Not
Changed)
IMM
DIR
EXT
IX2
IX1
IX
SP2
SP1
Object Code
A5
B5
C5
D5
E5
F5
9E D5
9E E5
ii
dd
hh ll
ee ff
ff
ee ff
ff
Cycles
Source
Form
Address
Mode
Table 8-2. Instruction Set Summary (Sheet 3 of 10)
Cyc-by-Cyc
Details
Affect
on CCR
V11H
INZC
2
3
4
4
3
3
5
4
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
0 1 1 –
– Þ Þ –
BLE rel
Branch if Less Than or Equal To
(if Z | (N ⊕ V) = 1) (Signed)
REL
93 rr
3
ppp
– 1 1 –
– – – –
BLO rel
Branch if Lower (if C = 1) (Same as
BCS)
REL
25 rr
3
ppp
– 1 1 –
– – – –
BLS rel
Branch if Lower or Same (if C | Z = 1)
REL
23 rr
3
ppp
– 1 1 –
– – – –
BLT rel
Branch if Less Than (if N ⊕ V = 1)
(Signed)
REL
91 rr
3
ppp
– 1 1 –
– – – –
BMC rel
Branch if Interrupt Mask Clear (if I = 0)
REL
2C rr
3
ppp
– 1 1 –
– – – –
BMI rel
Branch if Minus (if N = 1)
REL
2B rr
3
ppp
– 1 1 –
– – – –
BMS rel
Branch if Interrupt Mask Set (if I = 1)
REL
2D rr
3
ppp
– 1 1 –
– – – –
BNE rel
Branch if Not Equal (if Z = 0)
REL
26 rr
3
ppp
– 1 1 –
– – – –
BPL rel
Branch if Plus (if N = 0)
REL
2A rr
3
ppp
– 1 1 –
– – – –
BRA rel
Branch Always (if I = 1)
REL
20 rr
3
ppp
– 1 1 –
– – – –
BRCLR n,opr8a,rel
DIR (b0)
DIR (b1)
DIR (b2)
Branch if Bit n in Memory Clear (if (Mn) DIR (b3)
DIR (b4)
= 0)
DIR (b5)
DIR (b6)
DIR (b7)
01
03
05
07
09
0B
0D
0F
5
5
5
5
5
5
5
5
rpppp
rpppp
rpppp
rpppp
rpppp
rpppp
rpppp
rpppp
– 1 1 –
– – – Þ
BRN rel
Branch Never (if I = 0)
21 rr
3
ppp
– 1 1 –
– – – –
BRSET n,opr8a,rel
DIR (b0)
DIR (b1)
DIR (b2)
DIR (b3)
Branch if Bit n in Memory Set (if (Mn) = 1)
DIR (b4)
DIR (b5)
DIR (b6)
DIR (b7)
00
02
04
06
08
0A
0C
0E
dd
dd
dd
dd
dd
dd
dd
dd
5
5
5
5
5
5
5
5
rpppp
rpppp
rpppp
rpppp
rpppp
rpppp
rpppp
rpppp
– 1 1 –
– – – Þ
DIR (b0)
DIR (b1)
DIR (b2)
DIR (b3)
DIR (b4)
DIR (b5)
DIR (b6)
DIR (b7)
10
12
14
16
18
1A
1C
1E
dd
dd
dd
dd
dd
dd
dd
dd
5
5
5
5
5
5
5
5
rfwpp
rfwpp
rfwpp
rfwpp
rfwpp
rfwpp
rfwpp
rfwpp
– 1 1 –
– – – –
BSET n,opr8a
REL
Set Bit n in Memory (Mn ← 1)
dd
dd
dd
dd
dd
dd
dd
dd
rr
rr
rr
rr
rr
rr
rr
rr
rr
rr
rr
rr
rr
rr
rr
rr
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Operation
Object Code
Cycles
Source
Form
Address
Mode
Table 8-2. Instruction Set Summary (Sheet 4 of 10)
Cyc-by-Cyc
Details
Affect
on CCR
V11H
INZC
BSR rel
Branch to Subroutine
PC ← (PC) + $0002
push (PCL); SP ← (SP) – $0001
push (PCH); SP ← (SP) – $0001
PC ← (PC) + rel
REL
AD rr
5
ssppp
– 1 1 –
– – – –
CALL page, opr16a
Call Subroutine
EXT
AC pg hhll
8
ppsssppp
– 1 1 –
– – – –
CBEQ opr8a,rel
CBEQA #opr8i,rel
CBEQX #opr8i,rel
CBEQ oprx8,X+,rel
CBEQ ,X+,rel
CBEQ oprx8,SP,rel
Compare and...
5
4
4
5
5
6
rpppp
pppp
pppp
rpppp
rfppp
prpppp
– 1 1 –
– – – –
CLC
Clear Carry Bit (C ← 0)
INH
98
1
p
– 1 1 –
– – – 0
CLI
Clear Interrupt Mask Bit (I ← 0)
INH
9A
1
p
– 1 1 –
0 – – –
CLR opr8a
CLRA
CLRX
CLRH
CLR oprx8,X
CLR ,X
CLR oprx8,SP
Clear
DIR
INH
INH
INH
IX1
IX
SP1
3F dd
4F
5F
8C
6F ff
7F
9E 6F ff
5
1
1
1
5
4
6
rfwpp
p
p
p
rfwpp
rfwp
prfwpp
0 1 1 –
– 0 1 –
IMM
DIR
EXT
IX2
IX1
IX
SP2
SP1
A1
B1
C1
D1
E1
F1
9E D1
9E E1
2
3
4
4
3
3
5
4
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
Þ 1 1 –
– Þ Þ Þ
COM opr8a
COMA
COMX
COM oprx8,X
COM ,X
COM oprx8,SP
Complement
M ← (M)= $FF –
(M)
(One’s Complement) A ← (A) = $FF –
(A)
X ← (X) = $FF –
(X)
M ← (M) = $FF –
(M)
M ← (M) = $FF –
(M)
M ← (M) = $FF –
(M)
DIR
INH
INH
IX1
IX
SP1
33 dd
43
53
63 ff
73
9E 63 ff
5
1
1
5
4
6
rfwpp
p
p
rfwpp
rfwp
prfwpp
0 1 1 –
– Þ Þ 1
CPHX opr16a
CPHX #opr16i
CPHX opr8a
CPHX oprx8,SP
Compare Index Register (H:X) with
Memory
(H:X) – (M:M + $0001)
(CCR Updated But Operands Not
Changed)
EXT
IMM
DIR
SP1
3E
65
75
9E F3
6
3
5
6
prrfpp
ppp
rrfpp
prrfpp
Þ 1 1 –
– Þ Þ Þ
CMP
CMP
CMP
CMP
CMP
CMP
CMP
CMP
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
Branch if (A) = (M)
Branch if (A) = (M)
Branch if (X) = (M)
Branch if (A) = (M)
Branch if (A) = (M)
Branch if (A) = (M)
M ← $00
A ← $00
X ← $00
H ← $00
M ← $00
M ← $00
M ← $00
Compare Accumulator with Memory
A–M
(CCR Updated But Operands Not
Changed)
DIR
IMM
IMM
IX1+
IX+
SP1
31
41
51
61
71
9E 61
dd
ii
ii
ff
rr
ff
rr
rr
rr
rr
rr
ii
dd
hh ll
ee ff
ff
ee ff
ff
hh ll
jj kk
dd
ff
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
149
Chapter 8 Central Processor Unit (S08CPUV5)
Operation
Object Code
1
p
U 1 1 –
– Þ Þ Þ
7
4
4
7
6
8
rfwpppp
fppp
fppp
rfwpppp
rfwppp
prfwpppp
– 1 1 –
– – – –
3A dd
4A
5A
6A ff
7A
9E 6A ff
5
1
1
5
4
6
rfwpp
p
p
rfwpp
rfwp
prfwpp
Þ 1 1 –
– Þ Þ –
INH
52
6
fffffp
– 1 1 –
– – Þ Þ
Exclusive OR Memory with Accumulator IMM
A ← (A ⊕ M)
DIR
EXT
IX2
IX1
IX
SP2
SP1
A8
B8
C8
D8
E8
F8
9E D8
9E E8
2
3
4
4
3
3
5
4
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
0 1 1 –
– Þ Þ –
5
1
1
5
4
6
rfwpp
p
p
rfwpp
rfwp
prfwpp
Þ 1 1 –
– Þ Þ –
Decimal Adjust Accumulator
After ADD or ADC of BCD Values
INH
72
DBNZ opr8a,rel
DBNZA rel
DBNZX rel
DBNZ oprx8,X,rel
DBNZ ,X,rel
DBNZ oprx8,SP,rel
Decrement A, X, or M and Branch if Not
Zero
(if (result) ≠ 0)
DBNZX Affects X Not H
DIR
INH
INH
IX1
IX
SP1
3B
4B
5B
6B
7B
9E 6B
DIR
INH
INH
IX1
IX
SP1
EOR
EOR
EOR
EOR
EOR
EOR
EOR
EOR
Decrement
M ← (M) – $01
A ← (A) – $01
X ← (X) – $01
M ← (M) – $01
M ← (M) – $01
M ← (M) – $01
Divide
A ← (H:A)÷(X); H ← Remainder
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
INC opr8a
INCA
INCX
INC oprx8,X
INC ,X
INC oprx8,SP
INZC
– Þ Þ Þ
DAA
DIV
V11H
Þ 1 1 –
Compare X (Index Register Low) with
Memory
X–M
(CCR Updated But Operands Not
Changed)
DEC opr8a
DECA
DECX
DEC oprx8,X
DEC ,X
DEC oprx8,SP
Affect
on CCR
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
A3
B3
C3
D3
E3
F3
9E D3
9E E3
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
Cyc-by-Cyc
Details
2
3
4
4
3
3
5
4
IMM
DIR
EXT
IX2
IX1
IX
SP2
SP1
CPX
CPX
CPX
CPX
CPX
CPX
CPX
CPX
Cycles
Source
Form
Address
Mode
Table 8-2. Instruction Set Summary (Sheet 5 of 10)
Increment
M ← (M) + $01
A ← (A) + $01
X ← (X) + $01
M ← (M) + $01
M ← (M) + $01
M ← (M) + $01
ii
dd
hh ll
ee ff
ff
ee ff
ff
dd rr
rr
rr
ff rr
rr
ff rr
ii
dd
hh ll
ee ff
ff
ee ff
ff
DIR
INH
INH
IX1
IX
SP1
3C dd
4C
5C
6C ff
7C
9E 6C ff
BC
CC
DC
EC
FC
dd
hh ll
ee ff
ff
3
4
4
3
3
ppp
pppp
pppp
ppp
ppp
– 1 1 –
– – – –
BD
CD
DD
ED
FD
dd
hh ll
ee ff
ff
5
6
6
5
5
ssppp
pssppp
pssppp
ssppp
ssppp
– 1 1 –
– – – –
JMP
JMP
JMP
JMP
JMP
opr8a
opr16a
oprx16,X
oprx8,X
,X
Jump
PC ← Jump Address
DIR
EXT
IX2
IX1
IX
JSR
JSR
JSR
JSR
JSR
opr8a
opr16a
oprx16,X
oprx8,X
,X
Jump to Subroutine
PC ← (PC) + n (n = 1, 2, or 3)
Push (PCL); SP ← (SP) – $0001
Push (PCH); SP ← (SP) – $0001
PC ← Unconditional Address
DIR
EXT
IX2
IX1
IX
MC9S08LG32 MCU Series, Rev. 5
150
Freescale Semiconductor
Chapter 8 Central Processor Unit (S08CPUV5)
LDA
LDA
LDA
LDA
LDA
LDA
LDA
LDA
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
LDHX
LDHX
LDHX
LDHX
LDHX
LDHX
LDHX
LDX
LDX
LDX
LDX
LDX
LDX
LDX
LDX
#opr16i
opr8a
opr16a
,X
oprx16,X
oprx8,X
oprx8,SP
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
LSL opr8a
LSLA
LSLX
LSL oprx8,X
LSL ,X
LSL oprx8,SP
LSR opr8a
LSRA
LSRX
LSR oprx8,X
LSR ,X
LSR oprx8,SP
Operation
Object Code
3
4
5
5
6
5
5
ppp
rrpp
prrpp
prrfp
pprrpp
prrpp
prrpp
0 1 1 –
– Þ Þ –
2
3
4
4
3
3
5
4
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
0 1 1 –
– Þ Þ –
38 dd
48
58
68 ff
78
9E 68 ff
5
1
1
5
4
6
rfwpp
p
p
rfwpp
rfwp
prfwpp
Þ 1 1 –
– Þ Þ Þ
34 dd
44
54
64 ff
74
9E 64 ff
5
1
1
5
4
6
rfwpp
p
p
rfwpp
rfwp
prfwpp
Þ 1 1 –
– 0 Þ Þ
5
5
4
5
rpwpp
rfwpp
pwpp
rfwpp
0 1 1 –
– Þ Þ –
5
ffffp
– 1 1 0
– – – 0
Load Index Register (H:X)
H:X ← (M:M + $0001)
jj kk
dd
hh ll
9E
9E
9E
9E
45
55
32
AE
BE
CE
FE
Load X (Index Register Low) from
Memory
X ← (M)
IMM
DIR
EXT
IX2
IX1
IX
SP2
SP1
AE
BE
CE
DE
EE
FE
9E DE
9E EE
ii
dd
hh ll
ee ff
ff
DIR
INH
INH
IX1
IX
SP1
DIR
INH
INH
IX1
IX
SP1
0
b0
(Same as ASL)
Logical Shift Right
0
C
b7
b0
INZC
– Þ Þ –
IMM
DIR
EXT
IX
IX2
IX1
SP1
b7
V11H
0 1 1 –
ii
dd
hh ll
ee ff
ff
C
Affect
on CCR
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
A6
B6
C6
D6
E6
F6
9E D6
9E E6
Logical Shift Left
Cyc-by-Cyc
Details
2
3
4
4
3
3
5
4
IMM
DIR
EXT
IX2
IX1
IX
SP2
SP1
Load Accumulator from Memory
A ← (M)
Cycles
Source
Form
Address
Mode
Table 8-2. Instruction Set Summary (Sheet 6 of 10)
MOV opr8a,opr8a
MOV opr8a,X+
MOV #opr8i,opr8a
MOV ,X+,opr8a
Move
(M)destination ← (M)source
In IX+/DIR and DIR/IX+ Modes,
H:X ← (H:X) + $0001
DIR/DIR
DIR/IX+
IMM/DIR
IX+/DIR
4E
5E
6E
7E
MUL
Unsigned multiply
X:A ← (X) × (A)
INH
42
ee ff
ff
ee ff
ff
ff
ee ff
ff
dd dd
dd
ii dd
dd
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
151
Chapter 8 Central Processor Unit (S08CPUV5)
Operation
Object Code
Cycles
Source
Form
Address
Mode
Table 8-2. Instruction Set Summary (Sheet 7 of 10)
Cyc-by-Cyc
Details
Affect
on CCR
V11H
INZC
NEG opr8a
NEGA
NEGX
NEG oprx8,X
NEG ,X
NEG oprx8,SP
Negate
M ← – (M) = $00
– (M)
(Two’s Complement) A ← – (A) = $00 –
(A)
X ← – (X) = $00 –
(X)
M ← – (M) = $00
– (M)
M ← – (M) = $00
– (M)
M ← – (M) = $00
– (M)
DIR
INH
INH
IX1
IX
SP1
30 dd
40
50
60 ff
70
9E 60 ff
5
1
1
5
4
6
rfwpp
p
p
rfwpp
rfwp
prfwpp
Þ 1 1 –
– Þ Þ Þ
NOP
No Operation — Uses 1 Bus Cycle
INH
9D
1
p
– 1 1 –
– – – –
NSA
Nibble Swap Accumulator
A ← (A[3:0]:A[7:4])
INH
62
1
p
– 1 1 –
– – – –
IMM
DIR
EXT
Inclusive OR Accumulator and Memory IX2
A ← (A) | (M)
IX1
IX
SP2
SP1
AA
BA
CA
DA
EA
FA
9E DA
9E EA
2
3
4
4
3
3
5
4
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
0 1 1 –
– Þ Þ –
ORA
ORA
ORA
ORA
ORA
ORA
ORA
ORA
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
ii
dd
hh ll
ee ff
ff
ee ff
ff
PSHA
Push Accumulator onto Stack
Push (A); SP ← (SP) – $0001
INH
87
2
sp
– 1 1 –
– – – –
PSHH
Push H (Index Register High) onto Stack
INH
Push (H); SP ← (SP) – $0001
8B
2
sp
– 1 1 –
– – – –
PSHX
Push X (Index Register Low) onto Stack
INH
Push (X); SP ← (SP) – $0001
89
2
sp
– 1 1 –
– – – –
PULA
Pull Accumulator from Stack
SP ← (SP + $0001); Pull (A)
INH
86
3
ufp
– 1 1 –
– – – –
PULH
Pull H (Index Register High) from Stack
INH
SP ← (SP + $0001); Pull (H)
8A
3
ufp
– 1 1 –
– – – –
PULX
Pull X (Index Register Low) from Stack
SP ← (SP + $0001); Pull (X)
INH
88
3
ufp
– 1 1 –
– – – –
DIR
INH
INH
IX1
IX
SP1
39 dd
49
59
69 ff
79
9E 69 ff
5
1
1
5
4
6
rfwpp
p
p
rfwpp
rfwp
prfwpp
Þ 1 1 –
– Þ Þ Þ
DIR
INH
INH
IX1
IX
SP1
36 dd
46
56
66 ff
76
9E 66 ff
5
1
1
5
4
6
rfwpp
p
p
rfwpp
rfwp
prfwpp
Þ 1 1 –
– Þ Þ Þ
ROL opr8a
ROLA
ROLX
ROL oprx8,X
ROL ,X
ROL oprx8,SP
Rotate Left through Carry
ROR opr8a
RORA
RORX
ROR oprx8,X
ROR ,X
ROR oprx8,SP
Rotate Right through Carry
C
b7
b0
C
b7
b0
MC9S08LG32 MCU Series, Rev. 5
152
Freescale Semiconductor
Chapter 8 Central Processor Unit (S08CPUV5)
Operation
Object Code
Cycles
Source
Form
Address
Mode
Table 8-2. Instruction Set Summary (Sheet 8 of 10)
Cyc-by-Cyc
Details
Affect
on CCR
V11H
INZC
RSP
Reset Stack Pointer (Low Byte)
SPL ← $FF
(High Byte Not Affected)
INH
9C
1
p
– 1 1 –
– – – –
RTC
Return from CALL
INH
8D
7
uuufppp
– 1 1 –
– – – –
RTI
Return from Interrupt
SP ← (SP) + $0001; Pull (CCR)
SP ← (SP) + $0001; Pull (A)
SP ← (SP) + $0001; Pull (X)
SP ← (SP) + $0001; Pull (PCH)
SP ← (SP) + $0001; Pull (PCL)
INH
80
9
uuuuufppp
Þ 1 1 Þ
Þ Þ Þ Þ
RTS
Return from Subroutine
SP ← SP + $0001; Pull (PCH)
SP ← SP + $0001; Pull (PCL)
INH
81
5
ufppp
– 1 1 –
– – – –
Subtract with Carry
A ← (A) – (M) – (C)
IMM
DIR
EXT
IX2
IX1
IX
SP2
SP1
A2
B2
C2
D2
E2
F2
9E D2
9E E2
2
3
4
4
3
3
5
4
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
Þ 1 1 –
– Þ Þ Þ
SBC
SBC
SBC
SBC
SBC
SBC
SBC
SBC
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
ii
dd
hh ll
ee ff
ff
ee ff
ff
SEC
Set Carry Bit
(C ← 1)
INH
99
1
p
– 1 1 –
– – – 1
SEI
Set Interrupt Mask Bit
(I ← 1)
INH
9B
1
p
– 1 1 –
1 – – –
Store Accumulator in Memory
M ← (A)
DIR
EXT
IX2
IX1
IX
SP2
SP1
B7
C7
D7
E7
F7
9E D7
9E E7
wpp
pwpp
pwpp
wpp
wp
ppwpp
pwpp
0 1 1 –
– Þ Þ –
ee ff
ff
3
4
4
3
2
5
4
35 dd
96 hh ll
9E FF ff
4
5
5
wwpp
pwwpp
pwwpp
0 1 1 –
– Þ Þ –
2
fp...
– 1 1 –
0 – – –
3
4
4
3
2
5
4
wpp
pwpp
pwpp
wpp
wp
ppwpp
pwpp
0 1 1 –
– Þ Þ –
STA
STA
STA
STA
STA
STA
STA
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
STHX opr8a
STHX opr16a
STHX oprx8,SP
Store H:X (Index Reg.)
(M:M + $0001) ← (H:X)
DIR
EXT
SP1
STOP
Enable Interrupts: Stop Processing
Refer to MCU Documentation
I bit ← 0; Stop Processing
INH
8E
Store X (Low 8 Bits of Index Register)
in Memory
M ← (X)
DIR
EXT
IX2
IX1
IX
SP2
SP1
BF
CF
DF
EF
FF
9E DF
9E EF
STX
STX
STX
STX
STX
STX
STX
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
dd
hh ll
ee ff
ff
dd
hh ll
ee ff
ff
ee ff
ff
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
153
Chapter 8 Central Processor Unit (S08CPUV5)
Operation
Object Code
V11H
INZC
Þ 1 1 –
– Þ Þ Þ
83
11
sssssvvfppp
– 1 1 –
1 – – –
INH
84
1
p
Þ 1 1 Þ
Þ Þ Þ Þ
Transfer Accumulator to X (Index
Register Low)
X ← (A)
INH
97
1
p
– 1 1 –
– – – –
Transfer CCR to Accumulator
A ← (CCR)
INH
85
1
p
– 1 1 –
– – – –
DIR
INH
INH
IX1
IX
SP1
3D dd
4D
5D
6D ff
7D
9E 6D ff
4
1
1
4
3
5
rfpp
p
p
rfpp
rfp
prfpp
0 1 1 –
– Þ Þ –
SWI
Software Interrupt
PC ← (PC) + $0001
Push (PCL); SP ← (SP) – $0001
Push (PCH); SP ← (SP) – $0001
Push (X); SP ← (SP) – $0001
Push (A); SP ← (SP) – $0001
Push (CCR); SP ← (SP) – $0001
I ← 1;
PCH ← Interrupt Vector High Byte
PCL ← Interrupt Vector Low Byte
INH
TAP
Transfer Accumulator to CCR
CCR ← (A)
TAX
TPA
TST opr8a
TSTA
TSTX
TST oprx8,X
TST ,X
TST oprx8,SP
Affect
on CCR
pp
rpp
prpp
prpp
rpp
rfp
pprpp
prpp
A0
B0
C0
D0
E0
F0
9E D0
9E E0
#opr8i
opr8a
opr16a
oprx16,X
oprx8,X
,X
oprx16,SP
oprx8,SP
Cyc-by-Cyc
Details
2
3
4
4
3
3
5
4
IMM
DIR
EXT
IX2
IX1
IX
SP2
SP1
SUB
SUB
SUB
SUB
SUB
SUB
SUB
SUB
Cycles
Source
Form
Address
Mode
Table 8-2. Instruction Set Summary (Sheet 9 of 10)
Subtract
A ← (A) – (M)
Test for Negative or Zero
(M) – $00
(A) – $00
(X) – $00
(M) – $00
(M) – $00
(M) – $00
ii
dd
hh ll
ee ff
ff
ee ff
ff
TSX
Transfer SP to Index Reg.
H:X ← (SP) + $0001
INH
95
2
fp
– 1 1 –
– – – –
TXA
Transfer X (Index Reg. Low) to
Accumulator
A ← (X)
INH
9F
1
p
– 1 1 –
– – – –
MC9S08LG32 MCU Series, Rev. 5
154
Freescale Semiconductor
Chapter 8 Central Processor Unit (S08CPUV5)
Operation
Object Code
Cycles
Source
Form
Address
Mode
Table 8-2. Instruction Set Summary (Sheet 10 of 10)
Cyc-by-Cyc
Details
Affect
on CCR
V11H
INZC
TXS
Transfer Index Reg. to SP
SP ← (H:X) – $0001
INH
94
2
fp
– 1 1 –
– – – –
WAIT
Enable Interrupts; Wait for Interrupt
I bit ← 0; Halt CPU
INH
8F
2+
fp...
– 1 1 –
0 – – –
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
155
Chapter 8 Central Processor Unit (S08CPUV5)
Table 8-3. Opcode Map (Sheet 1 of 2)
Bit-Manipulation
Branch
00
5 10
5 20
3 30
BRSET0
3
01
BRCLR0
3
02
BRSET2
3
05
BRSET3
3
07
BRCLR4
3
0A
BRSET5
3
0B
BRSET6
3
0D
BRCLR6
3
0E
BRSET7
3
0F
BRCLR7
3
INH
IMM
DIR
EXT
DD
IX+D
DIR 2
5 2F
Inherent
Immediate
Direct
Extended
DIR to DIR
IX+ to DIR
DBNZ
INC
REL 2
3 3D
TST
REL 2
3 3E
BIL
BIH
REL 2
REL
IX
IX1
IX2
IMD
DIX+
CLR
DIR 1
INH 1
Relative
Indexed, No Offset
Indexed, 8-Bit Offset
Indexed, 16-Bit Offset
IMM to DIR
DIR to IX+
ROL
INH 2
1 6A
DEC
DBNZ
DEC
DBNZ
IX1 2
5 7C
INC
IX1 1
4 7D
TST
INH 2
5 6E
MOV
CLRX
IX1 1
CLR
ADD
INH 2
1
BSR
Page 2
WAIT
INH 1
2
5 BD
ADD
DIR 3
3 CC
LDX
2
1 AF
TXA
INH 2
Stack Pointer, 8-Bit Offset
Stack Pointer, 16-Bit Offset
Indexed, No Offset with
Post Increment
Indexed, 1-Byte Offset with
Post Increment
LDX
IMM 2
2 BF
AIX
DIR 3
Opcode in
Hexadecimal F0
Number of Bytes 1
EXT 3
4 DF
STX
EXT 3
EOR
ADC
IX2 2
STA
IX
3
EOR
IX
3
ADC
IX1 1
3 FA
ORA
IX
3
ORA
IX1 1
3 FB
ADD
JSR
LDX
IX1 1
3 FF
IX
5
JSR
IX1 1
3 FE
IX1 1
IX
3
JMP
IX1 1
5 FD
STX
IX
3
ADD
IX1 1
3 FC
JMP
IX2 2
4 EF
STX
IX
2
IX1 1
3 F9
IX2 2
4 EE
LDX
IX
3
LDA
IX1 1
3 F8
IX2 2
6 ED
JSR
EXT 3
4 DE
LDX
DIR 3
3 CF
STX
IMM 2
JSR
DIR 3
3 CE
BIT
STA
IX2 2
4 EC
JMP
EXT 3
6 DD
IX
3
IX1 1
3 F7
IX2 2
4 EB
ADD
EXT 3
4 DC
JMP
DIR 3
5 CD
JSR
REL 2
2 BE
EXT 3
4 DB
AND
LDA
IX2 2
4 EA
ORA
IX
3
IX1 1
3 F6
IX2 2
4 E9
ADC
CPX
BIT
IX2 2
4 E8
EOR
IX
3
IX1 1
3 F5
IX2 2
4 E7
EXT 3
4 DA
ORA
JMP
INH 2
AE
INH
2+ 9F
ADC
DIR 3
3 CB
ADD
IMM 2
BC
INH
1 AD
NOP
IX 1
IMM 2
2 BB
AND
LDA
EXT 3
4 D9
IX
3
SBC
IX1 1
3 F4
STA
EOR
DIR 3
3 CA
ORA
RSP
1
2+ 9E
STOP
ADC
CPX
IX2 2
4 E6
EXT 3
4 D8
CMP
IX1 1
3 F3
BIT
STA
DIR 3
3 C9
IMM 2
2 BA
ORA
SEI
INH 1
9D
IX
5 8E
MOV
ADC
INH 2
1 AB
INH 1
1 9C
CLRH
IX 1
3
IMD 2
IX+D 1
5 7F
4 8F
CLR
INH 2
INH 1
2 9B
EOR
SBC
IX2 2
4 E5
EXT 3
4 D7
DIR 3
3 C8
IMM 2
2 B9
INH 2
1 AA
CLI
TST
IX1 1
4 7E
MOV
SEC
INH 1
3 9A
PSHH
IX 1
4 8C
EOR
INH 2
1 A9
PULH
IX 1
6 8B
INC
INH 2
1 6D
PSHX
IX 1
4 8A
IX1 1
7 7B
INH 3
1 6C
IX1+
ROL
CLC
INH 1
2 99
AND
IX
3
IX1 1
3 F2
IX2 2
4 E4
EXT 3
4 D6
LDA
STA
IMM 2
2 B8
CPX
EXT 3
4 D5
DIR 3
3 C7
CMP
IX2 2
4 E3
BIT
LDA
AIS
INH 2
1 A8
AND
DIR 3
3 C6
IMM 2
2 B7
TAX
INH 1
3 98
PULX
IX 1
4 89
IX1 1
5 7A
INH 2
4 6B
SP1
SP2
IX+
LSL
IX1 1
5 79
LDA
SBC
3
SUB
IX1 1
3 F1
IX2 2
4 E2
EXT 3
4 D4
BIT
IMM 2
2 B6
EXT 2
1 A7
CPX
DIR 3
3 C5
BIT
STHX
INH 3
2 97
AND
CMP
EXT 3
4 D3
DIR 3
3 C4
IMM 2
2 B5
INH 2
5 A6
PSHA
IX 1
4 88
LSL
INH 2
1 69
DD 2
DIX+ 3
1 5F
1 6F
CLRA
ASR
IX1 1
5 78
TSTX
INH 1
5 5E
MOV
EXT 3
5 4F
ASR
INH 2
1 68
PULA
CPX
AND
TSX
INH 1
3 96
SBC
3 F0
SUB
IX2 2
4 E1
EXT 3
4 D2
DIR 3
3 C3
IMM 2
2 B4
INH 2
2 A5
TPA
IX 1
4 87
CPX
TXS
CMP
SBC
SUB
EXT 3
4 D1
DIR 3
3 C2
IMM 2
2 B3
REL 2
2 A4
INH 1
1 95
DIR 1
4 86
IX1 1
5 77
INCX
INH 1
1 5D
TSTA
DIR 1
6 4E
CPHX
REL 3
3 3F
INCA
DIR 1
4 4D
INH 2
1 67
DBNZX
INH 2
1 5C
CPHX
ROR
BLE
TAP
CMP
SBC
SUB
DIR 3
3 C1
IMM 2
2 B2
REL 2
3 A3
INH 2
1 94
IX 1
5 85
IMM 2
5 76
ROR
DECX
INH 1
4 5B
DBNZA
DIR 2
5 4C
CPHX
ROLX
INH 1
1 5A
DECA
DIR 1
7 4B
REL 3
3 3C
BMS
DIR 2
5 2E
DIR 2
DEC
BMC
DIR 2
5 2D
ROLA
DIR 1
5 4A
REL 2
3 3B
BMI
DIR 2
5 2C
BCLR7
DIR 2
ROL
LSR
CMP
BGT
SWI
SUB
IMM 2
2 B1
REL 2
3 A2
INH 2
11 93
IX 1
4 84
IX1 1
3 75
DIR 3
1 66
BGND
COM
SUB
BLT
INH 2
5+ 92
Register/Memory
3 C0
4 D0
4 E0
2 B0
REL 2
3 A1
RTS
INH 1
4 83
LSR
LSLX
INH 1
1 59
DAA
3 A0
BGE
INH 2
6 91
IX+ 1
1 82
IX1 1
5 74
INH 2
4 65
ASRX
INH 1
1 58
LSLA
DIR 1
5 49
REL 2
3 3A
DIR 2
5 2B
BSET7
DIR 2
5 1F
LSL
BHCS
BPL
ASRA
DIR 1
5 48
REL 2
3 39
DIR 2
5 2A
BCLR6
DIR 2
5 1E
ASR
COM
RORX
INH 1
1 57
CBEQ
INH 1
5 73
INH 2
1 64
LDHX
IMM 2
1 56
RORA
DIR 1
5 47
BHCC
DIR 2
5 29
BSET6
DIR 2
5 1D
ROR
INH 1
1 63
RTI
IX 1
5 81
IX1+ 2
1 72
LSRX
INH 1
3 55
NEG
NSA
COMX
INH 1
1 54
LDHX
DIR 3
5 46
REL 2
3 38
INH 1
1 53
LSRA
DIR 1
4 45
STHX
BEQ
DIR 2
5 28
BCLR5
DIR 2
5 1C
LSR
CBEQ
Control
9 90
4 80
IX1 1
5 71
IMM 3
6 62
DIV
COMA
DIR 1
5 44
REL 2
3 37
BSET5
DIR 2
5 1B
BRCLR5
3
0C
DIR 2
5 27
BCLR4
DIR 2
5 1A
COM
REL 2
3 36
BNE
MUL
5 70
NEG
INH 2
4 61
CBEQX
IMM 3
5 52
EXT 1
5 43
REL 2
3 35
BCS
CBEQA
LDHX
NEGX
INH 1
4 51
DIR 3
5 42
BCC
DIR 2
5 26
BSET4
DIR 2
5 19
CBEQ
REL 2
3 34
DIR 2
5 25
BCLR3
DIR 2
5 18
BRSET4
3
09
BLS
NEGA
DIR 1
5 41
REL 3
3 33
DIR 2
5 24
BSET3
DIR 2
5 17
BRCLR3
3
08
DIR 2
5 23
BCLR2
DIR 2
5 16
NEG
REL 3
3 32
BHI
BSET2
DIR 2
5 15
BRCLR2
3
06
BRN
DIR 2
5 22
BCLR1
DIR 2
5 14
5 40
REL 2
3 31
BSET1
DIR 2
5 13
BRCLR1
3
04
BRA
DIR 2
5 21
BCLR0
DIR 2
5 12
BRSET1
3
03
BSET0
DIR 2
5 11
Read-Modify-Write
1 50
1 60
IX
3
LDX
IX
2
STX
IX
3 HCS08 Cycles
Instruction Mnemonic
IX Addressing Mode
SUB
MC9S08LG32 MCU Series, Rev. 5
156
Freescale Semiconductor
Chapter 8 Central Processor Unit (S08CPUV5)
Table 8-3. Opcode Map (Sheet 2 of 2)
Bit-Manipulation
Branch
Read-Modify-Write
9E60
Control
Register/Memory
9ED0 5 9EE0
6
NEG
SUB
3
SP1
9E61
6
CBEQ
4
CMP
SP1
CMP
4
SP2 3
SP1
9ED2 5 9EE2 4
SBC
9E63
SBC
4
SP2 3
SP1
9ED3 5 9EE3 4 9EF3
6
COM
CPX
3
SP1
9E64
6
CPX
AND
SP1
SP1
AND
4
SP2 3
SP1
9ED5 5 9EE5 4
BIT
BIT
6
4
SP2 3
SP1
9ED6 5 9EE6 4
3
SP1
9E67
6
4
SP2 3
SP1
9ED7 5 9EE7 4
9E66
6
CPHX
4
SP2 3
SP1 3
9ED4 5 9EE4 4
LSR
3
4
SUB
4
SP2 3
SP1
9ED1 5 9EE1 4
ROR
LDA
ASR
LDA
STA
3
SP1
9E68
6
STA
4
SP2 3
SP1
9ED8 5 9EE8 4
LSL
EOR
3
SP1
9E69
6
EOR
4
SP2 3
SP1
9ED9 5 9EE9 4
ROL
ADC
3
SP1
9E6A 6
ADC
4
SP2 3
SP1
9EDA 5 9EEA 4
DEC
ORA
3
SP1
9E6B 8
ORA
4
SP2 3
SP1
9EDB 5 9EEB 4
DBNZ
ADD
4
SP1
9E6C 6
4
ADD
SP2 3
SP1
INC
3
SP1
9E6D 5
TST
3
SP1
9EAE
5 9EBE
LDHX
2
9E6F
IX 4
6 9ECE
LDHX
5 9EDE
LDHX
IX2 3
6
CLR
3
INH
IMM
DIR
EXT
DD
IX+D
Inherent
Immediate
Direct
Extended
DIR to DIR
IX+ to DIR
REL
IX
IX1
IX2
IMD
DIX+
Relative
Indexed, No Offset
Indexed, 8-Bit Offset
Indexed, 16-Bit Offset
IMM to DIR
DIR to IX+
SP1
SP2
IX+
5 9EEE
LDX
4 9EFE
LDX
5
LDHX
IX1 4
SP2 3
SP1 3
SP1
9EDF 5 9EEF 4 9EFF 5
STX
SP1
4
SP2 3
STX
SP1 3
STHX
SP1
Stack Pointer, 8-Bit Offset
Stack Pointer, 16-Bit Offset
Indexed, No Offset with
Post Increment
Indexed, 1-Byte Offset with
Post Increment
IX1+
Note: All Sheet 2 Opcodes are Preceded by the Page 2 Prebyte (9E)
Prebyte (9E) and Opcode in
Hexadecimal 9E60
6 HCS08 Cycles
Instruction Mnemonic
SP1 Addressing Mode
NEG
Number of Bytes 3
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
157
Chapter 9
LCD Module (S08LCDLPV1)
9.1
Introduction
On the MC9S08LG32 series, the LCD module (LCD) controls 45 LCD pins to generate the waveforms
necessary to drive a liquid crystal display. On the 80-pin package, the 45 LCD pins can be used to generate
4x41 or 8x37 configuration. On the 64-pin package, the 37 LCD pins can be used to generate 4x33 or 8x29
configuration. On the 48-pin package, there are 29 LCD pins available for driving 4x25 or 8x21
configurations.
NOTE
1. All references to VLL3 also applies to VLL3_2 in this chapter.
2. For MC9S08LG32 series MCUs, the devices working at –40 °C to 85 °C temperature range have
the change pump feature only, whereas devices working at –40 °C to 105 °C do not have this
feature. For higher temperatures (–40 °C to 105 °C) register bias in high gain mode is
recommended. For more details, see AN3802 – Interfacing LCD with MC9S08LG32.
9.1.1
LCD Clock Sources
The LCD module on MC9S08LG32 series can be clocked from the OSCOUT or the ICSIRCLK
(ALTCLK). See Section 1.3, “System Clock Distribution,” for more information.
9.1.2
LCD Modes of Operation
The LCD module can be configured to operate in stop modes by setting the LCDSTP bit. All clock sources
are available in all modes except stop2. In stop2 mode, only OSCOUT is available.
9.1.3
LCD Status after Stop2 Wakeup
The LCD control registers is set to their default state. These registers must be re-initialized before setting
the PPDACK. The contents of the LCD data registers (LCD waveform, LCD pin enable, and LCD
backplane enable) are retained.
9.1.4
LCD Clock Gating
The bus clock to the LCD can be gated on and off using the LCD bit in SCGC2. This bit is clear after any
reset that disables the bus clock to this module. To conserve power, the LCD bit can be cleared to disable
the clock to this module when not in use. For more details, see Section 5.7, “Peripheral Clock Gating.”
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
158
Chapter 9 LCD Module (S08LCDLPV1)
LVD
PORT A
BKGD/MS
RESET
IRQ
8-BIT KEYBOARD
INTERRUPT (KBI)
SERIAL PERIPHERAL
INTERFACE (SPI)
KBI[7:0]
SS
SPSCK
MISO
MOSI
SCL
IIC MODULE (IIC)
USER FLASH A
(LG32 = 16K BYTES)
(LG16 = 2K BYTES)
6-CHANNEL TIMER/PWM
(TPM2)
USER FLASH B
(LG32 = 16K BYTES)
(LG16 = 16K BYTES)
2-CHANNEL TIMER/PWM
(TPM1)
SERIAL COMMUNICATIONS
INTERFACE (SCI1)
USER RAM
SDA
TPM2CH[5:0]
TPMCLK
PORT D
IRQ
RESET/PTC6
BKGD/MS/PTC5
LCD[20:16]/PTC[4:0]
TMRCLK
LCD[7:0]/PTD[7:0]
PORT E
Modulo Timer
(MTIM)
COP
LCD[40:37]/PTB[7:4]
LCD[32:29]/PTB[3:0]
(RTC)
HCS08 SYSTEM CONTROL
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
PORT B
Real Time Counter
LCD[15:8]/PTE[7:0]
TPM1CH[1:0]
PORT F
BKP
EXTAL/PTF7
XTAL/PTF6
TPM2CH3/KBI2/MOSI/PTF5
TPM2CH4/KBI1/MISO/PTF4
TPM2CH5/KBI0/SS/PTF3
ADC14/IRQ/TPM1CH1/SPSCK/PTF2
ADC13/TPM1CH0/RX1/PTF1
ADC12/TPM2CH2/KBI3/TX1/PTF0
PORT G
BKGD
LCD[44:41]/PTG[7:4]
LCD[36:33]/PTG[3:0]
PORT H
INT
ON-CHIP ICE (ICE) and
DEBUG MODULE (DBG)
TPM2CH4/KBI1/PTH7
ADC15/KBI0/TPM2CH5/PTH6
ADC11/TPM1CH0/KBI3/TX1/PTH5
ADC10/TPM1CH1/KBI2/RX1/PTH4
ADC[9:6]/KBI[7:4]/PTH[3:0]
PORT I
CPU
LCD28/ADC5/TPMCLK/PTA7
LCD27/ADC4/TPM2CH1/KBI7/PTA6
LCD26/ADC3/TPM2CH0/KBI6/PTA5
LCD25/ADC2/RX2/KBI5/PTA4
LCD24/ADC1/TX2/KBI4/PTA3
LCD23/ADC0/SDA/PTA2
LCD22/SCL/PTA1
LCD21/PTA0
PORT C
HCS08 CORE
SS/SCL/TPM2CH0/PTI5
SPSCK/SDA/TPM2CH1/PTI4
MOSI/TPM2CH2/PTI3
MISO/TPM2CH3/PTI2
TX2/TMRCLK/PTI1
RX2/PTI0
TPMCLK
TxD1
RxD1
1984 BYTES
SERIAL COMMUNICATIONS
INTERFACE (SCI2)
INTERNAL CLOCK
Source (ICS)
TxD2
RxD2
XTAL
LOW-POWER OSCILLATOR
12-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
VLL3_2
VLL3
VLL1
VLL2
VCAP1
EXTAL
AD[15:0]
LIQUID CRYSTAL
DISPLAY DRIVER
(LCD)
VCAP2
LCD[44:0]
VDD
VSS
VSS2
VOLTAGE
REGULATOR
VDDA/VREFH
VSSA/VREFL
Available only on 80 pin package
Available only on 64 and 80 pin package
*/Default function out of reset/*
Figure 9-1. MC9S08LG32 Series Block Diagram Highlighting LCD Block and Pins
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
159
Chapter 8 LCD Module (S08LCDLPV1)
9.1.5
Features
The LCD module driver features include:
• LCD waveforms functional in wait, stop2 and stop3 low-power modes
• 45 LCD (LCD[44:0]) pins with selectable frontplane/backplane configuration
— Generate up to 44 frontplane signals
— Generate up to 8 backplanes signals
• Programmable LCD frame frequency
• Programmable blink modes and frequency
— All segments blank during blink period
— Alternate display for each LCD segment in x4 or less mode
— Blink operation in low-power modes
• Programmable LCD power supply switch, making it an ideal solution for battery-powered and
board-level applications
— Charge pump requires only four external capacitors
— Internal LCD power using VDD (1.8 to 3.6 V)
— External VLL3 power supply option (3V)
• Integrated charge pump for generating LCD bias voltages
— Hardware configurable to drive 3 V or 5 V LCD panels
— On-chip generation of bias voltages
• Waveform storage registers LCDWF
• Backplane reassignment to assist in vertical scrolling on dot-matrix displays
• Software configurable LCD frame frequency interrupt
• Internal ADC channels are connected to VLL1 to monitor their magnitudes. This feature allows
software to adjust the contrast.
MC9S08LG32 MCU Series, Rev. 5
160
Freescale Semiconductor
Chapter 8 LCD Module (S08LCDLPV1)
9.1.6
Modes of Operation
The LCD module supports the following operation modes:
Table 9-1. LCD-Module Operation Modes
Mode
Operation
Stop2
Depending on the state of the LCDSTP bit, the LCD module can operate an LCD panel in stop2 mode. If
LCDSTP = 1, LCD module clock generation is turned off and the LCD module enters a power
conservation state and is disabled.If LCDSTP = 0, the LCD module can operate an LCD panel in stop2,
and the LCD module continues to display the current LCD panel contents based on the LCD operation
prior to the stop2 event.
If the LCD is enabled in stop2, the selected LCD clock source, OSCOUT, must be enabled to operate in
stop2.
The LCD frame interrupt does not cause the MCU to exit stop2.
Stop3
Depending on the state of the LCDSTP bit, the LCD module can operate an LCD panel in stop3 mode. If
LCDSTP = 1, LCD module clock generation is turned off and the LCD module enters a power
conservation state and is disabled. If LCDSTP = 0, the LCD module can operate an LCD panel in stop3,
and the LCD module continues displaying the current LCD panel contents based on the LCD operation
prior to the stop3 event.
If the LCD is enabled in stop3, the selected LCD clock source, OSCOUT, must be enabled to operate in
stop3.
In stop3 mode, the LCD frame interrupt can cause the MCU to exit stop3.
Wait
Depending on the configuration, the LCD module can operate an LCD panel in wait mode. If LCDWAI = 1,
the LCD module clock generation is turned off and the LCD module enters a power-conservation state
and is disabled. If LCDWAI = 0, the LCD module can operate an LCD panel in wait, and the LCD module
continues displaying the current LCD panel contents base on the LCDWF registers.
In wait mode, the LCD frame interrupt can cause the MCU to exit wait.
Stop2 provides the lowest power consumption state where the LCD module is functional. To operate the
LCD in stop2 mode, use an external crystal.
9.1.7
Block Diagram
Figure 9-2 is a block diagram of the LCD module.
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
161
Chapter 8 LCD Module (S08LCDLPV1)
Alternate Clock
Frame Rate Clock
Prescaler
OSCOUT = 32.768 kHz
LCDCLK
DUTY
LCDIF
LCDIEN
BRATE
LADJ
SOURCE
Backplane Sequencer
ALT
BLANK
BLINK
BMODE
8 BP Phases
Write Buffer
IP
BUS
LCD
BUS
Sequenced
FP or BP data
LCD Waveform Registers
MUX
LCD[x]
FP or BP
LCDPEN
LCDBPEN
VDD
Charge Pump
VSUPPLY
CPSEL
Vcap1
0.1 μF
VLL1
RVEN
VLL2
VLL3/VLL3_2
Vcap2
Figure 9-2. LCD Driver Block Diagram
9.2
External Signal Description
The LCD module has several external pins dedicated to power supply and LCD frontplane/backplane
signaling. The LCD module can be configured to support eight backplane signals. The table below
itemizes all the LCD external pins. See the Chapter 2, “Pins and Connections,” for device-specific pin
configurations.
Table 9-2. Signal Properties
Name
45 LCD frontplane/backplane
LCD bias voltages
Port
Function
Reset State
LCD[44:0]
Switchable frontplane/backplane driver that connects directly
to the display
LCD[44:0] can operate as GPIO pins
High impedance
LCD bias voltages
VLL1,
VLL2,
VLL3, VLL3_2
LCD charge pump capacitance Vcap1, Vcap2 Charge pump capacitor pins
—
—
MC9S08LG32 MCU Series, Rev. 5
162
Freescale Semiconductor
Chapter 8 LCD Module (S08LCDLPV1)
9.2.1
LCD[44:0]
When LCD functionality is enabled by the PEN[44:0] bits in the LCDPEN registers, the corresponding
LCD[44:0] pin will generate a frontplane or backplane waveform depending on the configuration of the
backplane-enable bit field (BPEN[44:0]).
9.2.2
VLL1, VLL2, VLL3
VLL1, VLL2, and VLL3 are bias voltages for the LCD module driver waveforms which can be internally
generated using the internal charge pump (when enabled). The charge pump can also be configured to
accept VLL3 as an input and generate VLL1 and VLL2. Refer to VSUPPLY[1:0] bits explanation.
On 64 and 80 pin packages VLL3 and VLL3_2 pins provide the VLL3 supply to the LCD controller.
9.2.3
Vcap1, Vcap2
The charge pump capacitor is used to transfer charge from the input supply to the regulated output. A
ceramic capacitor is recommended.
9.3
Register Definition
This section consists of register descriptions. Each description includes a standard register diagram.
Details of register bit and field function follow the register diagrams, in bit order.
9.3.1
R
W
Reset
LCD Control Register 0 (LCDC0)
7
6
5
4
3
2
1
0
LCDEN
SOURCE
LCLK2
LCLK1
LCLK0
DUTY2
DUTY1
DUTY0
0
0
0
0
0
0
1
1
= Unimplemented or Reserved
Figure 9-3. LCD Control Register 0 (LCDC0)
Read: anytime
Write: LCDEN anytime. Do not change SOURCE, LCLCK, or DUTY while LCDEN = 1.
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
163
Chapter 8 LCD Module (S08LCDLPV1)
Table 9-3. LCDC0 Field Descriptions
Field
Description
7
LCDEN
LCD Driver Enable — LCDEN starts LCD-module-waveform generator.
0 All frontplane and backplane pins are disabled. The LCD module system is also disabled, and all LCD
waveform generation clocks are stopped. VLL3 is connected to VDD internally
1 LCD module driver system is enabled and frontplane and backplane waveforms are generated. All LCD pins
enabled using the LCD pin enable register (LCDPEN[x]) will output an LCD module driver waveform.The
backplane pins will output an LCD module driver backplane waveform based on the settings of DUTY[2:0].
Chargepump or resistor bias is enabled.
6
SOURCE
LCD Clock Source Select — The LCD module has two possible clock sources. This bit is used to select which
clock source is the basis for LCDCLK.
0 Selects the OSCOUT (external clock reference) as the LCD clock source.
1 Selects the alternate clock as the LCD clock source.
5:3
LCLK[2:0]
LCD Clock Prescaler — Used as a clock divider to generate the LCD module frame frequency as shown in
Equation 9-1. LCD-module-duty-cycle configuration is used to determine the LCD module frame frequency. LCD
module frame frequency calculations are provided in Table 9-1.
Eqn. 9-1
LCD Module Frame Frequency
=
LCDCLK
where 30< LCDCLK < 39.063 kHz
((DUTY+1) x 8 x (4 + LCLK[2:0]) x Y)
2:0
DUTY[2:0]
9.3.2
LCD Duty Select — DUTY[2:0] bits select the duty cycle of the LCD module driver.
000 Use 1 BP (1/1 duty cycle).
001 Use 2 BP (1/2 duty cycle).
010 Use 3 BP (1/3 duty cycle).
011 Use 4 BP (1/4 duty cycle). (Default)
100 Use 5 BP (1/5 duty cycle).
101 Use 6 BP (1/6 duty cycle).
110 Use 7 BP (1/7 duty cycle).
111 Use 8 BP (1/8 duty cycle).
LCD Control Register 1 (LCDC1)
7
R
W
Reset
where Y = 2,2,3,3,4,5,8,16 chosen
by module duty cycle configuration
LCDIEN
0
6
5
4
3
0
0
0
0
0
0
0
0
2
1
0
FCDEN
LCDWAI
LCDSTP
0
0
0
= Unimplemented or Reserved
Figure 9-4. LCD Control Register 1 (LCDC1)
Read: anytime
Write: anytime
MC9S08LG32 MCU Series, Rev. 5
164
Freescale Semiconductor
Chapter 8 LCD Module (S08LCDLPV1)
Table 9-4. LCDC1 Field Descriptions
Field
Description
7
LCDIEN
LCD Module Frame Frequency Interrupt Enable — Enables an LCD interrupt event that coincides with the
LCD module frame frequency.
0 No interrupt request is generated by this event.
1 The start of the LCD module frame causes an LCD module frame frequency interrupt request.
2
FCDEN
Full Complementary Drive Enable — This bit allows GPIO that are shared with LCD pins to operate as full
complementary if the other conditions necessary have been met. The other conditions are:
VSUPPLY = 11 and RVEN = 0.
0 GPIO shared with LCD operate as open drain outputs, input levels and internal pullup resistors are referenced
to VDD.
1 If VSUPPLY = 11 and RVEN = 0, GPIO shared with LCD operate as full complementary outputs. Input levels
and internal pullup resistors are referenced to VLL3.
1
LCDWAI
LCD Module Driver and Charge Pump Stop While in Wait Mode
0 Allows the LCD driver and charge pump to continue running during wait mode.
1 Disables the LCD driver and charge pump when MCU goes into wait mode.
0
LCDSTP
LCD Module Driver and Charge Pump Stop While in Stop2 or Stop3 Mode
0 Allows LCD module driver and charge pump to continue running during stop2 or stop3.
1 Disables LCD module driver and charge pump when MCU goes into stop2 or stop3.
9.3.3
LCD Voltage Supply Register (LCDSUPPLY)
Module Base + 0x0022
7
R
W
Reset
6
5
4
CPSEL
HREFSEL
LADJ1
LADJ0
0
0
1
1
3
0
0
2
1
0
BBYPASS
VSUPPLY1
VSUPPLY0
1
0
1
Unimplemented or Reserved
Figure 9-5. LCD Voltage Supply Register (LCDSUPPLY)
Read: anytime
Write: anytime.
For proper operation, do not modify VSUPPLY[1:0] while the LCDEN bit is asserted. VSUPPLY[1:0]
must also be configured according to the external hardware power supply configuration.
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
165
Chapter 8 LCD Module (S08LCDLPV1)
Table 9-5. LCDSUPPLY Field Descriptions
Field
Description
7
CPSEL
Charge Pump or Resistor Bias Select — Selects LCD module charge pump or a resistor network to supply the
LCD voltages VLL1, VLL2, and VLL3. See Figure 9-16 for more detail.
0 LCD charge pump is disabled. Resistor network selected (The internal 1/3-bias is forced.)
1 LCD charge pump is selected. Resistor network disabled (The internal 1/3-bias is forced.)
6
HREFSEL
High Reference Select— This feature is not available for MC9S08LG32 series. Writing to this bit is not
recommended.
5:4
LADJ[1:0]
LCD Module Load Adjust — The LCD load adjust bits are used to configure the LCD module to handle different
LCD glass capacitance.
For CPSEL = 1
Adjust the clock source for the charge pump. Higher loads require higher charge pump clock rates.
00 - Fastest clock source for charge pump (LCD glass capacitance 8000pf or lower)
01 - Intermediate clock source for charge pump (LCD glass capacitance 6000pf or lower))
10 - Intermediate clock source for charge pump (LCD glass capacitance 4000pf or lower)
11 - Slowest clock source for charge pump (LCD glass capacitance 2000pf or lower)
For CPSEL = 0
Adjust the resistor bias network for different LCD glass capacitance
00 - Low Load (LCD glass capacitance 2000pf or lower)
01 - Low Load (LCD glass capacitance 2000pf or lower)
10 - High Load (LCD glass capacitance 8000pf or lower)
11 - High Load (LCD glass capacitance 8000pf or lower)
2
BBYPASS
Op Amp Control — This feature is not available for MC9S08LG32 series. Writing to this bit is not recommended.
1:0
Voltage Supply Control — Configures whether the LCD module power supply is external or internal. Avoid
VSUPPLY[1:0]
modifying this bit field while the LCD module is enabled (e.g., LCDEN = 1). See Figure 9-16 for more detail.
00 Drive VLL2 internally from VDD
01 Drive VLL3 internally from VDD
10 Reserved
11 Drive VLL3 externally
9.3.4
LCD Regulated Voltage Control Register (LCDRVC)
7
R
W
Reset
RVEN
0
6
5
4
0
0
0
0
0
0
3
2
1
0
RVTRIM3
RVTRIM2
RVTRIM1
RVTRIM0
1
0
0
0
Unimplemented or Reserved
Figure 9-6. LCD Regulated Voltage Control Register (LCDRVC)
Read: anytime.
Write: anytime.
This register is not available for MC9S08LG32 series. Writing to this bit is not recommended.
MC9S08LG32 MCU Series, Rev. 5
166
Freescale Semiconductor
Chapter 8 LCD Module (S08LCDLPV1)
9.3.5
LCD Blink Control Register (LCDBCTL)
7
R
W
Reset
6
5
BLINK
ALT
BLANK
0
0
0
4
0
3
2
1
0
BMODE
BRATE2
BRATE1
BRATE0
0
0
0
0
0
Unimplemented or Reserved
Figure 9-7. LCD Blink Control Register (LCDBCTL)
Read: anytime
Write: anytime
Table 9-6. LCDBCTL Field Descriptions
Field
7
BLINK
6
ALT
Description
Blink Command — Starts or stops LCD module blinking
0 Disables blinking
1 Starts blinking at blinking frequency specified by LCD blink rate calculation (see Equation 9-2)
Alternate Display Mode — For four backplanes or less, the LCD backplane sequencer changes to output an
alternate display. ALT bit is ignored if Duty is 5 or greater.
