MC9S08RD8FJ [MOTOROLA]

Microcontrollers; 微控制器
MC9S08RD8FJ
型号: MC9S08RD8FJ
厂家: MOTOROLA    MOTOROLA
描述:

Microcontrollers
微控制器

微控制器和处理器 外围集成电路 时钟
文件: 总232页 (文件大小:1048K)
中文:  中文翻译
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MC9S08RC8/16/32/60  
MC9S08RD8/16/32/60  
MC9S08RE8/16/32/60  
MC9S08RG32/60  
Data Sheet  
HCS08  
Microcontrollers  
MC9S08RG60/D  
Rev 1.10  
08/2004  
freescale.com  
MC9S08RG60 Data Sheet  
Covers: MC9S08RC8/16/32/60  
MC9S08RD8/16/32/60  
MC9S08RE8/16/32/60  
MC9S08RG32/60  
MC9S08RG60/D  
Rev 1.10  
08/2004  
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://freescale.com  
The following revision history table summarizes changes contained in this document.  
Version  
Number  
Revision  
Date  
Description of Changes  
1.07  
1.08  
2/4/2004  
Initial external release.  
4/22/2004  
Changes to Table C-6 in electricals section.  
Added Table C-4; changes to Table C-6; changed to Freescale  
format  
1.09  
7/7/2004  
Removed BRK bit 13 and TXINV, which are not available on this  
module version; fixed typo in Figure 13-2; corrected the SPTEF  
description in section 12.3  
1.10  
8/11/2004  
This product contains SuperFlash® technology licensed from SST.  
Freescale™ and the Freescale logo are trademarks of Freescale Semiconductor, Inc.  
© Freescale Semiconductor, Inc., 2004. All rights reserved.  
SoC Guide — MC9S08RG60/D Rev 1.10  
List of Chapters  
Chapter 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15  
Chapter 2 Pins and Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19  
Chapter 3 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29  
Chapter 4 Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35  
Chapter 5 Resets, Interrupts, and System Configuration . . . . . . . . . . . . . . .57  
Chapter 6 Central Processor Unit (CPU). . . . . . . . . . . . . . . . . . . . . . . . . . . . .73  
Chapter 7 Carrier Modulator Timer (CMT) Module . . . . . . . . . . . . . . . . . . . . .93  
Chapter 8 Parallel Input/Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .111  
Chapter 9 Keyboard Interrupt (KBI) Module . . . . . . . . . . . . . . . . . . . . . . . . .121  
Chapter 10 Timer/PWM Module (TPM) Module . . . . . . . . . . . . . . . . . . . . . . .127  
Chapter 11 Serial Communications Interface (SCI) Module . . . . . . . . . . . .143  
Chapter 12 Serial Peripheral Interface (SPI) Module . . . . . . . . . . . . . . . . . .161  
Chapter 13 Analog Comparator (ACMP) Module . . . . . . . . . . . . . . . . . . . . .177  
Chapter 14 Development Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .183  
Appendix C Electrical Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .207  
Appendix D Ordering Information and Mechanical Drawings . . . . . . . . . .223  
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MC9S08RC/RD/RE/RG  
5
List of Chapters  
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6
MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
Contents  
Chapter 1 Introduction  
1.1  
Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15  
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15  
Standard Features of the HCS08 Family . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15  
Features of MC9S08RC/RD/RE/RG Series of MCUs . . . . . . . . . . . . . . . . . . . . . 15  
Devices in the MC9S08RC/RD/RE/RG Series. . . . . . . . . . . . . . . . . . . . . . . . . . . 16  
MCU Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17  
System Clock Distribution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18  
1.2  
1.2.1  
1.2.2  
1.2.3  
1.3  
1.4  
Chapter 2 Pins and Connections  
2.1  
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19  
Device Pin Assignment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19  
Recommended System Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21  
Power. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23  
Oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23  
PTD1/RESET. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23  
Background/Mode Select (PTD0/BKGD/MS). . . . . . . . . . . . . . . . . . . . . . . . . . . . 24  
IRO Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24  
General-Purpose I/O and Peripheral Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24  
Signal Properties Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26  
2.2  
2.3  
2.3.1  
2.3.2  
2.3.3  
2.3.4  
2.3.5  
2.3.6  
2.3.7  
Chapter 3 Modes of Operation  
3.1  
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29  
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29  
Run Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29  
Active Background Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29  
Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30  
Stop Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31  
Stop1 Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31  
Stop2 Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31  
Stop3 Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32  
Active BDM Enabled in Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33  
LVD Reset Enabled in Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33  
On-Chip Peripheral Modules in Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33  
3.2  
3.3  
3.4  
3.5  
3.6  
3.6.1  
3.6.2  
3.6.3  
3.6.4  
3.6.5  
3.6.6  
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Contents  
Chapter 4 Memory  
4.1  
MC9S08RC/RD/RE/RG Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35  
4.1.1  
4.2  
Reset and Interrupt Vector Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36  
Register Addresses and Bit Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37  
RAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41  
FLASH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42  
Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42  
Program and Erase Times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42  
Program and Erase Command Execution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43  
Burst Program Execution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45  
Access Errors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47  
FLASH Block Protection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47  
Vector Redirection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48  
Security. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48  
FLASH Registers and Control Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49  
FLASH Clock Divider Register (FCDIV). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50  
FLASH Options Register (FOPT and NVOPT) . . . . . . . . . . . . . . . . . . . . . . . . . . 51  
FLASH Configuration Register (FCNFG). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52  
FLASH Protection Register (FPROT and NVPROT) . . . . . . . . . . . . . . . . . . . . . . 52  
FLASH Status Register (FSTAT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54  
FLASH Command Register (FCMD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55  
4.3  
4.4  
4.4.1  
4.4.2  
4.4.3  
4.4.4  
4.4.5  
4.4.6  
4.4.7  
4.5  
4.6  
4.6.1  
4.6.2  
4.6.3  
4.6.4  
4.6.5  
4.6.6  
Chapter 5 Resets, Interrupts, and System Configuration  
5.1  
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57  
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57  
MCU Reset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58  
Computer Operating Properly (COP) Watchdog . . . . . . . . . . . . . . . . . . . . . . . . . . . 58  
Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59  
Interrupt Stack Frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60  
External Interrupt Request (IRQ) Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61  
Interrupt Vectors, Sources, and Local Masks . . . . . . . . . . . . . . . . . . . . . . . . . . . 61  
Low-Voltage Detect (LVD) System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62  
Power-On Reset Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63  
LVD Reset Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63  
LVD Interrupt and Safe State Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63  
Low-Voltage Warning (LVW) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63  
5.2  
5.3  
5.4  
5.5  
5.5.1  
5.5.2  
5.5.3  
5.6  
5.6.1  
5.6.2  
5.6.3  
5.6.4  
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SoC Guide — MC9S08RG60/D Rev 1.10  
5.7  
Real-Time Interrupt (RTI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64  
Reset, Interrupt, and System Control Registers and Control Bits . . . . . . . . . . . . . . 64  
Interrupt Pin Request Status and Control Register (IRQSC) . . . . . . . . . . . . . . . . 64  
System Reset Status Register (SRS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65  
System Background Debug Force Reset Register (SBDFR). . . . . . . . . . . . . . . . 67  
System Options Register (SOPT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67  
System Device Identification Register (SDIDH, SDIDL) . . . . . . . . . . . . . . . . . . . 69  
System Real-Time Interrupt Status and Control Register (SRTISC) . . . . . . . . . . 69  
System Power Management Status and Control 1 Register (SPMSC1) . . . . . . . 71  
System Power Management Status and Control 2 Register (SPMSC2) . . . . . . . 72  
5.8  
5.8.1  
5.8.2  
5.8.3  
5.8.4  
5.8.5  
5.8.6  
5.8.7  
5.8.8  
Chapter 6 Central Processor Unit (CPU)  
6.1  
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73  
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74  
Programmer’s Model and CPU Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74  
Accumulator (A) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75  
Index Register (H:X). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75  
Stack Pointer (SP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76  
Program Counter (PC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76  
Condition Code Register (CCR). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76  
Addressing Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78  
Inherent Addressing Mode (INH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78  
Relative Addressing Mode (REL). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78  
Immediate Addressing Mode (IMM). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78  
Direct Addressing Mode (DIR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78  
Extended Addressing Mode (EXT). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79  
Indexed Addressing Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79  
Special Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80  
Reset Sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80  
Interrupt Sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80  
Wait Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81  
Stop Mode Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81  
BGND Instruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82  
HCS08 Instruction Set Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82  
6.2  
6.3  
6.3.1  
6.3.2  
6.3.3  
6.3.4  
6.3.5  
6.4  
6.4.1  
6.4.2  
6.4.3  
6.4.4  
6.4.5  
6.4.6  
6.5  
6.5.1  
6.5.2  
6.5.3  
6.5.4  
6.5.5  
6.6  
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Contents  
Chapter 7 Carrier Modulator Timer (CMT) Module  
7.1  
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93  
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94  
CMT Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94  
Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95  
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95  
Carrier Generator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96  
Modulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98  
Extended Space Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101  
Transmitter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102  
CMT Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103  
Wait Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103  
Stop Mode Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103  
Background Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104  
CMT Registers and Control Bits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104  
CarrierGeneratorDataRegisters(CMTCGH1, CMTCGL1, CMTCGH2, andCMTCGL2)  
7.2  
7.3  
7.4  
7.5  
7.5.1  
7.5.2  
7.5.3  
7.5.4  
7.5.5  
7.5.6  
7.5.7  
7.5.8  
7.6  
7.6.1  
104  
7.6.2  
7.6.3  
CMT Output Control Register (CMTOC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106  
CMT Modulator Status and Control Register (CMTMSC) . . . . . . . . . . . . . . . . . 107  
CMT Modulator Data Registers (CMTCMD1, CMTCMD2, CMTCMD3, and CMTCMD4)  
7.6.4  
109  
Chapter 8 Parallel Input/Output  
8.1  
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111  
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111  
Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111  
Port A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112  
Port B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112  
Port C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113  
Port D. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113  
Port E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114  
Parallel I/O Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114  
Data Direction Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114  
Internal Pullup Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115  
Stop Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115  
Parallel I/O Registers and Control Bits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115  
8.2  
8.3  
8.3.1  
8.3.2  
8.3.3  
8.3.4  
8.3.5  
8.4  
8.4.1  
8.4.2  
8.5  
8.6  
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8.6.1  
8.6.2  
8.6.3  
8.6.4  
8.6.5  
Port A Registers (PTAD, PTAPE, and PTADD). . . . . . . . . . . . . . . . . . . . . . . . . 115  
Port B Registers (PTBD, PTBPE, and PTBDD). . . . . . . . . . . . . . . . . . . . . . . . . 117  
Port C Registers (PTCD, PTCPE, and PTCDD) . . . . . . . . . . . . . . . . . . . . . . . . 118  
Port D Registers (PTDD, PTDPE, and PTDDD) . . . . . . . . . . . . . . . . . . . . . . . . 119  
Port E Registers (PTED, PTEPE, and PTEDD). . . . . . . . . . . . . . . . . . . . . . . . . 120  
Chapter 9 Keyboard Interrupt (KBI) Module  
9.1  
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121  
KBI Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123  
Keyboard Interrupt (KBI) Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123  
Pin Enables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123  
Edge and Level Sensitivity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123  
KBI Interrupt Controls. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124  
KBI Registers and Control Bits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124  
KBI x Status and Control Register (KBIxSC) . . . . . . . . . . . . . . . . . . . . . . . . . . . 124  
KBI x Pin Enable Register (KBIxPE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126  
9.2  
9.3  
9.3.1  
9.3.2  
9.3.3  
9.4  
9.4.1  
9.4.2  
Chapter 10 Timer/PWM Module (TPM) Module  
10.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127  
10.2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127  
10.3 TPM Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129  
10.4 Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130  
10.4.1 External TPM Clock Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130  
10.4.2 TPM1CHn — TPM1 Channel n I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130  
10.5 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130  
10.5.1 Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131  
10.5.2 Channel Mode Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132  
10.5.3 Center-Aligned PWM Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133  
10.6 TPM Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135  
10.6.1 Clearing Timer Interrupt Flags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135  
10.6.2 Timer Overflow Interrupt Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135  
10.6.3 Channel Event Interrupt Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135  
10.6.4 PWM End-of-Duty-Cycle Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136  
10.7 TPM Registers and Control Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136  
10.7.1 Timer x Status and Control Register (TPM1SC) . . . . . . . . . . . . . . . . . . . . . . . . 136  
10.7.2 Timer x Counter Registers (TPM1CNTH:TPM1CNTL) . . . . . . . . . . . . . . . . . . . 138  
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10.7.3 Timer x Counter Modulo Registers (TPM1MODH:TPM1MODL) . . . . . . . . . . . . 139  
10.7.4 Timer x Channel n Status and Control Register (TPM1CnSC) . . . . . . . . . . . . . 140  
10.7.5 Timer x Channel Value Registers (TPM1CnVH:TPM1CnVL) . . . . . . . . . . . . . . 142  
Chapter 11 Serial Communications Interface (SCI) Module  
11.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144  
11.2 SCI System Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144  
11.3 Baud Rate Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144  
11.4 Transmitter Functional Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145  
11.4.1 Transmitter Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145  
11.4.2 Send Break and Queued Idle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147  
11.5 Receiver Functional Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147  
11.5.1 Receiver Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147  
11.5.2 Data Sampling Technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149  
11.5.3 Receiver Wakeup Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150  
11.6 Interrupts and Status Flags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150  
11.7 Additional SCI Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151  
11.7.1 8- and 9-Bit Data Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151  
11.8 Stop Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152  
11.8.1 Loop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152  
11.8.2 Single-Wire Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152  
11.9 SCI Registers and Control Bits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152  
11.9.1 SCI Baud Rate Registers (SCI1BDH, SCI1BHL). . . . . . . . . . . . . . . . . . . . . . . . 153  
11.9.2 SCI Control Register 1 (SCI1C1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153  
11.9.3 SCI Control Register 2 (SCI1C2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155  
11.9.4 SCI Status Register 1 (SCI1S1). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156  
11.9.5 SCI Status Register 2 (SCI1S2). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158  
11.9.6 SCI Control Register 3 (SCI1C3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159  
11.9.7 SCI Data Register (SCI1D) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160  
Chapter 12 Serial Peripheral Interface (SPI) Module  
12.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162  
12.2 Block Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162  
12.2.1 SPI System Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162  
12.2.2 SPI Module Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163  
12.2.3 SPI Baud Rate Generation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165  
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12.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165  
12.3.1 SPI Clock Formats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166  
12.3.2 SPI Pin Controls. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168  
12.3.3 SPI Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169  
12.3.4 Mode Fault Detection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169  
12.4 SPI Registers and Control Bits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170  
12.4.1 SPI Control Register 1 (SPI1C1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170  
12.4.2 SPI Control Register 2 (SPI1C2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172  
12.4.3 SPI Baud Rate Register (SPI1BR). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173  
12.4.4 SPI Status Register (SPI1S) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174  
12.4.5 SPI Data Register (SPI1D). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175  
Chapter 13 Analog Comparator (ACMP) Module  
13.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178  
13.2 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178  
13.3 Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178  
13.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179  
13.4.1 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179  
13.4.2 Wait Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179  
13.4.3 Stop Mode Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179  
13.4.4 Background Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179  
13.5 ACMP Status and Control Register (ACMP1SC) . . . . . . . . . . . . . . . . . . . . . . . . . . 180  
Chapter 14 Development Support  
14.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183  
14.2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184  
14.3 Background Debug Controller (BDC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185  
14.3.1 BKGD Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185  
14.3.2 Communication Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186  
14.3.3 BDC Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190  
14.3.4 BDC Hardware Breakpoint. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192  
14.4 On-Chip Debug System (DBG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193  
14.4.1 Comparators A and B. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193  
14.4.2 Bus Capture Information and FIFO Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 194  
14.4.3 Change-of-Flow Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194  
14.4.4 Tag vs. Force Breakpoints and Triggers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195  
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14.4.5 Trigger Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195  
14.4.6 Hardware Breakpoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197  
14.5 Registers and Control Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197  
14.5.1 BDC Registers and Control Bits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197  
14.5.2 System Background Debug Force Reset Register (SBDFR). . . . . . . . . . . . . . . 199  
14.5.3 DBG Registers and Control Bits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200  
Appendix C Electrical Characteristics  
C.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207  
C.2 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207  
C.3 Thermal Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208  
C.4 Electrostatic Discharge (ESD) Protection Characteristics . . . . . . . . . . . . . . . . . . . 209  
C.5 DC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209  
C.6 Supply Current Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213  
C.7 Analog Comparator (ACMP) Electricals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214  
C.8 Oscillator Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214  
C.9 AC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215  
C.9.1  
C.9.2  
C.9.3  
Control Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215  
Timer/PWM (TPM) Module Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216  
SPI Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217  
C.10 FLASH Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221  
Appendix D Ordering Information and Mechanical Drawings  
D.1 Ordering Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223  
D.2 Mechanical Drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224  
D.2.1  
D.2.2  
D.2.3  
D.2.4  
28-Pin SOIC Package Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225  
28-Pin PDIP Package Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226  
32-Pin LQFP Package Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227  
44-Pin LQFP Package Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228  
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MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
Chapter 1 Introduction  
1.1 Overview  
The MC9S08RC/RD/RE/RG are members of the low-cost, high-performance HCS08 Family of 8-bit  
microcontroller units (MCUs). All MCUs in this family use the enhanced HCS08 core and are available  
with a variety of modules, memory sizes, memory types, and package types.  