0 Normal Display
1 Alternate display mode
5
BLANK
Blank Display Mode — Asserting this bit clears all segments in the LCD display.
0 Normal or Alternate Display
1 Blank Display Mode
3
BMODE
Blink Mode — Selects the blink mode displayed during the blink period. See Table 9-6 for more information on
how BMODE affects the LCD display.
0 Display blank during the blink period
1 Display alternate display during blink period (Ignored if duty is 5 or greater)
2:0
Blink-Rate Configuration— Selects frequency at which the LCD display blinks when the BLINK is asserted.
BRATE[2:0] Equation 9-2 shows how BRATE[2:0] bit field is used in the LCD blink-rate calculation.
Equation 9-2 provides an expression for the LCD module blink rate
Eqn. 9-2
LCD module blink rate
=
LCDCLK
2 (12+ BRATE[2:0])
LCD module blink rate calculations are provided in Section 9.4.3.2, “Blink Frequency.”
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
167
Chapter 8 LCD Module (S08LCDLPV1)
9.3.6
LCD Status Register (LCDS)
7
R
W
Reset
LCDIF
0
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Unimplemented or Reserved
Figure 9-8. LCD Status Register (LCDS)
Read: anytime
Write: anytime
Table 9-7. LCDS Field Descriptions
Field
Description
7
LCDIF
LCD Interrupt Flag — LCDIF indicates an interrupt condition occurred. To clear the interrupt write a 1 to LCDIF.
0 interrupt condition has not occurred.
1 interrupt condition has occurred.
9.3.7
LCD Pin Enable Registers 0–5 (LCDPEN0–LCDPEN5)
When LCDEN = 1, these bits enable the corresponding LCD pin for LCD operation.
These registers should only be written with instructions that perform byte writes, using instructions that
perform word writes will lead to invalid data being placed in the register. Initialize these registers before
enabling the LCD module. Exiting stop2 mode does not require reinitializing the LCDPEN registers.
MC9S08LG32 MCU Series, Rev. 5
168
Freescale Semiconductor
Chapter 8 LCD Module (S08LCDLPV1)
R
LCDPEN0
W
7
6
5
4
3
2
1
0
PEN7
PEN6
PEN5
PEN4
PEN3
PEN2
PEN1
PEN0
PEN10
PEN9
PEN8
PEN18
PEN17
PEN16
PEN26
PEN25
PEN24
PEN34
PEN33
PEN32
PEN42
PEN41
PEN40
Reset
Indeterminate after reset
R
LCDPEN1
PEN15
W
PEN14
PEN13
Reset
PEN23
W
PEN22
PEN21
Reset
PEN31
W
PEN30
PEN29
Reset
PEN39
W
Reset
PEN28
PEN27
PEN38
PEN37
PEN36
PEN35
Indeterminate after reset
R
LCDPEN5
PEN19
Indeterminate after reset
R
LCDPEN4
PEN20
Indeterminate after reset
R
LCDPEN3
PEN11
Indeterminate after reset
R
LCDPEN2
PEN12
PEN44
W
Reset
PEN43
Indeterminate after reset
Unimplemented or Reserved
Figure 9-9. LCD Pin Enable Registers 0–5 (LCDPEN0–LCDPEN5)
Read: anytime
Write: anytime
Table 9-8. LCDPEN0–LCDPEN5 Field Descriptions
Field
Description
44:0
PEN[44:0]
LCD Pin Enable — The PEN[44:0] bit enables the LCD[44:0] pin for LCD operation. Each LCD[44:0] pin can be
configured as a backplane or a frontplane based on the corresponding BPEN[n] bit in the Backplane Enable
Register (LCDBPEN[5:0]). If LCDEN = 0, these bits have no effect on the state of the I/O pins. Set PEN[44:0]
bits before LCDEN is set.
0 LCD operation disabled on LCDnn.
1 LCD operation enabled on LCDnn.
9.3.8
Backplane Enable Registers 0–5 (BPEN0–BPEN5)
When LCDPEN[n] = 1, these bits configure the corresponding LCD pin to operate as an LCD backplane
or an LCD frontplane. Most applications set a maximum of eight of these bits. Initialize these registers
before enabling the LCD module. Exiting stop2 mode does not require reinitializing the LCDBPEN
registers.
These registers should only be written with instructions that perform byte writes, using instructions that
perform word writes will lead to invalid data being placed in the register.
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
169
Chapter 8 LCD Module (S08LCDLPV1)
R
LCDBPEN0
W
7
6
5
4
3
2
1
0
BPEN7
BPEN6
BPEN5
BPEN4
BPEN3
BPEN2
BPEN1
BPEN0
BPEN10
BPEN9
BPEN8
BPEN18
BPEN17
BPEN16
BPEN26
BPEN25
BPEN24
BPEN34
BPEN33
BPEN32
BPEN42
BPEN41
BPEN40
Reset
R
LCDBPEN1
W
Indeterminate after reset
BPEN15
BPEN14
BPEN13
Reset
R
LCDBPEN2
W
LCDBPEN3
W
BPEN23
BPEN22
BPEN21
LCDBPEN4
W
Reset
R
LCDBPEN5
W
Reset
BPEN20
BPEN19
Indeterminate after reset
BPEN31
BPEN30
BPEN29
Reset
R
BPEN11
Indeterminate after reset
Reset
R
BPEN12
BPEN28
BPEN27
Indeterminate after reset
BPEN39
BPEN38
BPEN37
BPEN36
BPEN35
Indeterminate after reset
BPEN44
BPEN43
Indeterminate after reset
Unimplemented or Reserved
Figure 9-10. Backplane Enable Registers 0–5 (BPEN0–BPEN5)
Read: anytime
Write: anytime
Table 9-9. LCDBPEN0–LCDBPEN5 Field Descriptions
Field
Description
44:0
BPEN[44:0]
Backplane Enable — The BPEN[44:0] bit configures the LCD[44:0] pin to operate as an LCD backplane or LCD
frontplane. If LCDEN = 0, these bits have no effect on the state of the I/O pins. It is recommended to set
BPEN[44:0] bits before LCDEN is set.
0 Frontplane operation enabled on LCD[n].
1 Backplane operation enabled on LCD[n].
9.3.9
LCD Waveform Registers (LCDWF[44:0])
For an LCD pin configured as a frontplante, the LCDWF registers control the on/off state for frontplane
segments. Each frontplane segment is associated with a backplane phase (A-H).
For an LCD pin configured as a backplane, the LCDWF registers controls the phase (A-H) in which the
associated backplane pin is active.
After reset, the LCDWF contents are indeterminate as indicated by Figure 9-11. Exiting stop2 mode does
not require reinitializing the LCDWF registers.
MC9S08LG32 MCU Series, Rev. 5
170
Freescale Semiconductor
Chapter 8 LCD Module (S08LCDLPV1)
LCDWF0
R
W
7
6
5
4
3
2
1
0
BPHLCD0
BPGLCD0
BPFLCD0
BPELCD0
BPDLCD0
BPCLCD0
BPBLCD0
BPALCD0
BPCLCD1
BPBLCD1
BPALCD1
BPCLCD2
BPBLCD2
BPALCD2
BPCLCD3
BPBLCD3
BPALCD3
BPCLCD4
BPBLCD4
BPALCD4
BPCLCD5
BPBLCD5
BPALCD5
BPCLCD6
BPBLCD6
BPALCD6
BPCLCD7
BPBLCD7
BPALCD7
BPCLCD8
BPBLCD8
BPALCD8
BPCLCD9
BPBLCD9
BPALCD9
Reset
LCDWF1
R
W
Indeterminate after reset
BPHLCD1
BPGLCD1
BPFLCD1
Reset
LCDWF2
R
W
R
W
BPHLCD2
BPGLCD2
BPFLCD2
R
W
BPHLCD3
BPGLCD3
BPFLCD3
R
W
BPHLCD4
BPGLCD4
BPFLCD4
LCDWF6
W
BPHLCD5
BPGLCD5
BPFLCD5
LCDWF7
W
BPHLCD6
BPGLCD6
BPFLCD6
LCDWF8
W
BPHLCD7
BPGLCD7
BPFLCD7
R
W
BPHLCD8
R
W
BPHLCD9
R
W
R
W
BPELCD6
BPDLCD6
BPELCD7
BPDLCD7
BPGLCD8
BPFLCD8
BPELCD8
BPDLCD8
BPGLCD9
BPFLCD9
BPELCD9
BPDLCD9
BPHLCD10 BPGLCD10 BPFLCD10 BPELCD10 BPDLCD10 BPCLCD10 BPBLCD10 BPALCD10
Indeterminate after reset
BPHLCD11 BPGLCD11 BPFLCD11 BPELCD11 BPDLCD11 BPCLCD11 BPBLCD11 BPALCD11
Reset
LCDWF12
BPDLCD5
Indeterminate after reset
Reset
LCDWF11
BPELCD5
Indeterminate after reset
Reset
LCDWF10
BPDLCD4
Indeterminate after reset
Reset
LCDWF9
BPELCD4
Indeterminate after reset
Reset
R
BPDLCD3
Indeterminate after reset
Reset
R
BPELCD3
Indeterminate after reset
Reset
R
BPDLCD2
Indeterminate after reset
Reset
LCDWF5
BPELCD2
Indeterminate after reset
Reset
LCDWF4
BPDLCD1
Indeterminate after reset
Reset
LCDWF3
BPELCD1
Indeterminate after reset
BPHLCD12 BPGLCD12 BPFLCD12 BPELCD12 BPDLCD12 BPCLCD12 BPBLCD12 BPALCD12
Reset
Indeterminate after reset
Figure 9-11. LCD Waveform Registers (LCDWF[44:0])
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
171
Chapter 8 LCD Module (S08LCDLPV1)
LCDWF13
R
W
Reset
LCDWF14
R
W
Reset
LCDWF15
R
W
Reset
LCDWF16
R
W
Reset
LCDWF17
R
W
Reset
LCDWF18
R
W
Reset
LCDWF19
R
W
Reset
LCDWF20
R
W
Reset
LCDWF21
R
W
Reset
LCDWF22
R
W
Reset
LCDWF23
R
W
Reset
LCDWF24
R
W
Reset
LCDWF25
R
W
Reset
LCDWF26
R
W
BPHLCD13 BPGLCD13 BPFLCD13 BPELCD13 BPDLCD13 BPCLCD13 BPBLCD13 BPALCD13
Indeterminate after reset
BPHLCD14 BPGLCD14 BPFLCD14 BPELCD14 BPDLCD14 BPCLCD14 BPBLCD14 BPALCD14
Indeterminate after reset
BPHLCD15 BPGLCD15 BPFLCD15 BPELCD15 BPDLCD15 BPCLCD15 BPBLCD15 BPALCD15
Indeterminate after reset
BPHLCD16 BPGLCD16 BPFLCD16 BPELCD16 BPDLCD16 BPCLCD16 BPBLCD16 BPALCD16
Indeterminate after reset
BPHLCD17 BPGLCD17 BPFLCD17 BPELCD17 BPDLCD17 BPCLCD17 BPBLCD17 BPALCD17
Indeterminate after reset
BPHLCD18 BPGLCD18 BPFLCD18 BPELCD18 BPDLCD18 BPCLCD18 BPBLCD18 BPALCD18
Indeterminate after reset
BPHLCD19 BPGLCD19 BPFLCD19 BPELCD19 BPDLCD19 BPCLCD19 BPBLCD19 BPALCD19
Indeterminate after reset
BPHLCD20 BPGLCD20 BPFLCD20 BPELCD20 BPDLCD20 BPCLCD20 BPBLCD20 BPALCD20
Indeterminate after reset
BPHLCD21 BPGLCD21 BPFLCD21 BPELCD21 BPDLCD21 BPCLCD21 BPBLCD21 BPALCD21
Indeterminate after reset
BPHLCD22 BPGLCD22 BPFLCD22 BPELCD22 BPDLCD22 BPCLCD22 BPBLCD22 BPALCD22
Indeterminate after reset
BPHLCD23 BPGLCD23 BPFLCD23 BPELCD23 BPDLCD23 BPCLCD23 BPBLCD23 BPALCD23
Indeterminate after reset
BPHLCD24 BPGLCD24 BPFLCD24 BPELCD24 BPDLCD24 BPCLCD24 BPBLCD24 BPALCD24
Indeterminate after reset
BPHLCD25 BPGLCD25 BPFLCD25 BPELCD25 BPDLCD25 BPCLCD25 BPBLCD25 BPALCD25
Indeterminate after reset
BPHLCD26 BPGLCD26 BPFLCD26 BPELCD26 BPDLCD26 BPCLCD26 BPBLCD26 BPALCD26
Figure 9-11. LCD Waveform Registers (LCDWF[44:0]) (continued)
MC9S08LG32 MCU Series, Rev. 5
172
Freescale Semiconductor
Chapter 8 LCD Module (S08LCDLPV1)
Reset
LCDWF27
R
W
Indeterminate after reset
BPHLCD27 BPGLCD27 BPFLCD27 BPELCD27 BPDLCD27 BPCLCD27 BPBLCD27 BPALCD27
Reset
LCDWF28
R
W
Indeterminate after reset
BPHLCD28 BPGLCD28 BPFLCD28 BPELCD28 BPDLCD28 BPCLCD28 BPBLCD28 BPALCD28
Reset
LCDWF29
R
W
Indeterminate after reset
BPHLCD29 BPGLCD29 BPFLCD29 BPELCD29 BPDLCD29 BPCLCD29 BPBLCD29 BPALCD29
Reset
LCDWF30
R
W
Indeterminate after reset
BPHLCD30 BPGLCD30 BPFLCD30 BPELCD30 BPDLCD30 BPCLCD30 BPBLCD30 BPALCD30
Reset
LCDWF31
R
W
Indeterminate after reset
BPHLCD31 BPGLCD31 BPFLCD31 BPELCD31 BPDLCD31 BPCLCD31 BPBLCD31 BPALCD31
Reset
LCDWF32
R
W
Indeterminate after reset
BPHLCD32 BPGLCD32 BPFLCD32 BPELCD32 BPDLCD32 BPCLCD32 BPBLCD32 BPALCD32
Reset
LCDWF33
R
W
Indeterminate after reset
BPHLCD33 BPGLCD33 BPFLCD33 BPELCD33 BPDLCD33 BPCLCD33 BPBLCD33 BPALCD33
Reset
LCDWF34
R
W
Indeterminate after reset
BPHLCD34 BPGLCD34 BPFLCD34 BPELCD34 BPDLCD34 BPCLCD34 BPBLCD34 BPALCD34
Reset
LCDWF35
R
W
Indeterminate after reset
BPHLCD35 BPGLCD35 BPFLCD35 BPELCD35 BPDLCD35 BPCLCD35 BPBLCD35 BPALCD35
Reset
LCDWF36
R
W
Indeterminate after reset
BPHLCD36 BPGLCD36 BPFLCD36 BPELCD36 BPDLCD36 BPCLCD36 BPBLCD36 BPALCD36
Reset
LCDWF37
R
W
Indeterminate after reset
BPHLCD37 BPGLCD37 BPFLCD37 BPELCD37 BPDLCD37 BPCLCD37 BPBLCD37 BPALCD37
Reset
LCDWF38
R
W
Indeterminate after reset
BPHLCD38 BPGLCD38 BPFLCD38 BPELCD38 BPDLCD38 BPCLCD38 BPBLCD38 BPALCD38
Reset
LCDWF39
R
W
Indeterminate after reset
BPHLCD39 BPGLCD39 BPFLCD39 BPELCD39 BPDLCD39 BPCLCD39 BPBLCD39 BPALCD39
Reset
Indeterminate after reset
Figure 9-11. LCD Waveform Registers (LCDWF[44:0]) (continued)
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
173
Chapter 8 LCD Module (S08LCDLPV1)
LCDWF40
R
W
BPHLCD40 BPGLCD40 BPFLCD40 BPELCD40 BPDLCD40 BPCLCD40 BPBLCD40 BPALCD40
Reset
LCDWF41
R
W
Indeterminate after reset
BPHLCD41 BPGLCD41 BPFLCD41 BPELCD41 BPDLCD41 BPCLCD41 BPBLCD41 BPALCD41
Reset
LCDWF42
R
W
Indeterminate after reset
BPHLCD42 BPGLCD42 BPFLCD42 BPELCD42 BPDLCD42 BPCLCD42 BPBLCD42 BPALCD42
Reset
LCDWF43
R
W
Indeterminate after reset
BPHLCD43 BPGLCD43 BPFLCD43 BPELCD43 BPDLCD43 BPCLCD43 BPBLCD43 BPALCD43
Reset
LCDWF44
R
W
Indeterminate after reset
BPHLCD44 BPGLCD44 BPFLCD44 BPELCD44 BPDLCD44 BPCLCD44 BPBLCD44 BPALCD44
Reset
Indeterminate after reset
Figure 9-11. LCD Waveform Registers (LCDWF[44:0]) (continued)
Table 9-10. LCDWF Field Descriptions
Field
Description
BP[y]LCD[x] Segment-on-Frontplane Operation — If the LCD[x] pin is enabled and configured to operate as a frontplane,
the BP[y]LCD[x] bit in the LCDWF registers controls the on/off state for the LCD segment connected between
LCD[x] and BP[y].BP[y] corresponds to an LCD[44:0] pin enabled and configured to operate as a backplane that
is active in phase [y]. Asserting BP[y]LCD[x] displays (turns on) the LCD segment connected between LCD[x]
and BP[y].
0 LCD segment off
1 LCD segment on
Segment-on-Backplane Operation — If the LCD[x] pin is enabled and configured to operate as a backplane,
the BP[y] LCD[x] bit in the LCDWF registers controls the phase (A-H) in which the LCD[x] pin is active.Backplane
phase assignment is done using this method.
0 LCD backplane inactive for phase[y]
1 LCD backplane active for phase[y].
9.4
Functional Description
This section provides a complete functional description of the LCD block, detailing the operation of the
design from the end-user perspective.
Before enabling the LCD module by asserting the LCDEN bit in the LCDC0 register, configure the LCD
module based on the end application requirements. Out of reset, the LCD module is configured with
default settings, but these settings are not optimal for every application.
The LCD module provides several versatile configuration settings and options to support varied
implementation requirements, including:
• Frame frequency
MC9S08LG32 MCU Series, Rev. 5
174
Freescale Semiconductor
Chapter 8 LCD Module (S08LCDLPV1)
•
•
•
•
•
Duty cycle (number of backplanes)
Backplane assignment (which LCD[44:0] pins operate as backplanes)
Frame frequency interrupt enable
Blinking frequency and options
Power-supply configurations
The LCD module also provides an LCD pin enable control. Setting the LCD pin enable bit (PEN[x] in the
LCDPEN[y] register) for a particular LCD[y] pin enables the LCD module functionality of that pin once
the LCDEN bit is set. When the BPEN[x] bit in the LCDBPEN[y] is set, the associated pin operates as a
backplane. The LCDWF registers can then activate (display) the corresponding LCD segments on an LCD
panel.
The LCDWF registers control the on/off state for the segments controlled by the LCD pins defined as front
planes and the active phase for the backplanes. Blank display modes do not use the data from the LCDWF
registers. When using the LCDWF register for frontplane operation, writing a 0 turns the segment off.
For pins enabled as backplane, the phase of the backplane (A-H) is assigned by the LCDWF register for
the corresponding backplane pin. For a detailed description of LCD module operation for a basic
seven-segment LCD display, see Section 9.6.1, “LCD Seven Segment Example Description.”
9.4.1
LCD Driver Description
The LCD module driver has 8 modes of operation:
• 1/1 duty (1 backplane) (Phase A), 1/3 bias (4 voltage levels)
• 1/2 duty (2 backplanes) (Phase A, B), 1/3 bias (4 voltage levels)
• 1/3 duty (3 backplanes) (Phase A, B, C), 1/3 bias (4 voltage levels)
• 1/4 duty (4 backplanes) (Phase A, B, C, D), 1/3 bias (4 voltage levels)
• 1/5 duty (5 backplanes) (Phase A, B, C, D, E), 1/3 bias (4 voltage levels)
• 1/6 duty (6 backplanes) (Phase A, B, C, D, E, F), 1/3 bias (4 voltage levels)
• 1/7 duty (7 backplanes) (Phase A, B, C, D, E, F, G), 1/3 bias (4 voltage levels)
• 1/8 duty (8 backplanes) (Phase A, B, C, D, E, F, G, H), 1/3 bias (4 voltage levels)
All modes are 1/3 bias. These modes of operation are described in more detail in the following sections.
9.4.1.1
LCD Duty Cycle
The denominator of the duty cycle indicates the number of LCD panel segments capable of being driven
by each individual frontplane output driver. Depending on the duty cycle, the LCD waveform drive can be
categorized as static or multiplexed.
In static-driving method, the LCD is driven with two square waveforms. The static-driving method is the
most basic method to drive an LCD panel, but because each frontplane driver can drive only one LCD
segment, static driving limits the LCD segments that can be driven with a given number of frontplane pins.
In static mode, only one backplane is required.
MC9S08LG32 MCU Series, Rev. 5
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Chapter 8 LCD Module (S08LCDLPV1)
In multiplexed mode, the LCD waveforms are multi-level and depend on the bias mode. Multiplex mode,
depending on the number of backplanes, can drive multiple LCD segments with a single frontplane driver.
This reduces the number of driver circuits and connections to LCD segments. For multiplex mode
operation, at least two backplane drivers are needed. The LCD module is optimized for multiplex mode.
The duty cycle indicates the amount of time the LCD panel segment is energized during each LCD module
frame cycle. The denominator of the duty cycle indicates the number of backplanes that are being used to
drive an LCD panel.
The duty cycle is used by the backplane phase generator to set the phase outputs. The phase outputs A-H
are driven according to the sequence shown below. The sequence is repeated at the LCD frame frequency.
The duty cycle is configured using the DUTY[2:0] bit field in the LCDC0 register, as shown in Table 9-11.
Table 9-11. LCD Module Duty Cycle Modes
LCDC0 Register
Number of Backplanes
Phase
Sequence
A
Duty
9.4.1.2
DUTY2
DUTY1
DUTY0
1/1
0
0
0
1
1/2
0
0
1
2
AB
1/3
0
1
0
3
ABC
1/4
0
1
1
4
ABCD
1/5
1
0
0
5
ABCDE
1/6
1
0
1
6
ABCDEF
1/7
1
1
0
7
ABCDEFG
1/8
1
1
1
8
ABCDEFGH
LCD Bias
Because a single frontplane driver is configured to drive more and more individual LCD segments, 3
voltage levels are required to generate the appropriate waveforms to drive the segment. The LCD module
is designed to operate using the 1/3 bias mode.
9.4.1.3
LCD Module Base Clock and Frame Frequency
The LCD module is optimized to operate using a 32.768 kHz clock input. Two clock sources are available
to the LCD module, which are selectable by configuring the SOURCE bit in the LCDC0 register. The two
clock sources include:
• External crystal — OSCOUT (SOURCE = 0)
• Alternate clock (SOURCE = 1)
Figure 9-12 shows the LCD clock tree. The clock tree shows the two possible clock sources and the LCD
frame frequency and blink frequency clock source. The LCD blink frequency is discussed in
Section 9.4.3.2, “Blink Frequency.”
MC9S08LG32 MCU Series, Rev. 5
176
Freescale Semiconductor
Chapter 8 LCD Module (S08LCDLPV1)
SOURCE
BRATE[2:0]
LCLK[2:0]
÷(212+BRATE[2:0])
Alternate Clock
Blink Frequency
LCDCLK
÷4
OSCOUT = 32.768 kHz
Blink Rate
÷12∗(2LADJ[1:0])
÷ 2 x (4+LCLK[2:0]) x Y)
LCD Base Clock
LCD Charge Pump Clock
Source
LADJ[1:0]
÷(DUTY+1)
LCD Frame Frequency
Figure 9-12. LCD Clock Tree
An external 32.768 kHz clock input is required to achieve lowest power consumption.
The value of LCDCLK is important because it is used to generate the LCD module frame frequency.
Equation 9-1 provides an expression for the LCD module frame frequency calculation.
The LCD module frame frequency is a function of the LCD module duty cycle as shown in Equation 9-1.
Table 9-13 and Table 9-12 show LCD module frame frequency calculations that consider several possible
LCD module configurations of LCLK[2:0] and DUTY[2:0].
The LCD module frame frequency is defined as the number of times the LCD segments are energized per
second. The LCD module frame frequency must be selected to prevent the LCD display from flickering
(LCD module frame frequency is too low) or ghosting (LCD module frame frequency is too high). To
avoid these issues, an LCD module frame frequency in the range of 28 to 58 Hz is required. LCD module
frame frequencies less than 28 Hz or greater than 58 Hz are out of specification, and so are invalid.
Selecting lower values for the LCD base and frame frequency results in lower current consumption for the
LCD module.
The LCD module base clock frequency is the LCD module frame frequency multiplied by the number of
backplane phases that are being generated. The number of backplane phases is selected using the
DUTY[2:0] bits. The LCD module base clock is used by the backplane sequencer to generate the LCD
waveform data for the enabled phases (A-H).
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
177
Chapter 8 LCD Module (S08LCDLPV1)
Table 9-12. LCD Module Frame Frequency Calculations1
Duty
Cycle
1/1
1/2
1/3
1/4
1/5
1/6
1/7
1/8
Y
16
8
5
4
3
3
2
2
64
64
68.3
64
LCLK[2:0]
0
68.3 56.9 73.1
64
1
51.2 51.2 54.6 51.2 54.6 45.5 58.5 51.2
2
42.7 42.7 45.5 42.7 45.5 37.9 48.8 42.7
3
36.6 36.6
4
32
32
39
36.6
34.1
32
39
32.5 41.8 36.6
34.1 28.4 36.6
32
5
28.4 28.4 30.3 28.4 30.3 25.3 32.5 28.4
6
25.6 25.6 27.3 25.6 27.3 22.8 29.3 25.6
7
23.3 23.3 24.8 23.3 24.8 20.7 26.6 23.3
1
LCD clock input ~ 32.768 kHz
Shaded table entries would take higher current.
Table 9-13. LCD Module Frame Frequency Calculations1
Duty
Cycle
1/1
1/2
1/3
1/4
1/5
1/6
1/7
1/8
Y
16
8
5
4
3
3
2
2
LCLK[2:0]
0
1
76.3 76.3 81.4 76.3 81.4 67.8 87.2 76.3
61
61
65.1
61
65.1 54.3 69.8
61
2
50.9 50.9 54.3 50.9 54.3 45.2 58.1 50.9
3
43.6 43.6 46.5 43.6 46.5 38.8 49.8 43.6
4
38.1 38.1 40.7 38.1 40.7 33.9 43.6 38.1
5
33.9 33.9 36.2 33.9 36.2 30.1 38.8 33.9
6
30.5 30.5 32.6 30.5 32.6 27.1 34.9 30.5
7
27.7 27.7 29.6 27.7 29.6 24.7 31.7 27.7
1
LCD clock input ~ 39.063 kHz
Shaded table entries would take higher current.
9.4.1.4
LCD Waveform Examples
This section shows the timing examples of the LCD output waveforms for the several modes of operation.
As shown in Table 9-14, all examples use 1/3 bias mode.
Table 9-14. Configurations for Example LCD Waveforms
Bias Mode
Example 1
Example 2
Example 3
1/3
DUTY[2:0]
Duty Cycle
001
1/2
011
1/4
111
1/8
MC9S08LG32 MCU Series, Rev. 5
178
Freescale Semiconductor
Chapter 8 LCD Module (S08LCDLPV1)
9.4.1.4.1
1/2 Duty Multiplexed with 1/3 Bias Mode (Low-power Waveform)
Duty=1/2:DUTY[2:0] = 001
LCD pin 0 (LCD[0])and LCD pin 1, LCD[1] enabled as backplanes:
BPEN0 =1 and BPEN1 =1 in the LCDBPEN0
LCD[0] assigned to Phase A: LCDWF0 = 0x01
LCD[1] assigned to Phase B: LCDWF1 = 0x02
1 Frame
A
Phase
B A
B
A
Phase
B A
B
A
Phase
B A
B
A
Phase
B A
B
Base_Clk
Frame Interrupt
LCD[0]/BP0
VLL3
VLL2
VLL1
0
LCD[1]/BP1
VLL3
VLL2
VLL1
0
VLL3
VLL2
VLL1
0
LCDWF[n]= 0x02
= 00000010
VLL3
VLL2
VLL1
0
-VLL1
-VLL2
-VLL3
BP0-FPn (OFF)
VLL3
VLL2
VLL1
0
-VLL1
-VLL2
-VLL3
BP1-FPn (ON)
Figure 9-13. 1/2 Duty and 1/3 Bias (Low-Power Waveform)
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
179
Chapter 8 LCD Module (S08LCDLPV1)
9.4.1.4.2
1/4 Duty Multiplexed with 1/3 Bias Mode (Low-power Waveform)
Duty = 1/4: DUTY[2:0] = 011
LCD pins 0 – 3 enabled as backplanes: LCDBPEN0 = 0x0F
LCD[0] assigned to Phase A: LCDWF0 = 0x01
LCD[1] assigned to Phase B: LCDWF1 = 0x02
LCD[2] assigned to Phase C: LCDWF2 = 0x04
LCD[3] assigned to Phase D: LCDWF3 = 0x08
1 Frame
A
B
C
Phase
D A
B
C
D
A
B
C
Phase
D A
B
C
D
Base_Clk
Frame Interrupt
LCD[0]/BP0
VLL3
VLL2
VLL1
0
LCD[1]/BP1
VLL3
VLL2
VLL1
0
LCD[2]/BP2
VLL3
VLL2
VLL1
0
LCD[3]/BP3
VLL3
VLL2
VLL1
0
VLL3
VLL2
VLL1
0
VLL3
VLL2
VLL1
0
-VLL1
-VLL2
-VLL3
LCDWFn(0x09)
=00001001
BP0–FPn (ON)
VLL3
VLL2
VLL1
0
-VLL1
-VLL2
-VLL3
BP1–FPn (OFF)
Figure 9-14. 1/4 Duty and 1/3 Bias (Low-Power Waveform)
MC9S08LG32 MCU Series, Rev. 5
180
Freescale Semiconductor
Chapter 8 LCD Module (S08LCDLPV1)
9.4.1.4.3
1/8 Duty Multiplexed with 1/3 Bias Mode (Low-power Waveform)
Duty = 1/8:DUTY[2:0] = 111
LCD pins 0 – 7 enabled as backplanes: LCDBPEN0 = 0xFF
LCD[0] assigned to Phase A: LCDWF0 = 0x01
LCD[1] assigned to Phase B: LCDWF1 = 0x02
LCD[2] assigned to Phase C: LCDWF2 = 0x04
LCD[3] assigned to Phase D: LCDWF3 = 0x08
LCD[4] assigned to Phase E: LCDWF4 = 0x10
LCD[5] assigned to Phase F: LCDWF5 = 0x20
LCD[6] assigned to Phase G: LCDWF6 = 0x40
LCD[7] assigned to Phase H: LCDWF7 = 0x80
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
181
Chapter 8 LCD Module (S08LCDLPV1)
1 Frame
A
B
C
Phase
D E
F
G H
A
B
Phase
C D E
F
G H
Base_Clk
LCD[0]/BP0
VLL3
VLL2
VLL1
0
LCD[1]/BP1
VLL3
VLL2
VLL1
0
LCD[2]/BP2
VLL3
VLL2
VLL1
0
LCD[3]/BP3
VLL3
VLL2
VLL1
0
LCD[4]/BP4
VLL3
VLL2
VLL1
0
LCD[5]/BP5
VLL3
VLL2
VLL1
0
LCD[6]/BP6
VLL3
VLL2
VLL1
0
LCD[7]/BP7
VLL3
VLL2
VLL1
0
VLL3
VLL2
VLL1
0
VLL3
VLL2
VLL1
0
-VLL1
-VLL2
-VLL3
LCDWFn(0x69)
BP0–FPn (ON)
VLL3
VLL2
VLL1
0
-VLL1
-VLL2
-VLL3
BP1–FPn (OFF)
Figure 9-15. 1/8 Duty and 1/3 Bias (Low-power Waveform)
MC9S08LG32 MCU Series, Rev. 5
182
Freescale Semiconductor
Chapter 8 LCD Module (S08LCDLPV1)
9.4.2
LCDWF Registers
For a segment on the LCD panel to be displayed, data must be written to the LCDWF registers. For LCD
pins enabled as frontplanes, each bit in the LCDWF registers corresponds to a segment on an LCD panel.
The different phases A-H represent the different backplanes of the LCD panel. The selected LCD duty
cycle controls the number of implemented phases. Refer to Table 9-11 for normal LCD operation the
phases follow the sequence shown.
For LCD pins enabled as a backplane, the LCDWF assigns the phase in which the backplane pin is active.
This is how backplane assignment is done.
An example of normal operation follows: enable LCD pin 0 to operate as backplane 0. Enable the LCD
pin 0 by setting PEN0 bit in the LCDPEN0 register. Configure LCD pin 0 as a backplane pin by setting
the BPEN0 bit in the LCDBPEN0 register. Finally, the BPALCD0 bit in the LCDWF0 is set to associate
LCD pin 0 with backplane phase A. This will configure LCD0 to operate as a backplane that is active in
Phase A.
For LCD pins enabled as a frontplane, writing a 1 to a given LCDWF location results in the corresponding
display segment being driven with the differential root mean square (RMS) voltage necessary to turn the
segment on during the phase selected. Writing a 0 to a given location results in the corresponding display
segment being driven with the differential RMS voltage necessary to turn the segment off during the phase
selected.
9.4.3
LCD Display Modes
The LCD module can be configured to implement several different display modes. The bits ALT and
BLANK in the LCD-blink-control register (LCDBCTL) configure the different display modes. In normal
display mode (default), LCD segments are controlled by the data placed in the LCDWF registers, as
described in Section 9.4.2, “LCDWF Registers.” For blank-display mode, the LCDWF data is bypassed
and the frontplane and backplane pins are configured to clear all segments.
For alternate-display mode, the backplane sequence is modified for duty cycles of 1/4, 1/3, 1/2, and 1/1.
For four backplanes or less, the backplane sequence is modified as shown below. The altered sequence
allows two complete displays to be placed in the LDCDWF registers. The first display is placed in phases
A-D and the second in phases E-H in the case of four backplanes. If the LCD duty cycle is five backplanes
or greater, the ALT bit is ignored and creates a blank display. Refer to Table 9-16 for additional
information.
Using the alternate display function an inverse display can be accomplished for x4 mode and less by
placing inverse data in the alternate phases of the LCDWF registers.
Table 9-15. Alternate Display Backplane Sequence
Duty
Backplane Sequence
Alt. Backplane Sequence
1/1
A
E
1/2
AB
EF
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
183
Chapter 8 LCD Module (S08LCDLPV1)
Table 9-15. Alternate Display Backplane Sequence (continued)
9.4.3.1
Duty
Backplane Sequence
Alt. Backplane Sequence
1/3
ABC
EFG
1/4
ABCD
EFGH
LCD Blink Modes
The blink mode is used as a means of alternating among different LCD display modes at a defined
frequency. The LCD module can be configured to implement two blink modes. The BMODE bit in the
LCD-blink-control register (LCDBCTL) configures the different blink modes. Blink modes are activated
by setting the BLINK bit in the LCDBCTL register. If BLINK = 0, the LCD module operates normally as
described Section 9.4.3, “LCD Display Modes.” If BLINK = 1, BMODE bit configures the blinking
operation. During a blink, the display data driven by the LCD module changes to the mode selected by the
BMODE bit. The BMODE bit selects two different blink modes, blank and alternate modes operate in the
same way, as defined in Section 9.4.3, “LCD Display Modes.” The table below shows the interaction
between display modes and blink modes. If the LCD duty cycle is five backplanes or greater, BMODE =
1 is ignored and will revert to create a blank display during the blink period.
Table 9-16. Display Mode Interaction
BLANK
0
9.4.3.2
ALT
0
BMODE
0
BLINK = 1
LCD Duty
1-4
Normal Period
Blink Period
Normal Display
Blank Display
0
0
1
1-4
Normal Display
Alternate display
0
1
0
1-4
Alternate display
Blank Display
Alternate Display Alternate display
0
1
1
1-4
1
X
0
1-4
1
X
1
0
X
X
1
X
X
5-8
Blank Display
Blank DIsplay
1-4
Blank Display
Alternate display
5-8
Normal Display
Blank Display
Blank Display
Blank Display
Blink Frequency
The LCD clock is the basis for the calculation of the LCD module blink frequency. The LCD module blink
frequency is equal to the LCD clock (LCDCLK) divided by the factor selected by the BRATE[2:0] bits.
Table 9-17 shows LCD module blink frequency calculations for all values of BRATE[2:0] at a few
common LCDCLK selections.
MC9S08LG32 MCU Series, Rev. 5
184
Freescale Semiconductor
Chapter 8 LCD Module (S08LCDLPV1)
Table 9-17. Blink Frequency Calculations
(Blink Rate = LCD Clock(Hz) ÷ Blink Divider)
BRATE[2:0]
0
1
2
LCD Clock
30 khz
9.4.4
3
4
5
6
7
.23
.11
.06
Blink Frequency (Hz)
7.32
3.66
1.831
.916
.46
32.768 khz
8
4
2
1
.5
.25
.13
.06
39.063 khz
9.54
4.77
2.38
1.19
.6
.30
.15
.075
LCD Charge Pump, Voltage Divider, and Power Supply Operation
This section describes the LCD charge pump, voltage divider, and LCD power supply configuration
options. Figure 9-16 provides a block diagram for the LCD charge pump and the resistor divider network.
For charge pump option please refer to Note 2 at start of chapter.
The LCD bias voltages (VLL1, VLL2 and VLL3) can be generated by the LCD charge pump or a resistor
divider network that is connected using the CPSEL bit. The input source to the LCD charge pump is
controlled by the VSUPPLY[1:0] bit field.
VSUPPLY[1:0] indicates the state of internal signals used to configure power switches as shown in the
table in Figure 9-16. The block diagram in Figure 9-16 illustrates several potential operational modes for
the LCD module including configuration of the LCD module power supply source using VDD or an
external supply on the VLL3/VLL3_2 pins.
Upon Reset the VSUPPLY[1:0] bits are configured to connect VLL3 to VDD. This configuration should be
changed to match the application requirements before the LCD module is enabled.
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
185
Chapter 8 LCD Module (S08LCDLPV1)
VDD
powersw1
powersw2
~CPSEL
~CPSEL
~CPSEL
VLL1
VLL2
CHARGE PUMP
VLL3
VSUPPLY[1:0]
Configuration
powersw1 powersw2
00
Drive VLL2 internally from VDD
1
0
01
Drive VLL3 internally from VDD
0
1
10
Reserved
0
0
11
Drive VLL3 externally from VDD
0
0
Figure 9-16. LCD Charge Pump and Voltage Divider Block Diagram
NOTE:
The charge pump is optimized for 1/3 bias mode operation only.
During the first 16 timebase clock cycles after the LCDPEN bit is set, all the
LCD frontplane and backplane outputs are disabled, regardless of the state
of the LCDEN bit.
The charge pump requires external capacitance for its operation. To provide
this external capacitance, the Vcap1 and Vcap2 external pins are provided. It
is recommended that a ceramic capacitor be used. Proper orientation is
imperative when using a polarized capacitor. The recommended value for
the external capacitor is 0.1 μF.
9.4.4.1
LCD Charge Pump and Voltage Divider
Using the voltage divider and charge pump, the LCD module can be used to generate various voltages.
This LCD module configurability makes the LCD module compatible with both 3 V or 5 V LCD glass.
MC9S08LG32 MCU Series, Rev. 5
186
Freescale Semiconductor
Chapter 8 LCD Module (S08LCDLPV1)
9.4.4.1.1
CPSEL: LCD Charge Pump or Resistor Bias Enable
The CPSEL bit in the LCDSUPPLY register selects the charge pump. When the charge pump is selected
(CPSEL = 1), VLL1, VLL2, and VLL3 can be generated internally or VLL1 and VLL2 can be generated from
supplied VLL3.
When the charge pump is unselected (CPSEL = 0), VLL3 must be supplied and VLL1, VLL2 are generated
by a resistor bias network.
9.4.4.2
LCD Power Supply and Voltage Buffer Configuration
The LCD bias voltages can be internally derived from VDD, or externally derived from a voltage source
(must not exceed VDD) connected to VLL3. Table 9-19 provides a more detailed description of the power
state of the LCD module which depends on the configuration of the VSUPPLY[1:0] and CPSEL bits.
Table 9-19 shows all possible configurations of the LCD Power Supply. All other combinations of the
configuration bits above are not permissible LCD power supply modes and should be avoided.
LCD Power Supply Configuration
VLL3 is driven internally for 5 V LCD Glass For 5 V glass operation VLL3 must equal 5 V.
operation.
Resistor Bias network enabled.
Charge pump is disabled.
VLL3 must equal VDD
Resistor Bias network is used to create VLL1 and VLL2.
VLL2 connected to VDD internally for 3 or
5 V glass operation.
CPSEL
LCD Operational State
VSUPPLY[1:0]
Table 9-19. LCD Power Supply Options
01
0
00
1
01
1
11
1
11
1
For 3 V glass operation VDD must equal 2 V.
For 5 V glass operation VDD must equal 3.33 V
Charge pump is used to generate VLL1 and VLL3
VLL3 connected to VDD internally for 3 V or For 3 V glass operation VDD must equal 3 V.
5 V glass operation
For 5 V glass operation VDD must equal 5 V.
Charge pump is used to generate VLL1 and VLL2
VLL3 is driven externally for
3 V LCD Glass operation.
For 3 V glass operation VLL3 must equal 3 V.
Charge pump is used to generate VLL1 and VLL2
VLL3 is driven externally for 5 V LCD Glass For 5 V glass operation VLL3 must equal 5 V.
operation.
VLL3 must equal VDD
Charge pump is used to generate VLL1 and VLL2
MC9S08LG32 MCU Series, Rev. 5
Freescale Semiconductor
187
Chapter 8 LCD Module (S08LCDLPV1)
VSUPPLY[1:0]
CPSEL
Table 9-19. LCD Power Supply Options (continued)
VLL3 is driven externally for 3 V LCD Glass For 3 V glass operation VLL3 must equal 3 V.
operation.
Charge pump is disabled.
Resistor Bias Network enabled.
Resistor Bias network is used to create VLL1 and VLL2
11
0
VLL3 is driven externally for 5 V LCD Glass For 5 V glass operation VLL3 must equal 5 V.
operation. Resistor Bias network enabled.
Charge pump is disabled.
VLL3 must equal VDD
Resistor Bias network is used to create VLL1 and VLL2 .
11
0
LCD Operational State
9.4.4.2.1
LCD Power Supply Configuration
LCD External Power Supply, VSUPPLY[1:0] = 11
When VSUPPLY[1:0] = 11, powersw1, and powersw2 are deasserted. VDD is not available to power the
LCD module internally, so the LCD module requires an external power source for VLL1, VLL2, and VLL3
when the charge pump is disabled.
If the charge pump is enabled, external power must be applied to VLL3. With this configuration, the charge
pump will generate the other LCD bias voltages VLL1 and VLL2.
9.4.4.2.2
LCD Internal Power Supply, VSUPPLY[1:0] = 00 or 01
VDD is used as the LCD module power supply when VSUPPLY[1:0] = 00 or 11 (Table 9-20). Table 9-20
provides recommendations regarding configuration of the VSUPPLY[1:0] bit field when using both 3 V
and 5 V LCD panels.
Table 9-20. VDD Switch Option
VSUPPLY[1:0]
9.4.5
VDD Switch Option
Recommend Use for 3-V Recommend Use for 5-V
LCD Panels
LCD Panels
00
VLL2 is generated from VDD
• VLL1 = 1 V
• VDD = VLL2 = 2 V
• VLL3 = 3 V
• VLL1 = 1.67 V
• VDD = VLL2 = 3.3 V
• VLL3 = 5 V
01
VLL3 is generated from VDD
• VLL1 = 1 V
• VLL2 = 2 V
• VDD = VLL3 = 3 V
• VLL1 = 1.67 V
• VLL2 = 3.33 V
• VDD = VLL3 = 5 V
Resets
During a reset, the LCD module system is configured in the default mode. The default mode includes the
following settings:
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•
•
•
•
9.4.6
LCDEN is cleared, thereby forcing all frontplane and backplane driver outputs to the high
impedance state.
1/4 duty
1/3 bias
LCLK[2:0], VSUPPLY[1:0], CPSEL and BRATE[2:0] revert to their reset values
Interrupts
When an LCD module frame-frequency interrupt event occurs, the LCDIF bit in the LCDS register is
asserted. The LCDIF bit remains asserted until software clears the LCD-module-frame-frequency
interrupt. The interrupt can be cleared by software writing a 1 to the LCDIF bit.
If both the LCDIF bit in the LCDS register and the LCDIEN bit in the LCDC1 register are set, an LCD
interrupt signal asserts.
9.5
Initialization Section
This section provides a recommended initialization sequence for the LCD module and also includes
initialization examples for several LCD application scenarios.
9.5.1
Initialization Sequence
The below list provides a recommended initialization sequence for the LCD module.
You must write to all LCDPEN, LCDBPEN, and LCDWF registers to initialize their values after a reset.
1. LCDC0 register
a) Configure LCD clock source (SOURCE bit).
2. LCDSUPPLY register
a) Enable charge pump (CPSEL bit).
b) Configure charge pump clock (LADJ[1:0]).
c) Configure LCD power supply (VSUPPLY[1:0]).
3. LCDC1 register
a) Configure LCD frame frequency interrupt (LCDIEN bit).
b) Configure LCD behavior in low-power mode (LCDWAI and LCDSTP bits).
4. LCDC0 register
a) Configure LCD duty cycle (DUTY[2:0]).
b) Select and configure LCD frame frequency (LCLK[2:0]).
5. LCDBCTL register
a) Configure display mode (ALT and BLANK bits).
b) Configure blink mode (BMODE).
c) Configure blink frequency (BRATE[2:0]).
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6. LCDPEN[5:0] register
a) Enable LCD module pins (PEN[44:0] bits).
7. LCDBPEN[5:0]
a) Enable LCD pins to operate as an LCD backplane (BPEN[44:0]).
8. LCDC0 register
a) Enable LCD module (LCDEN bit).
9.5.2
Initialization Examples
This section provides initialization information for LCD configuration. Each example details the register
and bit-field values required to achieve the appropriate LCD configuration for a given LCD application
scenario. The table below lists each example and the setup requirements.
Table 9-21. LCD Application Scenario
Example
Operating
LCD Glass
LCD Clock
Voltage,
Operating
Source
VDD
Voltage
Required
LCD
segments
LCD
Frame
Rate
Blinking
Mode/Rate
Behavior in
WAIT/STOP
modes
LCD Power
Input
1
5.0 V
External
32.768 kHz
5V
128
30 Hz
None
WAIT: on
STOP: on
Power via
VLL3
(CPump)
2
3.6 V
Internal
39.063 kHz
3V
100
50 Hz
Alternate
0.5 Hz
WAIT: on
STOP: off
Power via
VDD
3
5.0 V
External
32.768 kHz
5V
168
30 Hz
Blank
2.0 Hz
WAIT: off
STOP: off
Power via
VLL3
(RBias)
These examples illustrate the flexibility of the LCD module to be configured to meet a wide range of
application requirements including:
• Clock inputs/sources
• LCD power supply
• LCD glass operating voltage
• LCD segment count
• Varied blink modes/frequencies
• LCD frame rate
9.5.2.1
Initialization Example 1
Table 9-22. LCD Setup Requirements for Example 1
Example
Operating
LCD Glass
LCD Clock
Voltage,
Operating
Source
VDD
Voltage
Required
LCD
segments
LCD
Frame
Rate
Blinking
Mode/Rate
Behavior in
LCD Power
STOP and
Input
WAIT modes
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Chapter 8 LCD Module (S08LCDLPV1)
Table 9-22. LCD Setup Requirements for Example 1
1
5.0 V
External
32.768 kHz
5V
128
30 Hz
None
WAIT: on
STOP: on
Power via
VLL3
(CPump)
The table below lists the setup values required to initialize the LCD as specified by Example 1:
Table 9-23. Initialization Register Values for Example 1
Register
LCDSUPPLY
1-00--11
LCDC1
0------00
LCDC0
00101111
LCDBCTL
0XX-XXXX
LCDPEN[5:0]
LCDBPEN[5:0]
LCDWF[44:0]
bit or
bit field
Binary
Value
CPSEL
1
Enable charge pump
LADJ[1:0]
00
Configure LCD charge pump clock source
VSUPPLY[1:0]
11
When VSUPPLY[1:0] = 11, the LCD must be externally powered via VLL3 (see
Table 9-19). For 5V glass, the nominal value of VLL3 should be 5V.
LCDIEN
0
LCD frame interrupts disabled
LCDWAI
0
LCD is “on” in WAIT mode
LCDSTP
0
LCD is “on” in STOP mode
LCDEN
0
Initialization is done before initializing the LCD module
SOURCE
0
Selects the external clock reference as the LCD clock input (OSCOUT)
LCLK[2:0]
101
For 1/8 duty cycle, select closest value to the desired 30 Hz LCD frame frequency
(see Table 9-12)
DUTY[2:0]
111
For 128 segments (8x16), select 1/8 duty cycle
BLINK
0
No blinking
ALT
X
Alternate bit is configured during LCD operation
BLANK
X
Blank bit is configured during LCD operation
BMODE
X
N/A; Blink Blank = 0; Blink Alternate = 1
BRATE[2:0]
XXX
LCDPEN0
LCDPEN1
LCDPEN2
LCDPEN3
11111111
11111111
11111111
00000000
LCDBPEN0
LCDBPEN1
LCDBPEN2
LCDBPEN3
11111111
00000000
00000000
00000000
Eight backplane pins needed.
LCDWF0
LCDWF1
LCDWF2
LCDWF3
LCDWF4
LCDWF5
LCDWF6
LCDWF7
00000001
00000010
00000100
00001000
00010000
00100000
01000000
10000000
Configure which phase the eight backplane pins will be active in. This
configuration sets LCD[0] to be active in Phase A, LCD[1] to be active in Phase
B...etc
Comment
N/A
Only 24 LCD pins need to be enabled.
Note: Any of the 45 LCD pins can be used, this allows flexibility in the hardware
design.
Note: Any enabled LCD pin can be enabled to operate as a backplane.
Note: Any backplane pin can be active in any phase.
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Chapter 8 LCD Module (S08LCDLPV1)
9.5.2.2
Initialization Example 2
Example 2 LCD setup requirements are reiterated in the table below:
Example
Operating
LCD Glass
LCD Clock
Voltage,
Operating
Source
VDD
Voltage
2
3.6 V
Internal
39.063 kHz
3V
Required
LCD
segments
LCD
Frame
Rate
100
50 Hz
Blinking
Mode/Rate
Behavior in
LCD Power
STOP3 and
Input
WAIT modes
Alternate
0.5 Hz
WAIT: on
STOP: off
Power via
VDD
The table below lists the required setup values required to initialize the LCD as specified by Example 2:
Table 9-24. Initialization Register Values for Example 2
Register
LCDSUPPLY
1-00--01
LCDC1
0-----01
LCDC0
01010011
LCDBCTL
1XX-1100
LCDPEN[5:0]
bit or
bit field
Binary
Value
CPSEL
1
Enable charge pump
LADJ[1:0]
00
Configure LCD charge pump clock source
VSUPPLY[1:0]
01
Generate VLL3 from VDD (See Table 9-19)
LCDIEN
0
LCD Frame Interrupts disabled
LCDWAI
0
LCD is “on” in WAIT mode
LCDSTP
1
LCD is “off” in STOP mode
LCDEN
0
Initialization is done before initializing the LCD module
SOURCE
1
Selects the alternate-clock reference as the LCD clock input (ALTCLK)
This clock source is configured by the ICS TRIM bits to be 39.063Khz.
LCLK[2:0]
010
For 1/4 duty cycle, select closest value to the desired 50 Hz LCD frame
frequency (Table 9-13)
DUTY[2:0]
011
For 100 segments (4x25), select 1/4 duty cycle
BLINK
1
Blinking is turned on or off during LCD operation
ALT
X
Alternate bit is configured during LCD operation
BLANK
X
Blank bit is configured during LCD operation
BMODE
1
Blink Alternate = 1
BRATE[2:0]
100
LCDPEN0
LCDPEN1
LCDPEN2
LCDPEN3
11111111
11111111
11111111
00011111
Comment
Select.5 Hz blink frequency using Table 9-17
29 LCD pins need to be enabled.
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Table 9-24. Initialization Register Values for Example 2 (continued)
Register
LCDBPEN[5:0]
LCDWF[44:0]
bit or
bit field
Binary
Value
LCDBPEN0
LCDBPEN1
LCDBPEN2
LCDBPEN3
00001111
00000000
00000000
00000000
Four backplane pins needed.
LCDWF0
LCDWF1
LCDWF2
LCDWF3
00000001
00000010
00000100
00001000
Configure which phase the four backplane pins will be active in. This
configuration sets LCD[0] to be active in Phase A, LCD[1] to be active in
Phase B etc.
Comment
Note: Any enabled LCD pin can be enabled to operate as a backplane.
Note: Any backplane pin can be active in any of the phases.
9.5.2.3
Initialization Example 3
Example 3 LCD setup requirements are reiterated in the table below:
Example
3
LCD Glass
Operating
LCD Clock
Operating
Voltage,
Source
Voltage
VDD
5.0 V
External
32.768 kHz
5V
Required
LCD
segments
LCD
Frame
Rate
168
30 Hz
Blinking
Mode/Rate
Behavior in
STOP3 and
WAIT modes
LCD
Power
Input
Blank
2.0 Hz
WAIT: off
STOP: off
Power via
VLL3
(RBias)
The table below lists the required setup values required to initialize the LCD as specified by Example 3:
Table 9-25. Initialization Register Values for Example 3
Register
LCDSUPPLY
0-00--11
LCDC1
0-----11
LCDC0
00101111
bit or
bit field
Binary
Value
CPSEL
0
Disable charge pump, Resistor network selected.
LADJ[1:0]
00
Configure LCD charge pump clock source
VSUPPLY[1:0]
11
When VSUPPLY[1:0] = 11, the LCD powered via VLL3
(see Table 9-19).
LCDIEN
0
LCD Frame Interrupts disabled
LCDWAI
1
LCD is “off” in WAIT mode
LCDSTP
1
LCD is “off” in STOP mode
LCDEN
0
Initialization is done before initializing the LCD module
SOURCE
0
Selects OSCOUT as the LCD clock source (32.768 kHz crystal)
LCLK[2:0]
101
For 1/8 duty cycle, select closest value to the desired 30 Hz LCD frame
frequency (see Table 9-12)
DUTY[2:0]
111
For 168 segments (8x21), select 1/8 duty cycle
Comment
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Chapter 8 LCD Module (S08LCDLPV1)
Table 9-25. Initialization Register Values for Example 3 (continued)
bit or
bit field
Binary
Value
BLINK
X
Blinking is turned on or off during LCD operation
ALT
X
Alternate bit is configured during LCD operation
BLANK
X
Blank bit is configured during LCD operation
BMODE
0
Blink to a blank mode
BRATE[2:0]
010
LCDPEN[5:0]
LCDPEN0
LCDPEN1
LCDPEN2
LCDPEN3
11111111
11111111
11111111
00011111
29 LCD pins need to be enabled.
LCDBPEN[5:0]
LCDBPEN0
LCDBPEN1
LCDBPEN2
LCDBPEN3
11111111
00000000
00000000
00000000
Eight backplane pins needed.
LCDWF0
LCDWF1
LCDWF2
LCDWF3
LCDWF4
LCDWF5
LCDWF6
LCDWF7
00000001
00000010
00000100
00001000
00010000
00100000
01000000
10000000
Configure which phase the eight backplane pins will be active in. This
configuration sets LCD[0] to be active in Phase A, LCD[1] to be active in
Phase B. . . etc.
Register
LCDBCTL
XXX-0010
LCDWF[44:0]
9.6
Comment
Select 2 Hz blink frequency using Table 9-17
Note: Any enabled LCD pin can be enabled to operate as a backplane
This configuration sets LCD pins 0-7 to represent backplane 1-8.