1.2 Features  
Features have been organized to reflect:  
Standard features of the HCS08 Family  
Additional features of the MC9S08RC/RD/RE/RG MCU  
1.2.1 Standard Features of the HCS08 Family  
HCS08 CPU (central processor unit)  
HC08 instruction set with added BGND instruction  
Background debugging system (see also the Development Support section)  
Breakpoint capability to allow single breakpoint setting during in-circuit debugging (plus two more  
breakpoints in on-chip debug module)  
Debug module containing two 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.  
Support for up to 32 interrupt/reset sources  
Power-saving modes: wait plus three stops  
System protection features:  
– Optional computer operating properly (COP) reset  
– Low-voltage detection with reset or interrupt  
– Illegal opcode detection with reset  
– Illegal address detection with reset (some devices don’t have illegal addresses)  
1.2.2 Features of MC9S08RC/RD/RE/RG Series of MCUs  
8 MHz internal bus frequency  
On-chip in-circuit programmable FLASH memory with block protection and security option (see  
Table 1-1 for device specific information)  
On-chip random-access memory (RAM) (see Table 1-1 for device specific information)  
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MC9S08RC/RD/RE/RG  
15  
Introduction  
Low power oscillator capable of operating from crystal or resonator from 1 to 16 MHz  
On-chip analog comparator with internal reference (ACMP1) see Table 1-1  
– Full rail-to-rail supply operation  
– Option to compare to a fixed internal bandgap reference voltage  
Serial communications interface module (SCI1) — see Table 1-1  
Serial peripheral interface module (SPI1) — see Table 1-1  
2-channel, 16-bit timer/pulse-width modulator (TPM1) module with selectable input capture,  
output compare, and edge-aligned or center-aligned PWM capability on each channel.  
Keyboard interrupt ports (KBI1, KBI2)  
– Providing 12 keyboard interrupts  
– Eight with falling-edge/low-level plus four with selectable polarity  
Carrier modulator timer (CMT) with dedicated infrared output (IRO) pin  
– Drives IRO pin for remote control communications  
– Can be disconnected from IRO pin and used as output compare timer  
– IRO output pin has high-current sink capability  
Eight high-current pins (limited by maximum package dissipation)  
Software selectable pullups on ports when used as input. Selection is on an individual port bit basis.  
During output mode, pullups are disengaged.  
39 general-purpose input/output (I/O) pins, depending on package selection  
Four packages available  
– 28-pin plastic dual in-line package (PDIP)  
– 28-pin small outline integrated circuit (SOIC)  
– 32-pin low-profile quad flat package (LQFP)  
– 44-pin low-profile quad flat package (LQFP)  
1.2.3 Devices in the MC9S08RC/RD/RE/RG Series  
Table 1-1 below lists the devices available in the MC9S08RC/RD/RE/RG series and summarizes the  
differences in functions and configuration between them.  
Table 1-1 Devices in the MC9S08RC/RD/RE/RG Series  
(1)  
(2)  
Device  
FLASH  
SCI  
SPI  
RAM  
ACMP  
Yes  
9S08RG32/60  
32K/60K  
2K/2K  
Yes  
Yes  
Yes  
No  
Yes  
No  
No  
No  
9S08RE8/16/32/60  
9S08RD8/16/32/60  
9S08RC8/16/32/60  
8/16K/32K/60K  
8/16K/32K/60K  
8/16K/32K/60K  
1K/1K/2K/2K  
1K/1K/2K/2K  
1K/1K/2K/2K  
Yes  
No  
Yes  
NOTES:  
1. 3S08RC/RD/RE8/16 ROM MCU devices have 512 bytes RAM instead of 1K bytes.  
2. Only available in 32- or 44-pin LQFP packages.  
Freescale Semiconductor  
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MC9S08RC/RD/RE/RG  
 
SoC Guide — MC9S08RG60/D Rev 1.10  
1.3 MCU Block Diagram  
This block diagram shows the structure of the MC9S08RC/RD/RE/RG MCUs.  
INTERNAL BUS  
HCS08 CORE  
7
PTA7/KBI1P7–  
PTA1/KBI1P1  
NOTES1, 2, 6  
DEBUG  
MODULE (DBG)  
BDC  
CPU  
PTA0/KBI1P0  
HCS08 SYSTEM CONTROL  
PTB7/TPM1CH1  
8-BIT KEYBOARD  
PTE6  
PTB5  
PTB4  
PTB3  
INTERRUPT MODULE (KBI1)  
RESETS AND INTERRUPTS  
MODES OF OPERATION  
POWER MANAGEMENT  
NOTES 1, 5  
4-BIT KEYBOARD  
PTB2  
PTB1/RxD1  
PTB0/TxD1  
INTERRUPT MODULE (KBI2)  
RTI  
COP  
LVD  
IRQ  
SERIAL COMMUNICATIONS  
INTERFACE MODULE (SCI1)  
PTC7/SS1  
PTC6/SPSCK1  
PTC5/MISO1  
PTC4/MOSI1  
PTC3/KBI2P3  
PTC2/KBI2P2  
PTC1/KBI2P1  
PTC0/KBI2P0  
USER FLASH  
NOTE 1  
(RC/RD/RE/RG60 = 63,364 BYTES)  
(RC/RD/RE/RG32 = 32,768 BYTES)  
(RC/RD/RE16 = 16,384 BYTES)  
(RC/RD/RE8 = 8192 BYTES)  
ANALOG COMPARATOR  
MODULE (ACMP1)  
2-CHANNEL TIMER/PWM  
MODULE (TPM1)  
PTD6/TPM1CH0  
PTD5/ACMP1+  
PTD4/ACMP1–  
PTD3  
USER RAM  
(RC/RD/RE/RG32/60 = 2048 BYTES)  
(RC/RD/RE8/16 = 1024 BYTES)  
NOTES  
1, 3, 4  
PTD2/IRQ  
PTD1/RESET  
PTD0/BKGD/MS  
SERIAL PERIPHERAL  
EXTAL  
XTAL  
INTERFACE MODULE (SPI1)  
LOW-POWER OSCILLATOR  
8
PTE7–PTE0 NOTE 1  
V
DD  
VOLTAGE  
REGULATOR  
V
CARRIER MODULATOR  
TIMER MODULE (CMT)  
SS  
IRO NOTE 5  
NOTES:  
1. Port pins are software configurable with pullup device if input port  
2. PTA0 does not have a clamp diode to VDD. PTA0 should not be driven above VDD  
.
3. IRQ pin contains software configurable pullup/pulldown device if IRQ enabled (IRQPE = 1)  
4. The RESET pin contains integrated pullup device enabled if reset enabled (RSTPE = 1)  
5. High current drive  
6. Pins PTA[7:0] contain both pullup and pulldown devices. Pulldown available when KBI enabled (KBI1Pn = 1).  
Figure 1-1 MC9S08RC/RD/RE/RG Block Diagram  
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MC9S08RC/RD/RE/RG  
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Introduction  
Table 1-2 lists the functional versions of the on-chip modules.  
Table 1-2 Block Versions  
Module  
Version  
Analog Comparator (ACMP)  
Carrier Modulator Transmitter (CMT)  
Keyboard Interrupt (KBI)  
Serial Communications Interface (SCI)  
Serial Peripheral Interface (SPI)  
Timer Pulse-Width Modulator (TPM)  
Central Processing Unit (CPU)  
Debug Module (DBG)  
1
1
1
1
3
1
2
1
1
2
FLASH  
System Control  
1.4 System Clock Distribution  
SYSTEM  
CONTROL  
LOGIC  
SPI  
RTI  
OSC  
SCI  
TPM  
RTICLKS  
CMT  
RTI  
OSCOUT*  
BUSCLK  
÷2  
OSC  
CPU  
BDC  
RAM  
FLASH  
ACMP  
FLASH has frequency  
requirements for program  
and erase operation.  
See Appendix A.  
* OSCOUT is the alternate BDC clock source for the MC9S08RC/RD/RE/RG.  
Figure 1-2 System Clock Distribution Diagram  
Figure 1-2 shows a simplified clock connection diagram for the MCU. The CPU operates at the input  
frequency of the oscillator. The bus clock frequency is half of the oscillator frequency and is used by all  
of the internal circuits with the exception of the CPU and RTI. The RTI can use either the oscillator input  
or the internal RTI oscillator as its clock source.  
Freescale Semiconductor  
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SoC Guide — MC9S08RG60/D Rev 1.10  
Chapter 2 Pins and Connections  
2.1 Introduction  
This section describes signals that connect to package pins. It includes a pinout diagram, a table of signal  
properties, and detailed discussion of signals.  
2.2 Device Pin Assignment  
PTB0/TxD1  
PTB1/RxD1  
PTB2  
PTA0/KBI1P0  
33  
1
PTD6/TPM1CH0  
2
32  
31  
30  
29  
28  
27  
26  
25  
24  
PTD5/ACMP1+  
PTD4/ACMP1–  
EXTAL  
3
PTB3  
4
PTB4  
5
V
XTAL  
6
DD  
PTD3  
V
7
SS  
IRO  
PTB5  
PTD2/IRQ  
8
PTD1/RESET  
PTD0/BKGD/MS  
PTC7/SS1  
9
PTB6  
10  
PTB7/TPM1CH1  
11  
23  
Figure 2-1 MC9S08RC/RD/RE/RG in 44-Pin LQFP Package  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
19  
Pins and Connections  
PTB0/TxD1  
PTB1/RxD1  
PTB2  
24  
23  
22  
21  
20  
19  
18  
17  
1
PTD6/TPM1CH0  
PTD5/ACMP1+  
PTD4/ACMP1–  
EXTAL  
2
3
4
5
6
7
8
V
DD  
V
XTAL  
SS  
IRO  
PTB6  
PTD2/IRQ  
PTD1/RESET  
PTD0/BKGD/MS  
PTB7/TPM1CH1  
Figure 2-2 MC9S08RC/RD/RE/RG in 32-Pin LQFP Package  
Freescale Semiconductor  
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MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
PTA4/KBI1P4  
PTA3/KBI1P3  
PTA2/KBI1P2  
PTA1/KBI1P1  
PTA0/KBI1P0  
PTA5/KBI1P5  
PTA6/KBI1P6  
1
28  
27  
26  
25  
24  
23  
22  
21  
20  
19  
18  
17  
16  
15  
2
PTA7/KBI1P7  
PTB0/TxD1  
3
4
PTB1/RxD1  
PTB2  
5
PTD6/TPM1CH0  
EXTAL  
6
V
7
DD  
XTAL  
V
8
SS  
PTD1/RESET  
PTD0/BKGD/MS  
IRO  
PTB7/TPM1CH1  
PTC0/KBI2P0  
PTC1/KBI2P1  
PTC2/KBI2P2  
PTC3/KBI2P3  
9
10  
11  
12  
13  
14  
PTC7/SS1  
PTC6/SPSCK1  
PTC5/MISO1  
PTC4/MOSI1  
Figure 2-3 MC9S08RC/RD/RE/RG in 28-Pin SOIC Package and 28-Pin PDIP Package  
2.3 Recommended System Connections  
Figure 2-4 shows pin connections that are common to almost all MC9S08RC/RD/RE/RG application  
systems. A more detailed discussion of system connections follows.  
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MC9S08RC/RD/RE/RG  
21  
Pins and Connections  
MC9S08RC/RD/RE/RG  
PTA0/KBI1P0  
PTA1/KBI1P1  
PTA2/KBI1P2  
PTA3/KBI1P3  
PTA4/KBI1P4  
PTA5/KBI1P5  
PTA6/KBI1P6  
PTA7/KBI1P7  
V
+
DD  
SYSTEM  
POWER  
V
V
DD  
+
C
C
PORT  
A
BY  
BLK  
3 V  
0.1 µF  
10 µF  
SS  
R
F
XTAL  
PTB0/TxD1  
PTB1/RxD1  
PTB2  
C1  
C2  
X1  
EXTAL  
PTB3  
PORT  
B
PTB4  
BACKGROUND HEADER  
PTB5  
I/O AND  
PERIPHERAL  
INTERFACE TO  
APPLICATION  
SYSTEM  
PTB6  
1
PTB7/TPM1CH1  
V
DD  
BKGD/MS  
NOTE 1  
PTC0/KBI2P0  
PTC1/KBI2P1  
PTC2/KBI2P2  
PTC3/KBI2P3  
PTC4/MOSI1  
PTC5/MISO1  
PTC6/SPSCK1  
PTC7/SS1  
PORT  
C
RESET  
NOTE 2  
OPTIONAL  
MANUAL  
RESET  
PTD0/BKGD/MS  
PTD1/RESET  
PTD2/IRQ  
PTD3  
PORT  
D
PTD4/ACMP1–  
PTD5/ACMP1+  
PTD6/TPM1CH0  
IRO  
PTE0  
PTE1  
PTE2  
PTE3  
PTE4  
PTE5  
PTE6  
PTE7  
PORT  
E
NOTES:  
1. BKGD/MS is the  
same pin as PTD0.  
2. RESET is the  
same pin as PTD1.  
Figure 2-4 Basic System Connections  
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MC9S08RC/RD/RE/RG  
 
SoC Guide — MC9S08RG60/D Rev 1.10  
2.3.1 Power  
V
and V are the primary power supply pins for the MCU. This voltage source supplies power to all  
SS  
DD  
I/O buffer circuitry and to an internal voltage regulator. The internal voltage regulator provides a regulated  
lower-voltage source to the CPU and other internal circuitry of the MCU.  
Typically, application systems have two separate capacitors across the power pins. In this case, there  
should 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.  
2.3.2 Oscillator  
The oscillator in the MC9S08RC/RD/RE/RG is a traditional Pierce oscillator that can accommodate a  
crystal or ceramic resonator in the range of 1 MHz to 16 MHz.  
Refer to Figure 2-4 for the following discussion. R should be a low-inductance resistor such as a carbon  
F
composition resistor. Wire-wound resistors, and some metal film resistors, have too much inductance. C1  
and C2 normally should be high-quality ceramic capacitors specifically designed for high-frequency  
applications.  