Note: Any backplane pin can be active in any phase
Application Information
Figure 9-16 is a programmer’s model of the LCD module. The programmer’s model groups the LCD
module register bit and bit field into functional groups. The model is a high-level illustration of the LCD
module showing the module’s functional hierarchy including initialization and runtime control.
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Chapter 8 LCD Module (S08LCDLPV1)
LCD Segment Display and Blink Control
Data Bus
LCD Segment Energize
Display Mode Select
LCDBCTL
ALT
BLANK
Shown with 7-segment
LCD glass hardware
Blink Enable
and Command
Blink Mode Select
LCD GLASS PANEL
LCDBCTL
BMODE
LCD[10:4]
LCD[3:0]
Segment Energize
LCDWF
BPyLCDx
Segment Alternate
Display Energize
LCDWF
BPyLCDx
LCD Frame
Frequency
Interrupt
LCDC1
LCDIEN
Initialization Options
External Crystal = 32.768 kHz
Alternate Clock Source
LCD Pin Enable
LCDPENR[5:0]
PEN[44:0]
Module Enable
LCDC0
LCDEN
Input Clock Source
Power Options
LCDC0
SOURCE
VLL3
LCDSUPPLY
HREFSEL
CPSEL
BBYPASS
VSUPPLY[1:0]
LCDRVC
RVEN
RVTRIM[3:0]
Frame Frequency
LCDC0
LCLK[2:0]
DUTY[2:0]
Blink Rate & Mode
LCDBCTL
BMODE
BRATE[2:0]
Backplane Assignment
LCDWF
LCDWFx
LCDS
LCDIF
VLL2
VLL1
LCD Power Pins
NOTE: Configured
for power using
internal VDD
CTYP = 0.1 μF
Low Power
LCDC1
LCDWAI
LCDSTP
Backplane Enable
LCDBPEN[5:0]
BPEN[44:0]
Vcap1
0.1 μF
Vcap2
LCD charge pump capacitance
Figure 9-17. LCD Programmer’s Model Diagram
9.6.1
LCD Seven Segment Example Description
A description of the connection between the LCD module and a seven segment LCD character is illustrated
below to provide a basic example for a 1/3 duty cycle LCD implementation. The example uses three
backplane pins (LCD[3], LCD[4] and LCD[5] and 3 frontplane pins (LCD[0], LCD[1], and LCD[2]).
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Chapter 8 LCD Module (S08LCDLPV1)
LCDWF contents and output waveforms are also shown. Output waveforms are illustrated in Figure 9-18
and Figure 9-19.
FP Connection
a
g
BP Connection
a
b
f
c
e
BP0 (a, b COMMONED)
b
g
f
d
BP1 (c, f, g COMMONED)
c
d
e
BP2 (d, e COMMONED)
FP2 (b, c COMMONED)
FP1 (a, d, g COMMONED)
FP0 (e, f COMMONED)
The above segment assignments are provided by the specification for the LCD glass for this example.
For this LCD Module any of the LCD pins can be configured to be Frontplane 0-2 or Backplane 0-2.
For this example we will set LCD[0] as FP0, LCD[1] as FP1, and LCD[2] as FP2.
For this example we will set LCD[3] as BP0, LCD[4] as BP1 and LCD[5] as BP2.
Backplane assignment is done in the LCDWF register as shown below:
LCDWF3
0
0
0
0
0
0
0
1
LCDWF4
0
0
0
0
0
0
1
0
LCDWF5
0
0
0
0
0
1
0
0
With the above conditions the segment assignment is shown below:
LCDWF0
–
–
–
–
–
e
f
–
LCDWF1
–
–
–
–
–
d
g
a
LCDWF2
–
–
–
–
–
–
c
b
To display the character “4”: LCDWF0 = XXXXX01X, LCDWF1 = XXXXX010, LCDWF2 =XXXXXX11
LCDWF0
X
X
X
X
X
0
1
X
LCDWF1
X
X
X
X
X
0
1
0
a
f
e
LCDWF2
X
X
X
X
X
X
1
g
d
b
c
1
X = don’t care
Figure 9-18. Waveform Output from LCDWF Registers
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Chapter 8 LCD Module (S08LCDLPV1)
9.6.1.1
LCD Module Waveforms
DUTY = 1/3
1FRAME
V3
LCD3/BP0
V2
V1
V0
V3
V2
LCD4/BP1
V1
V0
V3
LCD5/BP2
V2
V1
V0
V3
BPCLCD0 BPBLCD0 BPALCD0
—
0
1
0
V2
LCD0/FP0
V1
V0
V3
BPCLCD1 BPBLCD1 BPALCD1
—
0
1
0
V2
LCD1/FP1
V1
V0
V3
V2
BPCLCD2 BPBLCD2 BPALCD2
—
0
1
1
LCD2/FP2
V1
V0
Figure 9-19. LCD Waveforms
MC9S08LG32 MCU Series, Rev. 5
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Chapter 8 LCD Module (S08LCDLPV1)
9.6.1.2
Segment On Driving Waveform
The voltage waveform across the “f” segment of the LCD (between LCD[4]/BP1 and LCD[0]/FP0) is
illustrated in Figure 9-20. As shown in the waveform, the voltage level reaches the value V3 therefore the
segment will be on.
+VLL3
+V2
+V1
BP1–FP0
V0
–V1
–V2
–V3
Figure 9-20. “f” Segment Voltage Waveform
9.6.1.3
Segment Off Driving Waveform
The voltage waveform across the “e” segment of the LCD (between LCD[5]/BP2 and LCD[0]/FP0) is
illustrated in Figure 9-21. As shown in the waveform, the voltage does not reach the voltage V3 threshold
therefore the segment will be off.
+V3
+V2
+V1
V0
BP2–FP0
–V1
–V2
–V3
Figure 9-21. “e” Segment Voltage Waveform
9.6.2
LCD Contrast Control
Contrast control for the LCD module is achieved when the LCD power supply is adjusted above and below
the LCD threshold voltage. The LCD threshold voltage is the nominal voltage required to energize the
LCD segments. For 3 V LCD glass, the LCD threshold voltage is 3 V; while for 5 V LCD glass it is 5 V.
By increasing the value of the LCD voltage, the energized segments on the LCD glass will become more
opaque. Decreasing the value of the LCD voltage makes the energized segments on the LCD glass become
more transparent. The LCD power supply can be adjusted to facilitate contrast control by using external
components like a variable resistor. Figure 9-22 shows two circuits that can be used to implement contrast
control.
Increasing the value of the LCD voltage will cause the energized segments on the LCD glass to become
more opaque. Decreasing the value of the LCD voltage makes the energized segments on the LCD glass
more transparent.
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NOTE:
Contrast control configuration when
LCD is powered using external VLL3
LCD[10:4]
LCD GLASS PANEL
LCD[3:0]
This is the recommended configuration
for contrast control.
LCD Power Supply
HC9S08LG32
VLL3
VLL2
LCD Power Pins
VLL1
R
CTYP = 0.1 μF
Vcap1
Vcap2
0.1 μF
LCD charge pump capacitance
NOTE:
Contrast control configuration
when LCD is powered using
internal VDD
LCD[10:4]
LCD GLASS PANEL
LCD[3:0]
HC9S08LG32
Power Supply
VLL3
LCD Power Pins
VLL2
VLL1
VDD
CTYP = 0.1 μF
R
Vcap1
Vcap2
0.1 μF
LCD charge pump capacitance
Figure 9-22. Power Connections for Contrast Control
9.6.3
Stop Mode Recovery
When the MCU recovers from stop2 mode a reset sequence is initiated. All Control Registers should be
re-written before the stop2 recovery acknowledge bit is set. The Registers LCDBPEN, LCDPEN and the
LCDWF retain their values upon stop2 recovery and do not need to be re-written.
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Chapter 10
Analog-to-Digital Converter (S08ADC12V1)
10.1
Introduction
The 12-bit analog-to-digital converter (ADC) is a successive approximation ADC designed for operation
within an integrated microcontroller system-on-chip.
Figure 10-1 shows the MC9S08LG32 series with the ADC module highlighted.
10.1.1
ADC shared with LCD
PTA2/SDA/ADC0/LCD23, PTA3/KBI4/TX2/ADC1/LCD24, PTA4/KBI5/RX2/ADC2/LCD25,
PTA5/KBI6/TPM2CH0/ADC3/LCD26, PTA6/KBI7/TPM2CH1/ADC4/LCD27 and
PTA7/TPMCLK/ADC5/LCD28 share ADC functionality with LCD pins. To avoid the possibility of
placing a voltage greater than VDD on an ADC input, LCD functionality must be disabled for these pins
to operate as ADC pins.
As ADC inputs, these pins operate just like other ADC pins. If the ADC channel input channel voltage is
more that the LCD reference voltage (VMCU or VLL3) then there would be some leakage through the ADC
input.
10.1.2
ADC Reference and Supply Voltage
For MC9S08LG32 series devices, the ADC reference inputs (VREFH and VREFL) are shorted with the ADC
supply (VDDA and VSSA). The ADC supply must be within ±100 mV of main supply VDD, otherwise there
would be some leakage through the VDDA pad.
10.1.3
ADC Clock Gating
The bus clock to the ADC can be gated on and off using the ADC bit in SCGC1. This bit is cleared after
any reset, which disables the bus clock to this module. To conserve power, the ADC bit can be cleared to
disable the clock to this module when not in use. See Section 5.7, “Peripheral Clock Gating,” for more
details.
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Chapter 10 Analog-to-Digital Converter (S08ADC12V1)
8-BIT KEYBOARD
INTERRUPT (KBI)
RESET
IRQ
SERIAL PERIPHERAL
INTERFACE (SPI)
KBI[7:0]
SS
SPSCK
MISO
RESET/PTC6
BKGD/MS/PTC5
LCD[20:16]/PTC[4:0]
MOSI
SCL
IIC MODULE (IIC)
USER FLASH A
(LG32 = 16K BYTES)
(LG16 = 2K BYTES)
6-CHANNEL TIMER/PWM
(TPM2)
USER FLASH B
(LG32 = 16K BYTES)
(LG16 = 16K BYTES)
2-CHANNEL TIMER/PWM
(TPM1)
SERIAL COMMUNICATIONS
INTERFACE (SCI1)
USER RAM
SDA
TPM2CH[5:0]
TPMCLK
PORT D
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
LVD
LCD[40:37]/PTB[7:4]
LCD[32:29]/PTB[3:0]
TMRCLK
LCD[7:0]/PTD[7:0]
PORT E
Modulo Timer
(MTIM)
IRQ
PORT A
Real Time Counter
(RTC)
HCS08 SYSTEM CONTROL
COP
PORT B
BKGD/MS
LCD[15:8]/PTE[7:0]
TPM1CH[1:0]
PORT F
BKP
EXTAL/PTF7
XTAL/PTF6
TPM2CH3/KBI2/MOSI/PTF5
TPM2CH4/KBI1/MISO/PTF4
TPM2CH5/KBI0/SS/PTF3
ADC14/IRQ/TPM1CH1/SPSCK/PTF2
ADC13/TPM1CH0/RX1/PTF1
ADC12/TPM2CH2/KBI3/TX1/PTF0
PORT G
BKGD
LCD[44:41]/PTG[7:4]
LCD[36:33]/PTG[3:0]
PORT H
INT
ON-CHIP ICE (ICE) and
DEBUG MODULE (DBG)
TPM2CH4/KBI1/PTH7
ADC15/KBI0/TPM2CH5/PTH6
ADC11/TPM1CH0/KBI3/TX1/PTH5
ADC10/TPM1CH1/KBI2/RX1/PTH4
ADC[9:6]/KBI[7:4]/PTH[3:0]
PORT I
CPU
LCD28/ADC5/TPMCLK/PTA7
LCD27/ADC4/TPM2CH1/KBI7/PTA6
LCD26/ADC3/TPM2CH0/KBI6/PTA5
LCD25/ADC2/RX2/KBI5/PTA4
LCD24/ADC1/TX2/KBI4/PTA3
LCD23/ADC0/SDA/PTA2
LCD22/SCL/PTA1
LCD21/PTA0
PORT C
HCS08 CORE
SS/SCL/TPM2CH0/PTI5
SPSCK/SDA/TPM2CH1/PTI4
MOSI/TPM2CH2/PTI3
MISO/TPM2CH3/PTI2
TX2/TMRCLK/PTI1
RX2/PTI0
TPMCLK
TxD1
RxD1
1984 BYTES
SERIAL COMMUNICATIONS
INTERFACE (SCI2)
INTERNAL CLOCK
Source (ICS)
TxD2
RxD2
XTAL
LOW-POWER OSCILLATOR
EXTAL
12-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
VLL3_2
VLL3
VLL1
VLL2
VCAP1
AD[15:0]
LIQUID CRYSTAL
DISPLAY DRIVER
(LCD)
VCAP2
LCD[44:0]
VDD
VSS
VSS2
VOLTAGE
REGULATOR
Available only on 80-pin package
Available only on 64-pin and 80-pin package
*/Default function out of reset/*
VDDA/VREFH
VSSA/VREFL
Figure 10-1. MC9S08LG32 Series Block Diagram Highlighting ADC Block and Pins
10.1.4
Module Configurations
This section provides device-specific information for configuring the ADC on MC9S08LG32 series.
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10.1.4.1
Configurations for Low Power Modes
The ADC, if enabled in stop3 mode, must be configured to use the asynchronous clock source, ADACK,
to meet the ADC minimum frequency requirements.
10.1.4.2
Channel Assignments
The ADC channel assignments for the MC9S08LG32 series devices are shown in Table 10-1. Reserved
channels convert to an unknown value.
Table 10-1. ADC Channel Assignment
1
ADCH
Channel
Input
Pin Control
ADCH
Channel
Input
Pin Control
00000
AD0
PTA2/ADP0
ADPC0
10000
AD16
Reserved
N/A
00001
AD1
PTA3/ADP1
ADPC1
10001
AD17
Reserved
N/A
00010
AD2
PTA4/ADP2
ADPC2
10010
AD18
Reserved
N/A
00011
AD3
PTA5/ADP3
ADPC3
10011
AD19
Reserved
N/A
00100
AD4
PTA6/ADP4
ADPC4
10100
AD20
Reserved
N/A
00101
AD5
PTA7/ADP5
ADPC5
10101
AD21
VLL2
N/A
00110
AD6
PTH0/ADP6
ADPC6
10110
AD22
VLL1
N/A
00111
AD7
PTH1/ADP7
ADPC7
10111
AD23
Reserved
N/A
01000
AD8
PTH2/ADP8
ADPC8
11000
AD24
Reserved
N/A
01001
AD9
PTH3/ADP9
ADPC9
11001
AD25
Reserved
N/A
01010
AD10
PTH4/ADP10
ADPC10
11010
AD26
Temperature
Sensor1
N/A
01011
AD11
PTH5/ADP11
ADPC11
11011
AD27
Internal Bandgap
N/A
01100
AD12
PTF0/ADP12
ADPC12
11100
—
Reserved
N/A
01101
AD13
PTF1/ADP13
ADPC13
11101
VREFH
VREFH
N/A
01110
AD14
PTF2/ADP14
ADPC14
11110
VREFL
VREFL
N/A
01111
AD15
PTH6/ADP15
ADPC15
11111
Module
Disabled
None
N/A
For information, see Section 10.1.4.5, “Temperature Sensor.”
NOTE
Selecting the internal bandgap channel requires BGBE = 1 in SPMSC1, see
Section 5.8.7, “System Power Management Status and Control 1 Register
(SPMSC1),” for more details. For value of bandgap voltage reference, see
MC9S08LG32 Data Sheet.
10.1.4.3
Alternate Clock
The ADC is capable of performing conversions using the MCU bus clock, the bus clock divided by two,
the local asynchronous clock (ADACK) within the module, or the alternate clock (ALTCLK). The
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ALTCLK on the MC9S08LG32 series is connected to the ICSERCLK. See Chapter 11, “Internal Clock
Source (S08ICSV3),” for more information.
10.1.4.4
Hardware Trigger
The RTC can be enabled as a hardware trigger for the ADC module by setting the ADTRG bit in the
ADCSC2 register. When enabled, the ADC will be triggered every time a RTC overflow condition occurs.
The RTC overflow interrupt does not have to be enabled to trigger the ADC.
The RTC can be configured to cause a hardware trigger in MCU run, wait, and stop3.
10.1.4.5
Temperature Sensor
The ADC module includes a temperature sensor whose output is connected to one of the ADC analog
channel inputs. Equation 10-1 provides an approximate transfer function of the temperature sensor.
Temp = 25 - ((VTEMP -VTEMP25) ÷ m)
Eqn. 10-1
where:
— VTEMP is the voltage of the temperature sensor channel at the ambient temperature.
— VTEMP25 is the voltage of the temperature sensor channel at 25 °C.
— m is the hot or cold voltage versus temperature slope in V/°C.
For temperature calculations, use the VTEMP25 and m values in the MC9S08LG32 Data Sheet.
In application code, you read the temperature sensor channel, calculate VTEMP, and compare it to
VTEMP25. If VTEMP is greater than VTEMP25 the cold slope value is applied in Equation 10-1. If VTEMP is
less than VTEMP25 the hot slope value is applied in Equation 10-1.
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10.1.5
Features
Features of the ADC module include:
• Linear successive approximation algorithm with 12-bit resolution
• Up to 28 analog inputs
• Output formatted in 12-, 10-, or 8-bit right-justified unsigned format
• Single or continuous conversion (automatic return to idle after single conversion)
• Configurable sample time and conversion speed/power
• Conversion complete flag and interrupt
• Input clock selectable from up to four sources
• Operation in wait or stop3 modes for lower noise operation
• Asynchronous clock source for lower noise operation
• Selectable asynchronous hardware conversion trigger
• Automatic compare with interrupt for less-than, or greater-than or equal-to, programmable value
• Temperature sensor
10.1.6
ADC Module Block Diagram
Figure 10-2 provides a block diagram of the ADC module.
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ADIV
ADLPC
MODE
ADLSMP
ADTRG
2
ADCO
ADCH
1
ADCCFG
complete
COCO
ADCSC1
ADICLK
Compare true
AIEN
3
Async
Clock Gen
ADACK
MCU STOP
ADCK
÷2
ALTCLK
abort
transfer
sample
initialize
•••
AD0
convert
Control Sequencer
ADHWT
Bus Clock
Clock
Divide
AIEN 1
COCO 2
ADVIN
Interrupt
SAR Converter
AD27
VREFH
Data Registers
Sum
VREFL
Compare true
3
Compare Value Registers
ACFGT
Value
Compare
Logic
ADCSC2
Figure 10-2. ADC Block Diagram
10.2
External Signal Description
The ADC module supports up to 28 separate analog inputs. It also requires four supply/reference/ground
connections.
Table 10-2. Signal Properties
Name
Function
AD27–AD0
Analog Channel inputs
VREFH
High reference voltage
VREFL
Low reference voltage
VDDA
Analog power supply
VSSA
Analog ground
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Chapter 9 Analog-to-Digital Converter (S08ADC12V1)
10.2.1
Analog Power (VDDA)
The ADC analog portion uses VDDA as its power connection. In some packages, VDDA is connected
internally to VDD. If externally available, connect the VDDA pin to the same voltage potential as VDD.
External filtering may be necessary to ensure clean VDDA for good results.
10.2.2
Analog Ground (VSSA)
The ADC analog portion uses VSSA as its ground connection. In some packages, VSSA is connected
internally to VSS. If externally available, connect the VSSA pin to the same voltage potential as VSS.
10.2.3
Voltage Reference High (VREFH)
VREFH is the high reference voltage for the converter. In some packages, VREFH is connected internally to
VDDA. If externally available, VREFH may be connected to the same potential as VDDA or may be driven
by an external source between the minimum VDDA spec and the VDDA potential (VREFH must never
exceed VDDA).
10.2.4
Voltage Reference Low (VREFL)
VREFL is the low-reference voltage for the converter. In some packages, VREFL is connected internally to
VSSA. If externally available, connect the VREFL pin to the same voltage potential as VSSA.
10.2.5
Analog Channel Inputs (ADx)
The ADC module supports up to 28 separate analog inputs. An input is selected for conversion through
the ADCH channel select bits.
10.3
Register Definition
These memory-mapped registers control and monitor operation of the ADC:
• Status and control register, ADCSC1
• Status and control register, ADCSC2
• Data result registers, ADCRH and ADCRL
• Compare value registers, ADCCVH and ADCCVL
• Configuration register, ADCCFG
• Pin control registers, APCTL1, APCTL2, APCTL3
10.3.1
Status and Control Register 1 (ADCSC1)
This section describes the function of the ADC status and control register (ADCSC1). Writing ADCSC1
aborts the current conversion and initiates a new conversion (if the ADCH bits are equal to a value other
than all 1s).
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7
R
6
5
AIEN
ADCO
0
0
4
3
2
1
0
1
1
COCO
ADCH
W
Reset:
0
1
1
1
Figure 10-3. Status and Control Register (ADCSC1)
Table 10-3. ADCSC1 Field Descriptions
Field
Description
7
COCO
Conversion Complete Flag. The COCO flag is a read-only bit set each time a conversion is completed when the
compare function is disabled (ACFE = 0). When the compare function is enabled (ACFE = 1), the COCO flag is
set upon completion of a conversion only if the compare result is true. This bit is cleared when ADCSC1 is written
or when ADCRL is read.
0 Conversion not completed
1 Conversion completed
6
AIEN
Interrupt Enable AIEN enables conversion complete interrupts. When COCO becomes set while AIEN is high,
an interrupt is asserted.
0 Conversion complete interrupt disabled
1 Conversion complete interrupt enabled
5
ADCO
Continuous Conversion Enable. ADCO enables continuous conversions.
0 One conversion following a write to the ADCSC1 when software triggered operation is selected, or one
conversion following assertion of ADHWT when hardware triggered operation is selected.
1 Continuous conversions initiated following a write to ADCSC1 when software triggered operation is selected.
Continuous conversions are initiated by an ADHWT event when hardware triggered operation is selected.
4:0
ADCH
Input Channel Select. The ADCH bits form a 5-bit field that selects one of the input channels. The input channels
are detailed in Table 10-4.
The successive approximation converter subsystem is turned off when the channel select bits are all set. This
feature allows for explicit disabling of the ADC and isolation of the input channel from all sources. Terminating
continuous conversions this way prevents an additional, single conversion from being performed. It is not
necessary to set the channel select bits to all ones to place the ADC in a low-power state when continuous
conversions are not enabled because the module automatically enters a low-power state when a conversion
completes.
Table 10-4. Input Channel Select
ADCH
Input Select
00000–01111
AD0–15
10000–11011
AD16–27
11100
Reserved
11101
VREFH
11110
VREFL
11111
Module disabled
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Chapter 9 Analog-to-Digital Converter (S08ADC12V1)
10.3.2
Status and Control Register 2 (ADCSC2)
The ADCSC2 register controls the compare function, conversion trigger, and conversion active of the
ADC module.
7
R
6
5
4
ADTRG
ACFE
ACFGT
0
0
0
ADACT
3
2
0
0
0
0
1
0
R1
R1
0
0
W
Reset:
0
Figure 10-4. Status and Control Register 2 (ADCSC2)
1
Bits 1 and 0 are reserved bits that must always be written to 0.
Table 10-5. ADCSC2 Register Field Descriptions
Field
Description
7
ADACT
Conversion Active. Indicates that a conversion is in progress. ADACT is set when a conversion is initiated and
cleared when a conversion is completed or aborted.
0 Conversion not in progress
1 Conversion in progress
6
ADTRG
Conversion Trigger Select. Selects the type of trigger used for initiating a conversion. Two types of triggers are
selectable: software trigger and hardware trigger. When software trigger is selected, a conversion is initiated
following a write to ADCSC1. When hardware trigger is selected, a conversion is initiated following the assertion
of the ADHWT input.
0 Software trigger selected
1 Hardware trigger selected
5
ACFE
4
ACFGT
10.3.3
Compare Function Enable. Enables the compare function.
0 Compare function disabled
1 Compare function enabled
Compare Function Greater Than Enable. Configures the compare function to trigger when the result of the
conversion of the input being monitored is greater than or equal to the compare value. The compare function
defaults to triggering when the result of the compare of the input being monitored is less than the compare value.
0 Compare triggers when input is less than compare value
1 Compare triggers when input is greater than or equal to compare value
Data Result High Register (ADCRH)
In 12-bit operation, ADCRH contains the upper four bits of the result of a 12-bit conversion. In 10-bit
mode, ADCRH contains the upper two bits of the result of a 10-bit conversion. When configured for 10-bit
mode, ADR[11:10] are cleared. When configured for 8-bit mode, ADR[11:8] are cleared.
In 12-bit and 10-bit mode, ADCRH is updated each time a conversion completes except when automatic
compare is enabled and the compare condition is not met. When a compare event does occur, the value is
the addition of the conversion result and the two’s complement of the compare value. In 12-bit and 10-bit
mode, reading ADCRH prevents the ADC from transferring subsequent conversion results into the result
registers until ADCRL is read. If ADCRL is not read until after the next conversion is completed, the
intermediate conversion result is lost. In 8-bit mode, there is no interlocking with ADCRL.
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If the MODE bits are changed, any data in ADCRH becomes invalid.
R
7
6
5
4
3
2
1
0
0
0
0
0
ADR11
ADR10
ADR9
ADR8
0
0
0
0
0
0
0
0
W
Reset:
Figure 10-5. Data Result High Register (ADCRH)
10.3.4
Data Result Low Register (ADCRL)
ADCRL contains the lower eight bits of the result of a 12-bit or 10-bit conversion, and all eight bits of an
8-bit conversion. This register is updated each time a conversion completes except when automatic
compare is enabled and the compare condition is not met. In 12-bit and 10-bit mode, reading ADCRH
prevents the ADC from transferring subsequent conversion results into the result registers until ADCRL
is read. If ADCRL is not read until the after next conversion is completed, the intermediate conversion
results are lost. In 8-bit mode, there is no interlocking with ADCRH. If the MODE bits are changed, any
data in ADCRL becomes invalid.
R
7
6
5
4
3
2
1
0
ADR7
ADR6
ADR5
ADR4
ADR3
ADR2
ADR1
ADR0
0
0
0
0
0
0
0
0
W
Reset:
Figure 10-6. Data Result Low Register (ADCRL)
10.3.5
Compare Value High Register (ADCCVH)
In 12-bit mode, the ADCCVH register holds the upper four bits of the 12-bit compare value. When the
compare function is enabled, these bits are compared to the upper four bits of the result following a
conversion in 12-bit mode.
R
7
6
5
4
0
0
0
0
3
2
1
0
ADCV11
ADCV10
ADCV9
ADCV8
0
0
0
0
W
Reset:
0
0
0
0
Figure 10-7. Compare Value High Register (ADCCVH)
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Chapter 9 Analog-to-Digital Converter (S08ADC12V1)
In 10-bit mode, the ADCCVH register holds the upper two bits of the 10-bit compare value (ADCV[9:8]).
These bits are compared to the upper two bits of the result following a conversion in 10-bit mode when the
compare function is enabled.
In 8-bit mode, ADCCVH is not used during compare.
10.3.6
Compare Value Low Register (ADCCVL)
This register holds the lower 8 bits of the 12-bit or 10-bit compare value or all 8 bits of the 8-bit compare
value. When the compare function is enabled, bits ADCV[7:0] are compared to the lower 8 bits of the
result following a conversion in 12-bit, 10-bit or 8-bit mode.
7
6
5
4
3
2
1
0
ADCV7
ADCV6
ADCV5
ADCV4
ADCV3
ADCV2
ADCV1
ADCV0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 10-8. Compare Value Low Register(ADCCVL)
10.3.7
Configuration Register (ADCCFG)
ADCCFG selects the mode of operation, clock source, clock divide, and configures for low-power and
long sample time.
7
6
5
4
3
2
1
0
R
ADLPC
ADIV
ADLSMP
MODE
ADICLK
W
Reset:
0
0
0
0
0
0
0
0
Figure 10-9. Configuration Register (ADCCFG)
Table 10-6. ADCCFG Register Field Descriptions
Field
Description
7
ADLPC
Low-Power Configuration. ADLPC controls the speed and power configuration of the successive approximation
converter. This optimizes power consumption when higher sample rates are not required.
0 High speed configuration
1 Low-power configuration:The power is reduced at the expense of maximum clock speed.
6:5
ADIV
4
ADLSMP
Clock Divide Select. ADIV selects the divide ratio used by the ADC to generate the internal clock ADCK.
Table 10-7 shows the available clock configurations.
Long Sample Time Configuration. ADLSMP selects between long and short sample time. This adjusts the
sample period to allow higher impedance inputs to be accurately sampled or to maximize conversion speed for
lower impedance inputs. Longer sample times can also be used to lower overall power consumption when
continuous conversions are enabled if high conversion rates are not required.
0 Short sample time
1 Long sample time
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Table 10-6. ADCCFG Register Field Descriptions (continued)
Field
Description
3:2
MODE
Conversion Mode Selection. MODE bits are used to select between 12-, 10-, or 8-bit operation. See Table 10-8.
1:0
ADICLK
Input Clock Select. ADICLK bits select the input clock source to generate the internal clock ADCK. See
Table 10-9.
Table 10-7. Clock Divide Select
ADIV
Divide Ratio
Clock Rate
00
1
Input clock
01
2
Input clock ÷ 2
10
4
Input clock ÷ 4
11
8
Input clock ÷ 8
Table 10-8. Conversion Modes
MODE
Mode Description
00
8-bit conversion (N=8)
01
12-bit conversion (N=12)
10
10-bit conversion (N=10)
11
Reserved
Table 10-9. Input Clock Select
ADICLK
00
10.3.8
Selected Clock Source
Bus clock
01
Bus clock divided by 2
10
Alternate clock (ALTCLK)
11
Asynchronous clock (ADACK)
Pin Control 1 Register (APCTL1)
The pin control registers disable the I/O port control of MCU pins used as analog inputs. APCTL1 is used
to control the pins associated with channels 0–7 of the ADC module.
7
6
5
4
3
2
1
0
ADPC7
ADPC6
ADPC5
ADPC4
ADPC3
ADPC2
ADPC1
ADPC0
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 10-10. Pin Control 1 Register (APCTL1)
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Chapter 9 Analog-to-Digital Converter (S08ADC12V1)
Table 10-10. APCTL1 Register Field Descriptions
Field
Description
7
ADPC7
ADC Pin Control 7. ADPC7 controls the pin associated with channel AD7.
0 AD7 pin I/O control enabled
1 AD7 pin I/O control disabled
6
ADPC6
ADC Pin Control 6. ADPC6 controls the pin associated with channel AD6.
0 AD6 pin I/O control enabled
1 AD6 pin I/O control disabled
5
ADPC5
ADC Pin Control 5. ADPC5 controls the pin associated with channel AD5.
0 AD5 pin I/O control enabled
1 AD5 pin I/O control disabled
4
ADPC4
ADC Pin Control 4. ADPC4 controls the pin associated with channel AD4.
0 AD4 pin I/O control enabled
1 AD4 pin I/O control disabled
3
ADPC3
ADC Pin Control 3. ADPC3 controls the pin associated with channel AD3.
0 AD3 pin I/O control enabled
1 AD3 pin I/O control disabled
2
ADPC2
ADC Pin Control 2. ADPC2 controls the pin associated with channel AD2.
0 AD2 pin I/O control enabled
1 AD2 pin I/O control disabled
1
ADPC1
ADC Pin Control 1. ADPC1 controls the pin associated with channel AD1.
0 AD1 pin I/O control enabled
1 AD1 pin I/O control disabled
0
ADPC0
ADC Pin Control 0. ADPC0 controls the pin associated with channel AD0.
0 AD0 pin I/O control enabled
1 AD0 pin I/O control disabled
10.3.9
Pin Control 2 Register (APCTL2)
APCTL2 controls channels 8–15 of the ADC module.
7
6
5
4
3
2
1
0
ADPC15
ADPC14
ADPC13
ADPC12
ADPC11
ADPC10
ADPC9
ADPC8
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 10-11. Pin Control 2 Register (APCTL2)
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Table 10-11. APCTL2 Register Field Descriptions
Field
Description
7
ADPC15
ADC Pin Control 15. ADPC15 controls the pin associated with channel AD15.
0 AD15 pin I/O control enabled
1 AD15 pin I/O control disabled
6
ADPC14
ADC Pin Control 14. ADPC14 controls the pin associated with channel AD14.
0 AD14 pin I/O control enabled
1 AD14 pin I/O control disabled
5
ADPC13
ADC Pin Control 13. ADPC13 controls the pin associated with channel AD13.
0 AD13 pin I/O control enabled
1 AD13 pin I/O control disabled
4
ADPC12
ADC Pin Control 12. ADPC12 controls the pin associated with channel AD12.
0 AD12 pin I/O control enabled
1 AD12 pin I/O control disabled
3
ADPC11
ADC Pin Control 11. ADPC11 controls the pin associated with channel AD11.
0 AD11 pin I/O control enabled
1 AD11 pin I/O control disabled
2
ADPC10
ADC Pin Control 10. ADPC10 controls the pin associated with channel AD10.
0 AD10 pin I/O control enabled
1 AD10 pin I/O control disabled
1
ADPC9
ADC Pin Control 9. ADPC9 controls the pin associated with channel AD9.
0 AD9 pin I/O control enabled
1 AD9 pin I/O control disabled
0
ADPC8
ADC Pin Control 8. ADPC8 controls the pin associated with channel AD8.
0 AD8 pin I/O control enabled
1 AD8 pin I/O control disabled
10.3.10 Pin Control 3 Register (APCTL3)
APCTL3 controls channels 16–23 of the ADC module.
7
6
5
4
3
2
1
0
ADPC23
ADPC22
ADPC21
ADPC20
ADPC19
ADPC18
ADPC17
ADPC16
0
0
0
0
0
0
0
0
R
W
Reset:
Figure 10-12. Pin Control 3 Register (APCTL3)
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Chapter 9 Analog-to-Digital Converter (S08ADC12V1)
Table 10-12. APCTL3 Register Field Descriptions
Field
Description
7
ADPC23
ADC Pin Control 23. ADPC23 controls the pin associated with channel AD23.
0 AD23 pin I/O control enabled
1 AD23 pin I/O control disabled
6
ADPC22
ADC Pin Control 22. ADPC22 controls the pin associated with channel AD22.
0 AD22 pin I/O control enabled
1 AD22 pin I/O control disabled
5
ADPC21
ADC Pin Control 21. ADPC21 controls the pin associated with channel AD21.
0 AD21 pin I/O control enabled
1 AD21 pin I/O control disabled
4
ADPC20
ADC Pin Control 20. ADPC20 controls the pin associated with channel AD20.
0 AD20 pin I/O control enabled
1 AD20 pin I/O control disabled
3
ADPC19
ADC Pin Control 19. ADPC19 controls the pin associated with channel AD19.
0 AD19 pin I/O control enabled
1 AD19 pin I/O control disabled
2
ADPC18
ADC Pin Control 18. ADPC18 controls the pin associated with channel AD18.
0 AD18 pin I/O control enabled
1 AD18 pin I/O control disabled
1
ADPC17
ADC Pin Control 17. ADPC17 controls the pin associated with channel AD17.
0 AD17 pin I/O control enabled
1 AD17 pin I/O control disabled
0
ADPC16
ADC Pin Control 16. ADPC16 controls the pin associated with channel AD16.
0 AD16 pin I/O control enabled
1 AD16 pin I/O control disabled
10.4
Functional Description
The ADC module is disabled during reset or when the ADCH bits are all high. The module is idle when a
conversion has completed and another conversion has not been initiated. When idle, the module is in its
lowest power state.
The ADC can perform an analog-to-digital conversion on any of the software selectable channels. In 12-bit
and 10-bit mode, the selected channel voltage is converted by a successive approximation algorithm into
a 12-bit digital result. In 8-bit mode, the selected channel voltage is converted by a successive
approximation algorithm into a 9-bit digital result.
When the conversion is completed, the result is placed in the data registers (ADCRH and ADCRL). In
10-bit mode, the result is rounded to 10 bits and placed in the data registers (ADCRH and ADCRL). In
8-bit mode, the result is rounded to 8 bits and placed in ADCRL. The conversion complete flag (COCO)
is then set and an interrupt is generated if the conversion complete interrupt has been enabled (AIEN = 1).
The ADC module has the capability of automatically comparing the result of a conversion with the
contents of its compare registers. The compare function is enabled by setting the ACFE bit and operates
with any of the conversion modes and configurations.
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10.4.1
Clock Select and Divide Control
One of four clock sources can be selected as the clock source for the ADC module. This clock source is
then divided by a configurable value to generate the input clock to the converter (ADCK). The clock is
selected from one of the following sources by means of the ADICLK bits.
• The bus clock, which is equal to the frequency at which software is executed. This is the default
selection following reset.
• The bus clock divided by two. For higher bus clock rates, this allows a maximum divide by 16 of
the bus clock.
• ALTCLK, as defined for this MCU (See module section introduction).
• The asynchronous clock (ADACK). This clock is generated from a clock source within the ADC
module. When selected as the clock source, this clock remains active while the MCU is in wait or
stop3 mode and allows conversions in these modes for lower noise operation.
Whichever clock is selected, its frequency must fall within the specified frequency range for ADCK. If the
available clocks are too slow, the ADC do not perform according to specifications. If the available clocks
are too fast, the clock must be divided to the appropriate frequency. This divider is specified by the ADIV
bits and can be divide-by 1, 2, 4, or 8.
10.4.2
Input Select and Pin Control
The pin control registers (APCTL3, APCTL2, and APCTL1) disable the I/O port control of the pins used
as analog inputs.When a pin control register bit is set, the following conditions are forced for the associated
MCU pin:
• The output buffer is forced to its high impedance state.
• The input buffer is disabled. A read of the I/O port returns a zero for any pin with its input buffer
disabled.
• The pullup is disabled.
10.4.3
Hardware Trigger
The ADC module has a selectable asynchronous hardware conversion trigger, ADHWT, that is enabled
when the ADTRG bit is set. This source is not available on all MCUs. Consult the module introduction for
information on the ADHWT source specific to this MCU.
When ADHWT source is available and hardware trigger is enabled (ADTRG=1), a conversion is initiated
on the rising edge of ADHWT. If a conversion is in progress when a rising edge occurs, the rising edge is
ignored. In continuous convert configuration, only the initial rising edge to launch continuous conversions
is observed. The hardware trigger function operates in conjunction with any of the conversion modes and
configurations.
10.4.4
Conversion Control
Conversions can be performed in 12-bit mode, 10-bit mode, or 8-bit mode as determined by the MODE
bits. Conversions can be initiated by a software or hardware trigger. In addition, the ADC module can be
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configured for low-power operation, long sample time, continuous conversion, and automatic compare of
the conversion result to a software determined compare value.
10.4.4.1
Initiating Conversions
A conversion is initiated:
• Following a write to ADCSC1 (with ADCH bits not all 1s) if software triggered operation is
selected.
• Following a hardware trigger (ADHWT) event if hardware triggered operation is selected.
• Following the transfer of the result to the data registers when continuous conversion is enabled.
If continuous conversions are enabled, a new conversion is automatically initiated after the completion of
the current conversion. In software triggered operation, continuous conversions begin after ADCSC1 is
written and continue until aborted. In hardware triggered operation, continuous conversions begin after a
hardware trigger event and continue until aborted.
10.4.4.2
Completing Conversions
A conversion is completed when the result of the conversion is transferred into the data result registers,
ADCRH and ADCRL. This is indicated by the setting of COCO. An interrupt is generated if AIEN is high
at the time that COCO is set.
A blocking mechanism prevents a new result from overwriting previous data in ADCRH and ADCRL if
the previous data is in the process of being read while in 12-bit or 10-bit MODE (the ADCRH register has
been read but the ADCRL register has not). When blocking is active, the data transfer is blocked, COCO
is not set, and the new result is lost. In the case of single conversions with the compare function enabled
and the compare condition false, blocking has no effect and ADC operation is terminated. In all other cases
of operation, when a data transfer is blocked, another conversion is initiated regardless of the state of
ADCO (single or continuous conversions enabled).
If single conversions are enabled, the blocking mechanism could result in several discarded conversions
and excess power consumption. To avoid this issue, the data registers must not be read after initiating a
single conversion until the conversion completes.
10.4.4.3
Aborting Conversions
Any conversion in progress is aborted when:
•
A write to ADCSC1 occurs (the current conversion will be aborted and a new conversion will be
initiated, if ADCH are not all 1s).
•
A write to ADCSC2, ADCCFG, ADCCVH, or ADCCVL occurs. This indicates a mode of
operation change has occurred and the current conversion is therefore invalid.
•
The MCU is reset.
•
The MCU enters stop mode with ADACK not enabled.
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When a conversion is aborted, the contents of the data registers, ADCRH and ADCRL, are not altered.
However, they continue to be the values transferred after the completion of the last successful conversion.
If the conversion was aborted by a reset, ADCRH and ADCRL return to their reset states.
10.4.4.4
Power Control
The ADC module remains in its idle state until a conversion is initiated. If ADACK is selected as the
conversion clock source, the ADACK clock generator is also enabled.
Power consumption when active can be reduced by setting ADLPC. This results in a lower maximum
value for fADCK (see the electrical specifications).
10.4.4.5
Sample Time and Total Conversion Time
The total conversion time depends on the sample time (as determined by ADLSMP), the MCU bus
frequency, the conversion mode (8-bit, 10-bit or 12-bit), and the frequency of the conversion clock (fADCK).
After the module becomes active, sampling of the input begins. ADLSMP selects between short (3.5
ADCK cycles) and long (23.5 ADCK cycles) sample times.When sampling is complete, the converter is
isolated from the input channel and a successive approximation algorithm is performed to determine the
digital value of the analog signal. The result of the conversion is transferred to ADCRH and ADCRL upon
completion of the conversion algorithm.
If the bus frequency is less than the fADCK frequency, precise sample time for continuous conversions
cannot be guaranteed when short sample is enabled (ADLSMP=0). If the bus frequency is less than 1/11th
of the fADCK frequency, precise sample time for continuous conversions cannot be guaranteed when long
sample is enabled (ADLSMP=1).
The maximum total conversion time for different conditions is summarized in Table 10-13.
Table 10-13. Total Conversion Time vs. Control Conditions
Conversion Type
ADICLK
ADLSMP
Max Total Conversion Time
Single or first continuous 8-bit
10
0
20 ADCK cycles + 5 bus clock cycles
Single or first continuous 10-bit or 12-bit
10
0
23 ADCK cycles + 5 bus clock cycles
Single or first continuous 8-bit
10
1
40 ADCK cycles + 5 bus clock cycles
Single or first continuous 10-bit or 12-bit
10
1
43 ADCK cycles + 5 bus clock cycles
Single or first continuous 8-bit
11
0
5 μs + 20 ADCK + 5 bus clock cycles
Single or first continuous 10-bit or 12-bit
11
0
5 μs + 23 ADCK + 5 bus clock cycles
Single or first continuous 8-bit
11
1
5 μs + 40 ADCK + 5 bus clock cycles
Single or first continuous 10-bit or 12-bit
11
1
5 μs + 43 ADCK + 5 bus clock cycles
Subsequent continuous 8-bit;
fBUS > fADCK
xx
0
17 ADCK cycles
Subsequent continuous 10-bit or 12-bit;
fBUS > fADCK
xx
0
20 ADCK cycles
Subsequent continuous 8-bit;
fBUS > fADCK/11
xx
1
37 ADCK cycles
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Table 10-13. Total Conversion Time vs. Control Conditions
(continued)
Conversion Type
ADICLK
ADLSMP
Max Total Conversion Time
Subsequent continuous 10-bit or 12-bit;
fBUS > fADCK/11
xx
1
40 ADCK cycles
The maximum total conversion time is determined by the clock source chosen and the divide ratio selected.
The clock source is selectable by the ADICLK bits, and the divide ratio is specified by the ADIV bits. For
example, in 10-bit mode, with the bus clock selected as the input clock source, the input clock divide-by-1
ratio selected, and a bus frequency of 8 MHz, then the conversion time for a single conversion is:
Conversion time =
23 ADCK Cyc
8 MHz
+
5 bus Cyc
8 MHz
= 3.5 μs
Number of bus cycles = 28 cycles
NOTE
The ADCK frequency must be between fADCK minimum and fADCK
maximum to meet ADC specifications.
10.4.5
Automatic Compare Function
The compare function can be configured to check for an upper or lower limit. After the input is sampled
and converted, the result is added to the two’s complement of the compare value (ADCCVH and
ADCCVL). When comparing to an upper limit (ACFGT = 1), if the result is greater-than or equal-to the
compare value, COCO is set. When comparing to a lower limit (ACFGT = 0), if the result is less than the
compare value, COCO is set. The value generated by the addition of the conversion result and the two’s
complement of the compare value is transferred to ADCRH and ADCRL.
Upon completion of a conversion while the compare function is enabled, if the compare condition is not
true, COCO is not set and no data is transferred to the result registers. An ADC interrupt is generated upon
the setting of COCO if the ADC interrupt is enabled (AIEN = 1).
NOTE
The compare function can monitor the voltage on a channel while the MCU
is in wait or stop3 mode. The ADC interrupt wakes the MCU when the
compare condition is met.
10.4.6
MCU Wait Mode Operation
Wait mode is a lower power-consumption standby mode from which recovery is fast because the clock
sources remain active. If a conversion is in progress when the MCU enters wait mode, it continues until
completion. Conversions can be initiated while the MCU is in wait mode by means of the hardware trigger
or if continuous conversions are enabled.
The bus clock, bus clock divided by two, and ADACK are available as conversion clock sources while in
wait mode. The use of ALTCLK as the conversion clock source in wait is dependent on the definition of
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ALTCLK for this MCU. Consult the module introduction for information on ALTCLK specific to this
MCU.
A conversion complete event sets the COCO and generates an ADC interrupt to wake the MCU from wait
mode if the ADC interrupt is enabled (AIEN = 1).
10.4.7
MCU Stop3 Mode Operation
Stop mode is a low-power-consumption standby mode during which most or all clock sources on the MCU
are disabled.
10.4.7.1
Stop3 Mode With ADACK Disabled
If the asynchronous clock, ADACK, is not selected as the conversion clock, executing a stop instruction
aborts the current conversion and places the ADC in its idle state. The contents of ADCRH and ADCRL
are unaffected by stop3 mode. After exiting from stop3 mode, a software or hardware trigger is required
to resume conversions.
10.4.7.2
Stop3 Mode With ADACK Enabled
If ADACK is selected as the conversion clock, the ADC continues operation during stop3 mode. For
guaranteed ADC operation, the MCU’s voltage regulator must remain active during stop3 mode. Consult
the module introduction for configuration information for this MCU.
If a conversion is in progress when the MCU enters stop3 mode, it continues until completion. Conversions
can be initiated while the MCU is in stop3 mode by means of the hardware trigger or if continuous
conversions are enabled.
A conversion complete event sets the COCO and generates an ADC interrupt to wake the MCU from stop3
mode if the ADC interrupt is enabled (AIEN = 1).
NOTE
The ADC module can wake the system from low-power stop and cause the
MCU to begin consuming run-level currents without generating a system
level interrupt. To prevent this scenario, software should ensure the data
transfer blocking mechanism (discussed in Section 10.4.4.2, “Completing
Conversions”) is cleared when entering stop3 and continuing ADC
conversions.
10.4.8
MCU Stop2 Mode Operation
The ADC module is automatically disabled when the MCU enters stop2 mode. All module registers
contain their reset values following exit from stop2. Therefore, the module must be re-enabled and
re-configured following exit from stop2.
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10.5
Initialization Information
This section gives an example that provides some basic direction on how to initialize and configure the
ADC module. You can configure the module for 8-, 10-, or 12-bit resolution, single or continuous
conversion, and a polled or interrupt approach, among many other options. Refer to Table 10-7,
Table 10-8, and Table 10-9 for information used in this example.
NOTE
Hexadecimal values designated by a preceding 0x, binary values designated
by a preceding %, and decimal values have no preceding character.
10.5.1
ADC Module Initialization Example
10.5.1.1
Initialization Sequence
Before the ADC module can be used to complete conversions, an initialization procedure must be
performed. A typical sequence is as follows:
1. Update the configuration register (ADCCFG) to select the input clock source and the divide ratio
used to generate the internal clock, ADCK. This register is also used for selecting sample time and
low-power configuration.
2. Update status and control register 2 (ADCSC2) to select the conversion trigger (hardware or
software) and compare function options, if enabled.
3. Update status and control register 1 (ADCSC1) to select whether conversions will be continuous
or completed only once, and to enable or disable conversion complete interrupts. The input channel
on which conversions will be performed is also selected here.
10.5.1.2
Pseudo-Code Example
In this example, the ADC module is set up with interrupts enabled to perform a single 10-bit conversion
at low-power with a long sample time on input channel 1, where the internal ADCK clock is derived from
the bus clock divided by 1.
ADCCFG = 0x98 (%10011000)
Bit
Bit
Bit
Bit
Bit
7
6:5
4
3:2
1:0
ADLPC
ADIV
ADLSMP
MODE
ADICLK
1
00
1
10
00
Configures for low-power (lowers maximum clock speed)
Sets the ADCK to the input clock ÷ 1
Configures for long sample time
Sets mode at 10-bit conversions
Selects bus clock as input clock source
ADCSC2 = 0x00 (%00000000)
Bit
Bit
Bit
Bit
Bit
Bit
7
6
5
4
3:2
1:0
ADACT
ADTRG
ACFE
ACFGT
0
0
0
0
00
00
Flag indicates if a conversion is in progress
Software trigger selected
Compare function disabled
Not used in this example
Reserved, always reads zero
Reserved for Freescale’s internal use; always write zero
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ADCSC1 = 0x41 (%01000001)
Bit
Bit
Bit
Bit
7
6
5
4:0
COCO
AIEN
ADCO
ADCH
0
1
0
00001
Read-only flag which is set when a conversion completes
Conversion complete interrupt enabled
One conversion only (continuous conversions disabled)
Input channel 1 selected as ADC input channel
ADCRH/L = 0xxx
Holds results of conversion. Read high byte (ADCRH) before low byte (ADCRL) so that
conversion data cannot be overwritten with data from the next conversion.
ADCCVH/L = 0xxx
Holds compare value when compare function enabled
APCTL1=0x02
AD1 pin I/O control disabled. All other AD pins remain general purpose I/O pins
APCTL2=0x00
All other AD pins remain general purpose I/O pins
Reset
Initialize ADC
ADCCFG = 0x98
ADCSC2 = 0x00
ADCSC1 = 0x41
Check
COCO=1?
No
Yes
Read ADCRH
Then ADCRL To
Clear COCO Bit
Continue
Figure 10-13. Initialization Flowchart for Example
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10.6
Application Information
This section contains information for using the ADC module in applications. The ADC has been designed
to be integrated into a microcontroller for use in embedded control applications requiring an A/D
converter.
10.6.1
External Pins and Routing
The following sections discuss the external pins associated with the ADC module and how they should be
used for best results.
10.6.1.1
Analog Supply Pins
The ADC module has analog power and ground supplies (VDDA and VSSA) available as separate pins on
some devices. VSSA is shared on the same pin as the MCU digital VSS on some devices. On other devices,
VSSA and VDDA are shared with the MCU digital supply pins. In these cases, there are separate pads for
the analog supplies bonded to the same pin as the corresponding digital supply so that some degree of
isolation between the supplies is maintained.
When available on a separate pin, both VDDA and VSSA must be connected to the same voltage potential
as their corresponding MCU digital supply (VDD and VSS) and must be routed carefully for maximum
noise immunity and bypass capacitors placed as near as possible to the package.
If separate power supplies are used for analog and digital power, the ground connection between these
supplies must be at the VSSA pin. This should be the only ground connection between these supplies if
possible. The VSSA pin makes a good single point ground location.
10.6.1.2
Analog Reference Pins
In addition to the analog supplies, the ADC module has connections for two reference voltage inputs. The
high reference is VREFH, which may be shared on the same pin as VDDA on some devices. The low
reference is VREFL, which may be shared on the same pin as VSSA on some devices.
When available on a separate pin, VREFH may be connected to the same potential as VDDA, or may be
driven by an external source between the minimum VDDA spec and the VDDA potential (VREFH must never
exceed VDDA). When available on a separate pin, VREFL must be connected to the same voltage potential
as VSSA. VREFH and VREFL must be routed carefully for maximum noise immunity and bypass capacitors
placed as near as possible to the package.
AC current in the form of current spikes required to supply charge to the capacitor array at each successive
approximation step is drawn through the VREFH and VREFL loop. The best external component to meet this
current demand is a 0.1 μF capacitor with good high frequency characteristics. This capacitor is connected
between VREFH and VREFL and must be placed as near as possible to the package pins. Resistance in the
path is not recommended because the current causes a voltage drop that could result in conversion errors.
Inductance in this path must be minimum (parasitic only).
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10.6.1.3
Analog Input Pins
The external analog inputs are typically shared with digital I/O pins on MCU devices. The pin I/O control
is disabled by setting the appropriate control bit in one of the pin control registers. Conversions can be
performed on inputs without the associated pin control register bit set. It is recommended that the pin
control register bit always be set when using a pin as an analog input. This avoids problems with contention
because the output buffer is in its high impedance state and the pullup is disabled. Also, the input buffer
draws DC current when its input is not at VDD or VSS. Setting the pin control register bits for all pins used
as analog inputs should be done to achieve lowest operating current.
Empirical data shows that capacitors on the analog inputs improve performance in the presence of noise
or when the source impedance is high. Use of 0.01 μF capacitors with good high-frequency characteristics
is sufficient. These capacitors are not necessary in all cases, but when used they must be placed as near as
possible to the package pins and be referenced to VSSA.
For proper conversion, the input voltage must fall between VREFH and VREFL. If the input is equal to or
exceeds VREFH, the converter circuit converts the signal to 0xFFF (full scale 12-bit representation), 0x3FF
(full scale 10-bit representation) or 0xFF (full scale 8-bit representation). If the input is equal to or less
than VREFL, the converter circuit converts it to 0x000. Input voltages between VREFH and VREFL are
straight-line linear conversions. There is a brief current associated with VREFL when the sampling
capacitor is charging. The input is sampled for 3.5 cycles of the ADCK source when ADLSMP is low, or
23.5 cycles when ADLSMP is high.
For minimal loss of accuracy due to current injection, pins adjacent to the analog input pins should not be
transitioning during conversions.
10.6.2
Sources of Error
Several sources of error exist for A/D conversions. These are discussed in the following sections.
10.6.2.1
Sampling Error
For proper conversions, the input must be sampled long enough to achieve the proper accuracy. Given the
maximum input resistance of approximately 7kΩ and input capacitance of approximately 5.5 pF, sampling
to within 1/4LSB (at 12-bit resolution) can be achieved within the minimum sample window (3.5 cycles @
8 MHz maximum ADCK frequency) provided the resistance of the external analog source (RAS) is kept
below 2 kΩ.
Higher source resistances or higher-accuracy sampling is possible by setting ADLSMP (to increase the
sample window to 23.5 cycles) or decreasing ADCK frequency to increase sample time.
10.6.2.2
Pin Leakage Error
Leakage on the I/O pins can cause conversion error if the external analog source resistance (RAS) is high.
If this error cannot be tolerated by the application, keep RAS lower than VDDA / (2N*ILEAK) for less than
1/4LSB leakage error (N = 8 in 8-bit, 10 in 10-bit or 12 in 12-bit mode).
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10.6.2.3
Noise-Induced Errors
System noise that occurs during the sample or conversion process can affect the accuracy of the
conversion. The ADC accuracy numbers are guaranteed as specified only if the following conditions are
met:
• There is a 0.1 μF low-ESR capacitor from VREFH to VREFL.
• There is a 0.1 μF low-ESR capacitor from VDDA to VSSA.
• If inductive isolation is used from the primary supply, an additional 1 μF capacitor is placed from
VDDA to VSSA.
• VSSA (and VREFL, if connected) is connected to VSS at a quiet point in the ground plane.
• Operate the MCU in wait or stop3 mode before initiating (hardware triggered conversions) or
immediately after initiating (hardware or software triggered conversions) the ADC conversion.
— For software triggered conversions, immediately follow the write to ADCSC1 with a wait
instruction or stop instruction.
— For stop3 mode operation, select ADACK as the clock source. Operation in stop3 reduces VDD
noise but increases effective conversion time due to stop recovery.
• There is no I/O switching, input or output, on the MCU during the conversion.
There are some situations where external system activity causes radiated or conducted noise emissions or
excessive VDD noise is coupled into the ADC. In these situations, or when the MCU cannot be placed in
wait or stop3 or I/O activity cannot be halted, these recommended actions may reduce the effect of noise
on the accuracy:
• Place a 0.01 μF capacitor (CAS) on the selected input channel to VREFL or VSSA (this improves
noise issues, but affects the sample rate based on the external analog source resistance).