R is used to provide a bias path to keep the EXTAL input in its linear range during crystal startup and its  
F
value is not generally critical. Typical systems use 1 M. 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 take into account printed circuit board (PCB) capacitance and MCU pin  
capacitance when sizing C1 and C2. The crystal manufacturer typically specifies a load capacitance that  
is the series combination of C1 and C2, which are usually the same size. As a first-order approximation,  
use 5 pF as an estimate of combined pin and PCB capacitance for each oscillator pin (EXTAL and XTAL).  
2.3.3 PTD1/RESET  
The external pin reset function is shared with an output-only port function on the PTD1/RESET pin. The  
reset function is enabled when RSTPE in SOPT is set. RSTPE is set following any reset of the MCU and  
must be cleared in order to use this pin as an output-only port.  
Whenever any reset is initiated (whether from an external signal or from an internal system), the reset pin  
is driven low for about 34 cycles of f  
, released, and sampled again about 38 cycles of f  
Self_reset  
Self_reset  
later. If reset was caused by an internal source such as low-voltage reset or watchdog timeout, the circuitry  
expects the reset pin sample to return a logic 1. If the pin is still low at this sample point, the reset is  
assumed to be from an external source. The reset circuitry decodes the cause of reset and records it by  
setting a corresponding bit in the system control reset status register (SRS).  
Never connect any significant capacitance to the reset pin because that would interfere with the circuit and  
sequence that detects the source of reset. If an external capacitance prevents the reset pin from rising to a  
valid logic 1 before the reset sample point, all resets will appear to be external resets.  
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Pins and Connections  
2.3.4 Background/Mode Select (PTD0/BKGD/MS)  
The background/mode select function is shared with an output-only port function on the PTD0/BKDG/MS  
pin. While in reset, the pin functions as a mode select pin. Immediately after reset rises, the pin functions  
as the background pin and can be used for background debug communication. While functioning as a  
background/mode select pin, this pin has an internal pullup device enabled. To use as an output-only port,  
BKGDPE in SOPT must be cleared.  
If nothing is connected to this pin, the MCU will enter normal operating mode at the rising edge of reset.  
If a debug system is connected to the 6-pin standard background debug header, it can hold BKGD/MS low  
during the rising edge of reset, which forces the MCU to active background mode.  
The BKGD pin is used primarily for background debug controller (BDC) communications using a custom  
protocol that uses 16 clock cycles of the target MCU’s BDC clock per bit time. The target MCU’s BDC  
clock could be as fast as the bus clock rate, so there should never be any significant capacitance connected  
to the BKGD/MS pin that could interfere with background serial communications.  
Although the BKGD 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 almost no role in determining rise and fall  
times on the BKGD pin.  
2.3.5 IRO Pin Description  
The IRO pin is the output of the CMT. See Carrier Modulator Timer (CMT) Module for a detailed  
description of this pin function.  
2.3.6 General-Purpose I/O and Peripheral Ports  
The remaining pins are shared among general-purpose I/O and on-chip peripheral functions such as timers  
and serial I/O systems. (Not all pins are available in all packages. See Table 2-2.) Immediately after reset,  
all 37 of these pins are configured as high-impedance general-purpose inputs with internal pullup devices  
disabled.  
NOTE: To avoid extra current drain from floating input pins, the reset initialization routine  
in the application program should either enable on-chip pullup devices or change  
the direction of unused pins to outputs so the pins do not float.  
For information about controlling these pins as general-purpose I/O pins, see the Parallel Input/Output  
section. For information about how and when on-chip peripheral systems use these pins, refer to the  
appropriate section from Table 2-1.  
Freescale Semiconductor  
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MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
Table 2-1 Pin Sharing References  
Alternate  
Function  
(1)  
Port Pins  
Reference  
PTA7–PTA0  
PTB7  
KBI1P7–KBI1P0 Keyboard Interrupt (KBI) Module  
TPM1CH1  
Timer/PWM Module (TPM) Module  
Parallel Input/Output  
PTB6–PTB2  
PTB1  
PTB0  
RxD1  
TxD1  
Serial Communications Interface (SCI) Module  
PTC7  
PTC6  
PTC5  
PTC4  
SS1  
SPSCK1  
MISO1  
MOSI1  
Serial Peripheral Interface (SPI) Module  
PTC3–PTC0  
PTD6  
KBI2P3–KBI2P0 Keyboard Interrupt (KBI) Module  
TPM1CH0  
Timer/PWM Module (TPM) Module  
Analog Comparator (ACMP) Module  
PTD5  
PTD4  
ACMP1+  
ACMP1–  
PTD2  
IRQ  
RESET  
BKGD/MS  
PTD1  
Resets, Interrupts, and System Configuration  
Parallel Input/Output  
PTD0  
PTE7–PTE0  
NOTES:  
1. See this section for information about modules that share these pins.  
When an on-chip peripheral system is controlling a pin, data direction control bits still determine what is  
read from port data registers even though the peripheral module controls the pin direction by controlling  
the enable for the pin’s output buffer. See the Parallel Input/Output section for more details.  
Pullup enable bits for each input pin control whether on-chip pullup devices are enabled whenever the pin  
is acting as an input even if it is being controlled by an on-chip peripheral module. When the PTA7–PTA4  
pins are controlled by the KBI module and are configured for rising-edge/high-level sensitivity, the pullup  
enable control bits enable pulldown devices rather than pullup devices. Similarly, when PTD2 is  
configured as the IRQ input and is set to detect rising edges, the pullup enable control bit enables a  
pulldown device rather than a pullup device.  
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MC9S08RC/RD/RE/RG  
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Pins and Connections  
2.3.7 Signal Properties Summary  
Table 2-2 summarizes I/O pin characteristics. These characteristics are determined by the way the  
common pin interfaces are hardwired to internal circuits.  
Table 2-2 Signal Properties  
Pin  
Name  
High  
Current Pin  
(1)  
(2)  
Comments  
Dir  
Pullup  
VDD  
VSS  
Y
XTAL  
EXTAL  
IRO  
O
I
Crystal oscillator output  
Crystal oscillator input  
Infrared output  
O
PTA0 does not have a clamp diode to VDD. PTA0 should not be  
driven above VDD  
PTA0/KBI1P0  
I
N
SWC  
.
PTA1/KBI1P1  
PTA2/KBI1P2  
PTA3/KBI1P3  
PTA4/KBI1P4  
PTA5/KBI1P5  
PTA6/KBI1P6  
PTA7/KBI1P7  
PTB0/TxD1  
PTB1/RxD1  
PTB2  
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
N
N
N
N
N
N
N
Y
Y
Y
Y
Y
Y
Y
Y
N
N
N
N
N
N
N
N
N
SWC  
SWC  
SWC  
SWC  
SWC  
SWC  
SWC  
SWC  
SWC  
SWC  
SWC  
SWC  
SWC  
SWC  
SWC  
SWC  
SWC  
SWC  
SWC  
SWC  
SWC  
SWC  
SWC  
PTB3  
Available only in 44-LQFP package  
Available only in 44-LQFP package  
Available only in 44-LQFP package  
Available only in 32- or 44-LQFP packages  
PTB4  
PTB5  
PTB6  
PTB7/TPM1CH1  
PTC0/KBI2P0  
PTC1/KBI2P1  
PTC2/KBI2P2  
PTC3/KBI2P3  
PTC4/MOSI1  
PTC5/MISO1  
PTC6/SPSCK1  
PTC7/SS1  
SWC(3)  
SWC(3)  
PTD0/BKGD/MS  
Output-only when configured as PTD0 pin. Pullup enabled.  
Output-only when configured as PTD1 pin.  
PTD1/RESET  
I/O  
N
SWC(4)  
SWC  
PTD2/IRQ  
PTD3  
I/O  
I/O  
I/O  
I/O  
N
N
N
N
Available only in 32- or 44-LQFP packages  
Available only in 44-LQFP package  
PTD4/ACMP1–  
PTD5/ACMP1+  
SWC  
Available only in 32- or 44-LQFP packages  
Available only in 32- or 44-LQFP packages  
SWC  
Freescale Semiconductor  
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MC9S08RC/RD/RE/RG  
 
SoC Guide — MC9S08RG60/D Rev 1.10  
Table 2-2 Signal Properties (Continued)  
Pin  
Name  
High  
Current Pin  
(1)  
(2)  
Comments  
Dir  
Pullup  
PTD6/TPM1CH0  
PTE0  
I/O  
N
N
N
N
N
N
N
N
N
SWC  
SWC  
SWC  
SWC  
SWC  
SWC  
SWC  
SWC  
SWC  
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
Available only in 44-LQFP package  
PTE1  
Available only in 44-LQFP package  
Available only in 44-LQFP package  
Available only in 44-LQFP package  
Available only in 44-LQFP package  
Available only in 44-LQFP package  
Available only in 44-LQFP package  
Available only in 44-LQFP package  
PTE2  
PTE3  
PTE4  
PTE5  
PTE6  
PTE7  
NOTES:  
1. Unless otherwise indicated, all digital inputs have input hysteresis.  
2. SWC is software-controlled pullup resistor, the register is associated with the respective port.  
3. When these pins are configured as RESET or BKGD/MS pullup device is enabled.  
4. When configured for the IRQ function, this pin will have a pullup device enabled when the IRQ is set for falling edge  
detection and a pulldown device enabled when the IRQ is set for rising edge detection.  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
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Pins and Connections  
Freescale Semiconductor  
28  
MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
Chapter 3 Modes of Operation  
3.1 Introduction  
The operating modes of the MC9S08RC/RD/RE/RG are described in this section. Entry into each mode,  
exit from each mode, and functionality while in each of the modes are described.  
3.2 Features  
Active background mode for code development  
Wait mode:  
– CPU shuts down to conserve power  
– System clocks running  
– Full voltage regulation maintained  
Stop modes:  
– System clocks stopped; voltage regulator in standby  
– Stop1 — Full power down of internal circuits for maximum power savings  
– Stop2 — Partial power down of internal circuits, RAM remains operational  
– Stop3 — All internal circuits powered for fast recovery  
3.3 Run Mode  
This is the normal operating mode for the MC9S08RC/RD/RE/RG. This mode is selected when the  
BKGD/MS pin is high at the rising edge of reset. In this mode, the CPU executes code from internal  
memory with execution beginning at the address fetched from memory at $FFFE:$FFFF after reset.  
3.4 Active Background Mode  
The active background mode functions are managed through the background debug controller (BDC) in  
the HCS08 core. The BDC, together with the on-chip debug module (DBG), provide the means for  
analyzing MCU operation during software development.  
Active background mode is entered in any of five ways:  
When the BKGD/MS pin is low at the rising edge of reset  
When a BACKGROUND command is received through the BKGD pin  
When a BGND instruction is executed  
When encountering a BDC breakpoint  
When encountering a DBG breakpoint  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
29  
Modes of Operation  
After active background mode is entered, the CPU is held in a suspended state waiting for serial  
background commands rather than executing instructions from the user’s application program.  
Background commands are of two types:  
Non-intrusive commands, 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 the active background  
mode. Non-intrusive commands include:  
– Memory access commands  
– Memory-access-with-status commands  
– BDC register access commands  
– BACKGROUND command  
Active background commands, which can only be executed while the MCU is in active background  
mode, 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’s application program (GO)  
The 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  
MC9S08RC/RD/RE/RG is shipped from the Freescale Semiconductor factory, the FLASH program  
memory is usually erased so there is no program that could be executed in run mode until the FLASH  
memory is initially programmed. The 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 Development Support section.  
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 the  
wait mode, enabling interrupts. When an interrupt request occurs, the CPU exits the wait mode and  
resumes processing, beginning with the stacking operations leading to the interrupt service routine.  
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 in either stop or wait mode. The BACKGROUND command  
can be used to wake the MCU from wait mode and enter active background mode.  
Freescale Semiconductor  
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MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
3.6 Stop Modes  
One of three stop modes is entered upon execution of a STOP instruction when the STOPE bit in the  
system option register is set. In all stop modes, all internal clocks are halted. If the STOPE bit is not set  
when the CPU executes a STOP instruction, the MCU will not enter any of the stop modes and an illegal  
opcode reset is forced. The stop modes are selected by setting the appropriate bits in SPMSC2.  
Table 3-1 summarizes the behavior of the MCU in each of the stop modes.  
Table 3-1 Stop Mode Behavior  
CPU, Digital  
PDC PPDC Peripherals,  
FLASH  
Mode  
RAM  
OSC  
ACMP  
Regulator I/O Pins  
RTI  
Stop1  
Stop2  
1
1
0
1
Off  
Off  
Off  
Off  
Off  
Standby  
Standby  
Standby  
Standby  
Reset  
Off  
States  
held  
Standby  
Optionally on  
Don’t  
care  
States  
held  
Stop3  
0
Standby  
Standby  
Off  
Standby  
Standby  
Optionally on  
3.6.1 Stop1 Mode  
Stop1 mode provides the lowest possible standby power consumption by causing the internal circuitry of  
the MCU to be powered down. To enter stop1, the user must execute a STOP instruction with the PDC bit  
in SPMSC2 set and the PPDC bit clear. Stop1 can be entered only if the LVD reset is disabled  
(LVDRE = 0).  
When the MCU is in stop1 mode, all internal circuits that are powered from the voltage regulator are  
turned off. The voltage regulator is in a low-power standby state, as are the OSC and ACMP.  
Exit from stop1 is done by asserting any of the wakeup pins on the MCU: RESET, IRQ, or KBI, which  
have been enabled. IRQ and KBI pins are always active-low when used as wakeup pins in stop1 regardless  
of how they were configured before entering stop1.  
Upon wakeup from stop1 mode, the MCU will start up as from a power-on reset (POR). The CPU will  
take the reset vector.  
3.6.2 Stop2 Mode  
Stop2 mode provides very low standby power consumption and maintains the contents of RAM and the  
current state of all of the I/O pins. To select entry into stop2 upon execution of a STOP instruction, the  
user must execute a STOP instruction with the PPDC and PDC bits in SPMSC2 set. Stop2 can be entered  
only if LVDRE = 0.  
Before entering stop2 mode, the user must save the contents of the I/O port registers, as well as any other  
memory-mapped registers that they want to restore after exit of stop2, to locations in RAM. Upon exit  
from stop2, these values can be restored by user software.  
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Modes of Operation  
When the MCU is in stop2 mode, all internal circuits that are powered from the voltage regulator are  
turned off, except for the RAM. The voltage regulator is in a low-power standby state, as is the ACMP.  
Upon entry into stop2, the states of the I/O pins are latched. The states are held while in stop2 mode and  
after exiting stop2 mode until a 1 is written to PPDACK in SPMSC2.  
Exit from stop2 is done by asserting any of the wakeup pins: RESET, IRQ, or KBI that have been enabled,  
or through the real-time interrupt. IRQ and KBI pins are always active-low when used as wakeup pins in  
stop2 regardless of how they were configured before entering stop2.  
Upon wakeup from stop2 mode, the MCU will start up as from a power-on reset (POR) except pin states  
remain latched. The CPU will take the reset vector. The system and all peripherals will be in their default  
reset states and must be initialized.  
After waking up from stop2, the PPDF bit in SPMSC2 is set. This flag may be 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.  
For pins that were configured as general-purpose I/O, the user must copy the contents of the I/O port  
registers, which have been saved in RAM, back 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 register bits will be in  
their reset states when the I/O pin latches are opened and the I/O pins will switch to their reset states.  
For pins that were configured as peripheral I/O, the user must 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 will be controlled by their associated port control registers when the I/O  
latches are opened.  