• Average the result by converting the analog input many times in succession and dividing the sum
of the results. Four samples are required to eliminate the effect of a 1LSB, one-time error.
• Reduce the effect of synchronous noise by operating off the asynchronous clock (ADACK) and
averaging. Noise that is synchronous to ADCK cannot be averaged out.
10.6.2.4
Code Width and Quantization Error
The ADC quantizes the ideal straight-line transfer function into 4096 steps (in 12-bit mode). Each step
ideally has the same height (1 code) and width. The width is defined as the delta between the transition
points to one code and the next. The ideal code width for an N bit converter (in this case N can be 8, 10 or
12), defined as 1LSB, is:
1 lsb = (VREFH - VREFL) / 2N
Eqn. 10-2
There is an inherent quantization error due to the digitization of the result. For 8-bit or 10-bit conversions
the code transitions when the voltage is at the midpoint between the points where the straight line transfer
function is exactly represented by the actual transfer function. Therefore, the quantization error will be ±
1/2 lsb in 8- or 10-bit mode. As a consequence, however, the code width of the first (0x000) conversion is
only 1/2 lsb and the code width of the last (0xFF or 0x3FF) is 1.5 lsb.
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For 12-bit conversions the code transitions only after the full code width is present, so the quantization
error is −1 lsb to 0 lsb and the code width of each step is 1 lsb.
10.6.2.5
Linearity Errors
The ADC may also exhibit non-linearity of several forms. Every effort has been made to reduce these
errors but the system should be aware of them because they affect overall accuracy. These errors are:
• Zero-scale error (EZS) (sometimes called offset) — This error is defined as the difference between
the actual code width of the first conversion and the ideal code width (1/2 lsb in 8-bit or 10-bit
modes and 1 lsb in 12-bit mode). If the first conversion is 0x001, the difference between the actual
0x001 code width and its ideal (1 lsb) is used.
• Full-scale error (EFS) — This error is defined as the difference between the actual code width of
the last conversion and the ideal code width (1.5 lsb in 8-bit or 10-bit modes and 1LSB in 12-bit
mode). If the last conversion is 0x3FE, the difference between the actual 0x3FE code width and its
ideal (1LSB) is used.
• Differential non-linearity (DNL) — This error is defined as the worst-case difference between the
actual code width and the ideal code width for all conversions.
• Integral non-linearity (INL) — This error is defined as the highest-value the (absolute value of the)
running sum of DNL achieves. More simply, this is the worst-case difference of the actual
transition voltage to a given code and its corresponding ideal transition voltage, for all codes.
• Total unadjusted error (TUE) — This error is defined as the difference between the actual transfer
function and the ideal straight-line transfer function and includes all forms of error.
10.6.2.6
Code Jitter, Non-Monotonicity, and Missing Codes
Analog-to-digital converters are susceptible to three special forms of error. These are code jitter,
non-monotonicity, and missing codes.
Code jitter is when, at certain points, a given input voltage converts to one of two values when sampled
repeatedly. Ideally, when the input voltage is infinitesimally smaller than the transition voltage, the
converter yields the lower code (and vice-versa). However, even small amounts of system noise can cause
the converter to be indeterminate (between two codes) for a range of input voltages around the transition
voltage. This range is normally around ±1/2 lsb in 8-bit or 10-bit mode, or around 2 lsb in 12-bit mode,
and increases with noise.
This error may be reduced by repeatedly sampling the input and averaging the result. Additionally the
techniques discussed in Section 10.6.2.3, “Noise-Induced Errors.” reduces this error.
Non-monotonicity is defined as when, except for code jitter, the converter converts to a lower code for a
higher input voltage. Missing codes are those values never converted for any input value.
In 8-bit or 10-bit mode, the ADC is guaranteed to be monotonic and have no missing codes.
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Chapter 11
Internal Clock Source (S08ICSV3)
11.1
Introduction
The internal clock source (ICS) module provides clock source choices for the MCU. The module contains
a frequency-locked loop (FLL) as a clock source that is controllable by either an internal or an external
reference clock. The module can provide this FLL clock or either of the internal or external reference
clocks as a source for the MCU system clock. There are also signals provided to control a low-power
oscillator (XOSC) module to allow the use of an external crystal/resonator as the external reference clock.
Whichever clock source is chosen for ICSOUT, it is passed through a reduced bus divider (BDIV) which
allows a lower final output clock frequency to be derived.
NOTE
The ICS on the MC9S08LG32 series is configured to support only the low
and mid range DCO, therefore the DRS[1] and DRST[1] bits in ICSSC have
no effect. The FLL will only multiply the reference clock by 512/1024 or
608/1216 depending on the state of the DMX32 bit.
Figure 11-1 shows the MC9S08LG32 series block diagram with the ICS block highlighted.
During user modes, the trim registers of ICS are automatically loaded with factory programmed values.
During debug modes, the trim registers of ICS default to predefined values (see Section 11.3.3, “ICS Trim
Register (ICSTRM)” and Section 11.3.4, “ICS Status and Control (ICSSC)”). To get trimmed clock values
in debug mode, the user can follow the steps as described in Section 4.4.1, “Reserved Flash Locations.”
MC9S08LG32 MCU Series, Rev. 5
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Chapter 11 Internal Clock Source (S08ICSV3)
8-BIT KEYBOARD
INTERRUPT (KBI)
RESET
IRQ
SERIAL PERIPHERAL
INTERFACE (SPI)
KBI[7:0]
SS
SPSCK
MISO
RESET/PTC6
BKGD/MS/PTC5
LCD[20:16]/PTC[4:0]
MOSI
SCL
IIC MODULE (IIC)
USER FLASH A
(LG32 = 16K BYTES)
(LG16 = 2K BYTES)
6-CHANNEL TIMER/PWM
(TPM2)
USER FLASH B
(LG32 = 16K BYTES)
(LG16 = 16K BYTES)
2-CHANNEL TIMER/PWM
(TPM1)
SERIAL COMMUNICATIONS
INTERFACE (SCI1)
USER RAM
SDA
TPM2CH[5:0]
TPMCLK
PORT D
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
LVD
LCD[40:37]/PTB[7:4]
LCD[32:29]/PTB[3:0]
TMRCLK
LCD[7:0]/PTD[7:0]
PORT E
Modulo Timer
(MTIM)
IRQ
PORT A
Real Time Counter
(RTC)
HCS08 SYSTEM CONTROL
COP
PORT B
BKGD/MS
LCD[15:8]/PTE[7:0]
TPM1CH[1:0]
PORT F
BKP
EXTAL/PTF7
XTAL/PTF6
TPM2CH3/KBI2/MOSI/PTF5
TPM2CH4/KBI1/MISO/PTF4
TPM2CH5/KBI0/SS/PTF3
ADC14/IRQ/TPM1CH1/SPSCK/PTF2
ADC13/TPM1CH0/RX1/PTF1
ADC12/TPM2CH2/KBI3/TX1/PTF0
PORT G
BKGD
LCD[44:41]/PTG[7:4]
LCD[36:33]/PTG[3:0]
PORT H
INT
ON-CHIP ICE (ICE) and
DEBUG MODULE (DBG)
TPM2CH4/KBI1/PTH7
ADC15/KBI0/TPM2CH5/PTH6
ADC11/TPM1CH0/KBI3/TX1/PTH5
ADC10/TPM1CH1/KBI2/RX1/PTH4
ADC[9:6]/KBI[7:4]/PTH[3:0]
PORT I
CPU
LCD28/ADC5/TPMCLK/PTA7
LCD27/ADC4/TPM2CH1/KBI7/PTA6
LCD26/ADC3/TPM2CH0/KBI6/PTA5
LCD25/ADC2/RX2/KBI5/PTA4
LCD24/ADC1/TX2/KBI4/PTA3
LCD23/ADC0/SDA/PTA2
LCD22/SCL/PTA1
LCD21/PTA0
PORT C
HCS08 CORE
SS/SCL/TPM2CH0/PTI5
SPSCK/SDA/TPM2CH1/PTI4
MOSI/TPM2CH2/PTI3
MISO/TPM2CH3/PTI2
TX2/TMRCLK/PTI1
RX2/PTI0
TPMCLK
TxD1
RxD1
1984 BYTES
SERIAL COMMUNICATIONS
INTERFACE (SCI2)
INTERNAL CLOCK
Source (ICS)
TxD2
RxD2
XTAL
LOW-POWER OSCILLATOR
12-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
VLL3_2
VLL3
VLL1
VLL2
VCAP1
EXTAL
AD[15:0]
LIQUID CRYSTAL
DISPLAY DRIVER
(LCD)
VCAP2
LCD[44:0]
VDD
VSS
VSS2
VOLTAGE
REGULATOR
VDDA/VREFH
VSSA/VREFL
Available only on 80-pin package
Available only on 64-pin and 80-pin package
*/Default function out of reset/*
Figure 11-1. MC9S08LG32 Series Block Diagram Highlighting ICS Block and Pins
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Chapter 16 Internal Clock Source (S08ICSV3)
11.1.1
Features
Key features of the ICS module are:
• Frequency-locked loop (FLL) is trimmable for accuracy
• Internal or external reference clocks can be used to control the FLL
• Reference divider is provided for external clock
• Internal reference clock has 9 trim bits available
• Internal or external reference clocks can be selected as the clock source for the MCU
• Whichever clock is selected as the source can be divided down
— 2 bit select for clock divider is provided
– Allowable dividers are: 1, 2, 4, 8
• Control signals for a low-power oscillator clock generator (OSCOUT) as the ICS external
reference clock are provided
— HGO, RANGE, EREFS, ERCLKEN, EREFSTEN
• FLL Engaged Internal mode is automatically selected out of reset
• BDC clock is provided as a constant divide by 2 of the low range DCO output
• Three selectable digitally controlled oscillators (DCO) optimized for different frequency ranges.
• Option to maximize output frequency for a 32768 Hz external reference clock source.
11.1.2
Block Diagram
Figure 11-2 is the ICS block diagram.
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Chapter 16 Internal Clock Source (S08ICSV3)
External Reference
Clock (XOSC)
STOP
OSCOUT
ICSERCLK
ERCLKEN
HGO
EREFS
IRCLKEN
ICSIRCLK
EREFSTEN
RANGE
CLKS
BDIV
IREFSTEN
/ 2n
Internal
Reference
Clock
DCOOUT
LP
ICSDCLK
FLL
n=0-10
RDIV
/2
ICSLCLK
DCOL
Filter DCOM
DCOH
/ 2n
FTRIM TRIM
ICSOUT
n=0-3
IREFS
DMX32
DRS
ICSFFCLK
DRST IREFST CLKST OSCINIT
Internal Clock Source Block
Figure 11-2. Internal Clock Source (ICS) Block Diagram
11.1.3
Modes of Operation
There are seven modes of operation for the ICS: FEI, FEE, FBI, FBILP, FBE, FBELP, and stop.
11.1.3.1
FLL Engaged Internal (FEI)
In FLL engaged internal mode, which is the default mode, the ICS supplies a clock derived from the FLL
which is controlled by the internal reference clock. The BDC clock is supplied from the FLL.
11.1.3.2
FLL Engaged External (FEE)
In FLL engaged external mode, the ICS supplies a clock derived from the FLL which is controlled by an
external reference clock source. The BDC clock is supplied from the FLL.
11.1.3.3
FLL Bypassed Internal (FBI)
In FLL bypassed internal mode, the FLL is enabled and controlled by the internal reference clock, but is
bypassed. The ICS supplies a clock derived from the internal reference clock. The BDC clock is supplied
from the FLL.
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Chapter 16 Internal Clock Source (S08ICSV3)
11.1.3.4
FLL Bypassed Internal Low Power (FBILP)
In FLL bypassed internal low-power mode, the FLL is disabled and bypassed, and the ICS supplies a clock
derived from the internal reference clock. The BDC clock is not available.
11.1.3.5
FLL Bypassed External (FBE)
In FLL bypassed external mode, the FLL is enabled and controlled by an external reference clock, but is
bypassed. The ICS supplies a clock derived from the external reference clock source. The BDC clock is
supplied from the FLL.
11.1.3.6
FLL Bypassed External Low Power (FBELP)
In FLL bypassed external low-power mode, the FLL is disabled and bypassed, and the ICS supplies a clock
derived from the external reference clock. The BDC clock is not available.
11.1.3.7
Stop (STOP)
In stop mode the FLL is disabled and the internal reference clock (ICSIRCLK) and XOSC output clock
(OSCOUT) can be selected to be enabled or disabled. The BDC clock is not available and the ICS does
not provide an MCU clock source.
NOTE
The DCO frequency changes from the pre-stop value to its reset value and
the FLL will need to re-acquire the lock before the frequency is stable.
Timing sensitive operations should wait for the FLL acquistition time,
tAquire, before executing.
11.2
External Signal Description
There are no ICS signals that connect off chip.
11.3
Register Definition
Figure 11-1 is a summary of ICS registers.
Table 11-1. ICS Register Summary
Name
7
6
5
4
3
2
1
0
IREFS
IRCLKEN
IREFSTEN
EREFS
ERCLKEN
EREFSTEN
R
ICSC1
CLKS
RDIV
W
R
ICSC2
BDIV
RANGE
HGO
LP
W
R
ICSTRM
TRIM
W
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Chapter 16 Internal Clock Source (S08ICSV3)
Table 11-1. ICS Register Summary (continued)
Name
7
6
R
5
DRST
3
IREFST
ICSSC
2
CLKST
1
0
OSCINIT
DMX32
W
11.3.1
4
FTRIM
DRS
ICS Control Register 1 (ICSC1)
7
6
5
4
3
2
1
0
IREFS
IRCLKEN
IREFSTEN
1
0
0
R
CLKS
RDIV
W
Reset:
0
0
0
0
0
Figure 11-3. ICS Control Register 1 (ICSC1)
Table 11-2. ICS Control Register 1 Field Descriptions
Field
Description
7:6
CLKS
Clock Source Select — Selects the clock source that controls the bus frequency. The actual bus frequency
depends on the value of the BDIV bits.
00 Output of FLL is selected.
01 Internal reference clock is selected.
10 External reference clock is selected.
11 Reserved, defaults to 00.
5:3
RDIV
Reference Divider — Selects the amount to divide down the external reference clock. Resulting frequency must
be in the range 31.25 kHz to 39.0625 kHz. See Table 11-3 for the divide-by factors.
2
IREFS
Internal Reference Select — The IREFS bit selects the reference clock source for the FLL.
1 Internal reference clock selected
0 External reference clock selected
1
IRCLKEN
0
IREFSTEN
Internal Reference Clock Enable — The IRCLKEN bit enables the internal reference clock for use as
ICSIRCLK.
1 ICSIRCLK active
0 ICSIRCLK inactive
Internal Reference Stop Enable — The IREFSTEN bit controls whether or not the internal reference clock
remains enabled when the ICS enters stop mode.
1 Internal reference clock stays enabled in stop if IRCLKEN is set before entering stop
0 Internal reference clock is disabled in stop
Table 11-3. Reference Divide Factor
RDIV
RANGE=0
RANGE=1
0
11
32
1
2
64
2
4
128
3
8
256
4
16
512
5
32
1024
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Chapter 16 Internal Clock Source (S08ICSV3)
Table 11-3. Reference Divide Factor
RDIV
1
RANGE=0
RANGE=1
6
64
Reserved
7
128
Reserved
Reset default
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Chapter 16 Internal Clock Source (S08ICSV3)
11.3.2
ICS Control Register 2 (ICSC2)
7
6
5
4
3
2
RANGE
HGO
LP
EREFS
0
0
0
0
1
0
R
BDIV
ERCLKEN EREFSTEN
W
Reset:
0
1
0
0
Figure 11-4. ICS Control Register 2 (ICSC2)
Table 11-4. ICS Control Register 2 Field Descriptions
Field
Description
7:6
BDIV
Bus Frequency Divider — Selects the amount to divide down the clock source selected by the CLKS bits. This
controls the bus frequency.
00 Encoding 0 — Divides selected clock by 1
01 Encoding 1 — Divides selected clock by 2 (reset default)
10 Encoding 2 — Divides selected clock by 4
11 Encoding 3 — Divides selected clock by 8
5
RANGE
Frequency Range Select — Selects the frequency range for the external oscillator.
1 High frequency range selected for the external oscillator
0 Low frequency range selected for the external oscillator
4
HGO
High Gain Oscillator Select — The HGO bit controls the external oscillator mode of operation.
1 Configure external oscillator for high-gain operation
0 Configure external oscillator for low-power operation
3
LP
Low Power Select — The LP bit controls whether the FLL is disabled in FLL bypassed modes.
1 FLL is disabled in bypass modes unless BDM is active
0 FLL is not disabled in bypass mode
2
EREFS
External Reference Select — The EREFS bit selects the source for the external reference clock.
1 Oscillator requested
0 External Clock Source requested
1
ERCLKEN
External Reference Enable — The ERCLKEN bit enables the external reference clock for use as ICSERCLK.
1 ICSERCLK active
0 ICSERCLK inactive
0
External Reference Stop Enable — The EREFSTEN bit controls whether or not the external reference clock
EREFSTEN source (OSCOUT) remains enabled when the ICS enters stop mode.
1 External reference clock source stays enabled in stop if ERCLKEN is set before entering stop
0 External reference clock source is disabled in stop
11.3.3
ICS Trim Register (ICSTRM)
7
6
5
4
3
2
1
0
R
TRIM
W
Reset: Note: TRIM is loaded during reset from a factory programmed location when not in BDM mode. If in a BDM
mode, a default value of 0x80 is loaded.
Figure 11-5. ICS Trim Register (ICSTRM)
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Chapter 16 Internal Clock Source (S08ICSV3)
Table 11-5. ICS Trim Register Field Descriptions
Field
Description
7:0
TRIM
ICS Trim Setting — The TRIM bits control the internal reference clock frequency by controlling the internal
reference clock period. The bits’ effect are binary weighted (i.e., bit 1 will adjust twice as much as bit 0).
Increasing the binary value in TRIM will increase the period, and decreasing the value will decrease the period.
An additional fine trim bit is available in ICSSC as the FTRIM bit.
11.3.4
ICS Status and Control (ICSSC)
7
R
6
5
DRST
4
3
IREFST
2
CLKST
1
OSCINIT
DMX32
W
Reset:
0
FTRIM1
DRS
0
0
0
1
0
0
0
Figure 11-6. ICS Status and Control Register (ICSSC)
1
FTRIM is loaded during reset from a factory programmed location when not in any BDM mode. If in a BDM mode, FTRIM
gets loaded with a value of 1’b0.
Table 11-6. ICS Status and Control Register Field Descriptions
Field
Description
7-61
DRST
DRS
DCO Range Status — The DRST read field indicates the current frequency range for the FLL output, DCOOUT.
See Table 11-7. The DRST field does not update immediately after a write to the DRS field due to internal
synchronization between clock domains. Writing the DRS bits to 2’b11 will be ignored and the DRST bits will
remain with the current setting.
DCO Range Select — The DRS field selects the frequency range for the FLL output, DCOOUT. Writes to the
DRS field while the LP bit is set are ignored.
00 Low range.
01 Mid range.
10 High range.
11 Reserved.
5
DMX32
DCO Maximum frequency with 32.768 kHz reference — The DMX32 bit controls whether or not the DCO
frequency range is narrowed to its maximum frequency with a 32.768 kHz reference. See Table 11-7.
0 DCO has default range of 25%.
1 DCO is fined tuned for maximum frequency with 32.768 kHz reference.
4
IREFST
Internal Reference Status — The IREFST bit indicates the current source for the reference clock. The IREFST
bit does not update immediately after a write to the IREFS bit due to internal synchronization between clock
domains.
0 Source of reference clock is external clock.
1 Source of reference clock is internal clock.
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Table 11-6. ICS Status and Control Register Field Descriptions (continued)
Field
3-2
CLKST
1
OSCINIT
0
FTRIM
1
Description
Clock Mode Status — The CLKST bits indicate the current clock mode. The CLKST bits don’t update
immediately after a write to the CLKS bits due to internal synchronization between clock domains.
00 Output of FLL is selected.
01 FLL Bypassed, Internal reference clock is selected.
10 FLL Bypassed, External reference clock is selected.
11
Reserved.
OSC Initialization — If the external reference clock is selected by ERCLKEN or by the ICS being in FEE, FBE,
or FBELP mode, and if EREFS is set, then this bit is set after the initialization cycles of the external oscillator
clock have completed. This bit is only cleared when either ERCLKEN or EREFS are cleared.
ICS Fine Trim — The FTRIM bit controls the smallest adjustment of the internal reference clock frequency.
Setting FTRIM will increase the period and clearing FTRIM will decrease the period by the smallest amount
possible.
Refer to NOTE in Section 11.1, “Introduction.”
Table 11-7. DCO frequency range1
DRS
DMX32
00
0
31.25 - 39.0625 kHz
512
16 - 20 MHz
1
32.768 kHz
608
19.92 MHz
0
31.25 - 39.0625 kHz
1024
32 - 40 MHz
1
32.768 kHz
1216
39.85 MHz
0
31.25 - 39.0625 kHz
1536
48 - 60 MHz
1
32.768 kHz
1824
59.77 MHz
01
10
11
1
Reference range
FLL factor
DCO range
Reserved
The resulting bus clock frequency should not exceed the maximum specified bus
clock frequency of the device.
r
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Chapter 16 Internal Clock Source (S08ICSV3)
11.4
Functional Description
11.4.1
Operational Modes
IREFS=1
CLKS=00
FLL Engaged
Internal (FEI)
IREFS=0
CLKS=10
BDM Enabled
or LP =0
FLL Bypassed
External Low
Power(FBELP)
FLL Bypassed
External (FBE)
IREFS=0
CLKS=10
BDM Disabled
and LP=1
IREFS=1
CLKS=01
BDM Enabled
or LP=0
FLL Bypassed
Internal (FBI)
FLL Engaged
External (FEE)
FLL Bypassed
Internal Low
Power(FBILP)
IREFS=1
CLKS=01
BDM Disabled
and LP=1
IREFS=0
CLKS=00
Entered from any state
when MCU enters stop
Stop
Returns to state that was active
before MCU entered stop, unless
RESET occurs while in stop.
Figure 11-7. Clock Switching Modes
The seven states of the ICS are shown as a state diagram and are described below. The arrows indicate the
allowed movements between the states.
11.4.1.1
FLL Engaged Internal (FEI)
FLL engaged internal (FEI) is the default mode of operation and is entered when all the following
conditions occur:
• CLKS bits are written to 00.
• IREFS bit is written to 1.
In FLL engaged internal mode, the ICSOUT clock is derived from the FLL clock, which is controlled by
the internal reference clock. The FLL loop will lock the frequency to the FLL factor times the internal
reference frequency. The ICSLCLK is available for BDC communications, and the internal reference
clock is enabled.
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11.4.1.2
FLL Engaged External (FEE)
The FLL engaged external (FEE) mode is entered when all the following conditions occur:
•
•
•
CLKS bits are written to 00.
IREFS bit is written to 0.
RDIV bits are written to divide external reference clock to be within the range of 31.25 kHz to
39.0625 kHz.
In FLL engaged external mode, the ICSOUT clock is derived from the FLL clock which is controlled by
the external reference clock source.The FLL loop will lock the frequency to the FLL factor times the
external reference frequency, as selected by the RDIV bits. The ICSLCLK is available for BDC
communications, and the external reference clock is enabled.
11.4.1.3
FLL Bypassed Internal (FBI)
The FLL bypassed internal (FBI) mode is entered when all the following conditions occur:
• CLKS bits are written to 01.
• IREFS bit is written to 1.
• BDM mode is active or LP bit is written to 0.
In FLL bypassed internal mode, the ICSOUT clock is derived from the internal reference clock. The FLL
clock is controlled by the internal reference clock, and the FLL loop will lock the FLL frequency to the
FLL factor times the internal reference frequency. The ICSLCLK will be available for BDC
communications, and the internal reference clock is enabled.
11.4.1.4
FLL Bypassed Internal Low Power (FBILP)
The FLL bypassed internal low-power (FBILP) mode is entered when all the following conditions occur:
• CLKS bits are written to 01
• IREFS bit is written to 1.
• BDM mode is not active and LP bit is written to 1
In FLL bypassed internal low-power mode, the ICSOUT clock is derived from the internal reference clock
and the FLL is disabled. The ICSLCLK will be not be available for BDC communications, and the internal
reference clock is enabled.
11.4.1.5
FLL Bypassed External (FBE)
The FLL bypassed external (FBE) mode is entered when all the following conditions occur:
• CLKS bits are written to 10.
• IREFS bit is written to 0.
• RDIV bits are written to divide external reference clock to be within the range of 31.25 kHz to
39.0625 kHz.
• BDM mode is active or LP bit is written to 0.
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Chapter 16 Internal Clock Source (S08ICSV3)
In FLL bypassed external mode, the ICSOUT clock is derived from the external reference clock source.
The FLL clock is controlled by the external reference clock, and the FLL loop will lock the FLL frequency
to the FLL factor times the external reference frequency, as selected by the RDIV bits, so that the
ICSLCLK will be available for BDC communications, and the external reference clock is enabled.
11.4.1.6
FLL Bypassed External Low Power (FBELP)
The FLL bypassed external low-power (FBELP) mode is entered when all the following conditions occur:
• CLKS bits are written to 10.
• IREFS bit is written to 0.
• BDM mode is not active and LP bit is written to 1.
In FLL bypassed external low-power mode, the ICSOUT clock is derived from the external reference
clock source and the FLL is disabled. The ICSLCLK will be not be available for BDC communications.
The external reference clock source is enabled.
11.4.1.7
Stop
Stop mode is entered whenever the MCU enters a STOP state. In this mode, all ICS clock signals are static
except in the following cases:
ICSIRCLK will be active in stop mode when all the following conditions occur:
• IRCLKEN bit is written to 1
• IREFSTEN bit is written to 1
OSCOUT will be active in stop mode when all the following conditions occur:
• ERCLKEN bit is written to 1
• EREFSTEN bit is written to 1
11.4.2
Mode Switching
The IREF bit can be changed at anytime, but the actual switch to the newly selected clock is shown by the
IREFST bit. When switching between FLL engaged internal (FEI) and FLL engaged external (FEE)
modes, the FLL will begin locking again after the switch is completed.
The CLKS bits can also be changed at anytime, but the actual switch to the newly selected clock is shown
by the CLKST bits. If the newly selected clock is not available, the previous clock will remain selected.
The DRS bits can be changed at anytime except when LP bit is 1. If the DRS bits are changed while in
FLL engaged internal (FEI) or FLL engaged external (FEE), the bus clock remains at the previous DCO
range until the new DCO starts. When the new DCO starts the bus clock switches to it. After switching to
the new DCO the FLL remains unlocked for several reference cycles. Once the selected DCO startup time
is over, the FLL is locked. The completion of the switch is shown by the DRST bits.
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Chapter 16 Internal Clock Source (S08ICSV3)
11.4.3
Bus Frequency Divider
The BDIV bits can be changed at anytime and the actual switch to the new frequency will occur
immediately.
11.4.4
Low Power Bit Usage
The low-power bit (LP) is provided to allow the FLL to be disabled and thus conserve power when it is
not being used. The DRS bits can not be written while LP bit is 1.
However, in some applications it may be desirable to allow the FLL to be enabled and to lock for maximum
accuracy before switching to an FLL engaged mode. Do this by writing the LP bit to 0.
11.4.5
DCO Maximum Frequency with 32.768 kHz Oscillator
The FLL has an option to change the clock multiplier for the selected DCO range such that it results in the
maximum bus frequency with a common 32.768 kHZ crystal reference clock.
11.4.6
Internal Reference Clock
When IRCLKEN is set the internal reference clock signal will be presented as ICSIRCLK, which can be
used as an additional clock source. The ICSIRCLK frequency can be re-targeted by trimming the period
of the internal reference clock. This can be done by writing a new value to the TRIM bits in the ICSTRM
register. Writing a larger value will slow down the ICSIRCLK frequency, and writing a smaller value to
the ICSTRM register will speed up the ICSIRCLK frequency. The TRIM bits will effect the ICSOUT
frequency if the ICS is in FLL engaged internal (FEI), FLL bypassed internal (FBI), or FLL bypassed
internal low-power (FBILP) mode.
Until ICSIRCLK is trimmed, programming low reference divider (RDIV) factors may result in ICSOUT
frequencies that exceed the maximum chip-level frequency and violate the chip-level clock timing
specifications (see Chapter 1, “Device Overview”).
If IREFSTEN is set and the IRCLKEN bit is written to 1, the internal reference clock will keep running
during stop mode in order to provide a fast recovery upon exiting stop.
All MCU devices are factory programmed with a trim value in a reserved memory location. This value is
uploaded to the ICSTRM register and ICS FTRIM register during any reset initialization. For finer
precision, the user can trim the internal oscillator in the application and set the FTRIM bit accordingly.
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Chapter 16 Internal Clock Source (S08ICSV3)
11.4.7
External Reference Clock
The ICS module supports an external reference clock with frequencies between 31.25 kHz to 40 MHz in
all modes. When the ERCLKEN is set, the external reference clock signal will be presented as
ICSERCLK, which can be used as an additional clock source in run mode. When IREFS = 1, the external
reference clock will not be used by the FLL and will only be used as ICSERCLK. In these modes, the
frequency can be equal to the maximum frequency the chip-level timing specifications will support (see
Chapter 1, “Device Overview”).
If EREFSTEN is set and the ERCLKEN bit is written to 1, the external reference clock source (OSCOUT)
will keep running during stop mode in order to provide a fast recovery upon exiting stop.
11.4.8
Fixed Frequency Clock
The ICS presents the divided FLL reference clock as ICSFFCLK for use as an additional clock source.
ICSFFCLK frequency must be no more than 1/4 of the ICSOUT frequency to be valid. Because of this
requirement, in bypass modes the ICSFFCLK is valid only in bypass external modes (FBE and FBELP)
for the following combinations of BDIV, RDIV, and RANGE values:
• RANGE = 1
• BDIV = 00 (divide by 1), RDIV ≥ 010
• BDIV = 01 (divide by 2), RDIV ≥ 011
• BDIV = 10 (divide by 4), RDIV ≥ 100
• BDIV = 11 (divide by 8), RDIV ≥ 101
11.4.9
Local Clock
The ICS presents the low range DCO output clock divided by two as ICSLCLK for use as a clock source
for BDC communications. ICSLCLK is not available in FLL bypassed internal low-power (FBILP) and
FLL bypassed external low-power (FBELP) modes.
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Chapter 12
Inter-Integrated Circuit (S08IICV2)
12.1
Introduction
The inter-integrated circuit (IIC) provides a method of communication between a number of devices. The
interface is designed to operate up to 100 kbps with maximum bus loading and timing. The device is
capable of operating at higher baud rates, up to a maximum of clock/20, with reduced bus loading. The
maximum communication length and the number of devices that can be connected are limited by a
maximum bus capacitance of 400 pF.
•
•
12.1.1
NOTE
MC9S08LG32 series of MCUs include only one IIC module, therefore
assume IICxA, IICxF, IICxC1, IICxS, IICxD, and IICxC2 register
definitions as IIC0A, IIC0F, IIC0C1, IIC0S, IIC0D, and IIC0C2.
The SDA and SCL must not be driven above VDD. These pins are
pseudo open-drain and contain a protection diode to VDD.
Module Configuration
The IIC module pins, SDA and SCL can be repositioned under software control using SDA and SCL bits
in PINPS3 as shown in Table 12-1. SDA and SCL bits in PINPS3 selects which general-purpose I/O ports
are associated with IIC operation.
Table 12-1. IIC Position Options
12.1.2
SDA/SCL in PINPS3
Port Pin for SDA
Port Pin for SCL
0 (default)
PTA2
PTA1
1
PTI4
PTI5
IIC Clock Gating
The bus clock to the IIC can be gated on and off using the IIC bit in SCGC1. This bit is cleared after any
reset, which disables the bus clock to this module. To conserve power, the IIC bit can be cleared to disable
the clock to this module when not in use. See Section 5.7, “Peripheral Clock Gating,” for details.
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Chapter 12 Inter-Integrated Circuit (S08IICV2)
8-BIT KEYBOARD
INTERRUPT (KBI)
RESET
IRQ
SERIAL PERIPHERAL
INTERFACE (SPI)
KBI[7:0]
SS
SPSCK
MISO
RESET/PTC6
BKGD/MS/PTC5
LCD[20:16]/PTC[4:0]
MOSI
SCL
IIC MODULE (IIC)
USER FLASH A
(LG32 = 16K BYTES)
(LG16 = 2K BYTES)
6-CHANNEL TIMER/PWM
(TPM2)
USER FLASH B
(LG32 = 16K BYTES)
(LG16 = 16K BYTES)
2-CHANNEL TIMER/PWM
(TPM1)
SERIAL COMMUNICATIONS
INTERFACE (SCI1)
USER RAM
SDA
TPM2CH[5:0]
TPMCLK
PORT D
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
LVD
LCD[40:37]/PTB[7:4]
LCD[32:29]/PTB[3:0]
TMRCLK
LCD[7:0]/PTD[7:0]
PORT E
Modulo Timer
(MTIM)
IRQ
PORT A
Real Time Counter
(RTC)
HCS08 SYSTEM CONTROL
COP
PORT B
BKGD/MS
LCD[15:8]/PTE[7:0]
TPM1CH[1:0]
PORT F
BKP
EXTAL/PTF7
XTAL/PTF6
TPM2CH3/KBI2/MOSI/PTF5
TPM2CH4/KBI1/MISO/PTF4
TPM2CH5/KBI0/SS/PTF3
ADC14/IRQ/TPM1CH1/SPSCK/PTF2
ADC13/TPM1CH0/RX1/PTF1
ADC12/TPM2CH2/KBI3/TX1/PTF0
PORT G
BKGD
LCD[44:41]/PTG[7:4]
LCD[36:33]/PTG[3:0]
PORT H
INT
ON-CHIP ICE (ICE) and
DEBUG MODULE (DBG)
TPM2CH4/KBI1/PTH7
ADC15/KBI0/TPM2CH5/PTH6
ADC11/TPM1CH0/KBI3/TX1/PTH5
ADC10/TPM1CH1/KBI2/RX1/PTH4
ADC[9:6]/KBI[7:4]/PTH[3:0]
PORT I
CPU
LCD28/ADC5/TPMCLK/PTA7
LCD27/ADC4/TPM2CH1/KBI7/PTA6
LCD26/ADC3/TPM2CH0/KBI6/PTA5
LCD25/ADC2/RX2/KBI5/PTA4
LCD24/ADC1/TX2/KBI4/PTA3
LCD23/ADC0/SDA/PTA2
LCD22/SCL/PTA1
LCD21/PTA0
PORT C
HCS08 CORE
SS/SCL/TPM2CH0/PTI5
SPSCK/SDA/TPM2CH1/PTI4
MOSI/TPM2CH2/PTI3
MISO/TPM2CH3/PTI2
TX2/TMRCLK/PTI1
RX2/PTI0
TPMCLK
TxD1
RxD1
1984 BYTES
SERIAL COMMUNICATIONS
INTERFACE (SCI2)
INTERNAL CLOCK
Source (ICS)
TxD2
RxD2
XTAL
LOW-POWER OSCILLATOR
12-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
VLL3_2
VLL3
VLL1
VLL2
VCAP1
EXTAL
AD[15:0]
LIQUID CRYSTAL
DISPLAY DRIVER
(LCD)
VCAP2
LCD[44:0]
VDD
VSS
VSS2
VDDA/VREFH
VSSA/VREFL
VOLTAGE
REGULATOR
Available only on 80-pin package
Available only on 64-pin and 80-pin package
*/Default function out of reset/*
Figure 12-1. MC9S08LG32 Series Block Diagram Highlighting IIC Block and Pins
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Chapter 10 Inter-Integrated Circuit (S08IICV2)
12.1.3
Features
The IIC includes these distinctive features:
• Compatible with IIC bus standard
• Multi-master operation
• Software programmable for one of 64 different serial clock frequencies
• Software selectable acknowledge bit
• Interrupt driven byte-by-byte data transfer
• Arbitration lost interrupt with automatic mode switching from master to slave
• Calling address identification interrupt
• Start and stop signal generation/detection
• Repeated start signal generation
• Acknowledge bit generation/detection
• Bus busy detection
• General call recognition
• 10-bit address extension
12.1.4
Modes of Operation
A brief description of the IIC in the various MCU modes is given here.
• Run mode — This is the basic mode of operation. To conserve power in this mode, disable the
module.
• Wait mode — The module continues to operate while the MCU is in wait mode and can provide
a wake-up interrupt.
• Stop mode — The IIC is inactive in stop3 mode for reduced power consumption. The stop
instruction does not affect IIC register states. Stop2 resets the register contents.
12.1.5
Block Diagram
Figure 12-2 is a block diagram of the IIC.
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Chapter 10 Inter-Integrated Circuit (S08IICV2)
Address
Data Bus
Interrupt
ADDR_DECODE
CTRL_REG
DATA_MUX
FREQ_REG
ADDR_REG
STATUS_REG
DATA_REG
Input
Sync
Start
Stop
Arbitration
Control
Clock
Control
In/Out
Data
Shift
Register
Address
Compare
SCL
SDA
Figure 12-2. IIC Functional Block Diagram
12.2
External Signal Description
This section describes each user-accessible pin signal.
12.2.1
SCL — Serial Clock Line
The bidirectional SCL is the serial clock line of the IIC system.
12.2.2
SDA — Serial Data Line
The bidirectional SDA is the serial data line of the IIC system.
12.3
Register Definition
This section consists of the IIC register descriptions in address order.
Refer to the direct-page register summary in Chapter 4, “Memory,” for the absolute address assignments
for all IIC registers. This section refers to registers and control bits only by their names. A
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Chapter 10 Inter-Integrated Circuit (S08IICV2)
Freescale-provided equate or header file is used to translate these names into the appropriate absolute
addresses.
12.3.1
IIC Address Register (IICxA)
7
6
5
4
3
2
1
AD7
AD6
AD5
AD4
AD3
AD2
AD1
0
0
0
0
0
0
0
R
0
0
W
Reset
0
= Unimplemented or Reserved
Figure 12-3. IIC Address Register (IICxA)
Table 12-2. IICxA Field Descriptions
Field
Description
7–1
AD[7:1]
Slave Address. The AD[7:1] field contains the slave address to be used by the IIC module. This field is used on
the 7-bit address scheme and the lower seven bits of the 10-bit address scheme.
12.3.2
IIC Frequency Divider Register (IICxF)
7
6
5
4
3
2
1
0
0
0
0
R
MULT
ICR
W
Reset
0
0
0
0
0
Figure 12-4. IIC Frequency Divider Register (IICxF)
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Table 12-3. IICxF Field Descriptions
Field
7–6
MULT
5–0
ICR
Description
IIC Multiplier Factor. The MULT bits define the multiplier factor, mul. This factor, along with the SCL divider,
generates the IIC baud rate. The multiplier factor mul as defined by the MULT bits is provided below.
00 mul = 01
01 mul = 02
10 mul = 04
11 Reserved
IIC Clock Rate. The ICR bits are used to prescale the bus clock for bit rate selection. These bits and the MULT
bits determine the IIC baud rate, the SDA hold time, the SCL Start hold time, and the SCL Stop hold time.
Table 12-5 provides the SCL divider and hold values for corresponding values of the ICR.
The SCL divider multiplied by multiplier factor mul generates IIC baud rate.
bus speed (Hz)
IIC baud rate = --------------------------------------------mul × SCLdivider
Eqn. 12-1
SDA hold time is the delay from the falling edge of SCL (IIC clock) to the changing of SDA (IIC data).
SDA hold time = bus period (s) × mul × SDA hold value
Eqn. 12-2
SCL start hold time is the delay from the falling edge of SDA (IIC data) while SCL is high (Start condition) to the
falling edge of SCL (IIC clock).
SCL Start hold time = bus period (s) × mul × SCL Start hold value
Eqn. 12-3
SCL stop hold time is the delay from the rising edge of SCL (IIC clock) to the rising edge of SDA
SDA (IIC data) while SCL is high (Stop condition).
SCL Stop hold time = bus period (s) × mul × SCL Stop hold value
Eqn. 12-4
For example, if the bus speed is 8 MHz, the table below shows the possible hold time values with different
ICR and MULT selections to achieve an IIC baud rate of 100kbps.
Table 12-4. Hold Time Values for 8 MHz Bus Speed
Hold Times (μs)
MULT
ICR
SDA
SCL Start
SCL Stop
0x2
0x00
3.500
3.000
5.500
0x1
0x07
2.500
4.000
5.250
0x1
0x0B
2.250
4.000
5.250
0x0
0x14
2.125
4.250
5.125
0x0
0x18
1.125
4.750
5.125
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Chapter 10 Inter-Integrated Circuit (S08IICV2)
Table 12-5. IIC Divider and Hold Values
ICR
(hex)
SCL
Divider
SDA Hold
Value
SCL Hold
(Start)
Value
SDA Hold
(Stop)
Value
ICR
(hex)
SCL
Divider
SDA Hold
Value
SCL Hold
(Start)
Value
SCL Hold
(Stop)
Value
00
20
7
6
11
20
160
17
78
81
01
22
7
7
12
21
192
17
94
97
02
24
8
8
13
22
224
33
110
113
03
26
8
9
14
23
256
33
126
129
04
28
9
10
15
24
288
49
142
145
05
30
9
11
16
25
320
49
158
161
06
34
10
13
18
26
384
65
190
193
07
40
10
16
21
27
480
65
238
241
08
28
7
10
15
28
320
33
158
161
09
32
7
12
17
29
384
33
190
193
0A
36
9
14
19
2A
448
65
222
225
0B
40
9
16
21
2B
512
65
254
257
0C
44
11
18
23
2C
576
97
286
289
0D
48
11
20
25
2D
640
97
318
321
0E
56
13
24
29
2E
768
129
382
385
0F
68
13
30
35
2F
960
129
478
481
10
48
9
18
25
30
640
65
318
321
11
56
9
22
29
31
768
65
382
385
12
64
13
26
33
32
896
129
446
449
13
72
13
30
37
33
1024
129
510
513
14
80
17
34
41
34
1152
193
574
577
15
88
17
38
45
35
1280
193
638
641
16
104
21
46
53
36
1536
257
766
769
17
128
21
58
65
37
1920
257
958
961
18
80
9
38
41
38
1280
129
638
641
19
96
9
46
49
39
1536
129
766
769
1A
112
17
54
57
3A
1792
257
894
897
1B
128
17
62
65
3B
2048
257
1022
1025
1C
144
25
70
73
3C
2304
385
1150
1153
1D
160
25
78
81
3D
2560
385
1278
1281
1E
192
33
94
97
3E
3072
513
1534
1537
1F
240
33
118
121
3F
3840
513
1918
1921
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Chapter 10 Inter-Integrated Circuit (S08IICV2)
12.3.3
IIC Control Register (IICxC1)
7
6
5
4
3
IICEN
IICIE
MST
TX
TXAK
R
W
Reset
2
1
0
0
0
0
0
0
RSTA
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 12-5. IIC Control Register (IICxC1)
Table 12-6. IICxC1 Field Descriptions
Field
Description
7
IICEN
IIC Enable. The IICEN bit determines whether the IIC module is enabled.
0 IIC is not enabled
1 IIC is enabled
6
IICIE
IIC Interrupt Enable. The IICIE bit determines whether an IIC interrupt is requested.
0 IIC interrupt request not enabled
1 IIC interrupt request enabled
5
MST
Master Mode Select. The MST bit changes from a 0 to a 1 when a start signal is generated on the bus and
master mode is selected. When this bit changes from a 1 to a 0 a stop signal is generated and the mode of
operation changes from master to slave.
0 Slave mode
1 Master mode
4
TX
Transmit Mode Select. The TX bit selects the direction of master and slave transfers. In master mode, this bit
should be set according to the type of transfer required. Therefore, for address cycles, this bit is always high.
When addressed as a slave, this bit should be set by software according to the SRW bit in the status register.
0 Receive
1 Transmit
3
TXAK
Transmit Acknowledge Enable. This bit specifies the value driven onto the SDA during data acknowledge
cycles for master and slave receivers.
0 An acknowledge signal is sent out to the bus after receiving one data byte
1 No acknowledge signal response is sent
2
RSTA
Repeat start. Writing a 1 to this bit generates a repeated start condition provided it is the current master. This
bit is always read as cleared. Attempting a repeat at the wrong time results in loss of arbitration.
12.3.4
R
IIC Status Register (IICxS)
7
6
5
TCF
IAAS
BUSY
4
3
2
0
SRW
ARBL
1
0
RXAK
IICIF
W
Reset
1
0
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 12-6. IIC Status Register (IICxS)
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Table 12-7. IICxS Field Descriptions
Field
Description
7
TCF
Transfer Complete Flag. This bit is set on the completion of a byte transfer and should be ignored when address
phase of IIC is going on. This bit is only valid during or immediately following a transfer to the IIC module or from
the IIC module.The TCF bit is cleared by reading the IICxD register in receive mode or writing to the IICxD in
transmit mode.
0 Transfer in progress
1 Transfer complete
6
IAAS
Addressed as a Slave. The IAAS bit is set when the calling address matches the programmed slave address or
when the GCAEN bit is set and a general call is received. Writing the IICxC register clears this bit.
0 Not addressed
1 Addressed as a slave
5
BUSY
Bus Busy. The BUSY bit indicates the status of the bus regardless of slave or master mode. The BUSY bit is set
when a start signal is detected and cleared when a stop signal is detected.
0 Bus is idle
1 Bus is busy
4
ARBL
Arbitration Lost. This bit is set by hardware when the arbitration procedure is lost. The ARBL bit must be cleared
by software by writing a 1 to it.
0 Standard bus operation
1 Loss of arbitration
2
SRW
Slave Read/Write. When addressed as a slave, the SRW bit indicates the value of the R/W command bit of the
calling address sent to the master.
0 Slave receive, master writing to slave
1 Slave transmit, master reading from slave
1
IICIF
IIC Interrupt Flag. The IICIF bit is set when an interrupt is pending. This bit must be cleared by software, by
writing a 1 to it in the interrupt routine. One of the following events can set the IICIF bit:
• One byte transfer completes
• Match of slave address to calling address
• Arbitration lost
0 No interrupt pending
1 Interrupt pending
0
RXAK
Receive Acknowledge. When the RXAK bit is low, it indicates an acknowledge signal has been received after
the completion of one byte of data transmission on the bus. If the RXAK bit is high it means that no acknowledge
signal is detected.
0 Acknowledge received
1 No acknowledge received
12.3.5
IIC Data I/O Register (IICxD)
7
6
5
4
3
2
1
0
0
0
0
0
R
DATA
W
Reset
0
0
0
0
Figure 12-7. IIC Data I/O Register (IICxD)
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Table 12-8. IICxD Field Descriptions
Field
Description
7–0
DATA
Data — In master transmit mode, when data is written to the IICxD, a data transfer is initiated. The most
significant bit is sent first. In master receive mode, reading this register initiates receiving of the next byte of data.
NOTE
When transitioning out of master receive mode, the IIC mode should be
switched before reading the IICxD register to prevent an inadvertent
initiation of a master receive data transfer.
In slave mode, the same functions are available after an address match has occurred.
The TX bit in IICxC must correctly reflect the desired direction of transfer in master and slave modes for
the transmission to begin. For instance, if the IIC is configured for master transmit but a master receive is
desired, reading the IICxD does not initiate the receive.
Reading the IICxD returns the last byte received while the IIC is configured in master receive or slave
receive modes. The IICxD does not reflect every byte transmitted on the IIC bus, nor can software verify
that a byte has been written to the IICxD correctly by reading it back.
In master transmit mode, the first byte of data written to IICxD following assertion of MST is used for the
address transfer and should comprise of the calling address (in bit 7 to bit 1) concatenated with the required
R/W bit (in position bit 0).
12.3.6
IIC Control Register 2 (IICxC2)
7
6
GCAEN
ADEXT
0
0
R
5
4
3
0
0
0
2
1
0
AD10
AD9
AD8
0
0
0
W
Reset
0
0
0
= Unimplemented or Reserved
Figure 12-8. IIC Control Register (IICxC2)
Table 12-9. IICxC2 Field Descriptions
Field
Description
7
GCAEN
General Call Address Enable. The GCAEN bit enables or disables general call address.
0 General call address is disabled
1 General call address is enabled
6
ADEXT
Address Extension. The ADEXT bit controls the number of bits used for the slave address.
0 7-bit address scheme
1 10-bit address scheme
2–0
AD[10:8]
Slave Address. The AD[10:8] field contains the upper three bits of the slave address in the 10-bit address
scheme. This field is only valid when the ADEXT bit is set.
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12.4
Functional Description
This section provides a complete functional description of the IIC module.
12.4.1
IIC Protocol
The IIC bus system uses a serial data line (SDA) and a serial clock line (SCL) for data transfer. All devices
connected to it must have open drain or open collector outputs. A logic AND function is exercised on both
lines with external pullup resistors. The value of these resistors is system dependent.
Normally, a standard communication is composed of four parts:
• Start signal
• Slave address transmission
• Data transfer
• Stop signal
The stop signal should not be confused with the CPU stop instruction. The IIC bus system communication
is described briefly in the following sections and illustrated in Figure 12-9.
msb
SCL
1
lsb
2
3
4
5
6
7
8
msb
9
AD7 AD6 AD5 AD4 AD3 AD2 AD1 R/W
SDA
Calling Address
Start
Signal
1
SDA
3
4
5
Calling Address
4
5
6
7
8
D7
D6
D5
D4
D3
D2
D1
D0
6
7
8
9
Read/ Ack
Write Bit
1
XX
Repeated
Start
Signal
9
No
Ack
Bit
msb
AD7 AD6 AD5 AD4 AD3 AD2 AD1 R/W
Start
Signal
3
Data Byte
lsb
2
2
Read/ Ack
Write Bit
msb
SCL
XXX
lsb
1
Stop
Signal
lsb
3
2
4
5
6
7
8
9
AD7 AD6 AD5 AD4 AD3 AD2 AD1 R/W
New Calling Address
Read/
Write
No
Ack
Bit
Stop
Signal
Figure 12-9. IIC Bus Transmission Signals
12.4.1.1
Start Signal
When the bus is free, no master device is engaging the bus (SCL and SDA lines are at logical high), a
master may initiate communication by sending a start signal. As shown in Figure 12-9, a start signal is
defined as a high-to-low transition of SDA while SCL is high. This signal denotes the beginning of a new
data transfer (each data transfer may contain several bytes of data) and brings all slaves out of their idle
states.
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12.4.1.2
Slave Address Transmission
The first byte of data transferred immediately after the start signal is the slave address transmitted by the
master. This is a seven-bit calling address followed by a R/W bit. The R/W bit tells the slave the desired
direction of data transfer.
1 = Read transfer, the slave transmits data to the master.
0 = Write transfer, the master transmits data to the slave.
Only the slave with a calling address that matches the one transmitted by the master responds by sending
back an acknowledge bit. This is done by pulling the SDA low at the ninth clock (see Figure 12-9).
No two slaves in the system may have the same address. If the IIC module is the master, it must not
transmit an address equal to its own slave address. The IIC cannot be master and slave at the same time.
However, if arbitration is lost during an address cycle, the IIC reverts to slave mode and operates correctly
even if it is being addressed by another master.
12.4.1.3
Data Transfer
After successful slave addressing is achieved, the data transfer can proceed byte-by-byte in a direction
specified by the R/W bit sent by the calling master.
All transfers that come after an address cycle are referred to as data transfers, even if they carry sub-address
information for the slave device
Each data byte is 8 bits long. Data may be changed only while SCL is low and must be held stable while
SCL is high as shown in Figure 12-9. There is one clock pulse on SCL for each data bit, the msb being
transferred first. Each data byte is followed by a 9th (acknowledge) bit, which is signalled from the
receiving device. An acknowledge is signalled by pulling the SDA low at the ninth clock. In summary, one
complete data transfer needs nine clock pulses.
If the slave receiver does not acknowledge the master in the ninth bit time, the SDA line must be left high
by the slave. The master interprets the failed acknowledge as an unsuccessful data transfer.
If the master receiver does not acknowledge the slave transmitter after a data byte transmission, the slave
interprets this as an end of data transfer and releases the SDA line.
In either case, the data transfer is aborted and the master does one of two things:
• Relinquishes the bus by generating a stop signal.
• Commences a new calling by generating a repeated start signal.
12.4.1.4
Stop Signal
The master can terminate the communication by generating a stop signal to free the bus. However, the
master may generate a start signal followed by a calling command without generating a stop signal first.
This is called repeated start. A stop signal is defined as a low-to-high transition of SDA while SCL at
logical 1 (see Figure 12-9).
The master can generate a stop even if the slave has generated an acknowledge at which point the slave
must release the bus.
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12.4.1.5
Repeated Start Signal
As shown in Figure 12-9, a repeated start signal is a start signal generated without first generating a stop
signal to terminate the communication. This is used by the master to communicate with another slave or
with the same slave in different mode (transmit/receive mode) without releasing the bus.
12.4.1.6
Arbitration Procedure
The IIC bus is a true multi-master bus that allows more than one master to be connected on it. If two or
more masters try to control the bus at the same time, a clock synchronization procedure determines the bus
clock, for which the low period is equal to the longest clock low period and the high is equal to the shortest
one among the masters. The relative priority of the contending masters is determined by a data arbitration
procedure, a bus master loses arbitration if it transmits logic 1 while another master transmits logic 0. The
losing masters immediately switch over to slave receive mode and stop driving SDA output. In this case,
the transition from master to slave mode does not generate a stop condition. Meanwhile, a status bit is set
by hardware to indicate loss of arbitration.
12.4.1.7
Clock Synchronization
Because wire-AND logic is performed on the SCL line, a high-to-low transition on the SCL line affects all
the devices connected on the bus. The devices start counting their low period and after a device’s clock has
gone low, it holds the SCL line low until the clock high state is reached. However, the change of low to
high in this device clock may not change the state of the SCL line if another device clock is still within its
low period. Therefore, synchronized clock SCL is held low by the device with the longest low period.
Devices with shorter low periods enter a high wait state during this time (see Figure 12-10). When all
devices concerned have counted off their low period, the synchronized clock SCL line is released and
pulled high. There is then no difference between the device clocks and the state of the SCL line and all the
devices start counting their high periods. The first device to complete its high period pulls the SCL line
low again.
Delay
Start Counting High Period
SCL1
SCL2
SCL
Internal Counter Reset
Figure 12-10. IIC Clock Synchronization
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12.4.1.8
Handshaking
The clock synchronization mechanism can be used as a handshake in data transfer. Slave devices may hold
the SCL low after completion of one byte transfer (9 bits). In such a case, it halts the bus clock and forces
the master clock into wait states until the slave releases the SCL line.
12.4.1.9
Clock Stretching
The clock synchronization mechanism can be used by slaves to slow down the bit rate of a transfer. After
the master has driven SCL low the slave can drive SCL low for the required period and then release it. If
the slave SCL low period is greater than the master SCL low period then the resulting SCL bus signal low
period is stretched.
12.4.2
10-bit Address
For 10-bit addressing, 0x11110 is used for the first 5 bits of the first address byte. Various combinations of
read/write formats are possible within a transfer that includes 10-bit addressing.
12.4.2.1
Master-Transmitter Addresses a Slave-Receiver
The transfer direction is not changed (see Table 12-10). When a 10-bit address follows a start condition,
each slave compares the first seven bits of the first byte of the slave address (11110XX) with its own
address and tests whether the eighth bit (R/W direction bit) is 0. More than one device can find a match
and generate an acknowledge (A1). Then, each slave that finds a match compares the eight bits of the
second byte of the slave address with its own address. Only one slave finds a match and generates an
acknowledge (A2). The matching slave remains addressed by the master until it receives a stop condition
(P) or a repeated start condition (Sr) followed by a different slave address.
Slave Address 1st 7 bits
R/W
Slave Address 2nd byte
A1
S
11110 + AD10 + AD9
0
A2
Data
A
...
Data
A/A
P
AD[8:1]
Table 12-10. Master-Transmitter Addresses Slave-Receiver with a 10-bit Address
After the master-transmitter has sent the first byte of the 10-bit address, the slave-receiver sees an IIC
interrupt. Software must ensure the contents of IICD are ignored and not treated as valid data for this
interrupt.