3.6.3 Stop3 Mode  
Upon entering stop3 mode, all of the clocks in the MCU, including the oscillator itself, are halted. The  
OSC is turned off, the ACMP is disabled, and the voltage regulator is put in standby. The states of all of  
the internal registers and logic, as well as the RAM content, are maintained. The I/O pin states are not  
latched at the pin as in stop2. Instead they are maintained by virtue of the states of the internal logic driving  
the pins being maintained.  
Exit from stop3 is done by asserting RESET, any asynchronous interrupt pin that has been enabled, or  
through the real-time interrupt. The asynchronous interrupt pins are the IRQ or KBI pins.  
If stop3 is exited by means of the RESET pin, then the MCU will be reset and operation will resume after  
taking the reset vector. Exit by means of an asynchronous interrupt or the real-time interrupt will result in  
the MCU taking the appropriate interrupt vector.  
A separate self-clocked source (1 kHz) for the real-time interrupt allows a wakeup from stop2 or stop3  
mode with no external components. When RTIS2:RTIS1:RTIS0 = 0:0:0, the real-time interrupt function  
and this 1-kHz source are disabled. Power consumption is lower when the 1-kHz source is disabled, but  
in that case the real-time interrupt cannot wake the MCU from stop.  
Freescale Semiconductor  
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MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
3.6.4 Active BDM Enabled in Stop Mode  
Entry into the active background mode from run mode is enabled if the ENBDM bit in BDCSCR is set.  
This register is described in the Development Support section of this data sheet. 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 stop mode so background debug communication is still possible. In addition, the  
voltage regulator does not enter its low-power standby state but maintains full internal regulation. The  
MCU cannot enter either stop1 mode or stop2 mode if ENBDM is set.  
Most background commands are not available in 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 stop and enter active  
background mode if the ENBDM bit is set. After active background mode is entered, all background  
commands are available. Table 3-2 summarizes the behavior of the MCU in stop when entry into the active  
background mode is enabled.  
Table 3-2 BDM Enabled Stop Mode Behavior  
CPU, Digital  
PDC PPDC Peripherals,  
FLASH  
Mode  
RAM  
OSC  
ACMP  
Regulator I/O Pins  
RTI  
Don’t Don’t  
Standby  
States  
held  
Stop3  
Standby  
On  
Standby  
On  
Optionally on  
care  
care  
3.6.5 LVD Reset Enabled in Stop Mode  
The LVD system is capable of generating either an interrupt or a reset when the supply voltage drops  
below the LVD voltage. If the LVD reset is enabled in stop by setting the LVDRE bit in SPMSC1 when  
the CPU executes a STOP instruction, then the voltage regulator remains active during stop mode. If the  
user attempts to enter either stop1 or stop2 with the LVD reset enabled (LVDRE = 1) the MCU will instead  
enter stop3. Table 3-3 summarizes the behavior of the MCU in stop when LVD reset is enabled.  
Table 3-3 LVD Enabled Stop Mode Behavior  
CPU, Digital  
PDC PPDC Peripherals,  
FLASH  
Mode  
RAM  
OSC  
ACMP  
Regulator I/O Pins  
RTI  
Don’t Don’t  
Standby  
States  
held  
Stop3  
Standby  
On  
Standby  
On  
Optionally on  
care  
care  
3.6.6 On-Chip Peripheral Modules in Stop Mode  
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 are kept alive to the background debug logic, clocks to  
the peripheral systems are halted to reduce power consumption.  
Freescale Semiconductor  
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Modes of Operation  
I/O Pins  
All I/O pin states remain unchanged when the MCU enters stop3 mode.  
If the MCU is configured to go into stop2 mode, all I/O pin states are latched before entering stop.  
Pin states remain latched until the PPDACK bit is written.  
If the MCU is configured to go into stop1 mode, all I/O pins are forced to their default reset state  
upon entry into stop.  
Memory  
All RAM and register contents are preserved while the MCU is in stop3 mode.  
All registers will be reset upon wakeup from stop2, but the contents of RAM are preserved. The  
user may save any memory-mapped register data into RAM before entering stop2 and restore the  
data upon exit from stop2.  
All registers will be reset upon wakeup from stop1 and the contents of RAM are not preserved. The  
MCU must be initialized as upon reset. The contents of the FLASH memory are non-volatile and  
are preserved in any of the stop modes.  
OSC — In any of the stop modes, the OSC stops running.  
TPM — When the MCU enters stop mode, the clock to the TPM module stops. The modules halt  
operation. If the MCU is configured to go into stop2 or stop1 mode, the TPM module will be reset upon  
wakeup from stop and must be reinitialized.  
ACMP — When the MCU enters any stop mode, the ACMP will enter a low-power standby state. No  
compare operation will occur while in stop. If the MCU is configured to go into stop2 or stop1 mode, the  
ACMP will be reset upon wakeup from stop and must be reinitialized.  
KBI — During stop3, the KBI pins that are enabled continue to function as interrupt sources. During stop1  
or stop2, enabled KBI pins function as wakeup inputs. When functioning as a wakeup, a KBI pin is always  
active low regardless of how it was configured before entering stop1 or stop2.  
SCI — When the MCU enters stop mode, the clock to the SCI module stops. The module halts operation.  
If the MCU is configured to go into stop2 or stop1 mode, the SCI module will be reset upon wakeup from  
stop and must be reinitialized.  
SPI — When the MCU enters stop mode, the clock to the SPI module stops. The module halts operation.  
If the MCU is configured to go into stop2 or stop1 mode, the SPI module will be reset upon wakeup from  
stop and must be reinitialized.  
CMT — When the MCU enters stop mode, the clock to the CMT module stops. The module halts  
operation. If the MCU is configured to go into stop2 or stop1 mode, the CMT module will be reset upon  
wakeup from stop and must be reinitialized.  
Voltage Regulator — The voltage regulator enters a low-power standby state when the MCU enters any  
of the stop modes unless the LVD reset function is enabled or BDM is enabled.  
Freescale Semiconductor  
34  
MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
Chapter 4 Memory  
4.1 MC9S08RC/RD/RE/RG Memory Map  
As shown in Figure 4-1, on-chip memory in the MC9S08RC/RD/RE/RG series of MCUs consists of  
RAM, FLASH program memory for nonvolatile data storage, and I/O and control/status registers. The  
registers are divided into three groups:  
Direct-page registers ($0000 through $0045 for 32K and 60K parts, and $0000 through $003F for  
16K and 8K parts)  
High-page registers ($1800 through $182B)  
Nonvolatile registers ($FFB0 through $FFBF)  
$0000  
$0000  
$0000  
$0000  
DIRECT PAGE REGISTERS  
DIRECT PAGE REGISTERS  
DIRECT PAGE REGISTERS  
DIRECT PAGE REGISTERS  
$0045  
$0046  
$0045  
$0046  
$003F  
$0040  
$003F  
$0040  
RAM  
2048 BYTES  
(1)  
(1)  
RAM  
2048 BYTES  
RAM  
RAM  
1024 BYTES  
1024 BYTES  
$043F  
$0440  
$043F  
$0440  
$0845  
$0846  
$0845  
$0846  
FLASH  
UNIMPLEMENTED  
4026 BYTES  
UNIMPLEMENTED  
5056 BYTES  
UNIMPLEMENTED  
5056 BYTES  
4026 BYTES  
$17FF  
$1800  
$17FF  
$1800  
$182B  
$182C  
$17FF  
$1800  
$17FF  
$1800  
HIGH PAGE REGISTERS  
HIGH PAGE REGISTERS  
HIGH PAGE REGISTERS  
HIGH PAGE REGISTERS  
$182B  
$182C  
$182B  
$182C  
$182B  
$182C  
UNIMPLEMENTED  
26580 BYTES  
UNIMPLEMENTED  
42964 BYTES  
$8000  
FLASH  
UNIMPLEMENTED  
51156 BYTES  
59348 BYTES  
FLASH  
$BFFF  
$C000  
32768 BYTES  
FLASH  
$DFFF  
$E000  
16384 BYTES  
FLASH  
8192 BYTES  
$FFFF  
$FFFF  
$FFFF  
MC9S08RC/RD/RE/RG60  
NOTE:  
1. MC3S08RC/RD/RE16/8 ROM MCU devices have 512 bytes of RAM instead of 1K bytes.  
MC9S08RC/RD/RE/RG32  
MC9S08RC/RD/RE16  
MC9S08RC/RD/RE8  
Figure 4-1 MC9S08RC/RD/RE/RG Memory Map  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
35  
 
Memory  
4.1.1 Reset and Interrupt Vector Assignments  
Table 4-1 shows address assignments for reset and interrupt vectors. The vector names shown in this table  
are the labels used in the Freescale-provided equate file for the MC9S08RC/RD/RE/RG. For more details  
about resets, interrupts, interrupt priority, and local interrupt mask controls, refer to the Resets, Interrupts,  
and System Configuration section.  
Table 4-1 Reset and Interrupt Vectors  
Vector  
Numbe  
r
Address  
(High/Low)  
Vector  
Vector Name  
$FFC0:FFC1  
16  
through  
31  
Unused Vector Space  
(available for user program)  
$FFDE:FFDF  
$FFE0:FFE1  
$FFE2:FFE3  
$FFE4:FFE5  
$FFE6:FFE7  
$FFE8:FFE9  
$FFEA:FFEB  
$FFEC:FFED  
SPI(1)  
RTI  
15  
14  
13  
12  
11  
10  
9
Vspi1  
Vrti  
KBI2  
KBI1  
Vkeyboard2  
Vkeyboard1  
Vacmp1  
Vcmt  
ACMP(2)  
CMT  
SCI Transmit(3)  
SCI Receive(3)  
Vsci1tx  
8
$FFEE:FFEF  
Vsci1rx  
SCI Error(3)  
TPM Overflow  
TPM Channel 1  
TPM Channel 0  
IRQ  
7
$FFF0:FFF1  
$FFF2:FFF3  
$FFF4:FFF5  
$FFF6:FFF7  
$FFF8:FFF9  
$FFFA:FFFB  
$FFFC:FFFD  
$FFFE:FFFF  
Vsci1err  
Vtpm1ovf  
Vtpm1ch1  
Vtpm1ch0  
Virq  
6
5
4
3
2
Low Voltage Detect  
SWI  
Vlvd  
1
0
Vswi  
Reset  
Vreset  
NOTES:  
1. The SPI module is not included on the MC9S08RC/RD/RE devices. This vector location is unused for those  
devices.  
2. The analog comparator (ACMP) module is not included on the MC9S08RD devices. This vector location is unused  
for those devices.  
3. The SCI module is not included on the MC9S08RC devices. This vector location is unused for those devices.  
Freescale Semiconductor  
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MC9S08RC/RD/RE/RG  
 
SoC Guide — MC9S08RG60/D Rev 1.10  
4.2 Register Addresses and Bit Assignments  
The registers in the MC9S08RC/RD/RE/RG are divided into these three groups:  
Direct-page registers are located within the first 256 locations in the memory map, so they are  
accessible with efficient direct addressing mode instructions.  
High-page registers are used much less often, so they are located above $1800 in the memory map.  
This leaves more room in the direct page for more frequently used registers and variables.  
The nonvolatile register area consists of a block of 16 locations in FLASH memory at  
$FFB0–$FFBF.  
Nonvolatile register locations include:  
– Three values that are loaded into working registers at reset  
– An 8-byte backdoor comparison key that optionally allows a user to gain 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 4-3 and Table 4-4, the whole address in column one is shown in bold. In Table 4-2,  
Table 4-3, and Table 4-4, 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.  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
37  
Memory  
Table 4-2 Direct-Page Register Summary  
Address Register Name  
Bit 7  
PTAD7  
PTAPE7  
6
5
4
3
2
1
PTAD1  
PTAPE1  
Bit 0  
PTAD0  
PTAPE0  
$0000  
$0001  
$0002  
$0003  
$0004  
$0005  
$0006  
$0007  
$0008  
$0009  
$000A  
$000B  
$000C  
$000D  
$000E  
$000F  
$0010  
$0011  
$0012  
$0013  
$0014  
$0015  
$0016  
$0017  
$0018  
$0019  
$001A  
$001B  
$001C  
$001D  
$001E  
$001F  
$0020  
$0021  
$0022  
$0023  
$0024  
$0025  
$0026  
$0027  
PTAD  
PTAD6  
PTAPE6  
PTAD5  
PTAPE5  
PTAD4  
PTAPE4  
PTAD3  
PTAPE3  
PTAD2  
PTAPE2  
PTAPE  
Reserved  
PTADD  
PTBD  
PTADD7  
PTBD7  
PTBPE7  
PTADD6  
PTBD6  
PTBPE6  
PTADD5  
PTBD5  
PTBPE5  
PTADD4  
PTBD4  
PTBPE4  
PTADD3  
PTBD3  
PTBPE3  
PTADD2  
PTBD2  
PTBPE2  
PTADD1  
PTBD1  
PTBPE1  
PTADD0  
PTBD0  
PTBPE0  
PTBPE  
Reserved  
PTBDD  
PTCD  
PTBDD7  
PTCD7  
PTCPE7  
PTBDD6  
PTCD6  
PTCPE6  
PTBDD5  
PTCD5  
PTCPE5  
PTBDD4  
PTCD4  
PTCPE4  
PTBDD3  
PTCD3  
PTCPE3  
PTBDD2  
PTCD2  
PTCPE2  
PTBDD1  
PTCD1  
PTCPE1  
PTBDD0  
PTCD0  
PTCPE0  
PTCPE  
Reserved  
PTCDD  
PTDD  
PTCDD7  
0
PTCDD6  
PTDD6  
PTDPE6  
PTCDD5  
PTDD5  
PTDPE5  
PTCDD4  
PTDD4  
PTDPE4  
PTCDD3  
PTDD3  
PTDPE3  
PTCDD2  
PTDD2  
PTDPE2  
PTCDD1  
PTDD1  
PTDPE1  
PTCDD0  
PTDD0  
PTDPE0  
PTDPE  
Reserved  
PTDDD  
PTED  
0
0
PTDDD6  
PTED6  
PTEPE6  
PTDDD5  
PTED5  
PTEPE5  
PTDDD4  
PTED4  
PTEPE4  
PTDDD3  
PTED3  
PTEPE3  
PTDDD2  
PTED2  
PTEPE2  
PTDDD1  
PTED1  
PTEPE1  
PTDDD0  
PTED0  
PTEPE0  
PTED7  
PTEPE7  
PTEPE  
Reserved  
PTEDD  
KBI1SC  
KBI1PE  
KBI2SC  
KBI2PE  
SCI1BDH  
PTEDD7  
PTEDD6  
PTEDD5  
PTEDD4  
PTEDD3  
KBF  
PTEDD2  
KBACK  
KBIPE2  
KBACK  
KBIPE2  
SBR10  
SBR2  
ILT  
PTEDD1  
KBIE  
PTEDD0  
KBIMOD  
KBIPE0  
KBIMOD  
KBIPE0  
SBR8  
SBR0  
PT  
KBEDG7 KBEDG6 KBEDG5 KBEDG4  
KBIPE7  
0
KBIPE6  
0
KBIPE5  
0
KBIPE4  
0
KBIPE3  
KBF  
KBIPE1  
KBIE  
0
0
0
0
KBIPE3  
SBR11  
SBR3  
WAKE  
TE  
KBIPE1  
SBR9  
SBR1  
PE  
(1)  
(1)  
0
0
0
SBR12  
SBR4  
M
SCI1BDL  
SBR7  
LOOPS  
TIE  
SBR6  
SCISWAI  
TCIE  
TC  
SBR5  
RSRC  
RIE  
(1)  
SCI1C1  
SCI1C2  
(1)  
ILIE  
IDLE  
0
RE  
RWU  
FE  
SBK  
(1)  
(1)  
(1)  
SCI1S1  
SCI1S2  
TDRE  
0
RDRF  
0
OR  
NF  
PF  
0
0
0
0
RAF  
SCI1C3  
R8  
T8  
TXDIR  
R5/T5  
PH5  
PL5  
0
ORIE  
R3/T3  
PH3  
NEIE  
FEIE  
PEIE  
(1)  
SCI1D  
R7/T7  
PH7  
PL7  
R6/T6  
PH6  
PL6  
R4/T4  
PH4  
PL4  
SH4  
SL4  
0
R2/T2  
PH2  
R1/T1  
PH1  
R0/T0  
PH0  
CMTCGH1  
CMTCGL1  
CMTCGH2  
CMTCGL2  
CMTOC  
PL3  
PL2  
PL1  
PL0  
SH7  
SL7  
SH6  
SL6  
SH5  
SL5  
SH3  
SH2  
SH1  
SH0  
SL3  
SL2  
SL1  
SL0  
IROL  
EOCF  
MB15  
MB7  
CMTPOL  
IROPEN  
0
0
0
0
CMTMSC  
CMTCMD1  
CMTCMD2  
CMTDIV1 CMTDIV0  
EXSPC  
MB12  
MB4  
BASE  
MB11  
MB3  
FSK  
EOCIE  
MB9  
MCGEN  
MB8  
MB14  
MB6  
MB13  
MB5  
MB10  
MB2  
MB1  
MB0  
Freescale Semiconductor  
38  
MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
Table 4-2 Direct-Page Register Summary (Continued)  
Address Register Name  
Bit 7  
SB15  
SB7  
6
SB14  
SB6  
5
SB13  
SB5  
4
3
2
SB10  
SB2  
1
Bit 0  
SB8  
$0028  
$0029  
$002A  
$002B  
CMTCMD3  
CMTCMD4  
IRQSC  
SB12  
SB4  
SB11  
SB3  
SB9  
SB1  
IRQIE  
SB0  
0
0
IRQEDG  
ACF  
IRQPE  
ACIE  
IRQF  
ACO  
IRQACK  
IRQMOD  
(2)  
ACMP1SC  
ACME  
ACBGS  
ACMOD1 ACMOD0  
$002C–  
$002F  
Reserved  
$0030  
$0031  
$0032  
$0033  
$0034  
$0035  
$0036  
$0037  
$0038  
$0039  
$003A  
TPM1SC  
TOF  
Bit 15  
Bit 7  
TOIE  
CPWMS  
CLKSB  
CLKSA  
PS2  
PS1  
9
PS0  
Bit 8  
Bit 0  
Bit 8  
Bit 0  
0
TPM1CNTH  
TPM1CNTL  
TPM1MODH  
TPM1MODL  
TPM1C0SC  
TPM1C0VH  
TPM1C0VL  
TPM1C1SC  
TPM1C1VH  
TPM1C1VL  
Reserved  
14  
13  
5
12  
4
11  
10  
6
14  
3
2
1
Bit 15  
Bit 7  
13  
12  
11  
10  
9
6
5
4
3
ELS0B  
11  
2
ELS0A  
10  
1
CH0F  
Bit 15  
Bit 7  
CH0IE  
14  
MS0B  
13  
MS0A  
12  
0
9
Bit 8  
Bit 0  
0
6
5
4
3
2
1
CH1F  
Bit 15  
Bit 7  
CH1IE  
14  
MS1B  
13  
MS1A  
12  
ELS1B  
11  
ELS1A  
10  
0
9
Bit 8  
Bit 0  
6
5
4
3
2
1
$003B–  
$003F  
(3)  
$0040  
$0041  
$0042  
$0043  
$0044  
$0045  
NOTES:  
SPI1C1  
SPIE  
0
SPE  
SPTIE  
0
MSTR  
CPOL  
CPHA  
SSOE  
LSBFE  
SPC0  
SPR0  
0
(3)  
SPI1C2  
0
MODFEN BIDIROE  
0
SPR2  
0
SPISWAI  
(3)  
SPI1BR  
(3)  
0
SPPR2  
SPPR1  
SPTEF  
SPPR0  
MODF  
0
0
SPR1  
SPI1S  
SPRF  
0
6
0
1
Reserved  
(3)  
3
SPI1D  
Bit 7  
5
4
2
Bit 0  
1. The SCI module is not included on the MC9S08RC devices. This is a reserved location for those devices.  
2. The analog comparator (ACMP) module is not included on the MC9S08RD devices. This is a reserved location for those  
devices.  
3. The SPI module is not included on the MC9S08RC/RD/RE devices. These are reserved locations on the 32K and 60K  
versions of these devices. The address range $0040–$004F are RAM locations on the 16K and 8K devices. There are  
no MC9S08RG8/16 devices.  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
39  
Memory  
High-page registers, shown in Table 4-3, 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 $1800.  
Table 4-3 High-Page Register Summary  
Address  
$1800  
Register Name  
SRS  
Bit 7  
POR  
0
6
PIN  
0
5
COP  
0
4
ILOP  
0
3
ILAD  
0
2
0
0
0
1
LVD  
Bit 0  
0
(1)  
$1801  
SBDFR  
SOPT  
0
BDFR  
RSTPE  
$1802  
COPE  
COPT  
STOPE  
0
BKGDPE  
$1803–  
$1804  
Reserved  
$1805  
$1806  
$1807  
$1808  
$1809  
$180A  
Reserved  
SDIDH  
0
0
0
REV1  
ID5  
0
0
0
ID10  
0
ID9  
0
REV3  
ID7  
REV2  
REV0  
ID4  
ID11  
ID3  
ID8  
SDIDL  
ID6  
ID2  
ID1  
ID0  
SRTISC  
SPMSC1  
SPMSC2  
RTIF  
LVDF  
LVWF  
RTIACK  
LVDACK  
LVWACK  
RTICLKS  
LVDIE  
0
RTIE  
SAFE  
0
0
RTIS2  
RTIS1  
RTIS0  
LVDRE  
PPDF  
PPDACK  
PDC  
PPDC  
$180B–  
$180F  
Reserved  
$1810  
$1811  
$1812  
$1813  
$1814  
$1815  
$1816  
$1817  
$1818  
DBGCAH  
DBGCAL  
DBGCBH  
DBGCBL  
DBGFH  
DBGFL  
DBGC  
Bit 15  
Bit 7  
14  
6
13  
5
12  
11  
3
10  
2
9
Bit 8  
Bit 0  
4
1
9
Bit 15  
Bit 7  
14  
13  
12  
11  
10  
Bit 8  
6
5
4
3
2
1
Bit 0  
Bit 15  
Bit 7  
14  
13  
12  
11  
10  
9
Bit 8  
6
5
4
3
2
1
Bit 0  
DBGEN  
TRGSEL  
AF  
ARM  
BEGIN  
BF  
TAG  
0
BRKEN  
RWA  
TRG3  
CNT3  
RWAEN  
TRG2  
CNT2  
RWB  
TRG1  
CNT1  
RWBEN  
TRG0  
CNT0  
DBGT  
0
0
DBGS  
ARMF  
$1819–  
$181F  
Reserved  
$1820  
$1821  
$1822  
$1823  
$1824  
$1825  
$1826  
FCDIV  
FOPT  
DIVLD  
KEYEN  
PRDIV8  
FNORED  
DIV5  
0
DIV4  
0
DIV3  
DIV2  
DIV1  
DIV0  
0
0
SEC01  
SEC00  
Reserved  
FCNFG  
FPROT  
FSTAT  
FCMD  
0
0
0
KEYACC  
FPS2  
0
0
0
0
FPOPEN  
FCBEF  
FCMD7  
FPDIS  
FCCF  
FCMD6  
FPS1  
FPS0  
0
0
0
0
0
0
FPVIOL FACCERR  
FBLANK  
FCMD2  
FCMD5  
FCMD4  
FCMD3  
FCMD1  
FCMD0  
$1827–  
$182B  
Reserved  
NOTES:  
1. The ILAD bit is only present on 16K and 8K versions of the devices.  
Freescale Semiconductor  
40  
MC9S08RC/RD/RE/RG  
 
SoC Guide — MC9S08RG60/D Rev 1.10  
Nonvolatile FLASH registers, shown in Table 4-4, are located in the FLASH memory. These registers  
include an 8-byte backdoor key that optionally can be used to gain access to secure memory resources.  
During reset events, the contents of NVPROT and NVOPT in the nonvolatile register area of the FLASH  
memory are transferred into corresponding FPROT and FOPT working registers in the high-page registers  
to control security and block protection options.  
Table 4-4 Nonvolatile Register Summary  
Address  
Register Name  
NVBACKKEY  
Bit 7  
6
5
4
3
2
1
Bit 0  
$FFB0–  
$FFB7  
8-Byte Comparison Key  
$FFB8–  
$FFBC  
Reserved  
$FFBD  
$FFBE  
$FFBF  
NVPROT  
Reserved  
NVOPT  
FPOPEN  
FPDIS  
FPS2  
FPS1  
FPS0  
0
0
0
0
KEYEN  
FNORED  
0
0
0
SEC01  
SEC00  
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 debug interface) and verifying that FLASH is blank. To avoid returning to secure mode  
after the next reset, program the security bits (SEC01:SEC00) to the unsecured state (1:0).  
4.3 RAM  
The MC9S08RC/RD/RE/RG includes static RAM. The locations in RAM below $0100 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.  
The RAM retains data when the MCU is in low-power wait, stop2, or stop3 mode. At power-on or after  
wakeup from stop1, 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.  
For compatibility with older M68HC05 MCUs, the HCS08 resets the stack pointer to $00FF. In the  
MC9S08RC/RD/RE/RG, 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-provided equate file).  
LDHX  
TXS  
#RamLast+1  
;point one past RAM  
;SP<-(H:X-1)  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
41  
 
Memory  
When security is enabled, the RAM is considered a secure memory resource and is not accessible through  
BDM or through code executing from non-secure memory. See 4.5 Security for a detailed description of  
the security feature.  
4.4 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.  
4.4.1 Features  
Features of the FLASH memory include:  
FLASH Size  
– MC9S08RC/RD/RE/RG60 — 63374 bytes (124 pages of 512 bytes each)  
– MC9S08RC/RD/RE/RG32 — 32768 bytes (64 pages of 512 bytes each)  
– MC9S08RC/RD/RE16 — 16384 bytes (32 pages of 512 bytes each)  
– MC9S08RC/RD/RE8 — 8192 bytes (16 pages of 512 bytes each)  
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  
4.4.2 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 (f  
) between 150 kHz and  
FCLK  
200 kHz (see 4.6.1 FLASH Clock Divider Register (FCDIV)). This register can be written only once, so  
normally this write is done during reset initialization. FCDIV cannot be written if the access error flag,  
FACCERR in FSTAT, is set. The user must ensure that FACCERR is not set before writing to the FCDIV  
register. One period of the resulting clock (1/f  
) is used by the command processor to time program  
FCLK  
and erase pulses. An integer number of these timing pulses are used by the command processor to complete  
a program or erase command.  
Freescale Semiconductor  
42  
MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
Table 4-5 shows program and erase times. The bus clock frequency and FCDIV determine the frequency  
of FCLK (f  
). The time for one cycle of FCLK is t  
= 1/f  
. The times are shown as a number  
FCLK  
FCLK  
FCLK  
of cycles of FCLK and as an absolute time for the case where t  
shown include overhead for the command state machine and enabling and disabling of program and erase  
voltages.  
= 5 µs. Program and erase times  
FCLK  
Table 4-5 Program and Erase Times  
Parameter  
Cycles of FCLK  
Time if FCLK = 200 kHz  
Byte program  
9
4
45 µs  
20 µs(1)  
20 ms  
Byte program (burst)  
Page erase  
4000  
20,000  
Mass erase  
100 ms  
NOTES:  
1. Excluding start/end overhead  
4.4.3 Program and Erase Command Execution  
The steps for executing any of the commands are listed below. The FCDIV register must be initialized and  
any error flags 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. In the 60K version,  
there are two instances where the size of a block that is accessible to the user is less than 512 bytes:  
the first page following RAM, and the first page following the high page registers. These pages are  
overlapped by the RAM and high page registers respectively.  
2. Write the command code for the desired command to FCMD. The five valid commands are blank  
check ($05), byte program ($20), burst program ($25), page erase ($40), and mass erase ($41). 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.  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
43  
 
 
Memory  
A strictly monitored procedure must be adhered to, 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.  
START  
0
FACCERR ?  
CLEAR ERROR  
(1)  
(1)  
Only required once  
after reset.  
WRITE TO FCDIV  
WRITE TO FLASH  
TO BUFFER ADDRESS AND DATA  
WRITE COMMAND TO FCMD  
(2)  
WRITE 1 TO FCBEF  
Wait at least four cycles before  
checking FCBEF or FCCF.  
TO LAUNCH COMMAND  
(2)  
AND CLEAR FCBEF  
YES  
FPVIO OR  
FACCERR ?  
ERROR EXIT  
NO  
0
FCCF ?  
1
DONE  
Figure 4-2 FLASH Program and Erase Flowchart  
Freescale Semiconductor  
44  
MC9S08RC/RD/RE/RG  
 
SoC Guide — MC9S08RG60/D Rev 1.10  
4.4.4 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 remains enabled after completion of  
the burst program operation if the following two conditions are met:  
The new burst program command has been queued before the current program operation completes.  
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.  
The first byte of a series of sequential bytes being programmed in burst mode will take the same amount  
of time to program as a byte programmed in standard mode. Subsequent bytes will 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 will be 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 will be  
disabled and high voltage removed from the array.  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
45  
Memory  
START  
0
FACCERR ?  
1
CLEAR ERROR  
(1)  
(1)  
WRITE TO FCDIV  
Only required once  
after reset.  
0
FCBEF ?  
1
WRITE TO FLASH  
TO BUFFER ADDRESS AND DATA  
WRITE COMMAND TO FCMD  
(2)  
WRITE 1 TO FCBEF  
Wait at least four cycles before  
checking FCBEF or FCCF.  
TO LAUNCH COMMAND  
(2)  
AND CLEAR FCBEF  
YES  
FPVIO OR  
FACCERR ?  
ERROR EXIT  
NO  
NEW BURST COMMAND ?  
NO  
YES  
0
FCCF ?  
1
DONE  
Figure 4-3 FLASH Burst Program Flowchart  
Freescale Semiconductor  
46  
MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
4.4.5 Access Errors  
An access error occurs whenever the command execution protocol is violated.  
Any of the following specific actions will cause the access error flag (FACCERR) in FSTAT to be set.  
FACCERR must be cleared by writing a 1 to FACCERR in FSTAT before any command can be  
processed:  
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 be started 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 other than the five allowed codes ($05, $20, $25, $40, or $41) to FCMD  
Accessing (read or write) 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 ($20, $25, or $40) 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  
4.4.6 FLASH Block Protection  
Block protection prevents program or erase changes for FLASH memory locations in a designated address  
range. Mass erase is disabled when any block of FLASH is protected. The MC9S08RC/RD/RE/RG allows  
a block of memory at the end of FLASH, and/or the entire FLASH memory to be block protected. A  
disable control bit and a 3-bit control field, for each of the blocks, allows the user to independently set the  
size of these blocks. A separate control bit allows block protection of the entire FLASH memory array. All  
seven of these control bits are located in the FPROT register (see 4.6.4 FLASH Protection Register  
(FPROT and NVPROT)).  