12.4.2.2
Master-Receiver Addresses a Slave-Transmitter
The transfer direction is changed after the second R/W bit (see Table 12-11). Up to and including
acknowledge bit A2, the procedure is the same as that described for a master-transmitter addressing a
slave-receiver. After the repeated start condition (Sr), a matching slave remembers that it was addressed
before. This slave then checks whether the first seven bits of the first byte of the slave address following
Sr are the same as they were after the start condition (S) and tests whether the eighth (R/W) bit is 1. If there
is a match, the slave considers that it has been addressed as a transmitter and generates acknowledge A3.
The slave-transmitter remains addressed until it receives a stop condition (P) or a repeated start condition
(Sr) followed by a different slave address.
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After a repeated start condition (Sr), all other slave devices also compare the first seven bits of the first
byte of the slave address with their own addresses and test the eighth (R/W) bit. However, none of them
are addressed because R/W = 1 (for 10-bit devices) or the 11110XX slave address (for 7-bit devices) does
not match.
S
Slave Address
1st 7 bits
R/W
11110 + AD10 + AD9
0
A1
Slave Address
2nd byte
A2
AD[8:1]
Sr
Slave Address
1st 7 bits
R/W
11110 + AD10 + AD9
1
A3
Data
A
...
Data
A
P
Table 12-11. Master-Receiver Addresses a Slave-Transmitter with a 10-bit Address
After the master-receiver has sent the first byte of the 10-bit address, the slave-transmitter sees an IIC
interrupt. Software must ensure the contents of IICD are ignored and not treated as valid data for this
interrupt.
12.4.3
General Call Address
General calls can be requested in 7-bit address or 10-bit address. If the GCAEN bit is set, the IIC matches
the general call address as well as its own slave address. When the IIC responds to a general call, it acts as
a slave-receiver and the IAAS bit is set after the address cycle. Software must read the IICD register after
the first byte transfer to determine whether the address matches is its own slave address or a general call.
If the value is 00, the match is a general call. If the GCAEN bit is clear, the IIC ignores any data supplied
from a general call address by not issuing an acknowledgement.
12.5
Resets
The IIC is disabled after reset. The IIC cannot cause an MCU reset.
12.6
Interrupts
The IIC generates a single interrupt.
An interrupt from the IIC is generated when any of the events in Table 12-12 occur, provided the IICIE bit
is set. The interrupt is driven by bit IICIF (of the IIC status register) and masked with bit IICIE (of the IIC
control register). The IICIF bit must be cleared by software by writing a 1 to it in the interrupt routine. You
can determine the interrupt type by reading the status register.
Table 12-12. Interrupt Summary
12.6.1
Interrupt Source
Status
Flag
Local Enable
Complete 1-byte transfer
TCF
IICIF
IICIE
Match of received calling address
IAAS
IICIF
IICIE
Arbitration Lost
ARBL
IICIF
IICIE
Byte Transfer Interrupt
The TCF (transfer complete flag) bit is set at the falling edge of the ninth clock to indicate the completion
of byte transfer.
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12.6.2
Address Detect Interrupt
When the calling address matches the programmed slave address (IIC address register) or when the
GCAEN bit is set and a general call is received, the IAAS bit in the status register is set. The CPU is
interrupted, provided the IICIE is set. The CPU must check the SRW bit and set its Tx mode accordingly.
12.6.3
Arbitration Lost Interrupt
The IIC is a true multi-master bus that allows more than one master to be connected on it. If two or more
masters try to control the bus at the same time, the relative priority of the contending masters is determined
by a data arbitration procedure. The IIC module asserts this interrupt when it loses the data arbitration
process and the ARBL bit in the status register is set.
Arbitration is lost in the following circumstances:
• SDA sampled as a low when the master drives a high during an address or data transmit cycle.
• SDA sampled as a low when the master drives a high during the acknowledge bit of a data receive
cycle.
• A start cycle is attempted when the bus is busy.
• A repeated start cycle is requested in slave mode.
• A stop condition is detected when the master did not request it.
This bit must be cleared by software writing a 1 to it.
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12.7
Initialization/Application Information
Module Initialization (Slave)
1. Write: IICC2
— to enable or disable general call
— to select 10-bit or 7-bit addressing mode
2. Write: IICA
— to set the slave address
3. Write: IICC1
— to enable IIC and interrupts
4. Initialize RAM variables (IICEN = 1 and IICIE = 1) for transmit data
5. Initialize RAM variables used to achieve the routine shown in Figure 12-12
Module Initialization (Master)
1. Write: IICF
— to set the IIC baud rate (example provided in this chapter)
2. Write: IICC1
— to enable IIC and interrupts
3. Initialize RAM variables (IICEN = 1 and IICIE = 1) for transmit data
4. Initialize RAM variables used to achieve the routine shown in Figure 12-12
5. Write: IICC1
— to enable TX
Register Model
AD[7:1]
IICA
0
When addressed as a slave (in slave mode), the module responds to this address
MULT
IICF
ICR
Baud rate = BUSCLK / (2 x MULT x (SCL DIVIDER))
IICC1
IICEN
IICIE
MST
TX
TXAK
RSTA
0
0
BUSY
ARBL
0
SRW
IICIF
RXAK
AD9
AD8
Module configuration
IICS
TCF
IAAS
Module status flags
DATA
IICD
Data register; Write to transmit IIC data read to read IIC data
IICC2 GCAEN ADEXT
0
0
0
AD10
Address configuration
Figure 12-11. IIC Module Quick Start
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Clear
IICIF
Master
Mode
?
Y
TX
N
Arbitration
Lost
?
Y
RX
Tx/Rx
?
N
Last Byte
Transmitted
?
N
Clear ARBL
Y
RXAK=0
?
Last
Byte to Be Read
?
N
N
N
Y
Y
IAAS=1
?
Y
IAAS=1
?
Y
Address Transfer
See Note 1
Y
End of
Addr Cycle
(Master Rx)
?
Y
Y
(Read)
2nd Last
Byte to Be Read
?
N
SRW=1
?
Write Next
Byte to IICD
Set TXACK =1
TX/RX
?
Generate
Stop Signal
(MST = 0)
Y
Set TX
Mode
RX
TX
N (Write)
N
N
Data Transfer
See Note 2
ACK from
Receiver
?
N
Set RX
Mode
Switch to
Rx Mode
Dummy Read
from IICD
Dummy Read
from IICD
Switch to
Rx Mode
Dummy Read
from IICD
Generate
Stop Signal
(MST = 0)
Read Data
from IICD
and Store
Read Data
from IICD
and Store
Tx Next
Byte
Write Data
to IICD
RTI
NOTES:
1. If general call is enabled, a check must be done to determine whether the received address was a general call address (0x00). If the received address was a
general call address, then the general call must be handled by user software.
2.
When 10-bit addressing is used to address a slave, the slave sees an interrupt following the first byte of the extended address. User software must ensure that for
this interrupt, the contents of IICD are ignored and not treated as a valid data transfer
Figure 12-12. Typical IIC Interrupt Routine
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Chapter 13
Serial Communications Interface (S08SCIV4)
13.1
Introduction
Figure 13-1 shows the MC9S08LG32 series block diagram with the SCI highlighted.
13.1.1
Module Instances
The MC9S08LG32 series MCUs contain two SCI modules: SCI1 and SCI2. The memory map, pins,
interrupts, etc. for the two modules can be differentiated using the SCI1 and SCI2 nomenclature.
13.1.2
Module Configuration
The SCI module pins, TX1, RX1, TX2, and RX2 can be repositioned under software control using TX1,
RX1, TX2, and RX2 bits in PINPS4 and PINPS3 as shown in Table 13-1. TX1, RX1, TX2, and RX2 bits
in PINPS4 and PINPS3 selects which general-purpose I/O ports are associated with IIC operation.
Table 13-1. SCI Position Options
TX1/RX1/TX2/RX2
Port Pin for TX1
Port Pin for RX1
Port Pin for TX2
Port Pin for RX2
0 (default)
PTF0
PTF1
PTA3
PTA4
1
PTH5
PTH4
PTI1
PTI0
13.1.3
SCI Clock Gating
The bus clock to the SCI can be gated on and off using the SCI bit in SCGC1. This bit is cleared after any
reset, which disables the bus clock to this module. To conserve power, the SCI bit can be cleared to disable
the clock to this module when not in use. For more details, see Section 5.7, “Peripheral Clock Gating.”
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Chapter 13 Serial Communications Interface (S08SCIV4)
8-BIT KEYBOARD
INTERRUPT (KBI)
RESET
IRQ
SERIAL PERIPHERAL
INTERFACE (SPI)
KBI[7:0]
SS
SPSCK
MISO
RESET/PTC6
BKGD/MS/PTC5
LCD[20:16]/PTC[4:0]
MOSI
SCL
IIC MODULE (IIC)
USER FLASH A
(LG32 = 16K BYTES)
(LG16 = 2K BYTES)
6-CHANNEL TIMER/PWM
(TPM2)
USER FLASH B
(LG32 = 16K BYTES)
(LG16 = 16K BYTES)
2-CHANNEL TIMER/PWM
(TPM1)
SERIAL COMMUNICATIONS
INTERFACE (SCI1)
USER RAM
SDA
TPM2CH[5:0]
TPMCLK
PORT D
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
LVD
LCD[40:37]/PTB[7:4]
LCD[32:29]/PTB[3:0]
TMRCLK
LCD[7:0]/PTD[7:0]
PORT E
Modulo Timer
(MTIM)
IRQ
PORT A
Real Time Counter
(RTC)
HCS08 SYSTEM CONTROL
COP
PORT B
BKGD/MS
LCD[15:8]/PTE[7:0]
TPM1CH[1:0]
PORT F
BKP
EXTAL/PTF7
XTAL/PTF6
TPM2CH3/KBI2/MOSI/PTF5
TPM2CH4/KBI1/MISO/PTF4
TPM2CH5/KBI0/SS/PTF3
ADC14/IRQ/TPM1CH1/SPSCK/PTF2
ADC13/TPM1CH0/RX1/PTF1
ADC12/TPM2CH2/KBI3/TX1/PTF0
PORT G
BKGD
LCD[44:41]/PTG[7:4]
LCD[36:33]/PTG[3:0]
PORT H
INT
ON-CHIP ICE (ICE) and
DEBUG MODULE (DBG)
TPM2CH4/KBI1/PTH7
ADC15/KBI0/TPM2CH5/PTH6
ADC11/TPM1CH0/KBI3/TX1/PTH5
ADC10/TPM1CH1/KBI2/RX1/PTH4
ADC[9:6]/KBI[7:4]/PTH[3:0]
PORT I
CPU
LCD28/ADC5/TPMCLK/PTA7
LCD27/ADC4/TPM2CH1/KBI7/PTA6
LCD26/ADC3/TPM2CH0/KBI6/PTA5
LCD25/ADC2/RX2/KBI5/PTA4
LCD24/ADC1/TX2/KBI4/PTA3
LCD23/ADC0/SDA/PTA2
LCD22/SCL/PTA1
LCD21/PTA0
PORT C
HCS08 CORE
SS/SCL/TPM2CH0/PTI5
SPSCK/SDA/TPM2CH1/PTI4
MOSI/TPM2CH2/PTI3
MISO/TPM2CH3/PTI2
TX2/TMRCLK/PTI1
RX2/PTI0
TPMCLK
TxD1
RxD1
1984 BYTES
SERIAL COMMUNICATIONS
INTERFACE (SCI2)
INTERNAL CLOCK
Source (ICS)
TxD2
RxD2
XTAL
LOW-POWER OSCILLATOR
12-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
VLL3_2
VLL3
VLL1
VLL2
VCAP1
EXTAL
AD[15:0]
LIQUID CRYSTAL
DISPLAY DRIVER
(LCD)
VCAP2
LCD[44:0]
VDD
VSS
VSS2
VDDA/VREFH
VSSA/VREFL
VOLTAGE
REGULATOR
Available only on 80-pin package
Available only on 64-pin and 80-pin package
*/Default function out of reset/*
Figure 13-1. MC9S08LG32 Series Block Diagram Highlighting SCI Block and Pins
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Chapter 11 Serial Communications Interface (S08SCIV4)
13.1.4
Features
Features of SCI module include:
• Full-duplex, standard non-return-to-zero (NRZ) format
• Double-buffered transmitter and receiver with separate enables
• Programmable baud rates (13-bit modulo divider)
• Interrupt-driven or polled operation:
— Transmit data register empty and transmission complete
— Receive data register full
— Receive overrun, parity error, framing error, and noise error
— Idle receiver detect
— Active edge on receive pin
— Break detect supporting LIN
• Hardware parity generation and checking
• Programmable 8-bit or 9-bit character length
• Receiver wakeup by idle-line or address-mark
• Optional 13-bit break character generation / 11-bit break character detection
• Selectable transmitter output polarity
13.1.5
Modes of Operation
See Section 13.3, “Functional Description,” for details concerning SCI operation in these modes:
• 8- and 9-bit data modes
• Stop mode operation
• Loop mode
• Single-wire mode
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13.1.6
Block Diagram
Figure 13-2 shows the transmitter portion of the SCI.
Internal Bus
(Write-Only)
LOOPS
SCID – Tx Buffer
RSRC
Loop
Control
Stop
M
8
7
6
5
4
3
2
1
0
To TxD Pin
L
lsb
H
1 ¥ Baud
Rate Clock
To Receive
Data In
Start
11-bit Transmit Shift Register
Shift Direction
PT
Break (All 0s)
Parity
Generation
Preamble (All 1s)
PE
Shift Enable
T8
Load From SCIxD
TXINV
SCI Controls TxD
TE
SBK
Transmit Control
TXDIR
To TxD
Pin Logic
TxD Direction
BRK13
TDRE
TIE
TC
Tx Interrupt
Request
TCIE
Figure 13-2. SCI Transmitter Block Diagram
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Figure 13-3 shows the receiver portion of the SCI.
Internal Bus
(Read-Only)
16 ¥ Baud
Rate Clock
Divide
By 16
SCID – Rx Buffer
From
Transmitter
H
Data Recovery
WAKE
8
7
6
5
3
2
1
0
L
Shift Direction
Wakeup
Logic
ILT
4
Start
LBKDE
lsb
From RxD Pin
RXINV
M
msb
RSRC
All 1s
Single-Wire
Loop Control
Stop
11-Bit Receive Shift Register
LOOPS
RWU
RWUID
Active Edge
Detect
RDRF
RIE
IDLE
ILIE
LBKDIF
Rx Interrupt
Request
LBKDIE
RXEDGIF
RXEDGIE
OR
ORIE
FE
FEIE
NF
Error Interrupt
Request
NEIE
PE
PT
PARITY
CHECKING
PF
PEIE
Figure 13-3. SCI Receiver Block Diagram
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Chapter 11 Serial Communications Interface (S08SCIV4)
13.2
Register Definition
The SCI has eight 8-bit registers to control baud rate, select SCI options, report SCI status, and for
transmit/receive data.
Refer to the direct-page register summary in Chapter 4, “Memory,” or the absolute address assignments
for all SCI registers. This section refers to registers and control bits only by their names. A
Freescale-provided equate or header file is used to translate these names into the appropriate absolute
addresses.
13.2.1
SCI Baud Rate Registers (SCIxBDH, SCIxBDL)
This pair of registers controls the prescale divisor for SCI baud rate generation. To update the 13-bit baud
rate setting [SBR12:SBR0], first write to SCIxBDH to buffer the high half of the new value and then write
to SCIxBDL. The working value in SCIxBDH does not change until SCIxBDL is written.
SCIxBDL is reset to a non-zero value, so after reset the baud rate generator remains disabled until the first
time the receiver or transmitter is enabled (RE or TE bits in SCIxC2 are written to 1).
7
6
5
LBKDIE
RXEDGIE
0
0
R
4
3
2
1
0
0
0
0
SBR[12:8]
W
Reset
0
0
0
0
= Unimplemented or Reserved
Figure 13-4. SCI Baud Rate Register (SCIxBDH)
Table 13-2. SCIxBDH Field Descriptions
Field
7
LBKDIE
Description
LIN Break Detect Interrupt Enable (for LBKDIF)
0 Hardware interrupts from LBKDIF disabled (use polling).
1 Hardware interrupt requested when LBKDIF flag is 1.
6
RXEDGIE
RxD Input Active Edge Interrupt Enable (for RXEDGIF)
0 Hardware interrupts from RXEDGIF disabled (use polling).
1 Hardware interrupt requested when RXEDGIF flag is 1.
4:0
SBR[12:8]
Baud Rate Modulo Divisor — The 13 bits in SBR[12:0] are referred to collectively as BR, and they set the
modulo divide rate for the SCI baud rate generator. When BR is cleared, the SCI baud rate generator is disabled
to reduce supply current. When BR is 1 – 8191, the SCI baud rate equals BUSCLK/(16×BR). See also BR bits
in Table 13-3.
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7
6
5
4
3
2
1
0
0
1
0
0
R
SBR[7:0]
W
Reset
0
0
0
0
Figure 13-5. SCI Baud Rate Register (SCIxBDL)
Table 13-3. SCIxBDL Field Descriptions
Field
Description
7:0
SBR[7:0]
Baud Rate Modulo Divisor — These 13 bits in SBR[12:0] are referred to collectively as BR, and they set the
modulo divide rate for the SCI baud rate generator. When BR is cleared, the SCI baud rate generator is disabled
to reduce supply current. When BR is 1 – 8191, the SCI baud rate equals BUSCLK/(16×BR). See also BR bits
in Table 13-2.
13.2.2
SCI Control Register 1 (SCIxC1)
This read/write register controls various optional features of the SCI system.
7
6
5
4
3
2
1
0
LOOPS
SCISWAI
RSRC
M
WAKE
ILT
PE
PT
0
0
0
0
0
0
0
0
R
W
Reset
Figure 13-6. SCI Control Register 1 (SCIxC1)
Table 13-4. SCIxC1 Field Descriptions
Field
Description
7
LOOPS
Loop Mode Select — Selects between loop back modes and normal 2-pin full-duplex modes. When LOOPS is
set, the transmitter output is internally connected to the receiver input.
0 Normal operation — RxD and TxD use separate pins.
1 Loop mode or single-wire mode where transmitter outputs are internally connected to receiver input. (See
RSRC bit.) RxD pin is not used by SCI.
6
SCISWAI
SCI Stops in Wait Mode
0 SCI clocks continue to run in wait mode so the SCI can be the source of an interrupt that wakes up the CPU.
1 SCI clocks freeze while CPU is in wait mode.
5
RSRC
Receiver Source Select — This bit has no meaning or effect unless the LOOPS bit is set to 1. When LOOPS is
set, the receiver input is internally connected to the TxD pin and RSRC determines whether this connection is
also connected to the transmitter output.
0 Provided LOOPS is set, RSRC is cleared, selects internal loop back mode and the SCI does not use the RxD
pins.
1 Single-wire SCI mode where the TxD pin is connected to the transmitter output and receiver input.
4
M
9-Bit or 8-Bit Mode Select
0 Normal — start + 8 data bits (lsb first) + stop.
1 Receiver and transmitter use 9-bit data characters
start + 8 data bits (lsb first) + 9th data bit + stop.
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Table 13-4. SCIxC1 Field Descriptions (continued)
Field
3
WAKE
Description
Receiver Wakeup Method Select — Refer to Section 13.3.3.2, “Receiver Wakeup Operation,” for more
information.
0 Idle-line wakeup.
1 Address-mark wakeup.
2
ILT
Idle Line Type Select — Setting this bit to 1 ensures that the stop bit and logic 1 bits at the end of a character
do not count toward the 10 or 11 bit times of logic high level needed by the idle line detection logic. Refer to
Section 13.3.3.2.1, “Idle-Line Wakeup,” for more information.
0 Idle character bit count starts after start bit.
1 Idle character bit count starts after stop bit.
1
PE
Parity Enable — Enables hardware parity generation and checking. When parity is enabled, the most significant
bit (msb) of the data character (eighth or ninth data bit) is treated as the parity bit.
0 No hardware parity generation or checking.
1 Parity enabled.
0
PT
Parity Type — Provided parity is enabled (PE = 1), this bit selects even or odd parity. Odd parity means the total
number of 1s in the data character, including the parity bit, is odd. Even parity means the total number of 1s in
the data character, including the parity bit, is even.
0 Even parity.
1 Odd parity.
13.2.3
SCI Control Register 2 (SCIxC2)
This register can be read or written at any time.
7
6
5
4
3
2
1
0
TIE
TCIE
RIE
ILIE
TE
RE
RWU
SBK
0
0
0
0
0
0
0
0
R
W
Reset
Figure 13-7. SCI Control Register 2 (SCIxC2)
Table 13-5. SCIxC2 Field Descriptions
Field
7
TIE
6
TCIE
Description
Transmit Interrupt Enable (for TDRE)
0 Hardware interrupts from TDRE disabled (use polling).
1 Hardware interrupt requested when TDRE flag is 1.
Transmission Complete Interrupt Enable (for TC)
0 Hardware interrupts from TC disabled (use polling).
1 Hardware interrupt requested when TC flag is 1.
5
RIE
Receiver Interrupt Enable (for RDRF)
0 Hardware interrupts from RDRF disabled (use polling).
1 Hardware interrupt requested when RDRF flag is 1.
4
ILIE
Idle Line Interrupt Enable (for IDLE)
0 Hardware interrupts from IDLE disabled (use polling).
1 Hardware interrupt requested when IDLE flag is 1.
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Table 13-5. SCIxC2 Field Descriptions (continued)
Field
Description
3
TE
Transmitter Enable
0 Transmitter off.
1 Transmitter on.
TE must be 1 in order to use the SCI transmitter. When TE is set, the SCI forces the TxD pin to act as an output
for the SCI system.
When the SCI is configured for single-wire operation (LOOPS = RSRC = 1), TXDIR controls the direction of
traffic on the single SCI communication line (TxD pin).
TE can also queue an idle character by clearing TE then setting TE while a transmission is in progress. Refer to
Section 13.3.2.1, “Send Break and Queued Idle,” for more details.
When TE is written to 0, the transmitter keeps control of the port TxD pin until any data, queued idle, or queued
break character finishes transmitting before allowing the pin to revert to a general-purpose I/O pin.
2
RE
Receiver Enable — When the SCI receiver is off, the RxD pin reverts to being a general-purpose port I/O pin. If
LOOPS is set, the RxD pin reverts to being a general-purpose I/O pin even if RE is set.
0 Receiver off.
1 Receiver on.
1
RWU
Receiver Wakeup Control — This bit can be written to 1 to place the SCI receiver in a standby state where it
waits for automatic hardware detection of a selected wakeup condition. The wakeup condition is an idle line
between messages (WAKE = 0, idle-line wakeup), or a logic 1 in the most significant data bit in a character
(WAKE = 1, address-mark wakeup). Application software sets RWU and (normally) a selected hardware
condition automatically clears RWU. Refer to Section 13.3.3.2, “Receiver Wakeup Operation,” for more details.
0 Normal SCI receiver operation.
1 SCI receiver in standby waiting for wakeup condition.
0
SBK
Send Break — Writing a 1 and then a 0 to SBK queues a break character in the transmit data stream. Additional
break characters of 10 or 11 (13 or 14 if BRK13 = 1) bit times of logic 0 are queued as long as SBK is set.
Depending on the timing of the set and clear of SBK relative to the information currently being transmitted, a
second break character may be queued before software clears SBK. Refer to Section 13.3.2.1, “Send Break and
Queued Idle,” for more details.
0 Normal transmitter operation.
1 Queue break character(s) to be sent.
13.2.4
SCI Status Register 1 (SCIxS1)
This register has eight read-only status flags. Writes have no effect. Special software sequences (which do
not involve writing to this register) are used to clear these status flags.
R
7
6
5
4
3
2
1
0
TDRE
TC
RDRF
IDLE
OR
NF
FE
PF
1
1
0
0
0
0
0
0
W
Reset
= Unimplemented or Reserved
Figure 13-8. SCI Status Register 1 (SCIxS1)
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Table 13-6. SCIxS1 Field Descriptions
Field
Description
7
TDRE
Transmit Data Register Empty Flag — TDRE is set out of reset and when a transmit data value transfers from
the transmit data buffer to the transmit shifter, leaving room for a new character in the buffer. To clear TDRE, read
SCIxS1 with TDRE set and then write to the SCI data register (SCIxD).
0 Transmit data register (buffer) full.
1 Transmit data register (buffer) empty.
6
TC
Transmission Complete Flag — TC is set out of reset and when TDRE is set and no data, preamble, or break
character is being transmitted.
0 Transmitter active (sending data, a preamble, or a break).
1 Transmitter idle (transmission activity complete).
TC is cleared automatically by reading SCIxS1 with TC set and then doing one of the following:
• Write to the SCI data register (SCIxD) to transmit new data
• Queue a preamble by changing TE from 0 to 1
• Queue a break character by writing 1 to SBK in SCIxC2
5
RDRF
Receive Data Register Full Flag — RDRF becomes set when a character transfers from the receive shifter into
the receive data register (SCIxD). To clear RDRF, read SCIxS1 with RDRF set and then read the SCI data
register (SCIxD).
0 Receive data register empty.
1 Receive data register full.
4
IDLE
Idle Line Flag — IDLE is set when the SCI receive line becomes idle for a full character time after a period of
activity. When ILT is cleared, the receiver starts counting idle bit times after the start bit. So if the receive character
is all 1s, these bit times and the stop bit time count toward the full character time of logic high (10 or 11 bit times
depending on the M control bit) needed for the receiver to detect an idle line. When ILT is set, the receiver doesn’t
start counting idle bit times until after the stop bit. The stop bit and any logic high bit times at the end of the
previous character do not count toward the full character time of logic high needed for the receiver to detect an
idle line.
To clear IDLE, read SCIxS1 with IDLE set and then read the SCI data register (SCIxD). After IDLE has been
cleared, it cannot become set again until after a new character has been received and RDRF has been set. IDLE
is set only once even if the receive line remains idle for an extended period.
0 No idle line detected.
1 Idle line was detected.
3
OR
Receiver Overrun Flag — OR is set when a new serial character is ready to be transferred to the receive data
register (buffer), but the previously received character has not been read from SCIxD yet. In this case, the new
character (and all associated error information) is lost because there is no room to move it into SCIxD. To clear
OR, read SCIxS1 with OR set and then read the SCI data register (SCIxD).
0 No overrun.
1 Receive overrun (new SCI data lost).
2
NF
Noise Flag — The advanced sampling technique used in the receiver takes seven samples during the start bit
and three samples in each data bit and the stop bit. If any of these samples disagrees with the rest of the samples
within any bit time in the frame, the flag NF is set at the same time as RDRF is set for the character. To clear NF,
read SCIxS1 and then read the SCI data register (SCIxD).
0 No noise detected.
1 Noise detected in the received character in SCIxD.
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Table 13-6. SCIxS1 Field Descriptions (continued)
Field
Description
1
FE
Framing Error Flag — FE is set at the same time as RDRF when the receiver detects a logic 0 where the stop
bit was expected. This suggests the receiver was not properly aligned to a character frame. To clear FE, read
SCIxS1 with FE set and then read the SCI data register (SCIxD).
0 No framing error detected. This does not guarantee the framing is correct.
1 Framing error.
0
PF
Parity Error Flag — PF is set at the same time as RDRF when parity is enabled (PE = 1) and the parity bit in
the received character does not agree with the expected parity value. To clear PF, read SCIxS1 and then read
the SCI data register (SCIxD).
0 No parity error.
1 Parity error.
13.2.5
SCI Status Register 2 (SCIxS2)
This register has one read-only status flag.
7
6
LBKDIF
RXEDGIF
0
0
R
5
4
3
2
1
RXINV
RWUID
BRK13
LBKDE
0
0
0
0
0
0
RAF
W
Reset
0
0
= Unimplemented or Reserved
Figure 13-9. SCI Status Register 2 (SCIxS2)
Table 13-7. SCIxS2 Field Descriptions
Field
Description
7
LBKDIF
LIN Break Detect Interrupt Flag — LBKDIF is set when the LIN break detect circuitry is enabled and a LIN break
character is detected. LBKDIF is cleared by writing a 1 to it.
0 No LIN break character has been detected.
1 LIN break character has been detected.
6
RXEDGIF
RxD Pin Active Edge Interrupt Flag — RXEDGIF is set when an active edge (falling if RXINV = 0, rising if
RXINV=1) on the RxD pin occurs. RXEDGIF is cleared by writing a 1 to it.
0 No active edge on the receive pin has occurred.
1 An active edge on the receive pin has occurred.
4
RXINV1
Receive Data Inversion — Setting this bit reverses the polarity of the received data input.
0 Receive data not inverted
1 Receive data inverted
3
RWUID
Receive Wake Up Idle Detect— RWUID controls whether the idle character that wakes up the receiver sets the
IDLE bit.
0 During receive standby state (RWU = 1), the IDLE bit does not get set upon detection of an idle character.
1 During receive standby state (RWU = 1), the IDLE bit gets set upon detection of an idle character.
2
BRK13
Break Character Generation Length — BRK13 is used to select a longer transmitted break character length.
Detection of a framing error is not affected by the state of this bit.
0 Break character is transmitted with length of 10 bit times (11 if M = 1)
1 Break character is transmitted with length of 13 bit times (14 if M = 1)
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Table 13-7. SCIxS2 Field Descriptions (continued)
1
Field
Description
1
LBKDE
LIN Break Detection Enable— LBKDE selects a longer break character detection length. While LBKDE is set,
framing error (FE) and receive data register full (RDRF) flags are prevented from setting.
0 Break character is detected at length of 10 bit times (11 if M = 1).
1 Break character is detected at length of 11 bit times (12 if M = 1).
0
RAF
Receiver Active Flag — RAF is set when the SCI receiver detects the beginning of a valid start bit, and RAF is
cleared automatically when the receiver detects an idle line. This status flag can be used to check whether an
SCI character is being received before instructing the MCU to go to stop mode.
0 SCI receiver idle waiting for a start bit.
1 SCI receiver active (RxD input not idle).
Setting RXINV inverts the RxD input for all cases: data bits, start and stop bits, break, and idle.
When using an internal oscillator in a LIN system, it is necessary to raise the break detection threshold one
bit time. Under the worst case timing conditions allowed in LIN, it is possible that a 0x00 data character
can appear to be 10.26 bit times long at a slave running 14% faster than the master. This would trigger
normal break detection circuitry designed to detect a 10-bit break symbol. When the LBKDE bit is set,
framing errors are inhibited and the break detection threshold changes from 10 bits to 11 bits, preventing
false detection of a 0x00 data character as a LIN break symbol.
13.2.6
SCI Control Register 3 (SCIxC3)
7
R
6
5
4
3
2
1
0
T8
TXDIR
TXINV
ORIE
NEIE
FEIE
PEIE
0
0
0
0
0
0
0
R8
W
Reset
0
= Unimplemented or Reserved
Figure 13-10. SCI Control Register 3 (SCIxC3)
Table 13-8. SCIxC3 Field Descriptions
Field
Description
7
R8
Ninth Data Bit for Receiver — When the SCI is configured for 9-bit data (M = 1), R8 can be thought of as a ninth
receive data bit to the left of the msb of the buffered data in the SCIxD register. When reading 9-bit data, read
R8 before reading SCIxD because reading SCIxD completes automatic flag clearing sequences that could allow
R8 and SCIxD to be overwritten with new data.
6
T8
Ninth Data Bit for Transmitter — When the SCI is configured for 9-bit data (M = 1), T8 may be thought of as a
ninth transmit data bit to the left of the msb of the data in the SCIxD register. When writing 9-bit data, the entire
9-bit value is transferred to the SCI shift register after SCIxD is written so T8 should be written (if it needs to
change from its previous value) before SCIxD is written. If T8 does not need to change in the new value (such
as when it is used to generate mark or space parity), it need not be written each time SCIxD is written.
5
TXDIR
TxD Pin Direction in Single-Wire Mode — When the SCI is configured for single-wire half-duplex operation
(LOOPS = RSRC = 1), this bit determines the direction of data at the TxD pin.
0 TxD pin is an input in single-wire mode.
1 TxD pin is an output in single-wire mode.
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Table 13-8. SCIxC3 Field Descriptions (continued)
Field
4
TXINV1
1
Description
Transmit Data Inversion — Setting this bit reverses the polarity of the transmitted data output.
0 Transmit data not inverted
1 Transmit data inverted
3
ORIE
Overrun Interrupt Enable — This bit enables the overrun flag (OR) to generate hardware interrupt requests.
0 OR interrupts disabled (use polling).
1 Hardware interrupt requested when OR is set.
2
NEIE
Noise Error Interrupt Enable — This bit enables the noise flag (NF) to generate hardware interrupt requests.
0 NF interrupts disabled (use polling).
1 Hardware interrupt requested when NF is set.
1
FEIE
Framing Error Interrupt Enable — This bit enables the framing error flag (FE) to generate hardware interrupt
requests.
0 FE interrupts disabled (use polling).
1 Hardware interrupt requested when FE is set.
0
PEIE
Parity Error Interrupt Enable — This bit enables the parity error flag (PF) to generate hardware interrupt
requests.
0 PF interrupts disabled (use polling).
1 Hardware interrupt requested when PF is set.
Setting TXINV inverts the TxD output for all cases: data bits, start and stop bits, break, and idle.
13.2.7
SCI Data Register (SCIxD)
This register is actually two separate registers. Reads return the contents of the read-only receive data
buffer and writes go to the write-only transmit data buffer. Reads and writes of this register are also
involved in the automatic flag clearing mechanisms for the SCI status flags.
7
6
5
4
3
2
1
0
R
R7
R6
R5
R4
R3
R2
R1
R0
W
T7
T6
T5
T4
T3
T2
T1
T0
0
0
0
0
0
0
0
0
Reset
Figure 13-11. SCI Data Register (SCIxD)
13.3
Functional Description
The SCI allows full-duplex, asynchronous, NRZ serial communication among the MCU and remote
devices, including other MCUs. The SCI comprises a baud rate generator, transmitter, and receiver block.
The transmitter and receiver operate independently, although they use the same baud rate generator.
During normal operation, the MCU monitors the status of the SCI, writes the data to be transmitted, and
processes received data. The following describes each of the blocks of the SCI.
13.3.1
Baud Rate Generation
As shown in Figure 13-12, the clock source for the SCI baud rate generator is the bus-rate clock.
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MODULO DIVIDE BY
(1 THROUGH 8191)
BUSCLK
SBR12:SBR0
BAUD RATE GENERATOR
OFF IF [SBR12:SBR0] = 0
DIVIDE BY
16
Tx BAUD RATE
Rx SAMPLING CLOCK
(16 × BAUD RATE)
BAUD RATE =
BUSCLK
[SBR12:SBR0] × 16
Figure 13-12. SCI Baud Rate Generation
SCI communications require the transmitter and receiver (which typically derive baud rates from
independent clock sources) to use the same baud rate. Allowed tolerance on this baud frequency depends
on the details of how the receiver synchronizes to the leading edge of the start bit and how bit sampling is
performed.
The MCU resynchronizes to bit boundaries on every high-to-low transition. In the worst case, there are no
such transitions in the full 10- or 11-bit time character frame so any mismatch in baud rate is accumulated
for the whole character time. For a Freescale Semiconductor SCI system whose bus frequency is driven
by a crystal, the allowed baud rate mismatch is about ±4.5 percent for 8-bit data format and about ±4
percent for 9-bit data format. Although baud rate modulo divider settings do not always produce baud rates
that exactly match standard rates, it is normally possible to get within a few percent, which is acceptable
for reliable communications.
13.3.2
Transmitter Functional Description
This section describes the overall block diagram for the SCI transmitter, as well as specialized functions
for sending break and idle characters. The transmitter block diagram is shown in Figure 13-2.
The transmitter output (TxD) idle state defaults to logic high (TXINV is cleared following reset). The
transmitter output is inverted by setting TXINV. The transmitter is enabled by setting the TE bit in SCIxC2.
This queues a preamble character that is one full character frame of the idle state. The transmitter then
remains idle until data is available in the transmit data buffer. Programs store data into the transmit data
buffer by writing to the SCI data register (SCIxD).
The central element of the SCI transmitter is the transmit shift register that is 10 or 11 bits long depending
on the setting in the M control bit. For the remainder of this section, assume M is cleared, selecting the
normal 8-bit data mode. In 8-bit data mode, the shift register holds a start bit, eight data bits, and a stop
bit. When the transmit shift register is available for a new SCI character, the value waiting in the transmit
data register is transferred to the shift register (synchronized with the baud rate clock) and the transmit data
register empty (TDRE) status flag is set to indicate another character may be written to the transmit data
buffer at SCIxD.
If no new character is waiting in the transmit data buffer after a stop bit is shifted out the TxD pin, the
transmitter sets the transmit complete flag and enters an idle mode, with TxD high, waiting for more
characters to transmit.
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Writing 0 to TE does not immediately release the pin to be a general-purpose I/O pin. Any transmit activity
in progress must first be completed. This includes data characters in progress, queued idle characters, and
queued break characters.
13.3.2.1
Send Break and Queued Idle
The SBK control bit in SCIxC2 sends break characters originally used to gain the attention of old teletype
receivers. Break characters are a full character time of logic 0 (10 bit times including the start and stop
bits). A longer break of 13 bit times can be enabled by setting BRK13. Normally, a program would wait
for TDRE to become set to indicate the last character of a message has moved to the transmit shifter, then
write 1 and then write 0 to the SBK bit. This action queues a break character to be sent as soon as the shifter
is available. If SBK remains 1 when the queued break moves into the shifter (synchronized to the baud rate
clock), an additional break character is queued. If the receiving device is another Freescale Semiconductor
SCI, the break characters are received as 0s in all eight data bits and a framing error (FE = 1) occurs.
When idle-line wakeup is used, a full character time of idle (logic 1) is needed between messages to wake
up any sleeping receivers. Normally, a program would wait for TDRE to become set to indicate the last
character of a message has moved to the transmit shifter, then write 0 and then write 1 to the TE bit. This
action queues an idle character to be sent as soon as the shifter is available. As long as the character in the
shifter does not finish while TE is cleared, the SCI transmitter never actually releases control of the TxD
pin. If there is a possibility of the shifter finishing while TE is cleard, set the general-purpose I/O controls
so the pin shared with TxD is an output driving a logic 1. This ensures that the TxD line looks like a normal
idle line even if the SCI loses control of the port pin between writing 0 and then 1 to TE.
The length of the break character is affected by the BRK13 and M bits as shown below.
Table 13-9. Break Character Length
13.3.3
BRK13
M
Break Character Length
0
0
10 bit times
0
1
11 bit times
1
0
13 bit times
1
1
14 bit times
Receiver Functional Description
In this section, the receiver block diagram (Figure 13-3) is used as a guide for the overall receiver
functional description. Next, the data sampling technique used to reconstruct receiver data is described in
more detail. Finally, two variations of the receiver wakeup function are explained.
The receiver input is inverted by setting RXINV. The receiver is enabled by setting the RE bit in SCIxC2.
Character frames consist of a start bit of logic 0, eight (or nine) data bits (lsb first), and a stop bit of logic
1. For information about 9-bit data mode, refer to Section 13.3.5.1, “8-Bit and 9-Bit Data Modes.” For the
remainder of this discussion, assume the SCI is configured for normal 8-bit data mode.
After receiving the stop bit into the receive shifter, and provided the receive data register is not already
full, the data character is transferred to the receive data register and the receive data register full (RDRF)
status flag is set. If RDRF was already set indicating the receive data register (buffer) was already full, the
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overrun (OR) status flag is set and the new data is lost. Because the SCI receiver is double-buffered, the
program has one full character time after RDRF is set before the data in the receive data buffer must be
read to avoid a receiver overrun.
When a program detects that the receive data register is full (RDRF = 1), it gets the data from the receive
data register by reading SCIxD. The RDRF flag is cleared automatically by a two-step sequence which is
normally satisfied in the course of the user’s program that handles receive data. Refer to Section 13.3.4,
“Interrupts and Status Flags,” for more details about flag clearing.
13.3.3.1
Data Sampling Technique
The SCI receiver uses a 16× baud rate clock for sampling. The receiver starts by taking logic level samples
at 16 times the baud rate to search for a falling edge on the RxD serial data input pin. A falling edge is
defined as a logic 0 sample after three consecutive logic 1 samples. The 16× baud rate clock divides the
bit time into 16 segments labeled RT1 through RT16. When a falling edge is located, three more samples
are taken at RT3, RT5, and RT7 to make sure this was a real start bit and not merely noise. If at least two
of these three samples are 0, the receiver assumes it is synchronized to a receive character.
The receiver then samples each bit time, including the start and stop bits, at RT8, RT9, and RT10 to
determine the logic level for that bit. The logic level is interpreted to be that of the majority of the samples
taken during the bit time. In the case of the start bit, the bit is assumed to be 0 if at least two of the samples
at RT3, RT5, and RT7 are 0 even if one or all of the samples taken at RT8, RT9, and RT10 are 1s. If any
sample in any bit time (including the start and stop bits) in a character frame fails to agree with the logic
level for that bit, the noise flag (NF) is set when the received character is transferred to the receive data
buffer.
The falling edge detection logic continuously looks for falling edges. If an edge is detected, the sample
clock is resynchronized to bit times. This improves the reliability of the receiver in the presence of noise
or mismatched baud rates. It does not improve worst case analysis because some characters do not have
any extra falling edges anywhere in the character frame.
In the case of a framing error, provided the received character was not a break character, the sampling logic
that searches for a falling edge is filled with three logic 1 samples so that a new start bit can be detected
almost immediately.
In the case of a framing error, the receiver is inhibited from receiving any new characters until the framing
error flag is cleared. The receive shift register continues to function, but a complete character cannot
transfer to the receive data buffer if FE remains set.
13.3.3.2
Receiver Wakeup Operation
Receiver wakeup is a hardware mechanism that allows an SCI receiver to ignore the characters in a
message intended for a different SCI receiver. In such a system, all receivers evaluate the first character(s)
of each message, and as soon as they determine the message is intended for a different receiver, they write
logic 1 to the receiver wake up (RWU) control bit in SCIxC2. When RWU bit is set, the status flags
associated with the receiver (with the exception of the idle bit, IDLE, when RWUID bit is set) are inhibited
from setting, thus eliminating the software overhead for handling the unimportant message characters. At
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the end of a message, or at the beginning of the next message, all receivers automatically force RWU to 0
so all receivers wakeup in time to look at the first character(s) of the next message.
13.3.3.2.1
Idle-Line Wakeup
When wake is cleared, the receiver is configured for idle-line wakeup. In this mode, RWU is cleared
automatically when the receiver detects a full character time of the idle-line level. The M control bit selects
8-bit or 9-bit data mode that determines how many bit times of idle are needed to constitute a full character
time (10 or 11 bit times because of the start and stop bits).
When RWU is one and RWUID is zero, the idle condition that wakes up the receiver does not set the IDLE
flag. The receiver wakes up and waits for the first data character of the next message that sets the RDRF
flag and generates an interrupt if enabled. When RWUID is one, any idle condition sets the IDLE flag and
generates an interrupt if enabled, regardless of whether RWU is zero or one.
The idle-line type (ILT) control bit selects one of two ways to detect an idle line. When ILT is cleared, the
idle bit counter starts after the start bit so the stop bit and any logic 1s at the end of a character count toward
the full character time of idle. When ILT is set, the idle bit counter does not start until after a stop bit time,
so the idle detection is not affected by the data in the last character of the previous message.
13.3.3.2.2
Address-Mark Wakeup
When wake is set, the receiver is configured for address-mark wakeup. In this mode, RWU is cleared
automatically when the receiver detects a logic 1 in the most significant bit of a received character (eighth
bit when M is cleared and ninth bit when M is set).
Address-mark wakeup allows messages to contain idle characters, but requires the msb be reserved for use
in address frames. The logic 1 msb of an address frame clears the RWU bit before the stop bit is received
and sets the RDRF flag. In this case, the character with the msb set is received even though the receiver
was sleeping during most of this character time.
13.3.4
Interrupts and Status Flags
The SCI system has three separate interrupt vectors to reduce the amount of software needed to isolate the
cause of the interrupt. One interrupt vector is associated with the transmitter for TDRE and TC events.
Another interrupt vector is associated with the receiver for RDRF, IDLE, RXEDGIF, and LBKDIF events.
A third vector is used for OR, NF, FE, and PF error conditions. Each of these ten interrupt sources can be
separately masked by local interrupt enable masks. The flags can be polled by software when the local
masks are cleared to disable generation of hardware interrupt requests.
The SCI transmitter has two status flags that can optionally generate hardware interrupt requests. Transmit
data register empty (TDRE) indicates when there is room in the transmit data buffer to write another
transmit character to SCIxD. If the transmit interrupt enable (TIE) bit is set, a hardware interrupt is
requested when TDRE is set. Transmit complete (TC) indicates that the transmitter is finished transmitting
all data, preamble, and break characters and is idle with TxD at the inactive level. This flag is often used
in systems with modems to determine when it is safe to turn off the modem. If the transmit complete
interrupt enable (TCIE) bit is set, a hardware interrupt is requested when TC is set. Instead of hardware
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interrupts, software polling may be used to monitor the TDRE and TC status flags if the corresponding
TIE or TCIE local interrupt masks are cleared.
When a program detects that the receive data register is full (RDRF = 1), it gets the data from the receive
data register by reading SCIxD. The RDRF flag is cleared by reading SCIxS1 while RDRF is set and then
reading SCIxD.
When polling is used, this sequence is naturally satisfied in the normal course of the user program. If
hardware interrupts are used, SCIxS1 must be read in the interrupt service routine (ISR). Normally, this is
done in the ISR anyway to check for receive errors, so the sequence is automatically satisfied.
The IDLE status flag includes logic that prevents it from getting set repeatedly when the RxD line remains
idle for an extended period of time. IDLE is cleared by reading SCIxS1 while IDLE is set and then reading
SCIxD. After IDLE has been cleared, it cannot become set again until the receiver has received at least
one new character and has set RDRF.
If the associated error was detected in the received character that caused RDRF to be set, the error flags
— noise flag (NF), framing error (FE), and parity error flag (PF) — are set at the same time as RDRF.
These flags are not set in overrun cases.
If RDRF was already set when a new character is ready to be transferred from the receive shifter to the
receive data buffer, the overrun (OR) flag is set instead of the data along with any associated NF, FE, or
PF condition is lost.
At any time, an active edge on the RxD serial data input pin causes the RXEDGIF flag to set. The
RXEDGIF flag is cleared by writing a 1 to it. This function does depend on the receiver being enabled
(RE = 1).
13.3.5
Additional SCI Functions
The following sections describe additional SCI functions.
13.3.5.1
8-Bit and 9-Bit Data Modes
The SCI system (transmitter and receiver) can be configured to operate in 9-bit data mode by setting the
M control bit in SCIxC1. In 9-bit mode, there is a ninth data bit to the left of the msb of the SCI data
register. For the transmit data buffer, this bit is stored in T8 in SCIxC3. For the receiver, the ninth bit is
held in R8 in SCIxC3.
For coherent writes to the transmit data buffer, write to the T8 bit before writing to SCIxD.
If the bit value to be transmitted as the ninth bit of a new character is the same as for the previous character,
it is not necessary to write to T8 again. When data is transferred from the transmit data buffer to the
transmit shifter, the value in T8 is copied at the same time data is transferred from SCIxD to the shifter.
The 9-bit data mode is typically used with parity to allow eight bits of data plus the parity in the ninth bit,
or it is used with address-mark wakeup so the ninth data bit can serve as the wakeup bit. In custom
protocols, the ninth bit can also serve as a software-controlled marker.
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13.3.5.2
Stop Mode Operation
During all stop modes, clocks to the SCI module are halted.
In stop2 mode, all SCI register data is lost and must be re-initialized upon recovery from this mode. No
SCI module registers are affected in stop3 mode.
The receive input active edge detect circuit remains active in stop3 mode, but not in stop2. An active edge
on the receive input brings the CPU out of stop3 mode if the interrupt is not masked (RXEDGIE = 1).
Because the clocks are halted, the SCI module resumes operation upon exit from stop (only in stop3 mode).
Software should ensure stop mode is not entered while there is a character being transmitted out of or
received into the SCI module.
13.3.5.3
Loop Mode
When LOOPS is set, the RSRC bit in the same register chooses between loop mode (RSRC = 0) or
single-wire mode (RSRC = 1). Loop mode is sometimes used to check software, independent of
connections in the external system, to help isolate system problems. In this mode, the transmitter output is
internally connected to the receiver input and the RxD pin is not used by the SCI, so it reverts to a
general-purpose port I/O pin.
13.3.5.4
Single-Wire Operation
When LOOPS is set, the RSRC bit in the same register chooses between loop mode (RSRC = 0) or
single-wire mode (RSRC = 1). Single-wire mode implements a half-duplex serial connection. The receiver
is internally connected to the transmitter output and to the TxD pin. The RxD pin is not used and reverts
to a general-purpose port I/O pin.
In single-wire mode, the TXDIR bit in SCIxC3 controls the direction of serial data on the TxD pin. When
TXDIR is cleared, the TxD pin is an input to the SCI receiver and the transmitter is temporarily
disconnected from the TxD pin so an external device can send serial data to the receiver. When TXDIR is
set, the TxD pin is an output driven by the transmitter. In single-wire mode, the internal loop back
connection from the transmitter to the receiver causes the receiver to receive characters that are sent out
by the transmitter.
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Serial Peripheral Interface (S08SPIV4)
14.1
Introduction
The serial peripheral interface (SPI) module provides for full-duplex, synchronous, serial communication
between the MCU and peripheral devices. These peripheral devices can include other microcontrollers,
analog-to-digital converters, shift registers, sensors, memories, etc.
The SPI runs at a baud rate up to the bus clock divided by two in master mode and up to the bus clock
divided by 4 in slave mode. Software can poll the status flags, or SPI operation can be interrupt driven.
The SPI also supports a data length of 8 or 16 bits and includes a hardware match feature for the receive
data buffer.
Figure 14-1 shows the MC9S08LG32 series block diagram with the SPI block and pins highlighted.
14.1.1
Module Configuration
The SPI module pins, MISO, MOSI, SPSCK, and SS can be repositioned under software control using
MISO, MOSI, SCK, and SS bits in PINPS3 register as shown in Table 14-1. MISO, MOSI, SCK, and SS
bits in PINPS3 register selects which general-purpose I/O ports are associated with SPI operation.
Table 14-1. SPI Position Options
MISO/MOSI/SPSCK/SS
Port Pin for MISO
Port Pin for MOSI
Port Pin for SPSCK
Port Pin for SS
0 (default)
PTF4
PTF5
PTF2
PTF3
1
PTI2
PTI3
PTI4
PTI5
14.1.2
SPI Clock Gating
The bus clock to the SPI can be gated on and off using the SPI bit in SCGC2. These bits are cleared after
any reset, which disables the bus clock to this module. To conserve power, these bits can be cleared to
disable the clock to this module when not in use. For more details, see Section 5.7, “Peripheral Clock
Gating.”
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8-BIT KEYBOARD
INTERRUPT (KBI)
RESET
IRQ
SERIAL PERIPHERAL
INTERFACE (SPI)
KBI[7:0]
SS
SPSCK
MISO
RESET/PTC6
BKGD/MS/PTC5
LCD[20:16]/PTC[4:0]
MOSI
SCL
IIC MODULE (IIC)
USER FLASH A
(LG32 = 16K BYTES)
(LG16 = 2K BYTES)
6-CHANNEL TIMER/PWM
(TPM2)
USER FLASH B
(LG32 = 16K BYTES)
(LG16 = 16K BYTES)
2-CHANNEL TIMER/PWM
(TPM1)
SERIAL COMMUNICATIONS
INTERFACE (SCI1)
USER RAM
SDA
TPM2CH[5:0]
TPMCLK
PORT D
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
LVD
LCD[40:37]/PTB[7:4]
LCD[32:29]/PTB[3:0]
TMRCLK
LCD[7:0]/PTD[7:0]
PORT E
Modulo Timer
(MTIM)
IRQ
PORT A
Real Time Counter
(RTC)
HCS08 SYSTEM CONTROL
COP
PORT B
BKGD/MS
LCD[15:8]/PTE[7:0]
TPM1CH[1:0]
PORT F
BKP
EXTAL/PTF7
XTAL/PTF6
TPM2CH3/KBI2/MOSI/PTF5
TPM2CH4/KBI1/MISO/PTF4
TPM2CH5/KBI0/SS/PTF3
ADC14/IRQ/TPM1CH1/SPSCK/PTF2
ADC13/TPM1CH0/RX1/PTF1
ADC12/TPM2CH2/KBI3/TX1/PTF0
PORT G
BKGD
LCD[44:41]/PTG[7:4]
LCD[36:33]/PTG[3:0]
PORT H
INT
ON-CHIP ICE (ICE) and
DEBUG MODULE (DBG)
TPM2CH4/KBI1/PTH7
ADC15/KBI0/TPM2CH5/PTH6
ADC11/TPM1CH0/KBI3/TX1/PTH5
ADC10/TPM1CH1/KBI2/RX1/PTH4
ADC[9:6]/KBI[7:4]/PTH[3:0]
PORT I
CPU
LCD28/ADC5/TPMCLK/PTA7
LCD27/ADC4/TPM2CH1/KBI7/PTA6
LCD26/ADC3/TPM2CH0/KBI6/PTA5
LCD25/ADC2/RX2/KBI5/PTA4
LCD24/ADC1/TX2/KBI4/PTA3
LCD23/ADC0/SDA/PTA2
LCD22/SCL/PTA1
LCD21/PTA0
PORT C
HCS08 CORE
SS/SCL/TPM2CH0/PTI5
SPSCK/SDA/TPM2CH1/PTI4
MOSI/TPM2CH2/PTI3
MISO/TPM2CH3/PTI2
TX2/TMRCLK/PTI1
RX2/PTI0
TPMCLK
TxD1
RxD1
1984 BYTES
SERIAL COMMUNICATIONS
INTERFACE (SCI2)
INTERNAL CLOCK
Source (ICS)
TxD2
RxD2
XTAL
LOW-POWER OSCILLATOR
12-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
VLL3_2
VLL3
VLL1
VLL2
VCAP1
EXTAL
AD[15:0]
LIQUID CRYSTAL
DISPLAY DRIVER
(LCD)
VCAP2
LCD[44:0]
VDD
VSS
VSS2
VOLTAGE
REGULATOR
VDDA/VREFH
VSSA/VREFL
Available only on 80-pin package
Available only on 64-pin and 80-pin package
*/Default function out of reset/*
Figure 14-1. MC9S08LG32 series Block Diagram Highlighting SPI Block and Pins
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14.1.3
Features
Features of the SPI module include:
• Master or slave mode operation
• Full-duplex or single-wire bidirectional option
• Programmable transmit bit rate
• Double-buffered transmit and receive
• Serial clock phase and polarity options
• Slave select output
• Selectable MSB-first or LSB-first shifting
14.1.4
Block Diagrams
This section includes block diagrams showing SPI system connections, the internal organization of the SPI
module, and the SPI clock dividers that control the master mode bit rate.
14.1.4.1
SPI System Block Diagram
Figure 14-2 shows the SPI modules of two MCUs connected in a master-slave arrangement. The master
device initiates all SPI data transfers. During a transfer, the master shifts data out (on the MOSI pin) to the
slave while simultaneously shifting data in (on the MISO pin) from the slave. The transfer effectively
exchanges the data that was in the SPI shift registers of the two SPI systems. The SPSCK signal is a clock
output from the master and an input to the slave. The slave device must be selected by a low level on the
slave select input (SS pin). In this system, the master device has configured its SS pin as an optional slave
select output.
SLAVE
MASTER
MOSI
MOSI
SPI SHIFTER
7
6
5
4
3
2
SPI SHIFTER
1
0
MISO
SPSCK
CLOCK
GENERATOR
SS
MISO
7
6
5
4
3
2
1
0
SPSCK
SS
Figure 14-2. SPI System Connections
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The most common uses of the SPI system include connecting simple shift registers for adding input or
output ports or connecting small peripheral devices such as serial A/D or D/A converters. Although
Figure 14-2 shows a system where data is exchanged between two MCUs, many practical systems involve
simpler connections where data is unidirectionally transferred from the master MCU to a slave or from a
slave to the master MCU.
14.1.4.2
SPI Module Block Diagram
Figure 14-3 is a block diagram of the SPI module. The central element of the SPI is the SPI shift register.
Data is written to the double-buffered transmitter (write to SPIxD) and gets transferred to the SPI shift
register at the start of a data transfer. After shifting in a byte of data, the data is transferred into the
double-buffered receiver where it can be read (read from SPIxD). Pin multiplexing logic controls
connections between MCU pins and the SPI module.
When the SPI is configured as a master, the clock output is routed to the SPSCK pin, the shifter output is
routed to MOSI, and the shifter input is routed from the MISO pin.