At reset, the high-page register (FPROT) is loaded with the contents of the NVPROT location that is in  
the nonvolatile register block of the FLASH memory. The value in FPROT cannot be changed directly  
from application software so a runaway program cannot alter the block protection settings. If the last  
512 bytes of FLASH (which includes the NVPROT register) is protected, the application program cannot  
alter the block protection settings (intentionally or unintentionally). The FPROT control bits can be written  
by background debug commands to allow a way to erase a protected FLASH memory.  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
47  
 
Memory  
One use for 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 during an erase and reprogram  
operation.  
4.4.7 Vector Redirection  
Whenever any block protection is enabled, the reset and interrupt vectors will be protected. For this reason,  
a mechanism for redirecting vector reads is provided. Vector redirection allows users to modify interrupt  
vector information without unprotecting bootloader and reset vector space. 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 $FFBD. All of the interrupt vectors (memory locations  
$FFC0–$FFFD) are redirected, while the reset vector ($FFFE:FFFF) is not.  
For example, if 512 bytes of FLASH are protected, the protected address region is from $FE00 through  
$FFFF. The interrupt vectors ($FFC0–$FFFD) are redirected to the locations $FDC0–$FDFD. Now, if an  
SPI interrupt is taken for instance, the values in the locations $FDE0:FDE1 are used for the vector instead  
of the values in the locations $FFE0:FFE1. This allows the user 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.  
4.5 Security  
The MC9S08RC/RD/RE/RG 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. A user engages security by programming the  
NVOPT location, which can be done at the same time the FLASH memory is programmed. The 1:0 state  
disengages security while the other three combinations engage security. Notice the erased state (1:1)  
makes the MCU secure. During development, whenever the FLASH is erased, it is good practice to  
immediately program the SEC00 bit to 0 in NVOPT so SEC01:SEC00 = 1:0. This would allow 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, but the MCU cannot enter active  
background mode except by holding BKGD/MS low at the rising edge of reset.  
A user 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  
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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  
will be disengaged until the next reset.  
The security key can be written only from RAM, so it cannot be entered through background commands  
without the cooperation of a secure user program. The FLASH memory cannot be accessed by read  
operations while KEYACC is set.  
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 performing 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.  
4.6 FLASH Registers and Control Bits  
The FLASH module has nine 8-bit registers in the high-page register space, three locations in the  
nonvolatile register space in FLASH memory that are copied into three corresponding high-page control  
registers at reset. There is also an 8-byte comparison key in FLASH memory. Refer to Table 4-3 and Table  
4-4 for the absolute address assignments for all FLASH registers. This section refers to registers and  
control bits only by their names. A Freescale-provided equate or header file normally is used to translate  
these names into the appropriate absolute addresses.  
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4.6.1 FLASH Clock Divider Register (FCDIV)  
Bit 7 of this register is a read-only status flag. Bits 6 through 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.  
Bit 7  
Read: DIVLD  
Write:  
6
PRDIV8  
0
5
DIV5  
0
4
DIV4  
0
3
DIV3  
0
2
DIV2  
0
1
DIV1  
0
Bit 0  
DIV0  
0
Reset:  
0
= Unimplemented or Reserved  
Figure 4-4 FLASH Clock Divider Register (FCDIV)  
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.  
1 = FCDIV has been written since reset; erase and program operations enabled for FLASH.  
0 = FCDIV has not been written since reset; erase and program operations disabled for FLASH.  
PRDIV8 — Prescale (Divide) FLASH Clock by 8  
1 = Clock input to the FLASH clock divider is the bus rate clock divided by 8.  
0 = Clock input to the FLASH clock divider is the bus rate clock.  
DIV5:DIV0 — 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 DIV5:DIV0 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.  
Equation 1 if PRDIV8 = 0 — f  
Equation 2 if PRDIV8 = 1 — f  
= f ÷ ([DIV5:DIV0] + 1)  
FCLK  
FCLK  
Bus  
= f ÷ (8 × ([DIV5:DIV0] + 1))  
Bus  
Table 4-6 shows the appropriate values for PRDIV8 and DIV5:DIV0 for selected bus frequencies.  
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Table 4-6 FLASH Clock Divider Settings  
PRDIV8  
(Binary)  
DIV5:DIV0  
(Decimal)  
Program/Erase Timing Pulse  
f
f
FCLK  
Bus  
(5 µs Min, 6.7 µs Max)  
8 MHz  
4 MHz  
0
0
0
0
0
0
39  
19  
9
200 kHz  
200 kHz  
200 kHz  
200 kHz  
200 kHz  
150 kHz  
5 µs  
5 µs  
2 MHz  
5 µs  
1 MHz  
4
5 µs  
200 kHz  
150 kHz  
0
5 µs  
0
6.7 µs  
4.6.2 FLASH Options Register (FOPT and NVOPT)  
During reset, the contents of the nonvolatile location NVOPT are copied from FLASH into FOPT. Bits 5  
through 2 are not used and always read 0. This register may be read at any time, but writes have no meaning  
or effect. 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.  
Bit 7  
6
5
4
3
2
1
Bit 0  
Read: KEYEN FNORED  
Write:  
0
0
0
0
SEC01  
SEC00  
Reset:  
This register is loaded from nonvolatile location NVOPT during reset.  
= Unimplemented or Reserved  
Figure 4-5 FLASH Options Register (FOPT)  
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 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 4.5 Security.  
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.  
0 = No backdoor key access allowed.  
FNORED — Vector Redirection Disable  
When this bit is 1, then vector redirection is disabled.  
1 = Vector redirection disabled.  
0 = Vector redirection enabled.  
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SEC01:SEC00 — Security State Code  
This 2-bit field determines the security state of the MCU as shown in Table 4-7. 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. For more detailed information about  
security, refer to 4.5 Security.  
Table 4-7 Security States  
SEC01:SEC00  
Description  
secure  
0:0  
0:1  
1:0  
1:1  
secure  
unsecured  
secure  
SEC01:SEC00 changes to 1:0 after successful backdoor key entry or a successful blank check of FLASH.  
4.6.3 FLASH Configuration Register (FCNFG)  
Bits 7 through 5 may be read or written at any time. Bits 4 through 0 always read 0 and cannot be written.  
Bit 7  
0
6
0
5
KEYACC  
0
4
0
3
0
2
0
1
0
Bit 0  
0
Read:  
Write:  
Reset:  
0
0
0
0
0
0
0
= Unimplemented or Reserved  
Figure 4-6 FLASH Configuration Register (FCNFG)  
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 4.5 Security.  
1 = Writes to NVBACKKEY ($FFB0–$FFB7) are interpreted as comparison key writes.  
Reads of the FLASH return invalid data.  
0 = Writes to $FFB0–$FFB7 are interpreted as the start of a FLASH programming or erase  
command.  
4.6.4 FLASH Protection Register (FPROT and NVPROT)  
During reset, the contents of the nonvolatile location NVPROT is copied from FLASH into FPROT. Bits  
0, 1, and 2 are not used and each always reads as 0. This register may be read at any time, but user program  
writes have no meaning or effect. Background debug commands can write to FPROT at $1824.  
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Bit 7  
6
5
4
3
2
0
1
0
Bit 0  
0
Read: FPOPEN  
FPDIS  
FPS2  
(1)  
FPS1  
(1)  
FPS0  
(1)  
(1)  
(1)  
Write:  
Reset:  
This register is loaded from nonvolatile location NVPROT during reset.  
= Unimplemented or Reserved  
NOTES:  
1. Background commands can be used to change the contents of these bits in FPROT.  
Figure 4-7 FLASH Protection Register (FPROT)  
FPOPEN — Open Unprotected FLASH for Program/Erase  
1 = Any FLASH location, not otherwise block protected or secured, may be erased or programmed.  
0 = Entire FLASH memory is block protected (no program or erase allowed).  
FPDIS — FLASH Protection Disable  
1 = No FLASH block is protected.  
0 = FLASH block specified by FPS2:FPS0 is block protected (program and erase not allowed).  
FPS2:FPS1:FPS0 — FLASH Protect Size Selects  
When FPDIS = 0, this 3-bit field determines the size of a protected block of FLASH locations at the  
high address end of the FLASH (see Table 4-8). Protected FLASH locations cannot be erased or  
programmed.  
Table 4-8 High Address Protected Block for 32K and 60K Versions  
(1)  
FPS2:FPS1:FPS0  
Protected Address Range  
Protected Block Size  
Redirected Vectors  
$FDC0–$FDFD(2)  
$FBC0–$FBFD  
$F7C0–$F7FD  
$EFC0–$EFFD  
$DFC0–$DFFD  
$BFC0–$BFFD  
$7FC0–$7FFD  
0:0:0  
0:0:1  
0:1:0  
0:1:1  
1:0:0  
1:0:1  
$FE00–$FFFF  
$FC00–$FFFF  
$F800–$FFFF  
$F000–$FFFF  
$E000–$FFFF  
$C000–$FFFF  
$8000–$FFFF  
512 bytes  
1 Kbytes  
2 Kbytes  
4 Kbytes  
8 Kbytes  
16 Kbytes  
32 Kbytes  
1:1:0(3)  
1:1:1(3)  
$8000–$FFFF  
32 Kbytes  
$7FC0–$7FFD  
NOTES:  
1. No redirection if FPOPEN = 0, or FNORED = 1.  
2. Reset vector is not redirected.  
3. Use for 60K version only. When protecting all of 32K version memory, use FPOPEN = 0.  
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Memory  
Table 4-9 High Address Protected Block for 8K and 16K Version  
(1)  
FPS2:FPS1:FPS0  
Protected Address Range  
Protected Block Size  
Redirected Vectors  
$FDC0–$FDFD(2)  
$FBC0–$FBFD  
$F7C0–$F7FD  
$EFC0–$EFFD  
$DFC0–$DFFD  
0:0:0  
0:0:1  
0:1:0  
0:1:1  
$FE00–$FFFF  
$FC00–$FFFF  
$F800–$FFFF  
$F000–$FFFF  
$E000–$FFFF  
512 bytes  
1 Kbytes  
2 Kbytes  
4 Kbytes  
8 Kbytes  
1:0:0(3)  
1:0:1(3)  
1:1:0(3)  
$E000–$FFFF  
$E000–$FFFF  
$E000–$FFFF  
8 Kbytes  
8 Kbytes  
8 Kbytes  
$DFC0–$DFFD  
$DFC0–$DFFD  
$DFC0–$DFFD  
1:1:1(3)  
NOTES:  
1. No redirection if FPOPEN = 0, or FNORED = 1.  
2. Reset vector is not redirected.  
3. Use for 60K version only. When protecting all of 32K version memory, use FPOPEN = 0.  
4.6.5 FLASH Status Register (FSTAT)  
Bits 3, 1, and 0 always read 0 and writes have no meaning or effect. The remaining five bits are status bits  
that can be read at any time. Writes to these bits have special meanings that are discussed in the bit  
descriptions.  
Bit 7  
FCBEF  
1
6
5
4
3
0
2
1
0
Bit 0  
0
Read:  
Write:  
Reset:  
FCCF  
FBLANK  
FPVIOL FACCERR  
1
0
0
0
0
0
0
= Unimplemented or Reserved  
Figure 4-8 FLASH Status Register (FSTAT)  
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.  
1 = A new burst program command may be written to the command buffer.  
0 = Command buffer is full (not ready for additional commands).  
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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.  
1 = All commands complete  
0 = Command in progress  
FPVIOL — Protection Violation Flag  
FPVIOL is set automatically when FCBEF is cleared to register a command 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.  
1 = An attempt was made to erase or program a protected location.  
0 = No protection violation.  
FACCERR — Access Error Flag  
FACCERR is set automatically when the proper command sequence is not followed 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 4.4.5 Access Errors. FACCERR  
is cleared by writing a 1 to FACCERR. Writing a 0 to FACCERR has no meaning or effect.  
1 = An access error has occurred.  
0 = No access error.  
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.  
1 = After a blank check command is completed and FCCF = 1, FBLANK = 1 indicates the FLASH  
array is completely erased (all $FF).  
0 = After a blank check command is completed and FCCF = 1, FBLANK = 0 indicates the FLASH  
array is not completely erased.  
4.6.6 FLASH Command Register (FCMD)  
Only four command codes are recognized in normal user modes as shown in Table 4-10. Refer to  
4.4.3 Program and Erase Command Execution for a detailed discussion of FLASH programming and erase  
operations.  
Bit 7  
0
6
5
0
4
0
3
0
2
0
1
0
Bit 0  
0
Read:  
0
FCMD6  
0
Write: FCMD7  
Reset:  
FCMD5 FCMD4 FCMD3 FCMD2 FCMD1 FCMD0  
0
0
0
0
0
0
0
Figure 4-9 FLASH Command Register (FCMD)  
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Memory  
Table 4-10 FLASH Commands  
Command  
FCMD  
$05  
Equate File Label  
Blank check  
mBlank  
Byte program  
$20  
mByteProg  
mBurstProg  
mPageErase  
mMassErase  
Byte program – burst mode  
Page erase (512 bytes/page)  
Mass erase (all FLASH)  
$25  
$40  
$41  
All other command codes are illegal and generate an access error.  
It is not necessary to perform a blank check command after a mass erase operation. Only blank check is  
required as part of the security unlocking mechanism.  
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Chapter 5 Resets, Interrupts, and System Configuration  
5.1 Introduction  
This section discusses basic reset and interrupt mechanisms and the various sources of reset and interrupts  
in the MC9S08RC/RD/RE/RG. Some interrupt sources from peripheral modules are discussed in greater  
detail within other sections of this data sheet. This section gathers basic information about all reset and  
interrupt sources in one place for easy reference. A few reset and interrupt sources, including the computer  
operating properly (COP) watchdog and real-time interrupt (RTI), are not part of on-chip peripheral  
systems having their own sections but are part of the system control logic.  
5.2 Features  
Reset and interrupt features include:  
Multiple sources of reset for flexible system configuration and reliable operation:  
– Power-on detection (POR)  
– Low voltage detection (LVD) with enable  
– External reset pin with enable (RESET)  
– COP watchdog with enable and two timeout choices  
– Illegal opcode  
– Illegal address (on 16K and 8K devices)  
– Serial command from a background debug host  
Reset status register (SRS) to indicate source of most recent reset; flag to indicate stop2 (partial  
power down) mode recovery (PPDF)  
Separate interrupt vectors for each module (reduces polling overhead) (see Table 5-1)  
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Resets, Interrupts, and System Configuration  
5.3 MCU Reset  
Resetting the MCU provides a way to start processing from a known set of initial conditions. During reset,  
most control and status registers are forced to initial values and the program counter is loaded from the  
reset vector ($FFFE:$FFFF). 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 until the user program has a chance to initialize the stack  
pointer (SP) and system control settings. SP is forced to $00FF at reset.  
The MC9S08RC/RD/RE/RG has six sources for reset:  
Power-on reset (POR)  
Low-voltage detect (LVD)  
Computer operating properly (COP) timer  
Illegal opcode detect  
Illegal address (16K and 8K devices only)  
Background debug forced reset  
The reset pin (RESET)  
Each of these sources, with the exception of the background debug forced reset, has an associated bit in  
the system reset status register. Whenever the MCU enters reset, the reset pin is driven low for 34 internal  
bus cycles where the internal bus frequency is one-half the OSC frequency. After the 34 cycles are  
completed, the pin is released and will be pulled up by the internal pullup resistor, unless it is held low  
externally. After the pin is released, it is sampled after another 38 cycles to determine whether the reset  
pin is the cause of the MCU reset.  
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 timer periodically. If the application program gets lost and fails to reset the COP before it  
times out, a system reset is generated to force the system back to a known starting point. The COP  
watchdog is enabled by the COPE bit in SOPT (see 5.8.4 System Options Register (SOPT) for additional  
information). The COP timer 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 timer.  
After any reset, the COP timer is enabled. This provides a reliable way to detect code that is not executing  
as intended. If the COP watchdog is not used in an application, it can be disabled by clearing the COPE  
bit in the write-once SOPT register. Also, the COPT bit can be used to choose one of two timeout periods  
18  
20  
(2 or 2 cycles of the bus rate clock). Even if the application will use the reset default settings in COPE  
and COPT, the user must write to write-once SOPT during reset initialization to lock in the settings. That  
way, they cannot be changed accidentally if the application program gets lost.  
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The write to SRS that services (clears) the COP timer 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.  
When the MCU is in active background mode, the COP timer is temporarily disabled.  
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 resumes where it was 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 will become set. The  
CPU will not respond until and unless the local interrupt enable is a logic 1 to enable the interrupt. The I  
bit in the CCR is logic 0 to allow interrupts. The global interrupt mask (I bit) in the CCR is initially set  
after reset, which masks (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 uses 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  
may 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 that restores the CCR, A,  
X, and PC registers to their pre-interrupt values by reading the previously saved information off the stack.  
NOTE: For compatibility with the M68HC08 Family, 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 just before the RTI that is  
used to return from the ISR.  
If two or more interrupts are pending when the I bit is cleared, the highest priority source is serviced first  
(see Table 5-1).  
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Resets, Interrupts, and System Configuration  
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, which is the address that 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.  
TOWARD LOWER ADDRESSES  
UNSTACKING  
ORDER  
7
0
SP AFTER  
INTERRUPT STACKING  
5
4
3
2
1
1
2
3
4
5
CONDITION CODE REGISTER  
ACCUMULATOR  
*
INDEX REGISTER (LOW BYTE X)  
PROGRAM COUNTER HIGH  
PROGRAM COUNTER LOW  
SP BEFORE  
THE INTERRUPT  
STACKING  
ORDER  
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 just recovered from the stack.  
The status flag causing the interrupt must be acknowledged (cleared) before returning from the ISR.  
Typically, the flag must be cleared at the beginning of the ISR so that if another interrupt is generated by  
this same source, it will be registered so it can be serviced after completion of the current ISR.  
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5.5.2 External Interrupt Request (IRQ) Pin  
External interrupts are managed by the IRQSC status and control register. 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 (if enabled)  
can wake the MCU.  
5.5.2.1 Pin Configuration Options  
The IRQ pin enable (IRQPE) control bit in the IRQSC register must be 1 in order for the IRQ pin to act as  
the interrupt request (IRQ) input. When the pin is configured as an IRQ input, the user 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 merely sets the IRQF flag (which can be polled  
by software).  
When the IRQ pin is configured to detect rising edges, an optional pulldown resistor is available rather  
than a pullup resistor. 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 this  
edge 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.  
5.5.3 Interrupt Vectors, Sources, and Local Masks  
Table 5-1 provides a summary of all interrupt sources. Higher-priority sources are located towards 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 will finish 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 5-1 Vector Summary  
Vector  
Vector  
Address  
Vector Name Module  
Source  
Enable  
Description  
Priority Number (High/Low)  
16  
through  
31  
$FFC0/FFC1  
through  
$FFDE/FFDF  
Unused Vector Space  
(available for user program)  
Lower  
SPIF  
MODF  
SPTEF  
SPIE  
SPIE  
SPTIE  
SPI(1)  
Vspi1  
15  
$FFE0/FFE1  
SPI  
System  
control  
14  
$FFE2/FFE3  
Vrti  
RTIF  
RTIE  
Real-time interrupt  
13  
12  
11  
10  
$FFE4/FFE5  
$FFE6/FFE7  
$FFE8/FFE9  
$FFEA/FFEB  
Vkeyboard2  
Vkeyboard1  
Vacmp1  
KBI2  
KBI1  
ACMP(2)  
CMT  
KBF  
KBF  
KBIE  
KBIE  
Keyboard 2 pins  
Keyboard 1 pins  
ACMP compare  
CMT  
ACF  
ACIE  
Vcmt  
EOCF  
EOCIE  
TDRE  
TC  
TIE  
TCIE  
SCI(3)  
SCI(3)  
9
8
$FFEC/FFED  
$FFEE/FFEF  
Vsci1tx  
Vsci1rx  
SCI transmit  
SCI receive  
IDLE  
RDRF  
ILIE  
RIE  
OR  
NF  
FE  
PF  
ORIE  
NFIE  
FEIE  
PFIE  
SCI(3)  
7
$FFF0/FFF1  
Vsci1err  
SCI error  
6
5
4
3
$FFF2/FFF3  
$FFF4/FFF5  
$FFF6/FFF7  
$FFF8/FFF9  
Vtpm1ovf  
Vtpm1ch1  
Vtpm1ch0  
Virq  
TPM  
TPM  
TPM  
IRQ  
TOF  
CH1F  
CH0F  
IRQF  
TOIE  
CH1IE  
CH0IE  
IRQIE  
TPM overflow  
TPM channel 1  
TPM channel 0  
IRQ pin  
System  
control  
2
1
$FFFA/FFFB  
$FFFC/FFFD  
Vlvd  
Vswi  
LVDF  
LVDIE  
Low-voltage detect  
Software interrupt  
SWI  
Instruction  
Core  
COP  
LVD  
RESET pin  
Illegal opcode  
Illegal address  
COPE  
LVDRE  
RSTPE  
Watchdog timer  
Low-voltage detect  
External pin  
Illegal opcode  
Illegal address  
System  
control  
0
$FFFE/FFFF  
Vreset  
Higher  
NOTES:  
1. The SPI module is not included on the MC9S08RC/RD/RE devices. This vector location is unused for those devices.  
2. The analog comparator (ACMP) module is not included on the MC9S08RD devices. This vector location is unused for  
those devices.  
3. The SCI module is not included on the MC9S08RC devices. This vector location is unused for those devices.  
5.6 Low-Voltage Detect (LVD) System  
The MC9S08RC/RD/RE/RG includes a system to protect against low-voltage conditions in order to  
protect memory contents and control MCU system states during supply voltage variations. The system is  
comprised of a power-on reset (POR) circuit, an LVD circuit with flag bits for warning and detection, and  
a mechanism for entering a system safe state following an LVD interrupt. The LVD circuit can be  
configured to generate an interrupt or a reset when low supply voltage has been detected.  
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5.6.1 Power-On Reset Operation  
When power is initially applied to the MCU, or when the supply voltage drops below the V  
level, the  
POR  
POR circuit will cause a reset condition. As the supply voltage rises, the LVD circuit will hold the chip in  
reset until the supply has risen above the V  
following a POR.  
level. Both the POR bit and the LVD bit in SRS are set  
LVD  
5.6.2 LVD Reset Operation  
The LVD can be configured to generate a reset upon detection of a low voltage condition. This is done by  
setting LVDRE to 1. LVDRE is a write-once bit that is set following a POR and is unaffected by other  
resets. When LVDRE = 1, setting the SAFE bit has no effect. After an LVD reset has occurred, the LVD  
system will hold the MCU in reset until the supply voltage is above the V  
SRS register is set following either an LVD reset or POR.  
level. The LVD bit in the  
LVD  
5.6.3 LVD Interrupt and Safe State Operation  
When the voltage on the supply pin V drops below V  
and the LVD circuit is configured for interrupt  
LVD  
DD  
operation (LVDIE is set and LVDRE is clear), an LVD interrupt will occur. The LVD trip point is set  
above the minimum voltage at which the MCU can reliably operate, but the supply voltage may still be  
dropping. It is recommended that the user place the MCU in the safe state as soon as possible following a  
LVD interrupt. For systems where the supply voltage may drop so rapidly that the MCU may not have  
time to service the LVD interrupt and enter the safe state, it is recommended that the LVD be configured  
to generate a reset. The safe state is entered by executing a STOP instruction with the SAFE bit in the  
system power management status and control 1 (SPMSC1) register set while in a low voltage condition  
(LVDF = 1).  
After the LVD interrupt has occurred, the user may configure the system to block all interrupts, resets, or  
wakeups by writing a 1 to the SAFE bit. While SAFE =1 and V is below V  
all interrupts, resets,  
DD  
REARM  
and wakeups are blocked. After V is above V  
, the SAFE bit is ignored (the SAFE bit will still  
DD  
REARM  
read a logic 1). After setting the SAFE bit, the MCU must be put into either the stop3 or stop2 mode before  
the supply voltage drops below the minimum operating voltage of the MCU. The supply voltage may now  
drop to a level just above the POR trip point and then restored to a level above V  
and the MCU state  
REARM  
(in the case of stop3) and RAM contents will be preserved. When the supply voltage has been restored,  
interrupts, resets, and wakeups are then unblocked. When the MCU has recovered from stop mode, the  
SAFE bit should be cleared.  
5.6.4 Low-Voltage Warning (LVW)  
The LVD system has a low-voltage warning flag to indicate to the user that the supply voltage is  
approaching, but is still above, the low-voltage detect voltage. The LVW does not have an interrupt  
associated with it. However, the FLASH memory cannot be reliably programmed or erased below the  
V
level, so the status of the LVWF bit in the system power management status and control 2  
LVW  
(SPMSC2) register must be checked before initiating any FLASH program or erase operation.  
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5.7 Real-Time Interrupt (RTI)  
The real-time interrupt (RTI) function can be used to generate periodic interrupts based on a divide of the  
external oscillator or an internal 1-kHz clock source. It can also be used to wake the MCU from stop2 or  
stop3 mode when using the internal 1-kHz clock source.  
The SRTISC register includes a read-only status flag, a write-only acknowledge bit, and a 3-bit control  
value (RTIS2:RTIS1:RTIS0) used to disable the clock source to the real-time interrupt or select one of  
seven wakeup delays between 8 ms and 1.024 seconds. The 1-kHz clock source and therefore the periodic  
rates have a tolerance of about ±30 percent. The RTI has a local interrupt enable, RTIE, to allow masking  
of the real-time interrupt. It can be disabled by writing 0:0:0 to RTIS2:RTIS1:RTIS0 so the clock source  
is disabled and no interrupts will be generated. See 5.8.6 System Real-Time Interrupt Status and Control  
Register (SRTISC) for detailed information about this register.  
5.8 Reset, Interrupt, and System Control Registers and Control Bits  
One 8-bit register in the direct page register space and five 8-bit registers in the high-page register space  
are related to reset and interrupt systems.  
Refer to the direct-page register summary in the Memory section of this data sheet 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 SOPT 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 Modes  
of Operation.  
5.8.1 Interrupt Pin Request Status and Control Register (IRQSC)  
This direct page register includes two unimplemented bits that always read 0, four read/write bits, one  
read-only status bit, and one write-only bit. These bits are used to configure the IRQ function, report status,  
and acknowledge IRQ events.  
Bit 7  
0
6
0
5
4
3
2
1
IRQIE  
0
Bit 0  
IRQMOD  
0
Read:  
Write:  
Reset:  
IRQF  
0
IRQACK  
0
IRQEDG IRQPE  
0
0
0
0
0
= Unimplemented or Reserved  
Figure 5-2 Interrupt Request Status and Control Register (IRQSC)  
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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 the IRQ pin is enabled as the IRQ input and is configured to detect  
rising edges, the optional pullup resistor is reconfigured as an optional pulldown resistor.  
1 = IRQ is rising edge or rising edge/high-level sensitive.  
0 = IRQ is falling edge or falling edge/low-level sensitive.  
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. Also, when this bit is set, either an internal pull-up or an internal pull-down  
resistor is enabled depending on the state of the IRQMOD bit.  
1 = IRQ pin function is enabled.  
0 = IRQ pin function is disabled.  
IRQF — IRQ Flag  
This read-only status bit indicates when an interrupt request event has occurred.  
1 = IRQ event detected.  
0 = No IRQ request.  
IRQACK — 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 logic 0. If edge-and-level detection is selected  
(IRQMOD = 1), IRQF cannot be cleared while the IRQ pin remains at its asserted level.  
IRQIE — IRQ Interrupt Enable  
This read/write control bit determines whether IRQ events generate a hardware interrupt request.  
1 = Hardware interrupt requested whenever IRQF = 1.  
0 = Hardware interrupt requests from IRQF disabled (use polling).  
IRQMOD — 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 5.5.2.2 Edge and Level Sensitivity for more details.  
1 = IRQ event on falling edges and low levels or on rising edges and high levels.  
0 = IRQ event on falling edges or rising edges only.  
5.8.2 System Reset Status Register (SRS)  
This register includes seven 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 will  
be 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.  
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Resets, Interrupts, and System Configuration  
Bit 7  
POR  
6
5
4
3
2
0
1
Bit 0  
0
(1)  
Read:  
Write:  
PIN  
COP  
ILOP  
ILAD  
LVD  
Writing any value to SRS address clears COP watchdog timer.  
Power-on reset:  
Low-voltage reset:  
Any other reset:  
1
U
0
0
0
0
0
0
0
0
1
1
0
0
0
0
0
0
0
0
(2)  
(2)  
(2)  
(2)  
U = Unaffected by reset  
NOTES:  
1. The ILAD bit is only present in 16K and 8K versions of the devices.  
2. Any of these reset sources that are active at the time of reset will cause the corresponding bit(s) to be set;  
bits corresponding to sources that are not active at the time of reset will be cleared.  
Figure 5-3 System Reset Status (SRS)  
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 (LVR) status bit is also set to indicate that the reset occurred while  
the internal supply was below the LVR threshold.  
1 = POR caused reset.  
0 = Reset not caused by POR.  
PIN — External Reset Pin  
Reset was caused by an active-low level on the external reset pin.  
1 = Reset came from external reset pin.  
0 = Reset not caused by external reset pin.  
COP — Computer Operating Properly (COP) Watchdog  
Reset was caused by the COP watchdog timer timing out. This reset source may be blocked by  
COPE = 0.  
1 = Reset caused by COP timeout.  
0 = Reset not caused by COP timeout.  
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.  
1 = Reset caused by an illegal opcode.  
0 = Reset not caused by an illegal opcode.  
ILAD — Illegal Address Access  
Reset was caused by an attempt to access a designated illegal address.  
1 = Reset caused by an illegal address access  
0 = Reset not caused by an illegal address access  
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Illegal address areas only exist in the 16K and 8K versions and are defined as:  
$0440–$17FF — Gap from end of RAM to start of high-page registers  
$1834–$BFFF — Gap from end of high-page registers to start of FLASH memory  
Unused and reserved locations in register areas are not considered designated illegal addresses and do  
not trigger illegal address resets.  
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.  
1 = Reset caused by LVD trip or POR  
0 = Reset not caused by LVD trip or POR  
5.8.3 System Background Debug Force Reset Register (SBDFR)  
This 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 $00.  
Bit 7  
0
6
0
5
0
4
0
3
0
2
0
1
0
Bit 0  
0
Read:  
Write:  
Reset:  
(1)  
BDFR  
0
0
0
0
0
0
0
0
= Unimplemented or Reserved  
NOTES:  
1. BDFR is writable only through serial background debug commands, not from user programs.  
Figure 5-4 System Background Debug Force Reset Register (SBDFR)  
BDFR — Background Debug Force Reset  
A serial background command such as WRITE_BYTE may be used to allow an external debug host  
to force a target system reset. Writing logic 1 to this bit forces an MCU reset. This bit cannot be written  
from a user program.  
5.8.4 System Options Register (SOPT)  
This register may be read at any time. Bits 3 and 2 are unimplemented and always read 0. This is a  
write-once register so only the first write after reset is honored. Any subsequent attempt to write to SOPT  
(intentionally or unintentionally) is ignored to avoid accidental changes to these sensitive settings. SOPT  
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.  