When the SPI is configured as a slave, the SPSCK pin is routed to the clock input of the SPI, the shifter
output is routed to MISO, and the shifter input is routed from the MOSI pin.
In the external SPI system, simply connect all SPSCK pins to each other, all MISO pins together, and all
MOSI pins together. Peripheral devices often use slightly different names for these pins.
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PIN CONTROL
M
SPE
MOSI
(MOMI)
S
Tx BUFFER (WRITE SPIxD)
ENABLE
SPI SYSTEM
M
SHIFT
OUT
SPI SHIFT REGISTER
SHIFT
IN
MISO
(SISO)
S
SPC0
Rx BUFFER (READ SPIxD)
BIDIROE
LSBFE
SHIFT
DIRECTION
SHIFT
CLOCK
Rx BUFFER
FULL
Tx BUFFER
EMPTY
MASTER CLOCK
BUS RATE
CLOCK
SPIBR
CLOCK GENERATOR
MSTR
CLOCK
LOGIC
SLAVE CLOCK
MASTER/SLAVE
M
SPSCK
S
MASTER/
SLAVE
MODE SELECT
MODFEN
SSOE
MODE FAULT
DETECTION
SPRF
SS
SPTEF
SPTIE
MODF
SPIE
SPI
INTERRUPT
REQUEST
Figure 14-3. SPI Module Block Diagram
14.1.5
SPI Baud Rate Generation
As shown in Figure 14-4, the clock source for the SPI baud rate generator is the bus clock. The three
prescale bits (SPPR2:SPPR1:SPPR0) choose a prescale divisor of 1, 2, 3, 4, 5, 6, 7, or 8. The three rate
select bits (SPR3:SPR2:SPR1:SPR0) divide the output of the prescaler stage by 2, 4, 8, 16, 32, 64, 128,
256,or 512 to get the internal SPI master mode bit-rate clock.
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BUS CLOCK
PRESCALER
CLOCK RATE DIVIDER
DIVIDE BY
1, 2, 3, 4, 5, 6, 7, or 8
DIVIDE BY
2, 4, 8, 16, 32, 64, 128, 256, or 512
SPPR2:SPPR1:SPPR0
SPR3:SPR2:SPR1:SPR0
MASTER
SPI
BIT RATE
Figure 14-4. SPI Baud Rate Generation
14.2
External Signal Description
The SPI optionally shares four port pins. The function of these pins depends on the settings of SPI control
bits. When the SPI is disabled (SPE = 0), these four pins revert to being general-purpose port I/O pins that
are not controlled by the SPI.
14.2.1
SPSCK — SPI Serial Clock
When the SPI is enabled as a slave, this pin is the serial clock input. When the SPI is enabled as a master,
this pin is the serial clock output.
14.2.2
MOSI — Master Data Out, Slave Data In
When the SPI is enabled as a master and SPI pin control zero (SPC0) is 0 (not bidirectional mode), this
pin is the serial data output. When the SPI is enabled as a slave and SPC0 = 0, this pin is the serial data
input. If SPC0 = 1 to select single-wire bidirectional mode, and master mode is selected, this pin becomes
the bidirectional data I/O pin (MOMI). Also, the bidirectional mode output enable bit determines whether
the pin acts as an input (BIDIROE = 0) or an output (BIDIROE = 1). If SPC0 = 1 and slave mode is
selected, this pin is not used by the SPI and reverts to being a general-purpose port I/O pin.
14.2.3
MISO — Master Data In, Slave Data Out
When the SPI is enabled as a master and SPI pin control zero (SPC0) is 0 (not bidirectional mode), this
pin is the serial data input. When the SPI is enabled as a slave and SPC0 = 0, this pin is the serial data
output. If SPC0 = 1 to select single-wire bidirectional mode, and slave mode is selected, this pin becomes
the bidirectional data I/O pin (SISO) and the bidirectional mode output enable bit determines whether the
pin acts as an input (BIDIROE = 0) or an output (BIDIROE = 1). If SPC0 = 1 and master mode is selected,
this pin is not used by the SPI and reverts to being a general-purpose port I/O pin.
14.2.4
SS — Slave Select
When the SPI is enabled as a slave, this pin is the low-true slave select input. When the SPI is enabled as
a master and mode fault enable is off (MODFEN = 0), this pin is not used by the SPI and reverts to being
a general-purpose port I/O pin. When the SPI is enabled as a master and MODFEN = 1, the slave select
output enable bit determines whether this pin acts as the mode fault input (SSOE = 0) or as the slave select
output (SSOE = 1).
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14.3
Modes of Operation
14.3.1
SPI in Stop Modes
The SPI is disabled in all stop modes, regardless of the settings before executing the STOP instruction.
During stop2 mode, the SPI module will be fully powered down. Upon wake-up from stop2 mode, the SPI
module will be in the reset state. During stop3 mode, clocks to the SPI module are halted. No registers are
affected. If stop3 is exited with a reset, the SPI will be put into its reset state. If stop3 is exited with an
interrupt, the SPI continues from the state it was in when stop3 was entered.
14.4
Register Definition
The SPI has five 8-bit registers to select SPI options, control baud rate, report SPI status, and for
transmit/receive data.
Refer to the direct-page register summary in Chapter 4, “Memory,” for the absolute address assignments
for all SPI registers. This section refers to registers and control bits only by their names, and a
Freescale-provided equate or header file is used to translate these names into the appropriate absolute
addresses.
14.4.1
SPI Control Register 1 (SPIxC1)
This read/write register includes the SPI enable control, interrupt enables, and configuration options.
7
6
5
4
3
2
1
0
SPIE
SPE
SPTIE
MSTR
CPOL
CPHA
SSOE
LSBFE
0
0
0
0
0
1
0
0
R
W
Reset
Figure 14-5. SPI Control Register 1 (SPIxC1)
Table 14-2. SPIxC1 Field Descriptions
Field
Description
7
SPIE
SPI Interrupt Enable (for SPRF and MODF) — This is the interrupt enable for SPI receive buffer full (SPRF)
and mode fault (MODF) events.
0 Interrupts from SPRF and MODF inhibited (use polling)
1 When SPRF or MODF is 1, request a hardware interrupt
6
SPE
SPI System Enable — Disabling the SPI halts any transfer that is in progress, clears data buffers, and initializes
internal state machines. SPRF is cleared and SPTEF is set to indicate the SPI transmit data buffer is empty.
0 SPI system inactive
1 SPI system enabled
5
SPTIE
SPI Transmit Interrupt Enable — This is the interrupt enable bit for SPI transmit buffer empty (SPTEF).
0 Interrupts from SPTEF inhibited (use polling)
1 When SPTEF is 1, hardware interrupt requested
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Table 14-2. SPIxC1 Field Descriptions (continued)
Field
Description
4
MSTR
Master/Slave Mode Select
0 SPI module configured as a slave SPI device
1 SPI module configured as a master SPI device
3
CPOL
Clock Polarity — This bit effectively places an inverter in series with the clock signal from a master SPI or to a
slave SPI device. Refer to Section 14.5.3, “SPI Clock Formats,” for more details.
0 Active-high SPI clock (idles low)
1 Active-low SPI clock (idles high)
2
CPHA
Clock Phase — This bit selects one of two clock formats for different kinds of synchronous serial peripheral
devices. Refer to Section 14.5.3, “SPI Clock Formats,” for more details.
0 First edge on SPSCK occurs at the middle of the first cycle of an 8-cycle data transfer
1 First edge on SPSCK occurs at the start of the first cycle of an 8-cycle data transfer
1
SSOE
Slave Select Output Enable — This bit is used in combination with the mode fault enable (MODFEN) bit in
SPCR2 and the master/slave (MSTR) control bit to determine the function of the SS pin as shown in Table 14-3.
0
LSBFE
LSB First (Shifter Direction)
0 SPI serial data transfers start with most significant bit
1 SPI serial data transfers start with least significant bit
Table 14-3. SS Pin Function
MODFEN
SSOE
Master Mode
Slave Mode
0
0
General-purpose I/O (not SPI)
Slave select input
0
1
General-purpose I/O (not SPI)
Slave select input
1
0
SS input for mode fault
Slave select input
1
1
Automatic SS output
Slave select input
NOTE
Ensure that the SPI should not be disabled (SPE=0) at the same time as a bit change to the CPHA bit. These
changes should be performed as separate operations or unexpected behavior may occur.
14.4.2
SPI Control Register 2 (SPIxC2)
This read/write register is used to control optional features of the SPI system. Bits 7, 6, 5, and 2 are not
implemented and always read 0.
R
7
6
5
0
0
0
4
3
MODFEN
BIDIROE
0
0
2
1
0
SPISWAI
SPC0
0
0
0
W
Reset
0
0
0
0
= Unimplemented or Reserved
Figure 14-6. SPI Control Register 2 (SPIxC2)
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Table 14-4. SPIxC2 Register Field Descriptions
Field
Description
4
MODFEN
Master Mode-Fault Function Enable — When the SPI is configured for slave mode, this bit has no meaning or
effect. (The SS pin is the slave select input.) In master mode, this bit determines how the SS pin is used (refer to
Table 14-3 for more details).
0 Mode fault function disabled, master SS pin reverts to general-purpose I/O not controlled by SPI
1 Mode fault function enabled, master SS pin acts as the mode fault input or the slave select output
3
BIDIROE
Bidirectional Mode Output Enable — When bidirectional mode is enabled by SPI pin control 0 (SPC0) = 1,
BIDIROE determines whether the SPI data output driver is enabled to the single bidirectional SPI I/O pin.
Depending on whether the SPI is configured as a master or a slave, it uses either the MOSI (MOMI) or MISO
(SISO) pin, respectively, as the single SPI data I/O pin. When SPC0 = 0, BIDIROE has no meaning or effect.
0 Output driver disabled so SPI data I/O pin acts as an input
1 SPI I/O pin enabled as an output
1
SPISWAI
SPI Stop in Wait Mode
0 SPI clocks continue to operate in wait mode
1 SPI clocks stop when the MCU enters wait mode
0
SPC0
14.4.3
SPI Pin Control 0 — The SPC0 bit chooses single-wire bidirectional mode. If MSTR = 0 (slave mode), the SPI
uses the MISO (SISO) pin for bidirectional SPI data transfers. If MSTR = 1 (master mode), the SPI uses the MOSI
(MOMI) pin for bidirectional SPI data transfers. When SPC0 = 1, BIDIROE is used to enable or disable the output
driver for the single bidirectional SPI I/O pin.
0 SPI uses separate pins for data input and data output
1 SPI configured for single-wire bidirectional operation
SPI Baud Rate Register (SPIxBR)
This register is used to set the prescaler and bit rate divisor for an SPI master. This register may be read or
written at any time.
7
R
6
5
4
3
2
1
0
SPPR2
SPPR1
SPPR0
SPR3
SPR2
SPR1
SPR0
0
0
0
0
0
0
0
0
W
Reset
0
= Unimplemented or Reserved
Figure 14-7. SPI Baud Rate Register (SPIxBR)
Table 14-5. SPIxBR Register Field Descriptions
Field
Description
6:4
SPPR[2:0]
SPI Baud Rate Prescale Divisor — This 3-bit field selects one of eight divisors for the SPI baud rate prescaler
as shown in Table 14-6. The input to this prescaler is the bus rate clock (BUSCLK). The output of this prescaler
drives the input of the SPI baud rate divider (see Figure 14-4).
2:0
SPR[3:0]
SPI Baud Rate Divisor — This 4-bit field selects one of eight divisors for the SPI baud rate divider as shown in
Table 14-7. The input to this divider comes from the SPI baud rate prescaler (see Figure 14-4). The output of this
divider is the SPI bit rate clock for master mode.
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Table 14-6. SPI Baud Rate Prescaler Divisor
SPPR2:SPPR1:SPPR0
Prescaler Divisor
0:0:0
1
0:0:1
2
0:1:0
3
0:1:1
4
1:0:0
5
1:0:1
6
1:1:0
7
1:1:1
8
Table 14-7. SPI Baud Rate Divisor
14.4.4
SPR3:SPR2:SPR1:SPR0
Rate Divisor
0:0:0:0
2
0:0:0:1
4
0:0:1:0
8
0:0:1:1
16
0:1:0:0
32
0:1:0:1
64
0:1:1:0
128
0:1:1:1
256
1:0:0:0
512
All other combinations
reserved
SPI Status Register (SPIxS)
This register has three read-only status bits. Bits 6, 3, 2, 1, and 0 are not implemented and always read 0.
Writes have no meaning or effect.
R
7
6
5
4
3
2
1
0
SPRF
0
SPTEF
MODF
0
0
0
0
0
0
1
0
0
0
0
0
W
Reset
= Unimplemented or Reserved
Figure 14-8. SPI Status Register (SPIxS)
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Table 14-8. SPIxS Register Field Descriptions
Field
Description
7
SPRF
SPI Read Buffer Full Flag — SPRF is set at the completion of an SPI transfer to indicate that received data may
be read from the SPI data register (SPIxD). SPRF is cleared by reading SPRF while it is set, then reading the
SPI data register.
0 No data available in the receive data buffer
1 Data available in the receive data buffer
5
SPTEF
SPI Transmit Buffer Empty Flag — This bit is set when there is room in the transmit data buffer. It is cleared by
reading SPIxS with SPTEF set, followed by writing a data value to the transmit buffer at SPIxD. SPIxS must be
read with SPTEF = 1 before writing data to SPIxD or the SPIxD write will be ignored. SPTEF generates an
SPTEF CPU interrupt request if the SPTIE bit in the SPIxC1 is also set. SPTEF is automatically set when a data
byte transfers from the transmit buffer into the transmit shift register. For an idle SPI (no data in the transmit buffer
or the shift register and no transfer in progress), data written to SPIxD is transferred to the shifter almost
immediately so SPTEF is set within two bus cycles allowing a second 8-bit data value to be queued into the
transmit buffer. After completion of the transfer of the value in the shift register, the queued value from the transmit
buffer will automatically move to the shifter and SPTEF will be set to indicate there is room for new data in the
transmit buffer. If no new data is waiting in the transmit buffer, SPTEF simply remains set and no data moves from
the buffer to the shifter.
0 SPI transmit buffer not empty
1 SPI transmit buffer empty
4
MODF
Master Mode Fault Flag — MODF is set if the SPI is configured as a master and the slave select input goes low,
indicating some other SPI device is also configured as a master. The SS pin acts as a mode fault error input only
when MSTR = 1, MODFEN = 1, and SSOE = 0; otherwise, MODF will never be set. MODF is cleared by reading
MODF while it is 1, then writing to SPI control register 1 (SPIxC1).
0 No mode fault error
1 Mode fault error detected
14.4.5
SPI Data Register (SPIxD)
7
6
5
4
3
2
1
0
Bit 7
6
5
4
3
2
1
Bit 0
0
0
0
0
0
0
0
0
R
W
Reset
Figure 14-9. SPI Data Register (SPIxD)
Reads of this register return the data read from the receive data buffer. Writes to this register write data to
the transmit data buffer. When the SPI is configured as a master, writing data to the transmit data buffer
initiates an SPI transfer.
Data should not be written to the transmit data buffer unless the SPI transmit buffer empty flag (SPTEF)
is set, indicating there is room in the transmit buffer to queue a new transmit byte.
Data may be read from SPIxD any time after SPRF is set and before another transfer is finished. Failure
to read the data out of the receive data buffer before a new transfer ends causes a receive overrun condition
and the data from the new transfer is lost.
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14.5
Functional Description
The SPI system is enabled by setting the SPI enable (SPE) bit in SPI Control Register 1. While the SPE
bit is set, the four associated SPI port pins are dedicated to the SPI function as:
• Slave select (SS)
• Serial clock (SPSCK)
• Master out/slave in (MOSI)
• Master in/slave out (MISO)
An SPI transfer is initiated in the master SPI device by reading the SPI status register (SPIxS) when SPTEF
= 1 and then writing data to the transmit data buffer (write to SPIxD). When a transfer is complete, received
data is moved into the receive data buffer. The SPIxD register acts as the SPI receive data buffer for reads
and as the SPI transmit data buffer for writes.
The clock phase control bit (CPHA) and a clock polarity control bit (CPOL) in the SPI Control Register 1
(SPIxC1) select one of four possible clock formats to be used by the SPI system. The CPOL bit simply
selects a non-inverted or inverted clock. The CPHA bit is used to accommodate two fundamentally
different protocols by sampling data on odd numbered SPSCK edges or on even numbered SPSCK edges.
The SPI can be configured to operate as a master or as a slave. When the MSTR bit in SPI control register
1 is set, master mode is selected, when the MSTR bit is clear, slave mode is selected.
14.5.1
Master Mode
The SPI operates in master mode when the MSTR bit is set. Only a master SPI module can initiate
transmissions. A transmission begins by reading the SPIxS register while SPTEF = 1 and writing to the
master SPI data registers. If the shift register is empty, the byte immediately transfers to the shift register.
The data begins shifting out on the MOSI pin under the control of the serial clock.
• SPSCK
The SPR3, SPR2, SPR1, and SPR0 baud rate selection bits in conjunction with the SPPR2, SPPR1, and
SPPR0 baud rate preselection bits in the SPI Baud Rate register control the baud rate generator and
determine the speed of the transmission. The SPSCK pin is the SPI clock output. Through the SPSCK pin,
the baud rate generator of the master controls the shift register of the slave peripheral.
• MOSI, MISO pin
In master mode, the function of the serial data output pin (MOSI) and the serial data input pin (MISO) is
determined by the SPC0 and BIDIROE control bits.
• SS pin
If MODFEN and SSOE bit are set, the SS pin is configured as slave select output. The SS output becomes
low during each transmission and is high when the SPI is in idle state.
If MODFEN is set and SSOE is cleared, the SS pin is configured as input for detecting mode fault error.
If the SS input becomes low this indicates a mode fault error where another master tries to drive the MOSI
and SPSCK lines. In this case, the SPI immediately switches to slave mode, by clearing the MSTR bit and
also disables the slave output buffer MISO (or SISO in bidirectional mode). So the result is that all outputs
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are disabled and SPSCK, MOSI and MISO are inputs. If a transmission is in progress when the mode fault
occurs, the transmission is aborted and the SPI is forced into idle state.
This mode fault error also sets the mode fault (MODF) flag in the SPI Status Register (SPIxS). If the SPI
interrupt enable bit (SPIE) is set when the MODF flag gets set, then an SPI interrupt sequence is also
requested.
When a write to the SPI Data Register in the master occurs, there is a half SPSCK-cycle delay. After the
delay, SPSCK is started within the master. The rest of the transfer operation differs slightly, depending on
the clock format specified by the SPI clock phase bit, CPHA, in SPI Control Register 1 (see Section 14.5.3,
“SPI Clock Formats”).
NOTE
A change of the bits CPOL, CPHA, SSOE, LSBFE, MODFEN, SPC0,
BIDIROE with SPC0 set, SPPR2-SPPR0 and SPR3-SPR0 in master mode
will abort a transmission in progress and force the SPI into idle state. The
remote slave cannot detect this, therefore the master has to ensure that the
remote slave is set back to idle state.
14.5.2
Slave Mode
The SPI operates in slave mode when the MSTR bit in SPI Control Register1 is clear.
• SPSCK
In slave mode, SPSCK is the SPI clock input from the master.
• MISO, MOSI pin
In slave mode, the function of the serial data output pin (MISO) and serial data input pin (MOSI) is
determined by the SPC0 bit and BIDIROE bit in SPI Control Register 2.
• SS pin
The SS pin is the slave select input. Before a data transmission occurs, the SS pin of the slave SPI must be
low. SS must remain low until the transmission is complete. If SS goes high, the SPI is forced into idle
state.
The SS input also controls the serial data output pin, if SS is high (not selected), the serial data output pin
is high impedance, and, if SS is low the first bit in the SPI Data Register is driven out of the serial data
output pin. Also, if the slave is not selected (SS is high), then the SPSCK input is ignored and no internal
shifting of the SPI shift register takes place.
Although the SPI is capable of duplex operation, some SPI peripherals are capable of only receiving SPI
data in a slave mode. For these simpler devices, there is no serial data out pin.
NOTE
When peripherals with duplex capability are used, take care not to
simultaneously enable two receivers whose serial outputs drive the same
system slave’s serial data output line.
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As long as no more than one slave device drives the system slave’s serial data output line, it is possible for
several slaves to receive the same transmission from a master, although the master would not receive return
information from all of the receiving slaves.
If the CPHA bit in SPI Control Register 1 is clear, odd numbered edges on the SPSCK input cause the data
at the serial data input pin to be latched. Even numbered edges cause the value previously latched from the
serial data input pin to shift into the LSB or MSB of the SPI shift register, depending on the LSBFE bit.
If the CPHA bit is set, even numbered edges on the SPSCK input cause the data at the serial data input pin
to be latched. Odd numbered edges cause the value previously latched from the serial data input pin to shift
into the LSB or MSB of the SPI shift register, depending on the LSBFE bit.
When CPHA is set, the first edge is used to get the first data bit onto the serial data output pin. When CPHA
is clear and the SS input is low (slave selected), the first bit of the SPI data is driven out of the serial data
output pin. After the eighth shift, the transfer is considered complete and the received data is transferred
into the SPI data registers. To indicate transfer is complete, the SPRF flag in the SPI Status Register is set.
NOTE
A change of the bits CPOL, CPHA, SSOE, LSBFE, MODFEN, SPC0 and
BIDIROE with SPC0 set in slave mode will corrupt a transmission in
progress and has to be avoided.
14.5.3
SPI Clock Formats
To accommodate a wide variety of synchronous serial peripherals from different manufacturers, the SPI
system has a clock polarity (CPOL) bit and a clock phase (CPHA) control bit to select one of four clock
formats for data transfers. CPOL selectively inserts an inverter in series with the clock. CPHA chooses
between two different clock phase relationships between the clock and data.
Figure 14-10 shows the clock formats when CPHA = 1. At the top of the figure, the eight bit times are
shown for reference with bit 1 starting at the first SPSCK edge and bit 8 ending one-half SPSCK cycle
after the sixteenth SPSCK edge. The MSB first and LSB first lines show the order of SPI data bits
depending on the setting in LSBFE. Both variations of SPSCK polarity are shown, but only one of these
waveforms applies for a specific transfer, depending on the value in CPOL. The SAMPLE IN waveform
applies to the MOSI input of a slave or the MISO input of a master. The MOSI waveform applies to the
MOSI output pin from a master and the MISO waveform applies to the MISO output from a slave. The SS
OUT waveform applies to the slave select output from a master (provided MODFEN and SSOE = 1). The
master SS output goes to active low one-half SPSCK cycle before the start of the transfer and goes back
high at the end of the eighth bit time of the transfer. The SS IN waveform applies to the slave select input
of a slave.
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BIT TIME #
(REFERENCE)
1
2
...
6
7
8
BIT 7
BIT 0
BIT 6
BIT 1
...
...
BIT 2
BIT 5
BIT 1
BIT 6
BIT 0
BIT 7
SPSCK
(CPOL = 0)
SPSCK
(CPOL = 1)
SAMPLE IN
(MISO OR MOSI)
MOSI
(MASTER OUT)
MSB FIRST
LSB FIRST
MISO
(SLAVE OUT)
SS OUT
(MASTER)
SS IN
(SLAVE)
Figure 14-10. SPI Clock Formats (CPHA = 1)
When CPHA = 1, the slave begins to drive its MISO output when SS goes to active low, but the data is not
defined until the first SPSCK edge. The first SPSCK edge shifts the first bit of data from the shifter onto
the MOSI output of the master and the MISO output of the slave. The next SPSCK edge causes both the
master and the slave to sample the data bit values on their MISO and MOSI inputs, respectively. At the
third SPSCK edge, the SPI shifter shifts one bit position which shifts in the bit value that was just sampled,
and shifts the second data bit value out the other end of the shifter to the MOSI and MISO outputs of the
master and slave, respectively. When CHPA = 1, the slave’s SS input is not required to go to its inactive
high level between transfers.
Figure 14-11 shows the clock formats when CPHA = 0. At the top of the figure, the eight bit times are
shown for reference with bit 1 starting as the slave is selected (SS IN goes low), and bit 8 ends at the last
SPSCK edge. The MSB first and LSB first lines show the order of SPI data bits depending on the setting
in LSBFE. Both variations of SPSCK polarity are shown, but only one of these waveforms applies for a
specific transfer, depending on the value in CPOL. The SAMPLE IN waveform applies to the MOSI input
of a slave or the MISO input of a master. The MOSI waveform applies to the MOSI output pin from a
master and the MISO waveform applies to the MISO output from a slave. The SS OUT waveform applies
to the slave select output from a master (provided MODFEN and SSOE = 1). The master SS output goes
to active low at the start of the first bit time of the transfer and goes back high one-half SPSCK cycle after
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the end of the eighth bit time of the transfer. The SS IN waveform applies to the slave select input of a
slave.
BIT TIME #
(REFERENCE)
1
2
BIT 7
BIT 0
BIT 6
BIT 1
...
6
7
8
BIT 2
BIT 5
BIT 1
BIT 6
BIT 0
BIT 7
SPSCK
(CPOL = 0)
SPSCK
(CPOL = 1)
SAMPLE IN
(MISO OR MOSI)
MOSI
(MASTER OUT)
MSB FIRST
LSB FIRST
...
...
MISO
(SLAVE OUT)
SS OUT
(MASTER)
SS IN
(SLAVE)
Figure 14-11. SPI Clock Formats (CPHA = 0)
When CPHA = 0, the slave begins to drive its MISO output with the first data bit value (MSB or LSB
depending on LSBFE) when SS goes to active low. The first SPSCK edge causes both the master and the
slave to sample the data bit values on their MISO and MOSI inputs, respectively. At the second SPSCK
edge, the SPI shifter shifts one bit position which shifts in the bit value that was just sampled and shifts the
second data bit value out the other end of the shifter to the MOSI and MISO outputs of the master and
slave, respectively. When CPHA = 0, the slave’s SS input must go to its inactive high level between
transfers.
14.5.4
14.5.4.1
Special Features
SS Output
The SS output feature automatically drives the SS pin low during transmission to select external devices
and drives it high during idle to deselect external devices. When SS output is selected, the SS output pin
is connected to the SS input pin of the external device.
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The SS output is available only in master mode during normal SPI operation by asserting the SSOE and
MODFEN bits as shown in Table 14-3.
The mode fault feature is disabled while SS output is enabled.
NOTE
Care must be taken when using the SS output feature in a multi-master
system since the mode fault feature is not available for detecting system
errors between masters.
14.5.4.2
Bidirectional Mode (MOMI or SISO)
The bidirectional mode is selected when the SPC0 bit is set in SPI Control Register 2 (see Table 14-9). In
this mode, the SPI uses only one serial data pin for the interface with external device(s). The MSTR bit
decides which pin to use. The MOSI pin becomes the serial data I/O (MOMI) pin for the master mode, and
the MISO pin becomes serial data I/O (SISO) pin for the slave mode. The MISO pin in master mode and
MOSI pin in slave mode are not used by the SPI.
Table 14-9. Normal Mode and Bidirectional Mode
When SPE = 1
Master Mode MSTR = 1
Serial Out
Normal Mode
SPC0 = 0
MOSI
Serial Out
SPI
MISO
Serial Out
SPI
Serial In
MOSI
SPI
Serial In
Bidirectional Mode
SPC0 = 1
Slave Mode MSTR = 0
MOMI
MISO
Serial In
Serial Out
SPI
BIDIROE
Serial In
BIDIROE
SOSI
The direction of each serial I/O pin depends on the BIDIROE bit. If the pin is configured as an output,
serial data from the shift register is driven out on the pin. The same pin is also the serial input to the shift
register.
The SPSCK is output for the master mode and input for the slave mode.
The SS is the input or output for the master mode, and it is always the input for the slave mode.
The bidirectional mode does not affect SPSCK and SS functions.
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NOTE
In bidirectional master mode, with mode fault enabled, both data pins MISO
and MOSI can be occupied by the SPI, though MOSI is normally used for
transmissions in bidirectional mode and MISO is not used by the SPI. If a
mode fault occurs, the SPI is automatically switched to slave mode, in this
case MISO becomes occupied by the SPI and MOSI is not used. This has to
be considered, if the MISO pin is used for another purpose.
14.5.5
SPI Interrupts
There are three flag bits, two interrupt mask bits, and one interrupt vector associated with the SPI system.
The SPI interrupt enable mask (SPIE) enables interrupts from the SPI receiver full flag (SPRF) and mode
fault flag (MODF). The SPI transmit interrupt enable mask (SPTIE) enables interrupts from the SPI
transmit buffer empty flag (SPTEF). When one of the flag bits is set, and the associated interrupt mask bit
is set, a hardware interrupt request is sent to the CPU. If the interrupt mask bits are cleared, software can
poll the associated flag bits instead of using interrupts. The SPI interrupt service routine (ISR) should
check the flag bits to determine what event caused the interrupt. The service routine should also clear the
flag bit(s) before returning from the ISR (usually near the beginning of the ISR).
14.5.6
Mode Fault Detection
A mode fault occurs and the mode fault flag (MODF) becomes set when a master SPI device detects an
error on the SS pin (provided the SS pin is configured as the mode fault input signal). The SS pin is
configured to be the mode fault input signal when MSTR = 1, mode fault enable is set (MODFEN = 1),
and slave select output enable is clear (SSOE = 0).
The mode fault detection feature can be used in a system where more than one SPI device might become
a master at the same time. The error is detected when a master’s SS pin is low, indicating that some other
SPI device is trying to address this master as if it were a slave. This could indicate a harmful output driver
conflict, so the mode fault logic is designed to disable all SPI output drivers when such an error is detected.
When a mode fault is detected, MODF is set and MSTR is cleared to change the SPI configuration back
to slave mode. The output drivers on the SPSCK, MOSI, and MISO (if not bidirectional mode) are
disabled.
MODF is cleared by reading it while it is set, then writing to the SPI control register 1 (SPIxC1). User
software should verify the error condition has been corrected before changing the SPI back to master
mode.
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Chapter 15
Real-Time Counter (S08RTCV1)
15.1
Introduction
The Real-Time Counter (RTC) module consists of one 8-bit counter, one 8-bit comparator, several
binary-based and decimal-based prescaler dividers, three clock sources, and one programmable periodic
interrupt. This module can be used for time-of-day, calendar, or any task scheduling functions. It can also
serve as a cyclic wake up from low-power modes without the need of external components.
NOTE
For details on low-power mode operation, refer to Table 3-2 in Chapter 3,
“Modes of Operation.”
15.1.1
RTC Clock Gating
The bus clock to the RTC can be gated on and off using the RTC bit in SCGC1. This bit is cleared after
any reset, which disables the bus clock to this module. To conserve power, this bit can be cleared to disable
the clock to this module when not in use. For more details, see Section 5.7, “Peripheral Clock Gating.”
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8-BIT KEYBOARD
INTERRUPT (KBI)
RESET
IRQ
SERIAL PERIPHERAL
INTERFACE (SPI)
KBI[7:0]
SS
SPSCK
MISO
RESET/PTC6
BKGD/MS/PTC5
LCD[20:16]/PTC[4:0]
MOSI
SCL
IIC MODULE (IIC)
USER FLASH A
(LG32 = 16K BYTES)
(LG16 = 2K BYTES)
6-CHANNEL TIMER/PWM
(TPM2)
USER FLASH B
(LG32 = 16K BYTES)
(LG16 = 16K BYTES)
2-CHANNEL TIMER/PWM
(TPM1)
SERIAL COMMUNICATIONS
INTERFACE (SCI1)
USER RAM
SDA
TPM2CH[5:0]
TPMCLK
PORT D
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
LVD
LCD[40:37]/PTB[7:4]
LCD[32:29]/PTB[3:0]
TMRCLK
LCD[7:0]/PTD[7:0]
PORT E
Modulo Timer
(MTIM)
IRQ
PORT A
Real Time Counter
(RTC)
HCS08 SYSTEM CONTROL
COP
PORT B
BKGD/MS
LCD[15:8]/PTE[7:0]
TPM1CH[1:0]
PORT F
BKP
EXTAL/PTF7
XTAL/PTF6
TPM2CH3/KBI2/MOSI/PTF5
TPM2CH4/KBI1/MISO/PTF4
TPM2CH5/KBI0/SS/PTF3
ADC14/IRQ/TPM1CH1/SPSCK/PTF2
ADC13/TPM1CH0/RX1/PTF1
ADC12/TPM2CH2/KBI3/TX1/PTF0
PORT G
BKGD
LCD[44:41]/PTG[7:4]
LCD[36:33]/PTG[3:0]
PORT H
INT
ON-CHIP ICE (ICE) and
DEBUG MODULE (DBG)
TPM2CH4/KBI1/PTH7
ADC15/KBI0/TPM2CH5/PTH6
ADC11/TPM1CH0/KBI3/TX1/PTH5
ADC10/TPM1CH1/KBI2/RX1/PTH4
ADC[9:6]/KBI[7:4]/PTH[3:0]
PORT I
CPU
LCD28/ADC5/TPMCLK/PTA7
LCD27/ADC4/TPM2CH1/KBI7/PTA6
LCD26/ADC3/TPM2CH0/KBI6/PTA5
LCD25/ADC2/RX2/KBI5/PTA4
LCD24/ADC1/TX2/KBI4/PTA3
LCD23/ADC0/SDA/PTA2
LCD22/SCL/PTA1
LCD21/PTA0
PORT C
HCS08 CORE
SS/SCL/TPM2CH0/PTI5
SPSCK/SDA/TPM2CH1/PTI4
MOSI/TPM2CH2/PTI3
MISO/TPM2CH3/PTI2
TX2/TMRCLK/PTI1
RX2/PTI0
TPMCLK
TxD1
RxD1
1984 BYTES
SERIAL COMMUNICATIONS
INTERFACE (SCI2)
INTERNAL CLOCK
Source (ICS)
TxD2
RxD2
XTAL
LOW-POWER OSCILLATOR
12-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
VLL3_2
VLL3
VLL1
VLL2
VCAP1
EXTAL
AD[15:0]
LIQUID CRYSTAL
DISPLAY DRIVER
(LCD)
VCAP2
LCD[44:0]
VDD
VSS
VSS2
VDDA/VREFH
VSSA/VREFL
VOLTAGE
REGULATOR
Available only on 80-pin package
Available only on 64-pin and 80-pin package
*/Default function out of reset/*
Figure 15-1. MC9S08LG32 Series Block Diagram Highlighting RTC Block and Pins
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15.1.2
Features
Features of the RTC module include:
• 8-bit up-counter
— 8-bit modulo match limit
— Software controllable periodic interrupt on match
• Three software selectable clock sources for input to prescaler with selectable binary-based and
decimal-based divider values
— 1 kHz internal low-power oscillator (LPO)
— External clock (OSCOUT)
— 32 kHz internal clock (IRCLK)
15.1.3
Modes of Operation
This section defines the operation in stop, wait and background debug modes.
15.1.3.1
Wait Mode
The RTC continues to run in wait mode if enabled before executing the appropriate instruction. Therefore,
the RTC can bring the MCU out of wait mode if the real-time interrupt is enabled. For lowest possible
current consumption, the RTC should be stopped by software if not needed as an interrupt source during
wait mode.
15.1.3.2
Stop Modes
The RTC continues to run in stop2 or stop3 mode if the RTC is enabled before executing the STOP
instruction. Therefore, the RTC can bring the MCU out of stop modes with no external components, if the
real-time interrupt is enabled.
The LPO clock can be used in stop2 and stop3 modes. OSCOUT and IRCLK clocks are only available in
stop3 mode.
Power consumption is lower when all clock sources are disabled, but in that case, the real-time interrupt
cannot wakeup the MCU from stop modes.
15.1.3.3
Active Background Mode
The RTC suspends all counting during active background mode until the microcontroller returns to normal
user operating mode. Counting resumes from the suspended value as long as the RTCMOD register is not
written and the RTCPS and RTCLKS bits are not altered.
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15.1.4
Block Diagram
The block diagram for the RTC module is shown in Figure 15-2.
LPO
Clock
Source
Select
OSCOUT
IRCLK
8-Bit Modulo
(RTCMOD)
RTCLKS
VDD
RTCLKS[0]
RTCPS
Prescaler
Divide-By
Q
D
Background
Mode
E
8-Bit Comparator
RTC
Clock
RTC
Interrupt
Request
RTIF
R
Write 1 to
RTIF
8-Bit Counter
(RTCCNT)
RTIE
Figure 15-2. Real-Time Counter (RTC) Block Diagram
15.2
External Signal Description
The RTC does not include any off-chip signals.
15.3
Register Definition
The RTC includes a status and control register, an 8-bit counter register, and an 8-bit modulo register.
Refer to the direct-page register summary in the memory section of this document for the absolute address
assignments for all RTC registers.This section refers to registers and control bits only by their names and
relative address offsets.
Table 15-1 is a summary of RTC registers.
Table 15-1. RTC Register Summary
Name
7
6
5
4
3
2
1
0
R
RTCSC
RTIF
RTCLKS
RTIE
RTCPS
W
R
RTCCNT
RTCCNT
W
R
RTCMOD
RTCMOD
W
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15.3.1
RTC Status and Control Register (RTCSC)
RTCSC contains the real-time interrupt status flag (RTIF), the clock select bits (RTCLKS), the real-time
interrupt enable bit (RTIE), and the prescaler select bits (RTCPS).
7
6
5
4
3
2
1
0
0
0
R
RTIF
RTCLKS
RTIE
RTCPS
W
Reset:
0
0
0
0
0
0
Figure 15-3. RTC Status and Control Register (RTCSC)
Table 15-2. RTCSC Field Descriptions
Field
Description
7
RTIF
Real-Time Interrupt Flag This status bit indicates the RTC counter register reached the value in the RTC modulo
register. Writing a logic 0 has no effect. Writing a logic 1 clears the bit and the real-time interrupt request. Reset
clears RTIF.
0 RTC counter has not reached the value in the RTC modulo register.
1 RTC counter has reached the value in the RTC modulo register.
6–5
RTCLKS
Real-Time Clock Source Select. These two read/write bits select the clock source input to the RTC prescaler.
Changing the clock source clears the prescaler and RTCCNT counters. When selecting a clock source, ensure
that the clock source is properly enabled (if applicable) to ensure correct operation of the RTC. Reset clears
RTCLKS.
00 Real-time clock source is the 1 kHz low power oscillator (LPO)
01 Real-time clock source is the external clock (OSCOUT)
1x Real-time clock source is the internal clock (IRCLK)
4
RTIE
Real-Time Interrupt Enable. This read/write bit enables real-time interrupts. If RTIE is set, then an interrupt is
generated when RTIF is set. Reset clears RTIE.
0 Real-time interrupt requests are disabled. Use software polling.
1 Real-time interrupt requests are enabled.
3–0
RTCPS
Real-Time Clock Prescaler Select. These four read/write bits select binary-based or decimal-based divide-by
values for the clock source. See Table 15-3. Changing the prescaler value clears the prescaler and RTCCNT
counters. Reset clears RTCPS.
Table 15-3. RTC Prescaler Divide-by values
RTCPS
RTCLKS[0]
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
0
Off
23
25
26
27
28
29
210
1
2
22
10
24
102
5x102
103
1
Off
210
211
212
213
214
215
216
103
105
2x105
2x103 5x103
104
2x104 5x104
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15.3.2
RTC Counter Register (RTCCNT)
RTCCNT is the read-only value of the current RTC count of the 8-bit counter.
7
6
5
4
R
3
2
1
0
0
0
0
0
RTCCNT
W
Reset:
0
0
0
0
Figure 15-4. RTC Counter Register (RTCCNT)
Table 15-4. RTCCNT Field Descriptions
Field
Description
7:0
RTCCNT
RTC Count. These eight read-only bits contain the current value of the 8-bit counter. Writes have no effect to this
register. Reset, writing to RTCMOD, or writing different values to RTCLKS and RTCPS clear the count to 0x00.
15.3.3
RTC Modulo Register (RTCMOD)
7
6
5
4
3
2
1
0
0
0
0
0
R
RTCMOD
W
Reset:
0
0
0
0
Figure 15-5. RTC Modulo Register (RTCMOD)
Table 15-5. RTCMOD Field Descriptions
Field
Description
7:0
RTC Modulo. These eight read/write bits contain the modulo value used to reset the count to 0x00 upon a compare
RTCMOD match and set the RTIF status bit. A value of 0x00 sets the RTIF bit on each rising edge of the prescaler output.
Writing to RTCMOD resets the prescaler and the RTCCNT counters to 0x00. Reset sets the modulo to 0x00.
15.4
Functional Description
The RTC is composed of a main 8-bit up-counter with an 8-bit modulo register, a clock source selector,
and a prescaler block with binary-based and decimal-based selectable values. The module also contains
software selectable interrupt logic.
After any MCU reset, the counter is stopped and reset to 0x00, the modulus register is set to 0x00, and the
prescaler is off. The 1 kHz internal oscillator clock is selected as the default clock source. To start the
prescaler, write any value other than zero to the prescaler select bits (RTCPS).
Three clock sources are software selectable: the low power oscillator clock (LPO), the external clock
(OSCOUT), and the internal clock (IRCLK). The RTC clock select bits (RTCLKS) select the desired clock
source. If a different value is written to RTCLKS, the prescaler and RTCCNT counters are reset to 0x00.
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RTCPS and the RTCLKS[0] bit select the desired divide-by value. If a different value is written to RTCPS,
the prescaler and RTCCNT counters are reset to 0x00. Table 15-6 shows different prescaler period values.
Table 15-6. Prescaler Period
RTCPS
1 kHz Internal Clock
(RTCLKS = 00)
1 MHz External Clock 32 kHz Internal Clock 32 kHz Internal Clock
(RTCLKS = 01)
(RTCLKS = 10)
(RTCLKS = 11)
0000
Off
Off
Off
Off
0001
8 ms
1.024 ms
250 μs
32 ms
0010
32 ms
2.048 ms
1 ms
64 ms
0011
64 ms
4.096 ms
2 ms
128 ms
0100
128 ms
8.192 ms
4 ms
256 ms
0101
256 ms
16.4 ms
8 ms
512 ms
0110
512 ms
32.8 ms
16 ms
1.024 s
0111
1.024 s
65.5 ms
32 ms
2.048 s
1000
1 ms
1 ms
31.25 μs
31.25 ms
1001
2 ms
2 ms
62.5 μs
62.5 ms
1010
4 ms
5 ms
125 μs
156.25 ms
1011
10 ms
10 ms
312.5 μs
312.5 ms
1100
16 ms
20 ms
0.5 ms
0.625 s
1101
0.1 s
50 ms
3.125 ms
1.5625 s
1110
0.5 s
0.1 s
15.625 ms
3.125 s
1111
1s
0.2 s
31.25 ms
6.25 s
The RTC modulo register (RTCMOD) allows the compare value to be set to any value from 0x00 to 0xFF.
When the counter is active, the counter increments at the selected rate until the count matches the modulo
value. When these values match, the counter resets to 0x00 and continues counting. The real-time interrupt
flag (RTIF) is set when a match occurs. The flag sets on the transition from the modulo value to 0x00.
Writing to RTCMOD resets the prescaler and the RTCCNT counters to 0x00.
The RTC allows for an interrupt to be generated when RTIF is set. To enable the real-time interrupt, set
the real-time interrupt enable bit (RTIE) in RTCSC. RTIF is cleared by writing a 1 to RTIF.
15.4.1
RTC Operation Example
This section shows an example of the RTC operation as the counter reaches a matching value from the
modulo register.
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Internal 1 kHz
Clock Source
RTC Clock
(RTCPS = 0xA)
RTCCNT
0x52
0x53
0x54
0x55
0x00
0x01
RTIF
RTCMOD
0x55
Figure 15-6. RTC Counter Overflow Example
In the example of Figure 15-6, the selected clock source is the 1 kHz internal oscillator clock source. The
prescaler (RTCPS) is set to 0xA or divide-by-4. The modulo value in the RTCMOD register is set to 0x55.
When the counter, RTCCNT, reaches the modulo value of 0x55, the counter overflows to 0x00 and
continues counting. The real-time interrupt flag, RTIF, sets when the counter value changes from 0x55 to
0x00. A real-time interrupt is generated when RTIF is set, if RTIE is set.
15.5
Initialization/Application Information
This section provides example code to give some basic direction to a user on how to initialize and
configure the RTC module. The example software is implemented in C language.
The example below shows how to implement time of day with the RTC using the 1 kHz clock source to
achieve the lowest possible power consumption. Because the 1 kHz clock source is not as accurate as a
crystal, software can be added for any adjustments. For accuracy without adjustments at the expense of
additional power consumption, the external clock (OSCOUT) or the internal clock (IRCLK) can be
selected with appropriate prescaler and modulo values.
/* Initialize the elapsed time counters */
Seconds = 0;
Minutes = 0;
Hours = 0;
Days=0;
/* Configure RTC to interrupt every 1 second from 1 kHz clock source */
RTCMOD.byte = 0x00;
RTCSC.byte = 0x1F;
/**********************************************************************
Function Name : RTC_ISR
Notes : Interrupt service routine for RTC module.
**********************************************************************/
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#pragma TRAP_PROC
void RTC_ISR(void)
{
/* Clear the interrupt flag */
RTCSC.byte = RTCSC.byte | 0x80;
/* RTC interrupts every 1 Second */
Seconds++;
/* 60 seconds in a minute */
if (Seconds > 59){
Minutes++;
Seconds = 0;
}
/* 60 minutes in an hour */
if (Minutes > 59){
Hours++;
Minutes = 0;
}
/* 24 hours in a day */
if (Hours > 23){
Days ++;
Hours = 0;
}
}
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Chapter 16
Timer/Pulse-Width Modulator (S08TPMV3)
16.1
Introduction
The TPM is a one-to-eight-channel timer system which supports traditional input capture, output compare,
or edge-aligned PWM on each channel. A control bit allows the TPM to be configured such that all
channels may be used for center-aligned PWM functions. Timing functions are based on a 16-bit counter
with prescaler and modulo features to control frequency and range (period between overflows) of the time
reference. This timing system is ideally suited for a wide range of control applications, and the
center-aligned PWM capability extends the field of application to motor control in small appliances.
Figure 16-1 shows the MC9S08LG32 series block diagram with the TPM blocks and pins highlighted.
16.1.1
TPM External Clock
The TPM modules on the MC9S08LG32 series use the TPMCLK pin.
16.1.2
Module Instances
The MC9S08LG32 series MCUs contain two TPM modules: TPM1 and TPM2. The memory map, pins,
interrupts, etc. for the two modules can be differentiated using the TPM1 and TPM2 nomenclature.
16.1.3
Module Configuration
The TPM module pins, TPMxCHn can be repositioned under software control using TPM2CH5,
TPM2CH4, TPM2CH3, TPM2CH2, TPM2CH1, TPM2CH0, TPM1CH1, and TPM1CH0 bits in PINPS2
register as shown in Table 16-1. TPM2CH5, TPM2CH4, TPM2CH3, TPM2CH2, TPM2CH1, TPM2CH0,
TPM1CH1, and TPM1CH0 bits in PINPS2 register selects which general-purpose I/O ports are associated
with TPM operation.
Table 16-1. TPM Position Options
TPMxCHn
Port Pin for TPM2CH5 Port Pin for TPM2CH4 Port Pin for TPM2CH3 Port Pin for TPM2CH2
0 (default)
PTF3
PTF4
PTF5
PTF0
1
PTH6
PTH7
PTI2
PTI3
TPMxCHn
Port Pin for TPM2CH1 Port Pin for TPM2CH0 Port Pin for TPM1CH1 Port Pin for TPM1CH0
0 (default)
PTA6
PTA5
PTF2
PTF1
1
PTI4
PTI5
PTH4
PTH5
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16.1.4
TPM Clock Gating
The bus clock to the TPMs can be gated on and off using the TPM2 bit and TPM1 bit in SCGC1. These
bits are cleared after any reset, which disables the bus clock to this module. To conserve power, these bits
can be cleared to disable the clock to this module when not in use. For more details, see Section 5.7,
“Peripheral Clock Gating.”
8-BIT KEYBOARD
INTERRUPT (KBI)
RESET
IRQ
SERIAL PERIPHERAL
INTERFACE (SPI)
KBI[7:0]
SS
SPSCK
MISO
RESET/PTC6
BKGD/MS/PTC5
LCD[20:16]/PTC[4:0]
MOSI
SCL
IIC MODULE (IIC)
USER FLASH A
(LG32 = 16K BYTES)
(LG16 = 2K BYTES)
6-CHANNEL TIMER/PWM
(TPM2)
USER FLASH B
(LG32 = 16K BYTES)
(LG16 = 16K BYTES)
2-CHANNEL TIMER/PWM
(TPM1)
SERIAL COMMUNICATIONS
INTERFACE (SCI1)
USER RAM
SDA
TPM2CH[5:0]
TPMCLK
PORT D
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
LVD
LCD[40:37]/PTB[7:4]
LCD[32:29]/PTB[3:0]
TMRCLK
LCD[7:0]/PTD[7:0]
PORT E
Modulo Timer
(MTIM)
IRQ
PORT A
Real Time Counter
(RTC)
HCS08 SYSTEM CONTROL
COP
PORT B
BKGD/MS
LCD[15:8]/PTE[7:0]
TPM1CH[1:0]
PORT F
BKP
EXTAL/PTF7
XTAL/PTF6
TPM2CH3/KBI2/MOSI/PTF5
TPM2CH4/KBI1/MISO/PTF4
TPM2CH5/KBI0/SS/PTF3
ADC14/IRQ/TPM1CH1/SPSCK/PTF2
ADC13/TPM1CH0/RX1/PTF1
ADC12/TPM2CH2/KBI3/TX1/PTF0
PORT G
BKGD
LCD[44:41]/PTG[7:4]
LCD[36:33]/PTG[3:0]
PORT H
INT
ON-CHIP ICE (ICE) and
DEBUG MODULE (DBG)
TPM2CH4/KBI1/PTH7
ADC15/KBI0/TPM2CH5/PTH6
ADC11/TPM1CH0/KBI3/TX1/PTH5
ADC10/TPM1CH1/KBI2/RX1/PTH4
ADC[9:6]/KBI[7:4]/PTH[3:0]
PORT I
CPU
LCD28/ADC5/TPMCLK/PTA7
LCD27/ADC4/TPM2CH1/KBI7/PTA6
LCD26/ADC3/TPM2CH0/KBI6/PTA5
LCD25/ADC2/RX2/KBI5/PTA4
LCD24/ADC1/TX2/KBI4/PTA3
LCD23/ADC0/SDA/PTA2
LCD22/SCL/PTA1
LCD21/PTA0
PORT C
HCS08 CORE
SS/SCL/TPM2CH0/PTI5
SPSCK/SDA/TPM2CH1/PTI4
MOSI/TPM2CH2/PTI3
MISO/TPM2CH3/PTI2
TX2/TMRCLK/PTI1
RX2/PTI0
TPMCLK
TxD1
RxD1
1984 BYTES
SERIAL COMMUNICATIONS
INTERFACE (SCI2)
INTERNAL CLOCK
Source (ICS)
TxD2
RxD2
XTAL
LOW-POWER OSCILLATOR
12-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
VLL3_2
VLL3
VLL1
VLL2
VCAP1
EXTAL
AD[15:0]
LIQUID CRYSTAL
DISPLAY DRIVER
(LCD)
VCAP2
LCD[44:0]
VDD
VSS
VSS2
VOLTAGE
REGULATOR
VDDA/VREFH
VSSA/VREFL
Available only on 80-pin package
Available only on 64-pin and 80-pin package
*/Default function out of reset/*
Figure 16-1. MC9S08LG32 Series Block Diagram Highlighting TPMx Blocks and Pins
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Chapter 13 Timer/Pulse-Width Modulator (S08TPMV3)
16.1.5
Features
The TPM includes these distinctive features:
• One to eight channels:
— Each channel is input capture, output compare, or edge-aligned PWM
— Rising-edge, falling-edge, or any-edge input capture trigger
— Set, clear, or toggle output compare action
— Selectable polarity on PWM outputs
• Module is configured for buffered, center-aligned pulse-width-modulation (CPWM) on all
channels
• Timer clock source selectable as bus clock, fixed frequency clock, or an external clock
— Prescale taps for divide-by 1, 2, 4, 8, 16, 32, 64, or 128 used for any clock input selection
— Fixed frequency clock is an additional clock input to allow the selection of an on chip clock
source other than bus clock
— Selecting external clock connects TPM clock to a chip level input pin therefore allowing to
synchronize the TPM counter with an off chip clock source
• 16-bit free-running or modulus count with up/down selection
• One interrupt per channel and one interrupt for TPM counter overflow
16.1.6
Modes of Operation
In general, TPM channels are independently configured to operate in input capture, output compare, or
edge-aligned PWM modes. A control bit allows the whole TPM (all channels) to switch to center-aligned
PWM mode. When center-aligned PWM mode is selected, input capture, output compare, and
edge-aligned PWM functions are not available on any channels of this TPM module.
When the MCU is in active BDM background or BDM foreground mode, the TPM temporarily suspends
all counting until the MCU returns to normal user operating mode. During stop mode, all TPM input clocks
are stopped, so the TPM is effectively disabled until clocks resume. During wait mode, the TPM continues
to operate normally. If the TPM does not need to produce a real time reference or provide the interrupt
sources needed to wake the MCU from wait mode, the power can then be saved by disabling TPM
functions before entering wait mode.
• Input capture mode
When a selected edge event occurs on the associated MCU pin, the current value of the 16-bit timer
counter is captured into the channel value register and an interrupt flag bit is set. Rising edges,
falling edges, any edge, or no edge (disable channel) are selected as the active edge that triggers
the input capture.
• Output compare mode
When the value in the timer counter register matches the channel value register, an interrupt flag
bit is set, and a selected output action is forced on the associated MCU pin. The output compare
action is selected to force the pin to zero, force the pin to one, toggle the pin, or ignore the pin (used
for software timing functions).
• Edge-aligned PWM mode
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•
The value of a 16-bit modulo register plus 1 sets the period of the PWM output signal. The channel
value register sets the duty cycle of the PWM output signal. You can also choose the polarity of the
PWM output signal. Interrupts are available at the end of the period and at the duty-cycle transition
point. This type of PWM signal is called edge-aligned because the leading edges of all PWM
signals are aligned with the beginning of the period that is same for all channels within a TPM.
Center-aligned PWM mode
Twice the value of a 16-bit modulo register sets the period of the PWM output, and the
channel-value register sets the half-duty-cycle duration. The timer counter counts up until it
reaches the modulo value and then counts down until it reaches zero. As the count matches the
channel value register while counting down, the PWM output becomes active. When the count
matches the channel value register while counting up, the PWM output becomes inactive. This type
of PWM signal is called center-aligned because the centers of the active duty cycle periods for all
channels are aligned with a count value of zero. This type of PWM is required for types of motors
used in small appliances.
This is a high-level description only. Detailed descriptions of operating modes are in later sections.
16.1.7
Block Diagram
The TPM uses one input/output (I/O) pin per channel, TPMxCHn (timer channel n) where n is the channel
number (1–8). The TPM shares its I/O pins with general purpose I/O port pins (refer to I/O pin descriptions
in full-chip specification for the specific chip implementation).
Figure 16-2 shows the TPM structure. The central component of the TPM is the 16-bit counter that can
operate as a free-running counter or a modulo up/down counter. The TPM counter (when operating in
normal up-counting mode) provides the timing reference for the input capture, output compare, and
edge-aligned PWM functions. The timer counter modulo registers, TPMxMODH:TPMxMODL, control
the modulo value of the counter (the values 0x0000 or 0xFFFF effectively make the counter free running).
Software can read the counter value at any time without affecting the counting sequence. Any write to
either half of the TPMxCNT counter resets the counter, regardless of the data value written.
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no clock selected
(TPM counter disable)
bus clock
Prescaler
³(1, 2, 4, 8, 16, 32, 64 or 128)
fixed frequency clock
external clock
synchronizer
PS[2:0]
CLKSB:CLKSA
CPWMS
TPM counter
(16-bit counter)
TOF
counter reset
TOIE
Interrupt
logic
16-bit comparator
TPMxMODH:TPMxMODL
channel 0
ELS0B
ELS0A
Port
logic
TPMxCH0
16-bit comparator
TPMxC0VH:TPMxC0VL
CH0F
Interrupt
logic
16-bit latch
TPM counter
channel 1
MS0B
MS0A
ELS1B
ELS1A
CH0IE
Port
logic
TPMxCH1
16-bit comparator
TPMxC1VH:TPMxC1VL
CH1F
Interrupt
logic
16-bit latch
MS1B
CH1IE
MS1A
up to 8 channels
channel 7
ELS7B
ELS7A
Port
logic
TPMxCH7
16-bit comparator
TPMxC7VH:TPMxC7VL
CH7F
Interrupt
logic
16-bit latch
MS7B
MS7A
CH7IE
Figure 16-2. TPM Block Diagram
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The TPM channels are programmable independently as input capture, output compare, or edge-aligned
PWM channels. Alternately, the TPM can be configured to produce CPWM outputs on all channels. When
the TPM is configured for CPWMs (the counter operates as an up/down counter) input capture, output
compare, and EPWM functions are not practical.
16.2
Signal Description
Table 16-2 shows the user-accessible signals for the TPM. The number of channels are varied from one to
eight. When an external clock is included, it can be shared with the same pin as any TPM channel;
however, it could be connected to a separate input pin. Refer to the I/O pin descriptions in full-chip
specification for the specific chip implementation.
Table 16-2. Signal Properties
Name
EXTCLK1
TPMxCHn2
Function
External clock source that is selected to drive the TPM counter.
I/O pin associated with TPM channel n.
1
The external clock pin can be shared with any channel pin. However, depending upon full-chip
implementation, this signal could be connected to a separate external pin.
2 n = channel number (1–8)
16.2.1
16.2.1.1
Detailed Signal Descriptions
EXTCLK — External Clock Source
The external clock signal can share the same pin as a channel pin, however the channel pin can not be used
for channel I/O function when external clock is selected. If this pin is used as an external clock
(CLKSB:CLKSA = 1:1), the channel can still be configured to output compare mode therefore allowing
its use as a timer (ELSnB:ELSnA = 0:0).
For proper TPM operation, the external clock frequency must not exceed one-fourth of the bus clock
frequency.
16.2.1.2
TPMxCHn — TPM Channel n I/O Pins
The TPM channel does not control the I/O pin when ELSnB:ELSnA or CLKSB:CLKSA are cleared so it
normally reverts to general purpose I/O control. When CPWMS is set and ELSnB:ELSnA are not cleared,
all TPM channels are configured for center-aligned PWM and the TPMxCHn pins are all controlled by
TPM. When CPWMS is cleared, the MSnB:MSnA control bits determine whether the channel is
configured for input capture, output compare, or edge-aligned PWM.
When a channel is configured for input capture (CPWMS = 0, MSnB:MSnA = 0:0, and
ELSnB:ELSnA ≠ 0:0), the TPMxCHn pin is forced to act as an edge-sensitive input to the TPM.
ELSnB:ELSnA control bits determine what polarity edge or edges trigger input capture events. The
channel input signal is synchronized on the bus clock. This implies the minimum pulse width—that can
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be reliably detected—on an input capture pin is four bus clock periods (with ideal clock pulses as near as
two bus clocks can be detected).
When a channel is configured for output compare (CPWMS = 0, MSnB:MSnA = 0:1, and
ELSnB:ELSnA ≠ 0:0), the TPMxCHn pin is an output controlled by the TPM. The ELSnB:ELSnA bits
determine whether the TPMxCHn pin is toggled, cleared, or set each time the 16-bit channel value register
matches the TPM counter.
When the output compare toggle mode is initially selected, the previous value on the pin is driven out until
the next output compare event, the pin is then toggled.
When a channel is configured for edge-aligned PWM (CPWMS = 0, MSnB = 1, and
ELSnB:ELSnA ≠ 0:0), the TPMxCHn pin is an output controlled by the TPM, and ELSnB:ELSnA bits
control the polarity of the PWM output signal. When ELSnB is set and ELSnA is cleared, the TPMxCHn
pin is forced high at the start of each new period (TPMxCNT=0x0000), and it is forced low when the
channel value register matches the TPM counter. When ELSnA is set, the TPMxCHn pin is forced low at
the start of each new period (TPMxCNT=0x0000), and it is forced high when the channel value register
matches the TPM counter.
TPMxMODH:TPMxMODL = 0x0008
TPMxCnVH:TPMxCnVL = 0x0005
TPMxCNTH:TPMxCNTL
...
0
1
2
3
4
5
6
7
8
0
1
2
...
2
...
TPMxCHn
CHnF bit
TOF bit
Figure 16-3. High-true pulse of an edge-aligned PWM
TPMxMODH:TPMxMODL = 0x0008
TPMxCnVH:TPMxCnVL = 0x0005
TPMxCNTH:TPMxCNTL
...
0
1
2
3
4
5
6
7
8
0
1
TPMxCHn
CHnF bit
TOF bit
Figure 16-4. Low-true pulse of an edge-aligned PWM
When the TPM is configured for center-aligned PWM (CPWMS = 1 and ELSnB:ELSnA ≠ 0:0), the
TPMxCHn pins are outputs controlled by the TPM, and ELSnB:ELSnA bits control the polarity of the
PWM output signal. If ELSnB is set and ELSnA is cleared, the corresponding TPMxCHn pin is cleared
when the TPM counter is counting up, and the channel value register matches the TPM counter; and it is
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set when the TPM counter is counting down, and the channel value register matches the TPM counter. If
ELSnA is set, the corresponding TPMxCHn pin is set when the TPM counter is counting up and the
channel value register matches the TPM counter; and it is cleared when the TPM counter is counting down
and the channel value register matches the TPM counter.
TPMxMODH:TPMxMODL = 0x0008
TPMxCnVH:TPMxCnVL = 0x0005
TPMxCNTH:TPMxCNTL
...
7
8
7
6
5
4
3
2
1
0
1
2
3
4
5
6
7
8
7
6
5
...
6
7
8
7
6
5
...
TPMxCHn
CHnF bit
TOF bit
Figure 16-5. High-true pulse of a center-aligned PWM
TPMxMODH:TPMxMODL = 0x0008
TPMxCnVH:TPMxCnVL = 0x0005
TPMxCNTH:TPMxCNTL
...
7
8
7
6
5
4
3
2
1
0
1
2
3
4
5
TPMxCHn
CHnF bit
TOF bit
Figure 16-6. Low-true pulse of a center-aligned PWM
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16.3
16.3.1
Register Definition
TPM Status and Control Register (TPMxSC)
TPMxSC contains the overflow status flag and control bits used to configure the interrupt enable, TPM
configuration, clock source, and prescale factor. These controls relate to all channels within this timer
module.
7
R
TOF
W
0
Reset
0
6
5
4
3
2
1
0
TOIE
CPWMS
CLKSB
CLKSA
PS2
PS1
PS0
0
0
0
0
0
0
0
Figure 16-7. TPM Status and Control Register (TPMxSC)
Table 16-3. TPMxSC Field Descriptions
Field
Description
7
TOF
Timer overflow flag. This read/write flag is set when the TPM counter resets to 0x0000 after reaching the modulo
value programmed in the TPM counter modulo registers. Clear TOF by reading the TPM status and control
register when TOF is set and then writing a logic 0 to TOF. If another TPM overflow occurs before the clearing
sequence is completed, the sequence is reset so TOF remains set after the clear sequence was completed for
the earlier TOF. This is done so a TOF interrupt request cannot be lost during the clearing sequence for a previous
TOF. Reset clears TOF. Writing a logic 1 to TOF has no effect.
0 TPM counter has not reached modulo value or overflow.
1 TPM counter has overflowed.
6
TOIE
Timer overflow interrupt enable. This read/write bit enables TPM overflow interrupts. If TOIE is set, an interrupt is
generated when TOF equals one. Reset clears TOIE.
0 TOF interrupts inhibited (use for software polling).
1 TOF interrupts enabled.
5
CPWMS
Center-aligned PWM select. This read/write bit selects CPWM operating mode. By default, the TPM operates in
up-counting mode for input capture, output compare, and edge-aligned PWM functions. Setting CPWMS
reconfigures the TPM to operate in up/down counting mode for CPWM functions. Reset clears CPWMS.
0 All channels operate as input capture, output compare, or edge-aligned PWM mode as selected by the
MSnB:MSnA control bits in each channel’s status and control register.
1 All channels operate in center-aligned PWM mode.
4–3
Clock source selection bits. As shown in Table 16-4, this 2-bit field is used to disable the TPM counter or select
CLKS[B:A] one of three clock sources to TPM counter and counter prescaler.
2–0
PS[2:0]
Prescale factor select. This 3-bit field selects one of eight division factors for the TPM clock as shown in
Table 16-5. This prescaler is located after any clock synchronization or clock selection so it affects the clock
selected to drive the TPM counter. The new prescale factor affects the selected clock on the next bus clock cycle
after the new value is updated into the register bits.
Table 16-4. TPM Clock Selection
CLKSB:CLKSA
TPM Clock to Prescaler Input
00
No clock selected (TPM counter disable)
01
Bus clock
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Table 16-4. TPM Clock Selection
CLKSB:CLKSA
TPM Clock to Prescaler Input
10
Fixed frequency clock
11
External clock
Table 16-5. Prescale Factor Selection
16.3.2
PS[2:0]
TPM Clock Divided-by
000
1
001
2
010
4
011
8
100
16
101
32
110
64
111
128
TPM-Counter Registers (TPMxCNTH:TPMxCNTL)
The two read-only TPM counter registers contain the high and low bytes of the value in the TPM counter.
Reading either byte (TPMxCNTH or TPMxCNTL) latches the contents of both bytes into a buffer where
they remain latched until the other half is read. This allows coherent 16-bit reads in big-endian or
little-endian order that makes this more friendly to various compiler implementations. The coherency
mechanism is automatically restarted by an MCU reset or any write to the timer status/control register
(TPMxSC).
Reset clears the TPM counter registers. Writing any value to TPMxCNTH or TPMxCNTL also clears the
TPM counter (TPMxCNTH:TPMxCNTL) and resets the coherency mechanism, regardless of the data
involved in the write.
7
6
5
4
3
2
R
TPMxCNT[15:8]
W
Any write to TPMxCNTH clears the 16-bit counter
Reset
0
0
0
0
0
0
1
0
0
0
1
0
0
0
Figure 16-8. TPM Counter Register High (TPMxCNTH)
7
6
5
4
3
2
R
TPMxCNT[7:0]
W
Any write to TPMxCNTL clears the 16-bit counter
Reset
0
0
0
0
0
0
Figure 16-9. TPM Counter Register Low (TPMxCNTL)
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When BDM is active, the timer counter is frozen (this is the value you read). The coherency mechanism
is frozen so the buffer latches remain in the state they were in when the BDM became active, even if one
or both counter halves are read while BDM is active. This assures that if you were in the middle of reading
a 16-bit register when BDM became active, it reads the appropriate value from the other half of the 16-bit
value after returning to normal execution.
In BDM mode, writing any value to TPMxSC, TPMxCNTH, or TPMxCNTL registers resets the read
coherency mechanism of the TPMxCNTH:TPMxCNTL registers, regardless of the data involved in the
write.
16.3.3
TPM Counter Modulo Registers (TPMxMODH:TPMxMODL)
The read/write TPM modulo registers contain the modulo value for the TPM counter. After the TPM
counter reaches the modulo value, the TPM counter resumes counting from 0x0000 at the next clock, and
the overflow flag (TOF) becomes set. Writing to TPMxMODH or TPMxMODL inhibits the TOF bit and
overflow interrupts until the other byte is written. Reset sets the TPM counter modulo registers to 0x0000
that results in a free running timer counter (modulo disabled).
Writes to any of the registers TPMxMODH and TPMxMODL actually writes to buffer registers and the
registers are updated with the value of their write buffer according to the value of CLKSB:CLKSA bits:
• If CLKSB and CLKSA are cleared, the registers are updated when the second byte is written
• If CLKSB and CLKSA are not cleared, the registers are updated after both bytes were written, and
the TPM counter changes from (TPMxMODH:TPMxMODL – 1) to
(TPMxMODH:TPMxMODL). If the TPM counter is a free-running counter, the update is made
when the TPM counter changes from 0xFFFE to 0xFFFF
The latching mechanism is manually reset by writing to the TPMxSC address (whether BDM is active or
not).
When BDM is active, the coherency mechanism is frozen (unless reset by writing to TPMxSC register) so
the buffer latches remain in the state they were in when the BDM became active, even if one or both halves
of the modulo register are written while BDM is active. Any write to the modulo registers bypasses the
buffer latches and directly writes to the modulo register while BDM is active.
7
6
5
4
3
2
1
0
0
0
0
2
1
0
0
0
0
R
TPMxMOD[15:8]
W
Reset
0
0
0
0
0
Figure 16-10. TPM Counter Modulo Register High (TPMxMODH)
7
6
5
4
3
R
TPMxMOD[7:0]
W
Reset
0
0
0
0
0
Figure 16-11. TPM Counter Modulo Register Low (TPMxMODL)
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Reset the TPM counter before writing to the TPM modulo registers to avoid confusion about when the first
counter overflow occurs.
16.3.4
TPM Channel n Status and Control Register (TPMxCnSC)
TPMxCnSC contains the channel-interrupt-status flag and control bits that configure the interrupt enable,
channel configuration, and pin function.
7
R
6
5
4
3
2
CHnIE
MSnB
MSnA
ELSnB
ELSnA
0
0
0
0
0
CHnF
W
0
Reset
0
1
0
0
0
0
0
= Unimplemented or Reserved
Figure 16-12. TPM Channel n Status and Control Register (TPMxCnSC)
Table 16-6. TPMxCnSC Field Descriptions
Field
Description
7
CHnF
Channel n flag. When channel n is an input capture channel, this read/write bit is set when an active edge occurs
on the channel n input. When channel n is an output compare or edge-aligned/center-aligned PWM channel,
CHnF is set when the value in the TPM counter registers matches the value in the TPM channel n value registers.
When channel n is an edge-aligned/center-aligned PWM channel and the duty cycle is set to 0% or 100%, CHnF
is not set even when the value in the TPM counter registers matches the value in the TPM channel n value
registers.
A corresponding interrupt is requested when this bit is set and channel n interrupt is enabled (CHnIE = 1). Clear
CHnF by reading TPMxCnSC while this bit is set and then writing a logic 0 to it. If another interrupt request occurs
before the clearing sequence is completed CHnF remains set. This is done so a CHnF interrupt request is not lost
due to clearing a previous CHnF.
Reset clears this bit. Writing a logic 1 to CHnF has no effect.
0 No input capture or output compare event occurred on channel n.
1 Input capture or output compare event on channel n.
6
CHnIE
Channel n interrupt enable. This read/write bit enables interrupts from channel n. Reset clears this bit.
0 Channel n interrupt requests disabled (use for software polling).
1 Channel n interrupt requests enabled.
5
MSnB
Mode select B for TPM channel n. When CPWMS is cleared, setting the MSnB bit configures TPM channel n for
edge-aligned PWM mode. Refer to the summary of channel mode and setup controls in Table 16-7.
4
MSnA
Mode select A for TPM channel n. When CPWMS and MSnB are cleared, the MSnA bit configures TPM channel
n for input capture mode or output compare mode. Refer to Table 16-7 for a summary of channel mode and setup
controls.
Note: If the associated port pin is not stable for at least two bus clock cycles before changing to input capture
mode, it is possible to get an unexpected indication of an edge trigger.
3–2
ELSnB
ELSnA
Edge/level select bits. Depending upon the operating mode for the timer channel as set by CPWMS:MSnB:MSnA
and shown in Table 16-7, these bits select the polarity of the input edge that triggers an input capture event, select
the level that is driven in response to an output compare match, or select the polarity of the PWM output.
If ELSnB and ELSnA bits are cleared, the channel pin is not controlled by TPM. This configuration can be used
by software compare only, because it does not require the use of a pin for the channel.
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Table 16-7. Mode, Edge, and Level Selection
CPWMS
MSnB:MSnA
ELSnB:ELSnA
X
XX
00
Pin is not controlled by TPM. It is reverted to general purpose I/O or
other peripheral control
0
00
01
Input capture
01
11
Capture on rising or falling edge
Output compare
Toggle output on channel match
10
Clear output on channel match
11
Set output on channel match
10
Edge-aligned
PWM
High-true pulses (clear output on channel match)
Center-aligned
PWM
High-true pulses (clear output on channel match
when TPM counter is counting up)
X1
16.3.5
Software compare only
01
10
XX
Capture on rising edge only
Capture on falling edge only
X1
1
Configuration
10
00
1X
Mode
Low-true pulses (set output on channel match)
Low-true pulses (set output on channel match when
TPM counter is counting up)
TPM Channel Value Registers (TPMxCnVH:TPMxCnVL)
These read/write registers contain the captured TPM counter value of the input capture function or the
output compare value for the output compare or PWM functions. The channel registers are cleared by
reset.
7
6
5
4
3
2
1
0
0
0
0
2
1
0
0
0
0
R
TPMxCnV[15:8]
W
Reset
0
0
0
0
0
Figure 16-13. TPM Channel Value Register High (TPMxCnVH)
7
6
5
4
3
R
TPMxCnV[7:0]
W
Reset
0
0
0
0
0
Figure 16-14. TPM Channel Value Register Low (TPMxCnVL)
In input capture mode, reading either byte (TPMxCnVH or TPMxCnVL) latches the contents of both bytes
into a buffer where they remain latched until the other half is read. This latching mechanism also resets
(becomes unlatched) when the TPMxCnSC register is written (whether BDM mode is active or not). Any
write to the channel registers is ignored during the input capture mode.
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When BDM is active, the coherency mechanism is frozen (unless reset by writing to TPMxCnSC register)
so the buffer latches remain in the state they were in when the BDM became active, even if one or both
halves of the channel register are read while BDM is active. This assures that if you were in the middle of
reading a 16-bit register when BDM became active, it reads the appropriate value from the other half of
the 16-bit value after returning to normal execution. The value read from the TPMxCnVH and
TPMxCnVL registers in BDM mode is the value of these registers and not the value of their read buffer.
In output compare or PWM modes, writing to either byte (TPMxCnVH or TPMxCnVL) latches the value
into a buffer. After both bytes were written, they are transferred as a coherent 16-bit value into the
timer-channel registers according to the value of CLKSB:CLKSA bits and the selected mode:
• If CLKSB and CLKSA are cleared, the registers are updated when the second byte is written.
• If CLKSB and CLKSA are not cleared and in output compare mode, the registers are updated after
the second byte is written and on the next change of the TPM counter (end of the prescaler
counting).
• If CLKSB and CLKSA are not cleared and in EPWM or CPWM modes, the registers are updated
after both bytes were written, and the TPM counter changes from
(TPMxMODH:TPMxMODL – 1) to (TPMxMODH:TPMxMODL). If the TPM counter is a
free-running counter, the update is made when the TPM counter changes from 0xFFFE to 0xFFFF.
The latching mechanism is manually reset by writing to the TPMxCnSC register (whether BDM mode is
active or not). This latching mechanism allows coherent 16-bit writes in either big-endian or little-endian
order that is friendly to various compiler implementations.
When BDM is active, the coherency mechanism is frozen so the buffer latches remain in the state they
were in when the BDM became active even if one or both halves of the channel register are written while
BDM is active. Any write to the channel registers bypasses the buffer latches and directly write to the
channel register while BDM is active. The values written to the channel register while BDM is active are
used for PWM and output compare operation after normal execution resumes. Writes to the channel
registers while BDM is active do not interfere with partial completion of a coherency sequence. After the
coherency mechanism is fully exercised, the channel registers are updated using the buffered values (while
BDM was not active).
16.4
Functional Description
All TPM functions are associated with a central 16-bit counter that allows flexible selection of the clock
and prescale factor. There is also a 16-bit modulo register associated with this counter.
The CPWMS control bit chooses between center-aligned PWM operation for all channels in the TPM
(CPWMS=1) or general purpose timing functions (CPWMS=0) where each channel can independently be
configured to operate in input capture, output compare, or edge-aligned PWM mode. The CPWMS control
bit is located in the TPM status and control register because it affects all channels within the TPM and
influences the way the main counter operates. (In CPWM mode, the counter changes to an up/down mode
rather than the up-counting mode used for general purpose timer functions.)
The following sections describe TPM counter and each of the timer operating modes (input capture, output
compare, edge-aligned PWM, and center-aligned PWM). Because details of pin operation and interrupt
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activity depend upon the operating mode, these topics are covered in the associated mode explanation
sections.
16.4.1
Counter
All timer functions are based on the main 16-bit counter (TPMxCNTH:TPMxCNTL). This section
discusses selection of the clock, end-of-count overflow, up-counting vs. up/down counting, and manual
counter reset.
16.4.1.1
Counter Clock Source
The 2-bit field, CLKSB:CLKSA, in the timer status and control register (TPMxSC) disables the TPM
counter or selects one of three clock sources to TPM counter (Table 16-4). After any MCU reset, CLKSB
and CLKSA are cleared so no clock is selected and the TPM counter is disabled (TPM is in a very low
power state). You can read or write these control bits at any time. Disabling the TPM counter by writing
00 to CLKSB:CLKSA bits, does not affect the values in the TPM counter or other registers.
The fixed frequency clock is an alternative clock source for the TPM counter that allows the selection of
a clock other than the bus clock or external clock. This clock input is defined by chip integration. You can
refer chip specific documentation for further information. Due to TPM hardware implementation
limitations, the frequency of the fixed frequency clock must not exceed the bus clock frequency. The fixed
frequency clock has no limitations for low frequency operation.
The external clock passes through a synchronizer clocked by the bus clock to assure that counter
transitions are properly aligned to bus clock transitions.Therefore, in order to meet Nyquist criteria
considering also jitter, the frequency of the external clock source must not exceed 1/4 of the bus clock
frequency.
When the external clock source is shared with a TPM channel pin, this pin must not be used in input
capture mode. However, this channel can be used in output compare mode with ELSnB:ELSnA = 0:0 for
software timing functions. In this case, the channel output is disabled, but the channel match events
continue to set the appropriate flag.
16.4.1.2
Counter Overflow and Modulo Reset
An interrupt flag and enable are associated with the 16-bit main counter. The flag (TOF) is a
software-accessible indication that the timer counter has overflowed. The enable signal selects between
software polling (TOIE = 0) where no interrupt is generated, or interrupt-driven operation (TOIE = 1)
where the interrupt is generated whenever the TOF is set.
The conditions causing TOF to become set depend on whether the TPM is configured for center-aligned
PWM (CPWMS = 1). If CPWMS is cleared and there is no modulus limit, the 16-bit timer counter counts
from 0x0000 through 0xFFFF and overflows to 0x0000 on the next counting clock. TOF is set at the
transition from 0xFFFF to 0x0000. When a modulus limit is set, TOF is set at the transition from the value
set in the modulus register to 0x0000. When the TPM is in center-aligned PWM mode (CPWMS = 1), the
TOF flag is set as the counter changes direction at the end of the count value set in the modulus register
(at the transition from the value set in the modulus register to the next lower count value). This corresponds
to the end of a PWM period (the 0x0000 count value corresponds to the center of a period).
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16.4.1.3
Counting Modes
The main timer counter has two counting modes. When center-aligned PWM is selected (CPWMS = 1),
the counter operates in up/down counting mode. Otherwise, the counter operates as a simple up counter.
As an up counter, the timer counter counts from 0x0000 through its terminal count and continues with
0x0000. The terminal count is 0xFFFF or a modulus value in TPMxMODH:TPMxMODL.
When center-aligned PWM operation is specified, the counter counts up from 0x0000 through its terminal
count and then down to 0x0000 where it changes back to up counting. The terminal count value and
0x0000 are normal length counts (one timer clock period long). In this mode, the timer overflow flag
(TOF) is set at the end of the terminal-count period (as the count changes to the next lower count value).
16.4.1.4
Manual Counter Reset
The main timer counter can be manually reset at any time by writing any value to TPMxCNTH or
TPMxCNTL. Resetting the counter in this manner also resets the coherency mechanism in case only half
of the counter was read before resetting the count.
16.4.2
Channel Mode Selection
If CPWMS is cleared, MSnB and MSnA bits determine the basic mode of operation for the corresponding
channel. Choices include input capture, output compare, and edge-aligned PWM.
16.4.2.1
Input Capture Mode
With the input capture function, the TPM can capture the time at which an external event occurs. When an
active edge occurs on the pin of an input capture channel, the TPM latches the contents of the TPM counter
into the channel-value registers (TPMxCnVH:TPMxCnVL). Rising edges, falling edges, or any edge is
chosen as the active edge that triggers an input capture.
In input capture mode, the TPMxCnVH and TPMxCnVL registers are read only.
When either half of the 16-bit capture register is read, the other half is latched into a buffer to support
coherent 16-bit accesses in big-endian or little-endian order. The coherency sequence can be manually
reset by writing to TPMxCnSC.
An input capture event sets a flag bit (CHnF) that optionally generates a CPU interrupt request.
While in BDM, the input capture function works as configured. When an external event occurs, the TPM
latches the contents of the TPM counter (frozen because of the BDM mode) into the channel value registers
and sets the flag bit.
16.4.2.2
Output Compare Mode
With the output compare function, the TPM can generate timed pulses with programmable position,
polarity, duration, and frequency. When the counter reaches the value in TPMxCnVH:TPMxCnVL
registers of an output compare channel, the TPM can set, clear, or toggle the channel pin.
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Writes to any of TPMxCnVH and TPMxCnVL registers actually write to buffer registers. In output
compare mode, the TPMxCnVH:TPMxCnVL registers are updated with the value of their write buffer
only after both bytes were written and according to the value of CLKSB:CLKSA bits:
• If CLKSB and CLKSA are cleared, the registers are updated when the second byte is written
• If CLKSB and CLKSA are not cleared, the registers are updated at the next change of the TPM
counter (end of the prescaler counting) after the second byte is written.
The coherency sequence can be manually reset by writing to the channel status/control register
(TPMxCnSC).
An output compare event sets a flag bit (CHnF) that optionally generates a CPU interrupt request.
16.4.2.3
Edge-Aligned PWM Mode
This type of PWM output uses the normal up-counting mode of the timer counter (CPWMS=0) and can
be used when other channels in the same TPM are configured for input capture or output compare
functions. The period of this PWM signal is determined by the value of the modulus register
(TPMxMODH:TPMxMODL) plus 1. The duty cycle is determined by the value of the timer channel
register (TPMxCnVH:TPMxCnVL). The polarity of this PWM signal is determined by ELSnA bit. 0% and
100% duty cycle cases are possible.
The time between the modulus overflow and the channel match value (TPMxCnVH:TPMxCnVL) is the
pulse width or duty cycle (Figure 16-15). If ELSnA is cleared, the counter overflow forces the PWM signal
high, and the channel match forces the PWM signal low. If ELSnA is set, the counter overflow forces the
PWM signal low, and the channel match forces the PWM signal high.
overflow
overflow
overflow
period
pulse width
TPMxCHn
channel
match
channel
match
channel
match
Figure 16-15. EPWM period and pulse width (ELSnA=0)
When the channel value register is set to 0x0000, the duty cycle is 0%. A 100% duty cycle is achieved by
setting the timer-channel register (TPMxCnVH:TPMxCnVL) to a value greater than the modulus setting.
This implies that the modulus setting must be less than 0xFFFF in order to get 100% duty cycle.
The timer channel registers are buffered to ensure coherent 16-bit updates and to avoid unexpected PWM
pulse widths. Writes to any of the registers TPMxCnVH and TPMxCnVL actually write to buffer registers.
In edge-aligned PWM mode, the TPMxCnVH:TPMxCnVL registers are updated with the value of their
write buffer according to the value of CLKSB:CLKSA bits:
• If CLKSB and CLKSA are cleared, the registers are updated when the second byte is written
• If CLKSB and CLKSA are not cleared, the registers are updated after both bytes were written, and
the TPM counter changes from (TPMxMODH:TPMxMODL – 1) to
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(TPMxMODH:TPMxMODL). If the TPM counter is a free-running counter, the update is made
when the TPM counter changes from 0xFFFE to 0xFFFF.
16.4.2.4
Center-Aligned PWM Mode
This type of PWM output uses the up/down counting mode of the timer counter (CPWMS=1). The channel
match value in TPMxCnVH:TPMxCnVL determines the pulse width (duty cycle) of the PWM signal
while the period is determined by the value in TPMxMODH:TPMxMODL. TPMxMODH:TPMxMODL
must be kept in the range of 0x0001 to 0x7FFF because values outside this range can produce ambiguous
results. ELSnA determines the polarity of the CPWM signal.
pulse width = 2 × (TPMxCnVH:TPMxCnVL)
period = 2 × (TPMxMODH:TPMxMODL); TPMxMODH:TPMxMODL = 0x0001–0x7FFF
If TPMxCnVH:TPMxCnVL is zero or negative (bit 15 set), the duty cycle is 0%. If
TPMxCnVH:TPMxCnVL is a positive value (bit 15 clear) and is greater than the non-zero modulus
setting, the duty cycle is 100% because the channel match never occurs. This implies the usable range of
periods set by the modulus register is 0x0001 through 0x7FFE (0x7FFF if you do not need to generate
100% duty cycle). This is not a significant limitation. The resulting period is much longer than required
for normal applications.
All zeros in TPMxMODH:TPMxMODL is a special case that must not be used with center-aligned PWM
mode. When CPWMS is cleared, this case corresponds to the counter running free from 0x0000 through
0xFFFF. When CPWMS is set, the counter needs a valid match to the modulus register somewhere other
than at 0x0000 in order to change directions from up-counting to down-counting.
The channel match value in the TPM channel registers (times two) determines the pulse width (duty cycle)
of the CPWM signal (Figure 16-16). If ELSnA is cleared, a channel match occurring while counting up
clears the CPWM output signal and a channel match occurring while counting down sets the output. The
counter counts up until it reaches the modulo setting in TPMxMODH:TPMxMODL, then counts down
until it reaches zero. This sets the period equal to two times TPMxMODH:TPMxMODL.
TPM counter =
TPMxMODH:TPMxMODL
TPM counter = 0
channel match
channel match
(count up)
(count down)
TPM counter =
TPMxMODH:TPMxMODL
TPMxCHn
pulse width
2 × TPMxCnVH:TPMxCnVL
period
2 × TPMxMODH:TPMxMODL
Figure 16-16. CPWM period and pulse width (ELSnA=0)
Center-aligned PWM outputs typically produce less noise than edge-aligned PWMs because fewer I/O pin
transitions are lined up at the same system clock edge. This type of PWM is also required for some types
of motor drives.
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Input capture, output compare, and edge-aligned PWM functions do not make sense when the counter is
operating in up/down counting mode so this implies that all active channels within a TPM must be used in
CPWM mode when CPWMS is set.
The timer channel registers are buffered to ensure coherent 16-bit updates and to avoid unexpected PWM
pulse widths. Writes to any of the registers TPMxCnVH and TPMxCnVL actually write to buffer registers.
In center-aligned PWM mode, the TPMxCnVH:TPMxCnVL registers are updated with the value of their
write buffer according to the value of CLKSB:CLKSA bits:
• If CLKSB and CLKSA are cleared, the registers are updated when the second byte is written
• If CLKSB and CLKSA are not cleared, the registers are updated after both bytes were written, and
the TPM counter changes from (TPMxMODH:TPMxMODL – 1) to
(TPMxMODH:TPMxMODL). If the TPM counter is a free-running counter, the update is made
when the TPM counter changes from 0xFFFE to 0xFFFF.
When TPMxCNTH:TPMxCNTL equals TPMxMODH:TPMxMODL, the TPM can optionally generate a
TOF interrupt (at the end of this count).
16.5
16.5.1
Reset Overview
General
The TPM is reset whenever any MCU reset occurs.
16.5.2
Description of Reset Operation
Reset clears TPMxSC that disables TPM counter clock and overflow interrupt (TOIE=0). CPWMS,
MSnB, MSnA, ELSnB, and ELSnA are all cleared. This configures all TPM channels for input capture
operation and the associated pins are not controlled by TPM.
16.6
16.6.1
Interrupts
General
The TPM generates an optional interrupt for the main counter overflow and an interrupt for each channel.
The meaning of channel interrupts depends on each channel’s mode of operation. If the channel is
configured for input capture, the interrupt flag is set each time the selected input capture edge is
recognized. If the channel is configured for output compare or PWM modes, the interrupt flag is set each
time the main timer counter matches the value in the 16-bit channel value register.
All TPM interrupts are listed in Table 16-8.
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Table 16-8. Interrupt Summary
Interrupt
Local
Enable
Source
Description
TOF
TOIE
Counter overflow
Set each time the TPM counter reaches its terminal
count (at transition to its next count value)
CHnF
CHnIE
Channel event
An input capture event or channel match took place
on channel n
The TPM module provides high-true interrupt signals.
16.6.2
Description of Interrupt Operation
For each interrupt source in the TPM, a flag bit is set upon recognition of the interrupt condition such as
timer overflow, channel input capture, or output compare events. This flag is read (polled) by software to
determine that the action has occurred, or an associated enable bit (TOIE or CHnIE) can be set to enable
the interrupt generation. While the interrupt enable bit is set, the interrupt is generated whenever the
associated interrupt flag is set. Software must perform a sequence of steps to clear the interrupt flag before
returning from the interrupt-service routine.
TPM interrupt flags are cleared by a two-step process including a read of the flag bit while it is set followed
by a write of zero to the bit. If a new event is detected between these two steps, the sequence is reset and
the interrupt flag remains set after the second step to avoid the possibility of missing the new event.
16.6.2.1
Timer Overflow Interrupt (TOF) Description
The meaning and details of operation for TOF interrupts varies slightly depending upon the mode of
operation of the TPM system (general purpose timing functions versus center-aligned PWM operation).
The flag is cleared by the two step sequence described above.
16.6.2.1.1
Normal Case
When CPWMS is cleared, TOF is set when the timer counter changes from the terminal count (the value
in the modulo register) to 0x0000. If the TPM counter is a free-running counter, the update is made when
the TPM counter changes from 0xFFFF to 0x0000.
16.6.2.1.2
Center-Aligned PWM Case
When CPWMS is set, TOF is set when the timer counter changes direction from up-counting to
down-counting at the end of the terminal count (the value in the modulo register).
16.6.2.2
Channel Event Interrupt Description
The meaning of channel interrupts depends on the channel’s current mode (input capture, output compare,
edge-aligned PWM, or center-aligned PWM).
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16.6.2.2.1
Input Capture Events
When a channel is configured as an input capture channel, the ELSnB:ELSnA bits select if channel pin is
not controlled by TPM, rising edges, falling edges, or any edge as the edge that triggers an input capture
event. When the selected edge is detected, the interrupt flag is set. The flag is cleared by the two-step
sequence described in Section 16.6.2, “Description of Interrupt Operation.”
16.6.2.2.2
Output Compare Events
When a channel is configured as an output compare channel, the interrupt flag is set each time the main
timer counter matches the 16-bit value in the channel value register. The flag is cleared by the two-step
sequence described in Section 16.6.2, “Description of Interrupt Operation.”
16.6.2.2.3
PWM End-of-Duty-Cycle Events
When the channel is configured for edge-aligned PWM, the channel flag is set when the timer counter
matches the channel value register that marks the end of the active duty cycle period. When the channel is
configured for center-aligned PWM, the timer count matches the channel value register twice during each
PWM cycle. In this CPWM case, the channel flag is set at the start and at the end of the active duty cycle
period when the timer counter matches the channel value register. The flag is cleared by the two-step
sequence described in Section 16.6.2, “Description of Interrupt Operation.”
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Chapter 17
Modulo Timer (S08MTIMV1)
17.1
Introduction
The MTIM is a simple 8-bit timer with four software-selectable clock sources and a programmable
interrupt.
The central component of the MTIM is the 8-bit counter that can operate as a free-running counter or a
modulo counter. A timer overflow interrupt can be enabled to generate periodic interrupts for time-based
software loops.
Figure 17-1 shows the MC9S08LG32 series block diagram highlighting the MTIM block and pin.
17.1.1
MTIM Clock Gating
The bus clock to the MTIM can be gated on and off using the MTIM bit in SCGC1. This bit is cleared after
any reset, which disables the bus clock to this module. To conserve power, the MTIM bit can be cleared
to disable the clock to this module when not in use. See Section 5.7, “Peripheral Clock Gating,” for details.
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Chapter 17 Modulo Timer (S08MTIMV1)
8-BIT KEYBOARD
INTERRUPT (KBI)
RESET
IRQ
SERIAL PERIPHERAL
INTERFACE (SPI)
KBI[7:0]
SS
SPSCK
MISO
RESET/PTC6
BKGD/MS/PTC5
LCD[20:16]/PTC[4:0]
MOSI
SCL
IIC MODULE (IIC)
USER FLASH A
(LG32 = 16K BYTES)
(LG16 = 2K BYTES)
6-CHANNEL TIMER/PWM
(TPM2)
USER FLASH B
(LG32 = 16K BYTES)
(LG16 = 16K BYTES)
2-CHANNEL TIMER/PWM
(TPM1)
SERIAL COMMUNICATIONS
INTERFACE (SCI1)
USER RAM
SDA
TPM2CH[5:0]
TPMCLK
PORT D
RESETS AND INTERRUPTS
MODES OF OPERATION
POWER MANAGEMENT
LVD
LCD[40:37]/PTB[7:4]
LCD[32:29]/PTB[3:0]
TMRCLK
LCD[7:0]/PTD[7:0]
PORT E
Modulo Timer
(MTIM)
IRQ
PORT A
Real Time Counter
(RTC)
HCS08 SYSTEM CONTROL
COP
PORT B
BKGD/MS
LCD[15:8]/PTE[7:0]
TPM1CH[1:0]
PORT F
BKP
EXTAL/PTF7
XTAL/PTF6
T2CH3/KBI2/MOSI/PTF5
T2CH4/KBI1/MISO/PTF4
T2CH5/KBI0/SS/PTF3
ADC14/IRQ/T1CH1/SPSCK/PTF2
ADC13/T1CH0/RX1/PTF1
ADC12/T2CH2/KBI3/TX1/PTF0
PORT G
BKGD
LCD[44:41]/PTG[7:4]
LCD[36:33]/PTG[3:0]
PORT H
INT
ON-CHIP ICE (ICE) and
DEBUG MODULE (DBG)
T2CH4/KBI1/PTH7
ADC15/KBI0/T2CH5/PTH6
ADC11/T1CH0/KBI3/TX1/PTH5
ADC10/T1CH1/KBI2/RX1/PTH4
ADC[9:6]/KBI[7:4]/PTH[3:0]
PORT I
CPU
LCD28/ADC5/TPMCLK/PTA7
LCD27/ADC4/T2CH1/KBI7/PTA6
LCD26/ADC3/T2CH0/KBI6/PTA5
LCD25/ADC2/RX2/KBI5/PTA4
LCD24/ADC1/TX2/KBI4/PTA3
LCD23/ADC0/SDA/PTA2
LCD22/SCL/PTA1
LCD21/PTA0
PORT C
HCS08 CORE
SS/SCL/T2CH0/PTI5
SPSCK/SDA/T2CH1/PTI4
MOSI/T2CH2/PTI3
MISO/T2CH3/PTI2
TX2/TMRCLK/PTI1
RX2/PTI0
TPMCLK
TxD1
RxD1
1984 BYTES
SERIAL COMMUNICATIONS
INTERFACE (SCI2)
INTERNAL CLOCK
Source (ICS)
TxD2
RxD2
XTAL
LOW-POWER OSCILLATOR
12-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
VLL3_2
VLL3
VLL1
VLL2
VCAP1
EXTAL
AD[15:0]
LIQUID CRYSTAL
DISPLAY DRIVER
(LCD)
VCAP2
LCD[44:0]
VDD
VSS
VSS2
VDDA/VREFH
VSSA/VREFL
VOLTAGE
REGULATOR
Available only on 80-pin package
Available only on 64-pin and 80-pin package
*/Default function out of reset/*
Figure 17-1. MC9S08LG32 Series Block Diagram Highlighting MTIM Block and Pins
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Chapter 15 Modulo Timer (S08MTIMV1)
17.1.2
Features
Timer system features include:
• 8-bit up-counter
— Free-running or 8-bit modulo limit
— Software controllable interrupt on overflow
— Counter reset bit (TRST)
— Counter stop bit (TSTP)
• Four software selectable clock sources for input to prescaler:
— System bus clock — rising edge
— Fixed frequency clock (XCLK) — rising edge
— External clock source on the TPMCLK pin — rising edge
— External clock source on the TPMCLK pin — falling edge
• Nine selectable clock prescale values:
— Clock source divide by 1, 2, 4, 8, 16, 32, 64, 128, or 256
17.1.3
Modes of Operation
This section defines the MTIM’s operation in stop, wait and background debug modes.
17.1.3.1
MTIM in Wait Mode
The MTIM continues to run in wait mode if enabled before executing the WAIT instruction. Therefore,
the MTIM can be used to bring the MCU out of wait mode if the timer overflow interrupt is enabled. For
lowest possible current consumption, the MTIM should be stopped by software if not needed as an
interrupt source during wait mode.
17.1.3.2
MTIM in Stop Modes
The MTIM is disabled in all stop modes, regardless of the settings before executing the STOP instruction.
Therefore, the MTIM cannot be used as a wake up source from stop modes.
Waking from stop2 modes, the MTIM will be put into its reset state. If stop3 is exited with a reset, the
MTIM will be put into its reset state. If stop3 is exited with an interrupt, the MTIM continues from the
state it was in when stop3 was entered. If the counter was active upon entering stop3, the count will resume
from the current value.
17.1.3.3
MTIM in Active Background Mode
The MTIM suspends all counting until the microcontroller returns to normal user operating mode.
Counting resumes from the suspended value as long as an MTIM reset did not occur (TRST written to a 1
or MTIMMOD written).
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17.1.4
Block Diagram
The block diagram for the modulo timer module is shown Figure 17-2.
BUSCLK
XCLK
TPMCLK
SYNC
MTIM
INTERRUPT
REQUEST
CLOCK
SOURCE
SELECT
PRESCALE
AND SELECT
DIVIDE BY
CLKS
PS
8-BIT COUNTER
(MTIMCNT)
TRST
TSTP
8-BIT COMPARATOR
TOF
8-BIT MODULO
(MTIMMOD)
TOIE
Figure 17-2. Modulo Timer (MTIM) Block Diagram
17.2
External Signal Description
The MTIM includes one external signal, TPMCLK, used to input an external clock when selected as the
MTIM clock source. The signal properties of TPMCLK are shown in Table 17-1.
Table 17-1. External Signal Description
Signal
TPMCLK
Function
External clock source input into MTIM
I/O
I
The TPMCLK input must be synchronized by the bus clock. Also, variations in duty cycle and clock jitter
must be accommodated. Therefore, the TPMCLK signal must be limited to one-fourth of the bus
frequency.
The TPMCLK pin can be muxed with a general-purpose port pin. See the Chapter 2, “Pins and
Connections,” chapter for the pin location and priority of this function.
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17.3
17.3.1
Memory Map and Register Definition
Memory Map (Register Summary)
Figure 17-3. MTIM Register Summary
Name
7
R
6
TOF
MTIMSC
5
4
0
TOIE
W
R
3
2
1
0
0
0
0
0
TSTP
TRST
0
0
MTIMCLK
CLKS
PS
W
COUNT
R
MTIMCNT
W
R
MOD
MTIMMOD
W
17.3.2
Register Descriptions
Each MTIM includes four registers:
• An 8-bit status and control register
• An 8-bit clock configuration register
• An 8-bit counter register
• An 8-bit modulo register
Refer to the direct-page register summary in the Chapter 4, “Memory,” for the absolute address
assignments for all MTIM registers.This section refers to registers and control bits only by their names and
relative address offsets.
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17.3.2.1
MTIM Status and Control Register (MTIMSC)
MTIMSC contains the overflow status flag and control bits which are used to configure the interrupt
enable, reset the counter, and stop the counter.
7
R
6
5
TOF
4
0
TOIE
W
Reset:
3
2
1
0
0
0
0
0
0
0
0
0
TSTP
TRST
0
0
0
1
Figure 17-4. MTIM Status and Control Register (MTIMSC)
Table 17-2. MTIMSC Field Descriptions
Field
Description
7
TOF
MTIM Overflow Flag — This read-only bit is set when the MTIM counter register overflows to $00 after reaching
the value in the MTIM modulo register. Clear TOF by reading the MTIMSC register while TOF is set, then writing
a 0 to TOF. TOF is also cleared when TRST is written to a 1 or when any value is written to the MTIMMOD register.
0 MTIM counter has not reached the overflow value in the MTIM modulo register.
1 MTIM counter has reached the overflow value in the MTIM modulo register.
6
TOIE
MTIM Overflow Interrupt Enable — This read/write bit enables MTIM overflow interrupts. If TOIE is set, then an
interrupt is generated when TOF = 1. Reset clears TOIE. Do not set TOIE if TOF = 1. Clear TOF first, then set TOIE.
0 TOF interrupts are disabled. Use software polling.
1 TOF interrupts are enabled.
5
TRST
MTIM Counter Reset — When a 1 is written to this write-only bit, the MTIM counter register resets to $00 and TOF
is cleared. Reading this bit always returns 0.
0 No effect. MTIM counter remains at current state.
1 MTIM counter is reset to $00.
4
TSTP
MTIM Counter Stop — When set, this read/write bit stops the MTIM counter at its current value. Counting resumes
from the current value when TSTP is cleared. Reset sets TSTP to prevent the MTIM from counting.
0 MTIM counter is active.
1 MTIM counter is stopped.
3:0
Unused register bits, always read 0.
17.3.2.2
MTIM Clock Configuration Register (MTIMCLK)
MTIMCLK contains the clock select bits (CLKS) and the prescaler select bits (PS).
R
7
6
0
0
5
4
3
2
CLKS
1
0
0
0
PS
W
Reset:
0
0
0
0
0
0
Figure 17-5. MTIM Clock Configuration Register (MTIMCLK)
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Table 17-3. MTIMCLK Field Descriptions
Field
7:6
5:4
CLKS
3:0
PS
Description
Unused register bits, always read 0.
Clock Source Select — These two read/write bits select one of four different clock sources as the input to the
MTIM prescaler. Changing the clock source while the counter is active does not clear the counter. The count
continues with the new clock source. Reset clears CLKS to 000.
00
Encoding 0. Bus clock (BUSCLK)
01
Encoding 1. Fixed-frequency clock (XCLK)
10
Encoding 3. External source (TPMCLK pin), falling edge
11
Encoding 4. External source (TPMCLK pin), rising edge
All other encodings default to the bus clock (BUSCLK).
Clock Source Prescaler — These four read/write bits select one of nine outputs from the 8-bit prescaler. Changing
the prescaler value while the counter is active does not clear the counter. The count continues with the new
prescaler value. Reset clears PS to 0000.
0000 Encoding 0. MTIM clock source ÷ 1
0001 Encoding 1. MTIM clock source ÷ 2
0010 Encoding 2. MTIM clock source ÷ 4
0011 Encoding 3. MTIM clock source ÷ 8
0100 Encoding 4. MTIM clock source ÷ 16
0101 Encoding 5. MTIM clock source ÷ 32
0110 Encoding 6. MTIM clock source ÷ 64
0111 Encoding 7. MTIM clock source ÷ 128
1000 Encoding 8. MTIM clock source ÷ 256
All other encodings default to MTIM clock source ÷ 256.
17.3.2.3
MTIM Counter Register (MTIMCNT)
MTIMCNT is the read-only value of the current MTIM count of the 8-bit counter.
7
6
5
4
R
3
2
1
0
0
0
0
0
COUNT
W
Reset:
0
0
0
0
Figure 17-6. MTIM Counter Register (MTIMCNT)
Table 17-4. MTIMCNT Field Descriptions
Field
Description
7:0
COUNT
MTIM Count — These eight read-only bits contain the current value of the 8-bit counter. Writes have no effect to
this register. Reset clears the count to $00.
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17.3.2.4
MTIM Modulo Register (MTIMMOD)
7
6
5
4
3
2
1
0
0
0
0
0
R
MOD
W
Reset:
0
0
0
0
Figure 17-7. MTIM Modulo Register (MTIMMOD)
Table 17-5. MTIMMOD Field Descriptions
Field
Description
7:0
MOD
MTIM Modulo — These eight read/write bits contain the modulo value used to reset the count and set TOF. A value
of $00 puts the MTIM in free-running mode. Writing to MTIMMOD resets the COUNT to $00 and clears TOF. Reset
sets the modulo to $00.
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Chapter 15 Modulo Timer (S08MTIMV1)
17.4
Functional Description
The MTIM is composed of a main 8-bit up-counter with an 8-bit modulo register, a clock source selector,
and a prescaler block with nine selectable values. The module also contains software selectable interrupt
logic.
The MTIM counter (MTIMCNT) has three modes of operation: stopped, free-running, and modulo. Out
of reset, the counter is stopped. If the counter is started without writing a new value to the modulo register,
then the counter will be in free-running mode. The counter is in modulo mode when a value other than $00
is in the modulo register while the counter is running.
After any MCU reset, the counter is stopped and reset to $00, and the modulus is set to $00. The bus clock
is selected as the default clock source and the prescale value is divide by 1. To start the MTIM in
free-running mode, simply write to the MTIM status and control register (MTIMSC) and clear the MTIM
stop bit (TSTP).
Four clock sources are software selectable: the internal bus clock, the fixed frequency clock (XCLK), and
an external clock on the TPMCLK pin, selectable as incrementing on either rising or falling edges. The
MTIM clock select bits (CLKS1:CLKS0) in MTIMSC are used to select the desired clock source. If the
counter is active (TSTP = 0) when a new clock source is selected, the counter will continue counting from
the previous value using the new clock source.
Nine prescale values are software selectable: clock source divided by 1, 2, 4, 8, 16, 32, 64, 128, or 256.
The prescaler select bits (PS[3:0]) in MTIMSC select the desired prescale value. If the counter is active
(TSTP = 0) when a new prescaler value is selected, the counter will continue counting from the previous
value using the new prescaler value.
The MTIM modulo register (MTIMMOD) allows the overflow compare value to be set to any value from
$01 to $FF. Reset clears the modulo value to $00, which results in a free running counter.
When the counter is active (TSTP = 0), the counter increments at the selected rate until the count matches
the modulo value. When these values match, the counter overflows to $00 and continues counting. The
MTIM overflow flag (TOF) is set whenever the counter overflows. The flag sets on the transition from the
modulo value to $00. Writing to MTIMMOD while the counter is active resets the counter to $00 and
clears TOF.
Clearing TOF is a two-step process. The first step is to read the MTIMSC register while TOF is set. The
second step is to write a 0 to TOF. If another overflow occurs between the first and second steps, the
clearing process is reset and TOF will remain set after the second step is performed. This will prevent the
second occurrence from being missed. TOF is also cleared when a 1 is written to TRST or when any value
is written to the MTIMMOD register.
The MTIM allows for an optional interrupt to be generated whenever TOF is set. To enable the MTIM
overflow interrupt, set the MTIM overflow interrupt enable bit (TOIE) in MTIMSC. TOIE should never
be written to a 1 while TOF = 1. Instead, TOF should be cleared first, then the TOIE can be set to 1.
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17.4.1
MTIM Operation Example
This section shows an example of the MTIM operation as the counter reaches a matching value from the
modulo register.
selected
clock source
MTIM clock
(PS=%0010)
MTIMCNT
$A7
$A8
$A9
$AA
$00
$01
TOF
MTIMMOD:
$AA
Figure 17-8. MTIM counter overflow example
In the example of Figure 17-8, the selected clock source could be any of the four possible choices. The
prescaler is set to PS = %0010 or divide-by-4. The modulo value in the MTIMMOD register is set to $AA.
When the counter, MTIMCNT, reaches the modulo value of $AA, the counter overflows to $00 and
continues counting. The timer overflow flag, TOF, sets when the counter value changes from $AA to $00.
An MTIM overflow interrupt is generated when TOF is set, if TOIE = 1.
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Development Support
18.1
Introduction
Development support systems in the HCS08 include the background debug controller (BDC) and the
on-chip debug module (DBG). The BDC provides a single-wire debug interface to the target MCU that
provides a convenient interface for programming the on-chip flash and other nonvolatile memories. The
BDC is also the primary debug interface for development and allows non-intrusive access to memory data
and traditional debug features such as CPU register modify, breakpoints, and single instruction trace
commands.
In the HCS08 Family, address and data bus signals are not available on external pins. Debug is done
through commands fed into the target MCU through the single-wire background debug interface. The
debug module provides a means to selectively trigger and capture bus information so an external
development system can reconstruct what happened inside the MCU on a cycle-by-cycle basis without
having external access to the address and data signals.
18.1.1
Forcing Active Background
The method for forcing active background mode depends on the specific HCS08 derivative. For the
MC9S08LG32 series, you can force active background after a power-on reset by holding the BKGD pin
low as the device exits the reset condition. You can also force active background by driving BKGD low
immediately after a serial background command that writes a one to the BDFR bit in the SBDFR register.
Other causes of reset, including an external pin reset or an internally generated error reset ignore the state
of the BKGD pin and reset into normal user mode. If no debug pod is connected to the BKGD pin, the
MCU will always reset into normal operating mode.
18.1.2
Module Configuration
The alternate BDC clock source is the ICSLCLK. To select this clock source, clear the CLKSW bit in the
BDCSCR register. For details on ICSLCLK, see Section 11.4, “Functional Description.”
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18.1.3
Features
Features of the BDC module include:
• Single pin for mode selection and background communications
• BDC registers are not located in the memory map
• SYNC command to determine target communications rate
• Non-intrusive commands for memory access
• Active background mode commands for CPU register access
• GO and TRACE1 commands
• BACKGROUND command can wake CPU from stop or wait modes
• One hardware address breakpoint built into BDC
• Oscillator runs in stop mode, if BDC enabled
• COP watchdog disabled while in active background mode
18.2
Background Debug Controller (BDC)
All MCUs in the HCS08 Family contain a single-wire background debug interface that supports in-circuit
programming of on-chip nonvolatile memory and sophisticated non-intrusive debug capabilities. Unlike
debug interfaces on earlier 8-bit MCUs, this system does not interfere with normal application resources.
It does not use any user memory or locations in the memory map and does not share any on-chip
peripherals.
BDC commands are divided into two groups:
• Active background mode commands require that the target MCU is in active background mode (the
user program is not running). Active background mode commands allow the CPU registers to be
read or written, and allow the user to trace one user instruction at a time, or GO to the user program
from active background mode.
• Non-intrusive commands can be executed at any time even while the user’s program is running.
Non-intrusive commands allow a user to read or write MCU memory locations or access status and
control registers within the background debug controller.
Typically, a relatively simple interface pod is used to translate commands from a host computer into
commands for the custom serial interface to the single-wire background debug system. Depending on the
development tool vendor, this interface pod may use a standard RS-232 serial port, a parallel printer port,
or some other type of communications such as a universal serial bus (USB) to communicate between the
host PC and the pod. The pod typically connects to the target system with ground, the BKGD pin, RESET,
and sometimes VDD. An open-drain connection to reset allows the host to force a target system reset,
which is useful to regain control of a lost target system or to control startup of a target system before the
on-chip nonvolatile memory has been programmed. Sometimes VDD can be used to allow the pod to use
power from the target system to avoid the need for a separate power supply. However, if the pod is powered
separately, it can be connected to a running target system without forcing a target system reset or otherwise
disturbing the running application program.
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BKGD 1
2 GND
NO CONNECT 3
4 RESET
NO CONNECT 5
6 VDD
Figure 18-1. BDM Tool Connector
18.2.1
BKGD Pin Description
BKGD is the single-wire background debug interface pin. The primary function of this pin is for
bidirectional serial communication of active background mode commands and data. During reset, this pin
is used to select between starting in active background mode or starting the user’s application program.
This pin is also used to request a timed sync response pulse to allow a host development tool to determine
the correct clock frequency for background debug serial communications.
BDC serial communications use a custom serial protocol first introduced on the M68HC12 Family of
microcontrollers. This protocol assumes the host knows the communication clock rate that is determined
by the target BDC clock rate. All communication is initiated and controlled by the host that drives a
high-to-low edge to signal the beginning of each bit time. Commands and data are sent most significant
bit first (MSB first). For a detailed description of the communications protocol, refer to Section 18.2.2,
“Communication Details.”
If a host is attempting to communicate with a target MCU that has an unknown BDC clock rate, a SYNC
command may be sent to the target MCU to request a timed sync response signal from which the host can
determine the correct communication speed.
BKGD is a pseudo-open-drain pin and there is an on-chip pullup so no external pullup resistor is required.
Unlike typical open-drain pins, the external RC time constant on this pin, which is influenced by external
capacitance, plays almost no role in signal rise time. The custom protocol provides for brief, actively
driven speedup pulses to force rapid rise times on this pin without risking harmful drive level conflicts.
Refer to Section 18.2.2, “Communication Details,” for more detail.
When no debugger pod is connected to the 6-pin BDM interface connector, the internal pullup on BKGD
chooses normal operating mode. When a debug pod is connected to BKGD it is possible to force the MCU
into active background mode after reset. The specific conditions for forcing active background depend
upon the HCS08 derivative (refer to the introduction to this Development Support section). It is not
necessary to reset the target MCU to communicate with it through the background debug interface.
18.2.2
Communication Details
The BDC serial interface requires the external controller to generate a falling edge on the BKGD pin to
indicate the start of each bit time. The external controller provides this falling edge whether data is
transmitted or received.
BKGD is a pseudo-open-drain pin that can be driven either by an external controller or by the MCU. Data
is transferred MSB first at 16 BDC clock cycles per bit (nominal speed). The interface times out if
512 BDC clock cycles occur between falling edges from the host. Any BDC command that was in progress
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when this timeout occurs is aborted without affecting the memory or operating mode of the target MCU
system.
The custom serial protocol requires the debug pod to know the target BDC communication clock speed.
The clock switch (CLKSW) control bit in the BDC status and control register allows the user to select the
BDC clock source. The BDC clock source can either be the bus or the alternate BDC clock source.
The BKGD pin can receive a high or low level or transmit a high or low level. The following diagrams
show timing for each of these cases. Interface timing is synchronous to clocks in the target BDC, but
asynchronous to the external host. The internal BDC clock signal is shown for reference in counting
cycles.
Figure 18-2 shows an external host transmitting a logic 1 or 0 to the BKGD pin of a target HCS08 MCU.
The host is asynchronous to the target so there is a 0-to-1 cycle delay from the host-generated falling edge
to where the target perceives the beginning of the bit time. Ten target BDC clock cycles later, the target
senses the bit level on the BKGD pin. Typically, the host actively drives the pseudo-open-drain BKGD pin
during host-to-target transmissions to speed up rising edges. Because the target does not drive the BKGD
pin during the host-to-target transmission period, there is no need to treat the line as an open-drain signal
during this period.
BDC CLOCK
(TARGET MCU)
HOST
TRANSMIT 1
HOST
TRANSMIT 0
10 CYCLES
SYNCHRONIZATION
UNCERTAINTY
EARLIEST START
OF NEXT BIT
TARGET SENSES BIT LEVEL
PERCEIVED START
OF BIT TIME
Figure 18-2. BDC Host-to-Target Serial Bit Timing
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Figure 18-3 shows the host receiving a logic 1 from the target HCS08 MCU. Because the host is
asynchronous to the target MCU, there is a 0-to-1 cycle delay from the host-generated falling edge on
BKGD to the perceived start of the bit time in the target MCU. The host holds the BKGD pin low long
enough for the target to recognize it (at least two target BDC cycles). The host must release the low drive
before the target MCU drives a brief active-high speedup pulse seven cycles after the perceived start of the
bit time. The host should sample the bit level about 10 cycles after it started the bit time.
BDC CLOCK
(TARGET MCU)
HOST DRIVE
TO BKGD PIN
TARGET MCU
SPEEDUP PULSE
HIGH-IMPEDANCE
HIGH-IMPEDANCE
HIGH-IMPEDANCE
PERCEIVED START
OF BIT TIME
R-C RISE
BKGD PIN
10 CYCLES
10 CYCLES
EARLIEST START
OF NEXT BIT
HOST SAMPLES BKGD PIN
Figure 18-3. BDC Target-to-Host Serial Bit Timing (Logic 1)
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Figure 18-4 shows the host receiving a logic 0 from the target HCS08 MCU. Because the host is
asynchronous to the target MCU, there is a 0-to-1 cycle delay from the host-generated falling edge on
BKGD to the start of the bit time as perceived by the target MCU. The host initiates the bit time but the
target HCS08 finishes it. Because the target wants the host to receive a logic 0, it drives the BKGD pin low
for 13 BDC clock cycles, then briefly drives it high to speed up the rising edge. The host samples the bit
level about 10 cycles after starting the bit time.
BDC CLOCK
(TARGET MCU)
HOST DRIVE
TO BKGD PIN
HIGH-IMPEDANCE
SPEEDUP
PULSE
TARGET MCU
DRIVE AND
SPEED-UP PULSE
PERCEIVED START
OF BIT TIME
BKGD PIN
10 CYCLES
10 CYCLES
EARLIEST START
OF NEXT BIT
HOST SAMPLES BKGD PIN
Figure 18-4. BDM Target-to-Host Serial Bit Timing (Logic 0)
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18.2.3
BDC Commands
BDC commands are sent serially from a host computer to the BKGD pin of the target HCS08 MCU. All
commands and data are sent MSB-first using a custom BDC communications protocol. Active background
mode commands require that the target MCU is currently in the active background mode while
non-intrusive commands may be issued at any time whether the target MCU is in active background mode
or running a user application program.
Table 18-1 shows all HCS08 BDC commands, a shorthand description of their coding structure, and the
meaning of each command.
Coding Structure Nomenclature
This nomenclature is used in Table 18-1 to describe the coding structure of the BDC commands.
Commands begin with an 8-bit hexadecimal command code in the host-to-target
direction (most significant bit first)
/ = separates parts of the command
d = delay 16 target BDC clock cycles
AAAA = a 16-bit address in the host-to-target direction
RD = 8 bits of read data in the target-to-host direction
WD = 8 bits of write data in the host-to-target direction
RD16 = 16 bits of read data in the target-to-host direction
WD16 = 16 bits of write data in the host-to-target direction
SS = the contents of BDCSCR in the target-to-host direction (STATUS)
CC = 8 bits of write data for BDCSCR in the host-to-target direction (CONTROL)
RBKP = 16 bits of read data in the target-to-host direction (from BDCBKPT breakpoint
register)
WBKP = 16 bits of write data in the host-to-target direction (for BDCBKPT breakpoint register)
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Table 18-1. BDC Command Summary
Command
Mnemonic
1
Active BDM/
Non-intrusive
Coding
Structure
Description
SYNC
Non-intrusive
n/a1
Request a timed reference pulse to determine
target BDC communication speed
ACK_ENABLE
Non-intrusive
D5/d
Enable acknowledge protocol. Refer to
Freescale document order no. HCS08RMv1/D.
ACK_DISABLE
Non-intrusive
D6/d
Disable acknowledge protocol. Refer to
Freescale document order no. HCS08RMv1/D.
BACKGROUND
Non-intrusive
90/d
Enter active background mode if enabled
(ignore if ENBDM bit equals 0)
READ_STATUS
Non-intrusive
E4/SS
Read BDC status from BDCSCR
WRITE_CONTROL
Non-intrusive
C4/CC
Write BDC controls in BDCSCR
READ_BYTE
Non-intrusive
E0/AAAA/d/RD
Read a byte from target memory
READ_BYTE_WS
Non-intrusive
E1/AAAA/d/SS/RD
Read a byte and report status
READ_LAST
Non-intrusive
E8/SS/RD
Re-read byte from address just read and report
status
WRITE_BYTE
Non-intrusive
C0/AAAA/WD/d
Write a byte to target memory
WRITE_BYTE_WS
Non-intrusive
C1/AAAA/WD/d/SS
Write a byte and report status
READ_BKPT
Non-intrusive
E2/RBKP
Read BDCBKPT breakpoint register
WRITE_BKPT
Non-intrusive
C2/WBKP
Write BDCBKPT breakpoint register
GO
Active BDM
08/d
Go to execute the user application program
starting at the address currently in the PC
TRACE1
Active BDM
10/d
Trace 1 user instruction at the address in the
PC, then return to active background mode
TAGGO
Active BDM
18/d
Same as GO but enable external tagging
(HCS08 devices have no external tagging pin)
READ_A
Active BDM
68/d/RD
Read accumulator (A)
READ_CCR
Active BDM
69/d/RD
Read condition code register (CCR)
READ_PC
Active BDM
6B/d/RD16
Read program counter (PC)
READ_HX
Active BDM
6C/d/RD16
Read H and X register pair (H:X)
READ_SP
Active BDM
6F/d/RD16
Read stack pointer (SP)
READ_NEXT
Active BDM
70/d/RD
Increment H:X by one then read memory byte
located at H:X
READ_NEXT_WS
Active BDM
71/d/SS/RD
Increment H:X by one then read memory byte
located at H:X. Report status and data.
WRITE_A
Active BDM
48/WD/d
Write accumulator (A)
WRITE_CCR
Active BDM
49/WD/d
Write condition code register (CCR)
WRITE_PC
Active BDM
4B/WD16/d
Write program counter (PC)
WRITE_HX
Active BDM
4C/WD16/d
Write H and X register pair (H:X)
WRITE_SP
Active BDM
4F/WD16/d
Write stack pointer (SP)
WRITE_NEXT
Active BDM
50/WD/d
Increment H:X by one, then write memory byte
located at H:X
WRITE_NEXT_WS
Active BDM
51/WD/d/SS
Increment H:X by one, then write memory byte
located at H:X. Also report status.
The SYNC command is a special operation that does not have a command code.
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The SYNC command is unlike other BDC commands because the host does not necessarily know the
correct communications speed to use for BDC communications until after it has analyzed the response to
the SYNC command.
To issue a SYNC command, the host:
• Drives the BKGD pin low for at least 128 cycles of the slowest possible BDC clock (The slowest
clock is normally the reference oscillator/64 or the self-clocked rate/64.)
• Drives BKGD high for a brief speedup pulse to get a fast rise time (This speedup pulse is typically
one cycle of the fastest clock in the system.)
• Removes all drive to the BKGD pin so it reverts to high impedance
• Monitors the BKGD pin for the sync response pulse
The target, upon detecting the SYNC request from the host (which is a much longer low time than would
ever occur during normal BDC communications):
• Waits for BKGD to return to a logic high
• Delays 16 cycles to allow the host to stop driving the high speedup pulse
• Drives BKGD low for 128 BDC clock cycles
• Drives a 1-cycle high speedup pulse to force a fast rise time on BKGD
• Removes all drive to the BKGD pin so it reverts to high impedance
The host measures the low time of this 128-cycle sync response pulse and determines the correct speed for
subsequent BDC communications. Typically, the host can determine the correct communication speed
within a few percent of the actual target speed and the communication protocol can easily tolerate speed
errors of several percent.
18.2.4
BDC Hardware Breakpoint
The BDC includes one relatively simple hardware breakpoint that compares the CPU address bus to a
16-bit match value in the BDCBKPT register. This breakpoint can generate a forced breakpoint or a tagged
breakpoint. A forced breakpoint causes the CPU to enter active background mode at the first instruction
boundary following any access to the breakpoint address. The tagged breakpoint causes the instruction
opcode at the breakpoint address to be tagged so that the CPU will enter active background mode rather
than executing that instruction if and when it reaches the end of the instruction queue. This implies that
tagged breakpoints can only be placed at the address of an instruction opcode while forced breakpoints can
be set at any address.
The breakpoint enable (BKPTEN) control bit in the BDC status and control register (BDCSCR) is used to
enable the breakpoint logic (BKPTEN = 1). When BKPTEN = 0, its default value after reset, the
breakpoint logic is disabled and no BDC breakpoints are requested regardless of the values in other BDC
breakpoint registers and control bits. The force/tag select (FTS) control bit in BDCSCR is used to select
forced (FTS = 1) or tagged (FTS = 0) type breakpoints.
18.3
Register Definition
This section contains the descriptions of the BDC registers and control bits.
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This section refers to registers and control bits only by their names. A Freescale-provided equate or header
file is used to translate these names into the appropriate absolute addresses.
18.3.1
BDC Registers and Control Bits
The BDC has two registers:
• The BDC status and control register (BDCSCR) is an 8-bit register containing control and status
bits for the background debug controller.
• The BDC breakpoint match register (BDCBKPT) holds a 16-bit breakpoint match address.
These registers are accessed with dedicated serial BDC commands and are not located in the memory
space of the target MCU (so they do not have addresses and cannot be accessed by user programs).
Some of the bits in the BDCSCR have write limitations; otherwise, these registers may be read or written
at any time. For example, the ENBDM control bit may not be written while the MCU is in active
background mode. (This prevents the ambiguous condition of the control bit forbidding active background
mode while the MCU is already in active background mode.) Also, the four status bits (BDMACT, WS,
WSF, and DVF) are read-only status indicators and can never be written by the WRITE_CONTROL serial
BDC command. The clock switch (CLKSW) control bit may be read or written at any time.
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18.3.1.1
BDC Status and Control Register (BDCSCR)
This register can be read or written by serial BDC commands (READ_STATUS and WRITE_CONTROL)
but is not accessible to user programs because it is not located in the normal memory map of the MCU.
7
6
R
5
4
3
BKPTEN
FTS
CLKSW
BDMACT
ENBDM
2
1
0
WS
WSF
DVF
W
Normal
Reset
0
0
0
0
0
0
0
0
Reset in
Active BDM:
1
1
0
0
1
0
0
0
= Unimplemented or Reserved
Figure 18-5. BDC Status and Control Register (BDCSCR)
Table 18-2. BDCSCR Register Field Descriptions
Field
Description
7
ENBDM
Enable BDM (Permit Active Background Mode) — Typically, this bit is written to 1 by the debug host shortly
after the beginning of a debug session or whenever the debug host resets the target and remains 1 until a normal
reset clears it.
0 BDM cannot be made active (non-intrusive commands still allowed)
1 BDM can be made active to allow active background mode commands
6
BDMACT
Background Mode Active Status — This is a read-only status bit.
0 BDM not active (user application program running)
1 BDM active and waiting for serial commands
5
BKPTEN
BDC Breakpoint Enable — If this bit is clear, the BDC breakpoint is disabled and the FTS (force tag select)
control bit and BDCBKPT match register are ignored.
0 BDC breakpoint disabled
1 BDC breakpoint enabled
4
FTS
Force/Tag Select — When FTS = 1, a breakpoint is requested whenever the CPU address bus matches the
BDCBKPT match register. When FTS = 0, a match between the CPU address bus and the BDCBKPT register
causes the fetched opcode to be tagged. If this tagged opcode ever reaches the end of the instruction queue,
the CPU enters active background mode rather than executing the tagged opcode.
0 Tag opcode at breakpoint address and enter active background mode if CPU attempts to execute that
instruction
1 Breakpoint match forces active background mode at next instruction boundary (address need not be an
opcode)
3
CLKSW
Select Source for BDC Communications Clock — CLKSW defaults to 0, which selects the alternate BDC clock
source.
0 Alternate BDC clock source
1 MCU bus clock
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Table 18-2. BDCSCR Register Field Descriptions (continued)
Field
Description
2
WS
Wait or Stop Status — When the target CPU is in wait or stop mode, most BDC commands cannot function.
However, the BACKGROUND command can be used to force the target CPU out of wait or stop and into active
background mode where all BDC commands work. Whenever the host forces the target MCU into active
background mode, the host should issue a READ_STATUS command to check that BDMACT = 1 before
attempting other BDC commands.
0 Target CPU is running user application code or in active background mode (was not in wait or stop mode when
background became active)
1 Target CPU is in wait or stop mode, or a BACKGROUND command was used to change from wait or stop to
active background mode
1
WSF
Wait or Stop Failure Status — This status bit is set if a memory access command failed due to the target CPU
executing a wait or stop instruction at or about the same time. The usual recovery strategy is to issue a
BACKGROUND command to get out of wait or stop mode into active background mode, repeat the command
that failed, then return to the user program. (Typically, the host would restore CPU registers and stack values and
re-execute the wait or stop instruction.)
0 Memory access did not conflict with a wait or stop instruction
1 Memory access command failed because the CPU entered wait or stop mode
0
DVF
Data Valid Failure Status — This status bit is not used in the MC9S08LG32 series because it does not have
any slow access memory.
0 Memory access did not conflict with a slow memory access
1 Memory access command failed because CPU was not finished with a slow memory access
18.3.1.2
BDC Breakpoint Match Register (BDCBKPT)
This 16-bit register holds the address for the hardware breakpoint in the BDC. The BKPTEN and FTS
control bits in BDCSCR are used to enable and configure the breakpoint logic. Dedicated serial BDC
commands (READ_BKPT and WRITE_BKPT) are used to read and write the BDCBKPT register but is
not accessible to user programs because it is not located in the normal memory map of the MCU.
Breakpoints are normally set while the target MCU is in active background mode before running the user
application program. For additional information about setup and use of the hardware breakpoint logic in
the BDC, refer to Section 18.2.4, “BDC Hardware Breakpoint.”
18.3.2
System Background Debug Force Reset Register (SBDFR)
This register contains a single write-only control bit. A serial background mode command such as
WRITE_BYTE must be used to write to SBDFR. Attempts to write this register from a user program are
ignored. Reads always return 0x00.
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R
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
BDFR1
W
Reset
0
0
0
0
0
0
0
0
= Unimplemented or Reserved
1
BDFR is writable only through serial background mode debug commands, not from user programs.
Figure 18-6. System Background Debug Force Reset Register (SBDFR)
Table 18-3. SBDFR Register Field Description
Field
Description
0
BDFR
Background Debug Force Reset — A serial active background mode command such as WRITE_BYTE allows
an external debug host to force a target system reset. Writing 1 to this bit forces an MCU reset. This bit cannot
be written from a user program.
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Debug Module (DBG) (64K)
19.1
Introduction
The DBG module implements an on-chip ICE (in-circuit emulation) system and allows non-intrusive
debug of application software by providing an on-chip trace buffer with flexible triggering capability. The
trigger also can provide extended breakpoint capacity. The on-chip ICE system is optimized for the HCS08
8-bit architecture and supports 64K bytes or 128K bytes of memory space.
19.1.1
Features
The on-chip ICE system includes these distinctive features:
• Three comparators (A, B, and C) with ability to match addresses in 64K space
— Dual mode, Comparators A and B used to compare addresses
— Full mode, Comparator A compares address and Comparator B compares data
— Can be used as triggers and/or breakpoints
— Comparator C can be used as a normal hardware breakpoint
— Loop1 capture mode, Comparator C is used to track most recent COF event captured into FIFO
• Tag and Force type breakpoints
• Nine trigger modes
— A
— A Or B
— A Then B
— A And B, where B is data (Full mode)
— A And Not B, where B is data (Full mode)
— Event Only B, store data
— A Then Event Only B, store data
— Inside Range, A ≤ Address ≤ B
— Outside Range, Address < Α or Address > B
• FIFO for storing change of flow information and event only data
— Source address of conditional branches taken
— Destination address of indirect JMP and JSR instruction
— Destination address of interrupts, RTI, RTC, and RTS instruction
— Data associated with Event B trigger modes
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•
Ability to End-trace until reset and Begin-trace from reset
19.1.2
Modes of Operation
The on-chip ICE system can be enabled in all MCU functional modes. The DBG module is disabled if the
MCU is secure. The DBG module comparators are disabled when executing a Background Debug Mode
(BDM) command.
19.1.3
Block Diagram
Figure 19-1 shows the structure of the DBG module.
core_cpu_aob_14_t2 1
core_cpu_aob_15_t2 1
core_ppage_t2[2:0] 1
DBG Read Data Bus
FIFO Data
Address Bus[16:0]1
Address/Data/Control Registers
c
o
n
t
r
o
l
Write Data Bus
Read Data Bus
Read/Write
DBG Module Enable
Trigger
Break
Control
Logic
match_A
Comparator A
match_B
Comparator B
mmu_ppage_sel1
core_cof[1:0]
control
Tag
Force
match_C
Comparator C
Change of Flow Indicators
MCU in BDM
MCU reset
event only
store
Read DBGFL
Read DBGFH
Read DBGFX
Instr. Lastcycle
register
Bus Clk
m
u
x
subtract 2
ppage_sel1
m
u
x
m
u
x
8 deep
FIFO
FIFO Data
addr[16:0]1
Write Data Bus
Read Data Bus
m
u
x
Read/Write
1. In 64K versions of this module there are only 16 address lines [15:0], there are no core_cpu_aob_14_t2,
core_cpu_aob_15_t2, core_ppage_t2[2:0], and ppage_sel signals.
Figure 19-1. DBG Block Diagram
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Chapter 19 Debug Module (DBG) (64K)
19.2
Signal Description
The DBG module contains no external signals.
19.3
Memory Map and Registers
This section provides a detailed description of all DBG registers accessible to the end user.
19.3.1
Module Memory Map
Table 19-1 shows the registers contained in the DBG module.
Table 19-1. Module Memory Map
Address
Use
Access
Base + $0000
Debug Comparator A High Register (DBGCAH)
Read/write
Base + $0001
Debug Comparator A Low Register (DBGCAL)
Read/write
Base + $0002
Debug Comparator B High Register (DBGCBH)
Read/write
Base + $0003
Debug Comparator B Low Register (DBGCBL)
Read/write
Base + $0004
Debug Comparator C High Register (DBGCCH)
Read/write
Base + $0005
Debug Comparator C Low Register (DBGCCL)
Read/write
Base + $0006
Debug FIFO High Register (DBGFH)
Read only
Base + $0007
Debug FIFO Low Register (DBGFL)
Read only
Base + $0008
Debug Comparator A Extension Register (DBGCAX)
Read/write
Base + $0009
Debug Comparator B Extension Register (DBGCBX)
Read/write
Base + $000A
Debug Comparator C Extension Register (DBGCCX)
Read/write
Base + $000B
reserved
Read only
Base + $000C
Debug Control Register (DBGC)
Read/write
Base + $000D
Debug Trigger Register (DBGT)
Read/write
Base + $000E
Debug Status Register (DBGS)
Read only
Base + $000F
Debug FIFO Count Register (DBGCNT)
Read only
Table 19-2 shows the register bit summary for the registers contained in the DBG module.
Table 19-2. Register Bit Summary (Sheet 1 of 2)
7
6
5
4
3
2
1
0
DBGCAH
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
DBGCAL
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
DBGCBH
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
DBGCBL
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
DBGCCH
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
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Table 19-2. Register Bit Summary (Sheet 2 of 2)
7
6
5
4
3
2
1
0
DBGCCL
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
DBGFH
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
DBGFL
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
DBGCAX
RWAEN
RWA
0
0
0
0
0
0
DBGCBX
RWBEN
RWB
0
0
0
0
0
0
DBGCCX
RWCEN
RWC
0
0
0
0
0
0
reserved
0
0
0
0
0
0
0
0
DBGC
DBGEN
ARM
TAG
BRKEN
-
-
-
LOOP1
DBGT
TRGSEL
BEGIN
0
0
DBGS
AF
BF
CF
0
0
ARMF
0
0
0
0
DBGCNT
TRG[3:0]
0
0
CNT[3:0]
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19.3.2
Register Descriptions
This section consists of the DBG register descriptions in address order.
NOTE
For all registers below, consider: U = Unchanged, bit maintain its value after
reset.
19.3.2.1
Debug Comparator A High Register (DBGCAH)
Module Base + 0x0000
7
6
5
4
3
2
1
0
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
POR
or nonend-run
1
1
1
1
1
1
1
1
Reset
end-run1
U
U
U
U
U
U
U
U
R
W
Figure 19-2. Debug Comparator A High Register (DBGCAH)
1
In the case of an end-trace to reset where DBGEN=1 and BEGIN=0, the bits in this register do not change after reset.
Table 19-3. DBGCAH Field Descriptions
Field
Description
Bits 15–8
Comparator A High Compare Bits — The Comparator A High compare bits control whether Comparator A will
compare the address bus bits [15:8] to a logic 1 or logic 0.
0 Compare corresponding address bit to a logic 0
1 Compare corresponding address bit to a logic 1
19.3.2.2
Debug Comparator A Low Register (DBGCAL)
Module Base + 0x0001
7
6
5
4
3
2
1
0
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
POR
or nonend-run
1
1
1
1
1
1
1
0
Reset
end-run1
U
U
U
U
U
U
U
U
R
W
Figure 19-3. Debug Comparator A Low Register (DBGCAL)
1
In the case of an end-trace to reset where DBGEN=1 and BEGIN=0, the bits in this register do not change after reset.
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Table 19-4. DBGCAL Field Descriptions
Field
Description
Bits 7–0
Comparator A Low Compare Bits — The Comparator A Low compare bits control whether Comparator A will
compare the address bus bits [7:0] to a logic 1 or logic 0.
0 Compare corresponding address bit to a logic 0
1 Compare corresponding address bit to a logic 1
19.3.2.3
Debug Comparator B High Register (DBGCBH)
Module Base + 0x0002
7
6
5
4
3
2
1
0
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
POR
or nonend-run
0
0
0
0
0
0
0
0
Reset
end-run1
U
U
U
U
U
U
U
U
R
W
Figure 19-4. Debug Comparator B High Register (DBGCBH)
1
In the case of an end-trace to reset where DBGEN=1 and BEGIN=0, the bits in this register do not change after reset.
Table 19-5. DBGCBH Field Descriptions
Field
Description
Bits 15–8
Comparator B High Compare Bits — The Comparator B High compare bits control whether Comparator B will
compare the address bus bits [15:8] to a logic 1 or logic 0. Not used in Full mode.
0 Compare corresponding address bit to a logic 0
1 Compare corresponding address bit to a logic 1
19.3.2.4
Debug Comparator B Low Register (DBGCBL)
Module Base + 0x0003
7
6
5
4
3
2
1
0
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
POR
or nonend-run
0
0
0
0
0
0
0
0
Reset
end-run1
U
U
U
U
U
U
U
U
R
W
Figure 19-5. Debug Comparator B Low Register (DBGCBL)
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1
In the case of an end-trace to reset where DBGEN=1 and BEGIN=0, the bits in this register do not change after reset.
Table 19-6. DBGCBL Field Descriptions
Field
Description
Bits 7–0
Comparator B Low Compare Bits — The Comparator B Low compare bits control whether Comparator B will
compare the address bus or data bus bits [7:0] to a logic 1 or logic 0.
0 Compare corresponding address bit to a logic 0, compares to data if in Full mode
1 Compare corresponding address bit to a logic 1, compares to data if in Full mode
19.3.2.5
Debug Comparator C High Register (DBGCCH)
Module Base + 0x0004
7
6
5
4
3
2
1
0
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
POR
or nonend-run
0
0
0
0
0
0
0
0
Reset
end-run1
U
U
U
U
U
U
U
U
R
W
Figure 19-6. Debug Comparator C High Register (DBGCCH)
1
In the case of an end-trace to reset where DBGEN=1 and BEGIN=0, the bits in this register do not change after reset.
Table 19-7. DBGCCH Field Descriptions
Field
Description
Bits 15–8
Comparator C High Compare Bits — The Comparator C High compare bits control whether Comparator C will
compare the address bus bits [15:8] to a logic 1 or logic 0.
0 Compare corresponding address bit to a logic 0
1 Compare corresponding address bit to a logic 1
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19.3.2.6
Debug Comparator C Low Register (DBGCCL)
Module Base + 0x0005
7
6
5
4
3
2
1
0
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
POR
or nonend-run
0
0
0
0
0
0
0
0
Reset
end-run1
U
U
U
U
U
U
U
U
R
W
Figure 19-7. Debug Comparator C Low Register (DBGCCL)
1
In the case of an end-trace to reset where DBGEN=1 and BEGIN=0, the bits in this register do not change after reset.
Table 19-8. DBGCCL Field Descriptions
Field
Description
Bits 7–0
Comparator C Low Compare Bits — The Comparator C Low compare bits control whether Comparator C will
compare the address bus bits [7:0] to a logic 1 or logic 0.
0 Compare corresponding address bit to a logic 0
1 Compare corresponding address bit to a logic 1
19.3.2.7
Debug FIFO High Register (DBGFH)
Module Base + 0x0006
7
6
5
4
3
2
1
0
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
POR
or nonend-run
0
0
0
0
0
0
0
0
Reset
end-run1
U
U
U
U
U
U
U
U
R
W
= Unimplemented or Reserved
Figure 19-8. Debug FIFO High Register (DBGFH)
1
In the case of an end-trace to reset where DBGEN=1 and BEGIN=0, the bits in this register do not change after reset.
Table 19-9. DBGFH Field Descriptions
Field
Description
Bits 15–8
FIFO High Data Bits — The FIFO High data bits provide access to bits [15:8] of data in the FIFO. This register
is not used in event only modes and will read a $00 for valid FIFO words.
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19.3.2.8
Debug FIFO Low Register (DBGFL)
Module Base + 0x0007
7
6
5
4
3
2
1
0
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
POR
or nonend-run
0
0
0
0
0
0
0
0
Reset
end-run1
U
U
U
U
U
U
U
U
R
W
= Unimplemented or Reserved
Figure 19-9. Debug FIFO Low Register (DBGFL)
1
In the case of an end-trace to reset where DBGEN=1 and BEGIN=0, the bits in this register do not change after reset.
Table 19-10. DBGFL Field Descriptions
Field
Description
Bits 7–0
FIFO Low Data Bits — The FIFO Low data bits contain the least significant byte of data in the FIFO. When
reading FIFO words, read DBGFX and DBGFH before reading DBGFL because reading DBGFL causes the
FIFO pointers to advance to the next FIFO location. In event-only modes, there is no useful information in DBGFX
and DBGFH so it is not necessary to read them before reading DBGFL.
19.3.2.9
Debug Comparator A Extension Register (DBGCAX)
Module Base + 0x0008
7
6
5
4
3
2
1
0
RWAEN
RWA
0
0
0
0
0
0
POR
or nonend-run
0
0
0
0
0
0
0
0
Reset
end-run1
U
U
U
0
0
0
0
U
R
W
= Unimplemented or Reserved
Figure 19-10. Debug Comparator A Extension Register (DBGCAX)
1
In the case of an end-trace to reset where DBGEN=1 and BEGIN=0, the bits in this register do not change after reset.
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Table 19-11. DBGCAX Field Descriptions
Field
Description
7
RWAEN
Read/Write Comparator A Enable Bit — The RWAEN bit controls whether read or write comparison is enabled
for Comparator A.
0 Read/Write is not used in comparison
1 Read/Write is used in comparison
6
RWA
Read/Write Comparator A Value Bit — The RWA bit controls whether read or write is used in compare for
Comparator A. The RWA bit is not used if RWAEN = 0.
0 Write cycle will be matched
1 Read cycle will be matched
19.3.2.10 Debug Comparator B Extension Register (DBGCBX)
Module Base + 0x0009
7
6
5
4
3
2
1
0
RWBEN
RWB
0
0
0
0
0
0
POR
or nonend-run
0
0
0
0
0
0
0
0
Reset
end-run1
U
U
U
0
0
0
0
U
R
W
= Unimplemented or Reserved
Figure 19-11. Debug Comparator B Extension Register (DBGCBX)
1
In the case of an end-trace to reset where DBGEN=1 and BEGIN=0, the bits in this register do not change after reset.
Table 19-12. DBGCBX Field Descriptions
Field
Description
7
RWBEN
Read/Write Comparator B Enable Bit — The RWBEN bit controls whether read or write comparison is enabled
for Comparator B. In full modes, RWAEN and RWA are used to control comparison of R/W and RWBEN is
ignored.
0 Read/Write is not used in comparison
1 Read/Write is used in comparison
6
RWB
Read/Write Comparator B Value Bit — The RWB bit controls whether read or write is used in compare for
Comparator B. The RWB bit is not used if RWBEN = 0. In full modes, RWAEN and RWA are used to control
comparison of R/W and RWB is ignored.
0 Write cycle will be matched
1 Read cycle will be matched
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19.3.2.11 Debug Comparator C Extension Register (DBGCCX)
Module Base + 0x000A
7
6
5
4
3
2
1
0
RWCEN
RWC
0
0
0
0
0
0
POR
or nonend-run
0
0
0
0
0
0
0
0
Reset
end-run1
U
U
U
0
0
0
0
U
R
W
= Unimplemented or Reserved
Figure 19-12. Debug Comparator C Extension Register (DBGCCX)
1
In the case of an end-trace to reset where DBGEN=1 and BEGIN=0, the bits in this register do not change after reset.
Table 19-13. DBGCCX Field Descriptions
Field
Description
7
RWCEN
Read/Write Comparator C Enable Bit — The RWCEN bit controls whether read or write comparison is enabled
for Comparator C.
0 Read/Write is not used in comparison
1 Read/Write is used in comparison
6
RWC
Read/Write Comparator C Value Bit — The RWC bit controls whether read or write is used in compare for
Comparator C. The RWC bit is not used if RWCEN = 0.
0 Write cycle will be matched
1 Read cycle will be matched
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19.3.2.12 Debug Control Register (DBGC)
Module Base + 0x000C
7
6
5
4
DBGEN
ARM
TAG
BRKEN
POR
or nonend-run
1
1
0
0
0
0
0
0
Reset
end-run1
U
0
U
0
0
0
0
U
R
3
2
1
0
0
0
0
LOOP1
W
= Unimplemented or Reserved
Figure 19-13. Debug Control Register (DBGC)
1
In the case of an end-trace to reset where DBGEN=1 and BEGIN=0, the ARM and BRKEN bits are cleared but the remaining
control bits in this register do not change after reset.
Table 19-14. DBGC Field Descriptions
Field
7
DBGEN
Description
DBG Module Enable Bit — The DBGEN bit enables the DBG module. The DBGEN bit is forced to zero and
cannot be set if the MCU is secure.
0 DBG not enabled
1 DBG enabled
6
ARM
Arm Bit — The ARM bit controls whether the debugger is comparing and storing data in FIFO. See
Section 19.4.4.2, “Arming the DBG Module,” for more information.
0 Debugger not armed
1 Debugger armed
5
TAG
Tag or Force Bit — The TAG bit controls whether a debugger or comparator C breakpoint will be requested as
a tag or force breakpoint to the CPU. The TAG bit is not used if BRKEN = 0.
0 Force request selected
1 Tag request selected
4
BRKEN
Break Enable Bit — The BRKEN bit controls whether the debugger will request a breakpoint to the CPU at the
end of a trace run, and whether comparator C will request a breakpoint to the CPU.
0 CPU break request not enabled
1 CPU break request enabled
0
LOOP1
Select LOOP1 Capture Mode — This bit selects either normal capture mode or LOOP1 capture mode. LOOP1
is not used in event-only modes.
0 Normal operation - capture COF events into the capture buffer FIFO
1 LOOP1 capture mode enabled. When the conditions are met to store a COF value into the FIFO, compare the
current COF address with the address in comparator C. If these addresses match, override the FIFO capture
and do not increment the FIFO count. If the address does not match comparator C, capture the COF address,
including the PPACC indicator, into the FIFO and into comparator C.
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19.3.2.13 Debug Trigger Register (DBGT)
Module Base + 0x000D
7
6
TRGSEL
BEGIN
POR
or nonend-run
0
1
0
0
0
Reset
end-run1
U
U
0
0
U
R
W
2
5
4
0
0
3
2
1
0
0
0
0
U
U
U
TRG
= Unimplemented or Reserved
Figure 19-14. Debug Trigger Register (DBGT)
1
2
In the case of an end-trace to reset where DBGEN=1 and BEGIN=0, the control bits in this register do not change after reset.
The DBG trigger register (DBGT) can not be changed unless ARM=0.
Table 19-15. DBGT Field Descriptions
Field
7
TRGSEL
6
BEGIN
3–0
TRG
Description
Trigger Selection Bit — The TRGSEL bit controls the triggering condition for the comparators. See
Section 19.4.4, “Trigger Break Control (TBC),” for more information.
0 Trigger on any compare address access
1 Trigger if opcode at compare address is executed
Begin/End Trigger Bit — The BEGIN bit controls whether the trigger begins or ends storing of data in FIFO.
0 Trigger at end of stored data
1 Trigger before storing data
Trigger Mode Bits — The TRG bits select the trigger mode of the DBG module as shown in Table 19-16.
Table 19-16. Trigger Mode Encoding
TRG Value
Meaning
0000
A Only
0001
A Or B
0010
A Then B
0011
Event Only B
0100
A Then Event Only B
0101
A And B (Full Mode)
0110
A And Not B (Full mode)
0111
Inside Range
1000
Outside Range
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Table 19-16. Trigger Mode Encoding
TRG Value
Meaning
1001
↓
1111
No Trigger
NOTE
The DBG trigger register (DBGT) can not be changed unless ARM=0.
19.3.2.14 Debug Status Register (DBGS)
Module Base + 0x000E
7
6
5
4
3
2
1
0
AF
BF
CF
0
0
0
0
ARMF
POR
or nonend-run
0
0
0
0
0
0
0
1
Reset
end-run1
U
U
U
0
0
0
0
0
R
W
= Unimplemented or Reserved
Figure 19-15. Debug Status Register (DBGS)
1
In the case of an end-trace to reset where DBGEN=1 and BEGIN=0, ARMF gets cleared by reset but AF, BF, and CF do not
change after reset.
Table 19-17. DBGS Field Descriptions
Field
Description
7
AF
Trigger A Match Bit — The AF bit indicates if Trigger A match condition was met since arming.
0 Comparator A did not match
1 Comparator A match
6
BF
Trigger B Match Bit — The BF bit indicates if Trigger B match condition was met since arming.
0 Comparator B did not match
1 Comparator B match
5
CF
Trigger C Match Bit — The CF bit indicates if Trigger C match condition was met since arming.
0 Comparator C did not match
1 Comparator C match
0
ARMF
Arm Flag Bit — The ARMF bit indicates whether the debugger is waiting for trigger or waiting for the FIFO to fill.
While DBGEN = 1, this status bit is a read-only image of the ARM bit in DBGC. See Section 19.4.4.2, “Arming
the DBG Module,” for more information.
0 Debugger not armed
1 Debugger armed
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19.3.2.15 Debug Count Status Register (DBGCNT)
Module Base + 0x000F
7
6
5
4
0
0
0
0
POR
or nonend-run
0
0
0
0
0
Reset
end-run1
0
0
0
0
U
R
3
2
1
0
0
0
0
U
U
U
CNT
W
= Unimplemented or Reserved
Figure 19-16. Debug Count Status Register (DBGCNT)
1
In the case of an end-trace to reset where DBGEN=1 and BEGIN=0, the CNT[3:0] bits do not change after reset.
Table 19-18. DBGS Field Descriptions
Field
Description
3–0
CNT
FIFO Valid Count Bits — The CNT bits indicate the amount of valid data stored in the FIFO. Table 19-16 shows
the correlation between the CNT bits and the amount of valid data in FIFO. The CNT will stop after a count to
eight even if more data is being stored in the FIFO. The CNT bits are cleared when the DBG module is armed,
and the count is incremented each time a new word is captured into the FIFO. The host development system is
responsible for checking the value in CNT[3:0] and reading the correct number of words from the FIFO because
the count does not decrement as data is read out of the FIFO at the end of a trace run.
Table 19-19. CNT Bits
CNT Value
Meaning
0000
No data valid
0001
1 word valid
0010
2 words valid
0011
3 words valid
0100
4 words valid
0101
5 words valid
0110
6 words valid
0111
7 words valid
1000
8 words valid
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19.4
Functional Description
This section provides a complete functional description of the on-chip ICE system. The DBG module is
enabled by setting the DBGEN bit in the DBGC register. Enabling the module allows the arming,
triggering and storing of data in the FIFO. The DBG module is made up of three main blocks, the
Comparators, Trigger Break Control logic and the FIFO.
19.4.1
Comparator
The DBG module contains three comparators, A, B, and C. Comparator A compares the core address bus
with the address stored in the DBGCAH and DBGCAL registers. Comparator B compares the core address
bus with the address stored in the DBGCBH and DBGCBL registers except in full mode, where it
compares the data buses to the data stored in the DBGCBL register. Comparator C compares the core
address bus with the address stored in the DBGCCH and DBGCCL registers. Matches on Comparators A,
B, and C are signaled to the Trigger Break Control (TBC) block.
19.4.1.1
RWA and RWAEN in Full Modes
In full modes ("A And B" and "A And Not B") RWAEN and RWA are used to select read or write
comparisons for both comparators A and B. To select write comparisons and the write data bus in Full
Modes set RWAEN=1 and RWA=0, otherwise read comparisons and the read data bus will be selected.
The RWBEN and RWB bits are not used and will be ignored in Full Modes.
19.4.1.2
Comparator C in LOOP1 Capture Mode
Normally comparator C is used as a third hardware breakpoint and is not involved in the trigger logic for
the on-chip ICE system. In this mode, it compares the core address bus with the address stored in the
DBGCCH and DBGCCL registers. However, in LOOP1 capture mode, comparator C is managed by logic
in the DBG module to track the address of the most recent change-of-flow event that was captured into the
FIFO buffer. In LOOP1 capture mode, comparator C is not available for use as a normal hardware
breakpoint.
When the ARM and DBGEN bits are set to one in LOOP1 capture mode, comparator C value registers are
cleared to prevent the previous contents of these registers from interfering with the LOOP1 capture mode
operation. When a COF event is detected, the address of the event is compared to the contents of the
DBGCCH and DBGCCL registers to determine whether it is the same as the previous COF entry in the
capture FIFO. If the values match, the capture is inhibited to prevent the FIFO from filling up with
duplicate entries. If the values do not match, the COF event is captured into the FIFO and the DBGCCH
and DBGCCL registers are updated to reflect the address of the captured COF event.
19.4.2
Breakpoints
A breakpoint request to the CPU at the end of a trace run can be created if the BRKEN bit in the DBGC
register is set. The value of the BEGIN bit in DBGT register determines when the breakpoint request to
the CPU will occur. If the BEGIN bit is set, begin-trigger is selected and the breakpoint request will not
occur until the FIFO is filled with 8 words. If the BEGIN bit is cleared, end-trigger is selected and the
breakpoint request will occur immediately at the trigger cycle.
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When traditional hardware breakpoints from comparators A or B are desired, set BEGIN=0 to select an
end-trace run and set the trigger mode to either 0x0 (A-only) or 0x1 (A OR B) mode.
There are two types of breakpoint requests supported by the DBG module, tag-type and force-type. Tagged
breakpoints are associated with opcode addresses and allow breaking just before a specific instruction
executes. Force breakpoints are not associated with opcode addresses and allow breaking at the next
instruction boundary. The TAG bit in the DBGC register determines whether CPU breakpoint requests will
be a tag-type or force-type breakpoints. When TAG=0, a force-type breakpoint is requested and it will take
effect at the next instruction boundary after the request. When TAG=1, a tag-type breakpoint is registered
into the instruction queue and the CPU will break if/when this tag reaches the head of the instruction queue
and the tagged instruction is about to be executed.
19.4.2.1
Hardware Breakpoints
Comparators A, B, and C can be used as three traditional hardware breakpoints whether the on-chip ICE
real-time capture function is required or not. To use any breakpoint or trace run capture functions set
DBGEN=1. BRKEN and TAG affect all three comparators. When BRKEN=0, no CPU breakpoints are
enabled. When BRKEN=1, CPU breakpoints are enabled and the TAG bit determines whether the
breakpoints will be tag-type or force-type breakpoints. To use comparators A and B as hardware
breakpoints, set DBGT=0x81 for tag-type breakpoints and 0x01 for force-type breakpoints. This sets up
an end-type trace with trigger mode “A OR B”.
Comparator C is not involved in the trigger logic for the on-chip ICE system.
19.4.3
Trigger Selection
The TRGSEL bit in the DBGT register is used to determine the triggering condition of the on-chip ICE
system. TRGSEL applies to both trigger A and B except in the event only trigger modes. By setting the
TRGSEL bit, the comparators will qualify a match with the output of opcode tracking logic. The opcode
tracking logic is internal to each comparator and determines whether the CPU executed the opcode at the
compare address. With the TRGSEL bit cleared a comparator match is all that is necessary for a trigger
condition to be met.
NOTE
If the TRGSEL is set, the address stored in the comparator match address
registers must be an opcode address for the trigger to occur.
19.4.4
Trigger Break Control (TBC)
The TBC is the main controller for the DBG module. Its function is to decide whether data should be stored
in the FIFO based on the trigger mode and the match signals from the comparator. The TBC also
determines whether a request to break the CPU should occur.
The TAG bit in DBGC controls whether CPU breakpoints are treated as tag-type or force-type breakpoints.
The TRGSEL bit in DBGT controls whether a comparator A or B match is further qualified by opcode
tracking logic. Each comparator has a separate circuit to track opcodes because the comparators could
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correspond to separate instructions that could be propagating through the instruction queue at the same
time.
In end-type trace runs (BEGIN=0), when the comparator registers match, including the optional R/W
match, this signal goes to the CPU break logic where BRKEN determines whether a CPU break is
requested and the TAG control bit determines whether the CPU break will be a tag-type or force-type
breakpoint. When TRGSEL is set, the R/W qualified comparator match signal also passes through the
opcode tracking logic. If/when it propagates through this logic, it will cause a trigger to the ICE logic to
begin or end capturing information into the FIFO. In the case of an end-type (BEGIN=0) trace run, the
qualified comparator signal stops the FIFO from capturing any more information.
If a CPU breakpoint is also enabled, you would want TAG and TRGSEL to agree so that the CPU break
occurs at the same place in the application program as the FIFO stopped capturing information. If
TRGSEL was 0 and TAG was 1 in an end-type trace run, the FIFO would stop capturing as soon as the
comparator address matched, but the CPU would continue running until a TAG signal could propagate
through the CPUs instruction queue which could take a long time in the case where changes of flow caused
the instruction queue to be flushed. If TRGSEL was one and TAG was zero in an end-type trace run, the
CPU would break before the comparator match signal could propagate through the opcode tracking logic
to end the trace run.
In begin-type trace runs (BEGIN=1), the start of FIFO capturing is triggered by the qualified comparator
signals, and the CPU breakpoint (if enabled by BRKEN=1) is triggered when the FIFO becomes full. Since
this FIFO full condition does not correspond to the execution of a tagged instruction, it would not make
sense to use TAG=1 for a begin-type trace run.
19.4.4.1
Begin- and End-Trigger
The definition of begin- and end-trigger as used in the DBG module are as follows:
• Begin-trigger: Storage in FIFO occurs after the trigger and continues until 8 locations are filled.
• End-trigger: Storage in FIFO occurs until the trigger with the least recent data falling out of the
FIFO if more than 8 words are collected.
19.4.4.2
Arming the DBG Module
Arming occurs by enabling the DBG module by setting the DBGEN bit and by setting the ARM bit in the
DBGC register. The ARM bit in the DBGC register and the ARMF bit in the DBGS register are cleared
when the trigger condition is met in end-trigger mode or when the FIFO is filled in begin-trigger mode. In
the case of an end-trace where DBGEN=1 and BEGIN=0, ARM and ARMF are cleared by any reset to
end the trace run that was in progress. The ARMF bit is also cleared if ARM is written to zero or when the
DBGEN bit is low. The TBC logic determines whether a trigger condition has been met based on the
trigger mode and the trigger selection.
19.4.4.3
Trigger Modes
The on-chip ICE system supports nine trigger modes. The trigger modes are encoded as shown in
Table 19-16. The trigger mode is used as a qualifier for either starting or ending the storing of data in the
FIFO. When the match condition is met, the appropriate flag AF or BF is set in DBGS register. Arming
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the DBG module clears the AF, BF, and CF flags in the DBGS register. In all trigger modes except for the
event only modes change of flow addresses are stored in the FIFO. In the event only modes only the value
on the data bus at the trigger event B comparator match address will be stored.
19.4.4.3.1
A Only
In the A Only trigger mode, if the match condition for A is met, the AF flag in the DBGS register is set.
19.4.4.3.2
A Or B
In the A Or B trigger mode, if the match condition for A or B is met, the corresponding flag(s) in the DBGS
register are set.
19.4.4.3.3
A Then B
In the A Then B trigger mode, the match condition for A must be met before the match condition for B is
compared. When the match condition for A or B is met, the corresponding flag in the DBGS register is set.
19.4.4.3.4
Event Only B
In the Event Only B trigger mode, if the match condition for B is met, the BF flag in the DBGS register is
set. The Event Only B trigger mode is considered a begin-trigger type and the BEGIN bit in the DBGT
register is ignored.
19.4.4.3.5
A Then Event Only B
In the A Then Event Only B trigger mode, the match condition for A must be met before the match
condition for B is compared. When the match condition for A or B is met, the corresponding flag in the
DBGS register is set. The A Then Event Only B trigger mode is considered a begin-trigger type and the
BEGIN bit in the DBGT register is ignored.
19.4.4.3.6
A And B (Full Mode)
In the A And B trigger mode, Comparator A compares to the address bus and Comparator B compares to
the data bus. In the A and B trigger mode, if the match condition for A and B happen on the same bus cycle,
both the AF and BF flags in the DBGS register are set. If a match condition on only A or only B happens,
no flags are set.
For Breakpoint tagging operation with an end-trigger type trace, only matches from Comparator A will be
used to determine if the Breakpoint conditions are met and Comparator B matches will be ignored.
19.4.4.3.7
A And Not B (Full Mode)
In the A And Not B trigger mode, comparator A compares to the address bus and comparator B compares
to the data bus. In the A And Not B trigger mode, if the match condition for A and Not B happen on the
same bus cycle, both the AF and BF flags in the DBGS register are set. If a match condition on only A or
only Not B occur no flags are set.
For Breakpoint tagging operation with an end-trigger type trace, only matches from Comparator A will be
used to determine if the Breakpoint conditions are met and Comparator B matches will be ignored.
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19.4.4.3.8
Inside Range, A ≤ address ≤ B
In the Inside Range trigger mode, if the match condition for A and B happen on the same bus cycle, both
the AF and BF flags in the DBGS register are set. If a match condition on only A or only B occur no flags
are set.
19.4.4.3.9
Outside Range, address < A or address > B
In the Outside Range trigger mode, if the match condition for A or B is met, the corresponding flag in the
DBGS register is set.
The four control bits BEGIN and TRGSEL in DBGT, and BRKEN and TAG in DBGC, determine the basic
type of debug run as shown in Table 1.21. Some of the 16 possible combinations are not used (refer to the
notes at the end of the table).
Table 19-20. Basic Types of Debug Runs
BEGIN
1
TRGSEL
BRKEN
TAG
Type of Debug Run
(1)
Fill FIFO until trigger address (No CPU breakpoint - keep
running)
0
0
0
x
0
0
1
0
Fill FIFO until trigger address, then force CPU breakpoint
0
0
1
1
Do not use(2)
0
1
0
(1)
x
0
1
1
0
0
1
1
1
Fill FIFO until trigger opcode about to execute (trigger causes
CPU breakpoint)
1
0
0
(1)
Start FIFO at trigger address (No CPU breakpoint - keep
running)
1
0
1
0
Start FIFO at trigger address, force CPU breakpoint when
FIFO full
1
0
1
1
1
1
0
1
1
1
1
x
Fill FIFO until trigger opcode about to execute (No CPU
breakpoint - keep running)
Do not use(3)
Do not use(4)
(1)
Start FIFO at trigger opcode (No CPU breakpoint - keep
running)
1
0
Start FIFO at trigger opcode, force CPU breakpoint when FIFO
full
1
1
x
Do not use(4)
When BRKEN = 0, TAG is do not care (x in the table).
2
In end trace configurations (BEGIN = 0) where a CPU breakpoint is enabled (BRKEN = 1), TRGSEL should agree with TAG. In this case, where
TRGSEL = 0 to select no opcode tracking qualification and TAG = 1 to specify a tag-type CPU breakpoint, the CPU breakpoint would not take
effect until sometime after the FIFO stopped storing values. Depending on program loops or interrupts, the delay could be very long.
3
In end trace configurations (BEGIN = 0) where a CPU breakpoint is enabled (BRKEN = 1), TRGSEL should agree with TAG. In this case, where
TRGSEL = 1 to select opcode tracking qualification and TAG = 0 to specify a force-type CPU breakpoint, the CPU breakpoint would erroneously
take effect before the FIFO stopped storing values and the debug run would not complete normally.
4 In begin trace configurations (BEGIN = 1) where a CPU breakpoint is enabled (BRKEN = 1), TAG should not be set to 1. In begin trace debug
runs, the CPU breakpoint corresponds to the FIFO full condition which does not correspond to a taggable instruction fetch.
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19.4.5
FIFO
The FIFO is an eight word deep FIFO. In all trigger modes except for event only, the data stored in the
FIFO will be change of flow addresses. In the event only trigger modes only the data bus value
corresponding to the event is stored. In event only trigger modes, the high byte of the valid data from the
FIFO will always read a 0x00.
19.4.5.1
Storing Data in FIFO
In all trigger modes except for the event only modes, the address stored in the FIFO will be determined by
the change of flow indicators from the core. The signal core_cof[1] indicates the current core address is
the destination address of an indirect JSR or JMP instruction, or a RTS or RTI instruction or interrupt
vector and the destination address should be stored. The signal core_cof[0] indicates that a conditional
branch was taken and that the source address of the conditional branch should be stored.
19.4.5.2
Storing with Begin-Trigger
Storing with Begin-Trigger can be used in all trigger modes. Once the DBG module is enabled and armed
in the begin-trigger mode, data is not stored in the FIFO until the trigger condition is met. Once the trigger
condition is met the DBG module will remain armed until 8 words are stored in the FIFO. If the
core_cof[1] signal becomes asserted, the current address is stored in the FIFO. If the core_cof[0] signal
becomes asserted, the address registered during the previous last cycle is decremented by two and stored
in the FIFO.
19.4.5.3
Storing with End-Trigger
Storing with End-Trigger cannot be used in event-only trigger modes. Once the DBG module is enabled
and armed in the end-trigger mode, data is stored in the FIFO until the trigger condition is met. If the
core_cof[1] signal becomes asserted, the current address is stored in the FIFO. If the core_cof[0] signal
becomes asserted, the address registered during the previous last cycle is decremented by two and stored
in the FIFO. When the trigger condition is met, the ARM and ARMF will be cleared and no more data will
be stored. In non-event only end-trigger modes, if the trigger is at a change of flow address the trigger event
will be stored in the FIFO.
19.4.5.4
Reading Data from FIFO
The data stored in the FIFO can be read using BDM commands provided the DBG module is enabled and
not armed (DBGEN=1 and ARM=0). The FIFO data is read out first-in-first-out. By reading the CNT bits
in the DBGCNT register at the end of a trace run, the number of valid words can be determined. The FIFO
data is read by optionally reading the DBGFH register followed by the DBGFL register. Each time the
DBGFL register is read the FIFO is shifted to allow reading of the next word however the count does not
decrement. In event-only trigger modes where the FIFO will contain only the data bus values stored, to
read the FIFO only DBGFL needs to be accessed.
The FIFO is normally only read while ARM and ARMF=0, however reading the FIFO while the DBG
module is armed will return the data value in the oldest location of the FIFO and the TBC will not allow
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the FIFO to shift. This action could cause a valid entry to be lost because the unexpected read blocked the
FIFO advance.
If the DBG module is not armed and the DBGFL register is read, the TBC will store the current opcode
address. Through periodic reads of the DBGFH and DBGFL registers while the DBG module is not armed,
host software can provide a histogram of program execution. This is called profile mode.
19.4.6
Interrupt Priority
When TRGSEL is set and the DBG module is armed to trigger on begin- or end-trigger types, a trigger is
not detected in the condition where a pending interrupt occurs at the same time that a target address reaches
the top of the instruction pipe. In these conditions, the pending interrupt has higher priority and code
execution switches to the interrupt service routine.
When TRGSEL is clear and the DBG module is armed to trigger on end-trigger types, the trigger event is
detected on a program fetch of the target address, even when an interrupt becomes pending on the same
cycle. In these conditions, the pending interrupt has higher priority, the exception is processed by the core
and the interrupt vector is fetched. Code execution is halted before the first instruction of the interrupt
service routine is executed. In this scenario, the DBG module will have cleared ARM without having
recorded the change-of-flow that occurred as part of the interrupt exception. Note that the stack will hold
the return addresses and can be used to reconstruct execution flow in this scenario.
When TRGSEL is clear and the DBG module is armed to trigger on begin-trigger types, the trigger event
is detected on a program fetch of the target address, even when an interrupt becomes pending on the same
cycle. In this scenario, the FIFO captures the change of flow event. Because the system is configured for
begin-trigger, the DBG remains armed and does not break until the FIFO has been filled by subsequent
change of flow events.
19.5
Resets
The DBG module cannot cause an MCU reset.
There are two different ways this module will respond to reset depending upon the conditions before the
reset event. If the DBG module was setup for an end trace run with DBGEN=1 and BEGIN=0, ARM,
ARMF, and BRKEN are cleared but the reset function on most DBG control and status bits is overridden
so a host development system can read out the results of the trace run after the MCU has been reset. In all
other cases including POR, the DBG module controls are initialized to start a begin trace run starting from
when the reset vector is fetched. The conditions for the default begin trace run are:
• DBGCAH=0xFF, DBGCAL=0xFE so comparator A is set to match when the 16-bit CPU address
0xFFFE appears during the reset vector fetch
• DBGC=0xC0 to enable and arm the DBG module
• DBGT=0x40 to select a force-type trigger, a BEGIN trigger, and A-only trigger mode
19.6
Interrupts
The DBG contains no interrupt source.
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