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Bit 7  
COPE  
1
6
COPT  
1
5
STOPE  
0
4
1
3
0
2
0
1
Bit 0  
Read:  
Write:  
Reset:  
BKGDPE RSTPE  
0
0
1
1
= Unimplemented or Reserved  
Figure 5-5 System Options Register (SOPT)  
COPE — COP Watchdog Enable  
This write-once bit defaults to 1 after reset.  
1 = COP watchdog timer enabled (force reset on timeout).  
0 = COP watchdog timer disabled.  
COPT — COP Watchdog Timeout  
This write-once bit defaults to 1 after reset.  
20  
1 = Long timeout period selected (2 cycles of BUSCLK).  
18  
0 = Short timeout period selected (2 cycles of BUSCLK).  
STOPE — Stop Mode Enable  
This write-once bit defaults to 0 after reset, which disables stop mode. If stop mode is disabled and a  
user program attempts to execute a STOP instruction, an illegal opcode reset is forced.  
1 = Stop mode enabled.  
0 = Stop mode disabled.  
BKGDPE — Background Debug Mode Pin Enable  
The BKGDPE bit enables the PTD0/BKGD/MS pin to function as BKGD/MS. When the bit is clear,  
the pin will function as PTD0, which is an output only general purpose I/O. This pin always defaults  
to BKGD/MS function after any reset.  
1 = BKGD pin enabled.  
0 = BKGD pin disabled.  
RSTPE — RESET Pin Enable  
The RSTPE bit enables the PTD1/RESET pin to function as RESET. When the bit is clear, the pin will  
function as PTD1, which is an output only general purpose I/O. This pin always defaults to RESET  
function after any reset.  
1 = RESET pin enabled  
0 = RESET pin disabled  
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5.8.5 System Device Identification Register (SDIDH, SDIDL)  
This read-only register is included so host development systems can identify the HCS08 derivative and  
revision number. This allows the development software to recognize where specific memory blocks,  
registers, and control bits are located in a target MCU.  
Bit 7  
6
5
4
3
ID11  
0
2
ID10  
0
1
ID9  
0
Bit 0  
ID8  
0
Read: REV3  
REV2  
REV1  
REV0  
(1)  
(1)  
(1)  
(1)  
Reset:  
Read:  
0
0
0
0
ID7  
0
ID6  
0
ID5  
0
ID4  
0
ID3  
0
ID2  
0
ID1  
1
ID0  
1
Reset, 8/16K:  
Reset, 32/60K:  
0
0
0
0
0
1
0
0
= Unimplemented or Reserved  
NOTES:  
1. The revision number that is hard coded into these bits reflects the current silicon revision level.  
Figure 5-6 System Device Identification Register (SDIDH, SDIDL)  
REV[3:0] — Revision Number  
The high-order 4 bits of address $1806 are hard coded to reflect the current mask set revision number  
(0–F).  
ID[11:0] — Part Identification Number  
Each derivative in the HCS08 Family has a unique identification number. The  
MC9S08RC/RD/RE/RG32/60 is hard coded to the value $004 and the MC9S08RC/RD/RE8/16 is hard  
coded to the value $003.  
5.8.6 System Real-Time Interrupt Status and Control Register (SRTISC)  
This register contains one read-only status flag, one write-only acknowledge bit, three read/write delay  
selects, and three unimplemented bits, which always read 0.  
Bit 7  
6
5
RTICLKS  
0
4
RTIE  
0
3
2
RTIS2  
0
1
RTIS1  
0
Bit 0  
RTIS0  
0
RTIF  
0
RTIACK  
0
0
Read:  
Write:  
Reset:  
0
0
= Unimplemented or Reserved  
Figure 5-7 System RTI Status and Control Register (SRTISC)  
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RTIF — Real-Time Interrupt Flag  
This read-only status bit indicates the periodic wakeup timer has timed out.  
1 = Periodic wakeup timer timed out.  
0 = Periodic wakeup timer not timed out.  
RTIACK — Real-Time Interrupt Acknowledge  
This write-only bit is used to acknowledge real-time interrupt request (write 1 to clear RTIF). Writing  
0 has no meaning or effect. Reads always return logic 0.  
RTICLKS — Real-Time Interrupt Clock Select  
This read/write bit selects the clock source for the real-time interrupt.  
1 = Real-time interrupt request clock source is external clock.  
0 = Real-time interrupt request clock source is internal 1-kHz oscillator.  
RTIE — Real-Time Interrupt Enable  
This read-write bit enables real-time interrupts.  
1 = Real-time interrupts enabled.  
0 = Real-time interrupts disabled.  
RTIS2:RTIS1:RTIS0 — Real-Time Interrupt Delay Selects  
These read/write bits select the wakeup delay for the RTI. The clock source for the real-time interrupt  
is a self-clocked source that oscillates at about 1 kHz and is independent of other MCU clock sources.  
Using an external clock source, the delays will be crystal frequency divided by the value in  
RTIS2:RTIS1:RTIS0.  
Table 5-2 Real-Time Interrupt Frequency  
Using External Clock Source Delay  
(crystal frequency)  
(1)  
RTIS2:RTIS1:RTIS0  
1-kHz Clock Source Delay  
0:0:0  
0:0:1  
Disable periodic wakeup timer  
Disable periodic wakeup timer  
divide by 256  
8 ms  
0:1:0  
32 ms  
divide by 1024  
0:1:1  
64 ms  
divide by 2048  
1:0:0  
128 ms  
256 ms  
512 ms  
1.024 s  
divide by 4096  
1:0:1  
divide by 8192  
1:1:0  
divide by 16384  
divide by 32768  
1:1:1  
NOTES:  
1. Normal values are shown in this column based on fRTI = 1 kHz. See Table C-9 Control Timing fRTI for the tolerance  
on these values.  
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5.8.7 System Power Management Status and Control 1 Register (SPMSC1)  
Bit 7  
Read: LVDF  
Write:  
6
5
4
3
2
0
1
0
Bit 0  
0
0
(1)  
(1)  
LVDIE  
SAFE  
LVDRE  
LVDACK  
Power-on reset:  
Any other reset:  
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
U
= Unimplemented or Reserved  
U = Unaffected by reset  
NOTES:  
1. This bit can be written only one time after reset. Additional writes are ignored.  
Figure 5-8 System Power Management Status and Control 1 Register (SPMSC1)  
LVDF — Low-Voltage Detect Flag  
Provided LVDE = 1, this read-only status bit indicates a low-voltage detect error.  
LVDACK — Low-Voltage Detect Acknowledge  
This write-only bit is used to acknowledge low voltage detection errors (write 1 to clear LVDF). Reads  
always return logic 0.  
LVDIE — Low-Voltage Detect Interrupt Enable  
This read/write bit enables hardware interrupt requests for LVDF.  
1 = Request a hardware interrupt when LVDF = 1.  
0 = Hardware interrupt disabled (use polling).  
SAFE — SAFE System from interrupts  
This read/write bit enables hardware to block interrupts and resets from waking the MCU from stop  
mode while the supply voltage V is below the V  
voltage. For a more detailed description see  
REARM  
DD  
section 5.6.3 LVD Interrupt and Safe State Operation.  
1 = Interrupts and resets are blocked while supply voltage is below re-arm voltage  
0 = Enable pending interrupts and resets  
LVDRE — Low-Voltage Detect Reset Enable  
This bit enables the LVD reset function. This bit can be written only once after a reset and additional  
writes have no meaning or effect. It is set following a POR and is unaffected by any other resets,  
including an LVD reset.  
1 = Force an MCU reset when LVDF = 1.  
0 = LVDF does not generate hardware resets.  
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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.  
Bit 7  
Read: LVWF  
Write:  
6
5
0
4
0
3
2
1
PDC  
0
Bit 0  
PPDC  
0
0
LVWACK  
0
PPDF  
0
PPDACK  
0
0(1)  
0
0
Reset:  
0
= Unimplemented or Reserved  
U = Unaffected by reset  
NOTES:  
1. LVWF will be set in the case when VSupply transitions below the trip point or after reset and VSupply is already  
below VLVW  
.
Figure 5-9 System Power Management Status and Control 2 Register (SPMSC2)  
LVWF — Low-Voltage Warning Flag  
The LVWF bit indicates the low voltage warning status.  
1 = Low voltage warning is present or was present.  
0 = Low voltage warning not present.  
LVWACK — Low-Voltage Warning Acknowledge  
The LVWF bit indicates the low voltage warning status.  
Writing a logic 1 to LVWACK clears LVWF to a logic 0 if a low voltage warning is not present.  
PPDF — Partial Power Down Flag  
The PPDF bit indicates that the MCU has exited the stop2 mode.  
1 = Stop2 mode recovery.  
0 = Not stop2 mode recovery.  
PPDACK — Partial Power Down Acknowledge  
Writing a logic 1 to PPDACK clears the PPDF bit.  
PDC — Power Down Control  
The write-once PDC bit controls entry into the power down (stop2 and stop1) modes.  
1 = Power down modes are enabled.  
0 = Power down modes are disabled.  
PPDC — Partial Power Down Control  
The write-once PPDC bit controls which power down mode, stop1 or stop2, is selected.  
1 = Stop2, partial power down, mode enabled if PDC set.  
0 = Stop1, full power down, mode enabled if PDC set.  
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Chapter 6 Central Processor Unit (CPU)  
6.1 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, 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 that replaces the monitor mode of earlier M68HC08 microcontrollers  
(MCU).  
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Central Processor Unit (CPU)  
6.2 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-Kbyte address space  
16-bit stack pointer (any size stack anywhere in 64-Kbyte 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 $0000–$00FF  
– Extended — Operand anywhere in 64-Kbyte 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  
6.3 Programmer’s Model and CPU Registers  
Figure 6-1 shows the five CPU registers. CPU registers are not part of the memory map.  
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0
ACCUMULATOR  
A
16-BIT INDEX REGISTER H:X  
INDEX REGISTER (HIGH) INDEX REGISTER (LOW)  
H
X
15  
8
7
0
SP  
PC  
STACK POINTER  
15  
0
PROGRAM COUNTER  
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 6-1 CPU Registers  
6.3.1 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.  
6.3.2 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 $00 during reset. Reset has no effect  
on the contents of X.  
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6.3.3 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-Kbyte 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 $00FF 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 $00FF).  
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.  
6.3.4 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 $FFFE and $FFFF. The  
vector stored there is the address of the first instruction that will be executed after exiting the reset state.  
6.3.5 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 logic 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/D.  
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 6-2 Condition Code Register  
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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.  
1 = Overflow  
0 = No overflow  
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.  
1 = Carry between bits 3 and 4  
0 = No carry between bits 3 and 4  
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.  
1 = Interrupts disabled  
0 = Interrupts enabled  
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.  
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.  
1 = Negative result  
0 = Non-negative result  
Z — Zero Flag  
The CPU sets the zero flag when an arithmetic operation, logic operation, or data manipulation  
produces a result of $00 or $0000. 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.  
1 = Zero result  
0 = Non-zero result  
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.  
1 = Carry out of bit 7  
0 = No carry out of bit 7  
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6.4 Addressing Modes  
Addressing modes define the way the CPU accesses operands and data. In the HCS08, all memory, status  
and control registers, and input/output (I/O) ports share a single 64-Kbyte linear address space so a 16-bit  
binary address can uniquely identify any memory location. 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.  
6.4.1 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.  
6.4.2 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.  
6.4.3 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.  
6.4.4 Direct Addressing Mode (DIR)  
In direct addressing mode, the instruction includes the low-order eight bits of an address in the direct page  
($0000–$00FF). During execution a 16-bit address is formed by concatenating an implied $00 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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6.4.5 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).  
6.4.6 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.  
6.4.6.1 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.  
6.4.6.2 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 + $0001) after the operand has been fetched. This addressing mode is only used for MOV and  
CBEQ instructions.  
6.4.6.3 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.  
6.4.6.4 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 + $0001) after the operand has been fetched. This  
addressing mode is used only for the CBEQ instruction.  
6.4.6.5 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.  
6.4.6.6 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.  
6.4.6.7 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.  
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6.5 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.  
6.5.1 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 the Resets, Interrupts, and System Configuration  
section.  
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 $FFFE and $FFFF and to fill the  
instruction queue in preparation for execution of the first program instruction.  
6.5.2 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  
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).  
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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.  
6.5.3 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.  
6.5.4 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 Modes of Operation for more details.  
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6.5.5 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.  
6.6 HCS08 Instruction Set Summary  
Instruction Set Summary Nomenclature  
The nomenclature listed here is used in the instruction descriptions in Table 6-1.  
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
CCR  
H
X
PC  
PCH  
PCL  
SP  
=
=
=
=
=
=
=
=
Accumulator  
Condition code register  
Index register, higher order (most significant) 8 bits  
Index register, lower order (least significant) 8 bits  
Program counter  
Program counter, higher order (most significant) 8 bits  
Program counter, lower order (least significant) 8 bits  
Stack pointer  
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Memory and addressing  
M = A memory location or absolute data, depending on addressing mode  
M:M + $0001= 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
H
I
N
Z
C
=
=
=
=
=
=
Two’s complement overflow indicator, bit 7  
Half carry, bit 4  
Interrupt mask, bit 3  
Negative indicator, bit 2  
Zero indicator, bit 1  
Carry/borrow, bit 0 (carry out of bit 7)  
CCR activity notation  
0
1
=
=
=
=
=
Bit not affected  
Bit forced to 0  
Bit forced to 1  
Bit set or cleared according to results of operation  
Undefined after the operation  
U
Machine coding notation  
dd  
=
Low-order 8 bits of a direct address $0000–$00FF (high byte assumed to be  
$00)  
ee  
ff  
ii  
=
=
=
=
=
=
=
=
Upper 8 bits of 16-bit offset  
Lower 8 bits of 16-bit offset or 8-bit offset  
One byte of immediate data  
High-order byte of a 16-bit immediate data value  
Low-order byte of a 16-bit immediate data value  
High-order byte of 16-bit extended address  
Low-order byte of 16-bit extended address  
Relative offset  
jj  
kk  
hh  
ll  
rr  
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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-Kbyte address space ($00xx).  
opr16a — Any label or expression that evaluates to a 16-bit value. The instruction treats  
this value as an address in the 64-Kbyte 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  
IMM  
DIR  
EXT  
IX  
IX+  
IX1  
IX1+  
=
=
=
=
=
=
=
=
Inherent (no operands)  
8-bit or 16-bit immediate  
8-bit direct  
16-bit extended  
16-bit indexed no offset  
16-bit indexed no offset, post increment (CBEQ and MOV only)  
16-bit indexed with 8-bit offset from H:X  
16-bit indexed with 8-bit offset, post increment  
(CBEQ only)  
IX2  
REL  
SP1  
SP2  
=
=
=
=
16-bit indexed with 16-bit offset from H:X  
8-bit relative offset  
Stack pointer with 8-bit offset  
Stack pointer with 16-bit offset  
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84  
MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
Table 6-1 HCS08 Instruction Set Summary (Sheet 1 of 6)  
Effect  
on CCR  
Source  
Form  
Operation  
Description  
V H I N Z C  
ADC #opr8i  
IMM  
DIR  
EXT  
IX2  
A9 ii  
B9 dd  
2
3
4
4
3
3
5
4
ADC opr8a  
ADC opr16a  
ADC oprx16,X  
ADC oprx8,X  
ADC ,X  
ADC oprx16,SP  
ADC oprx8,SP  
C9 hh ll  
D9 ee ff  
E9 ff  
Add with Carry  
A (A) + (M) + (C)  
IX1  
IX  
SP2  
SP1  
F9  
9ED9 ee ff  
9EE9 ff  
ADD #opr8i  
ADD opr8a  
IMM  
DIR  
EXT  
IX2  
AB ii  
BB dd  
2
3
4
4
3
3
5
4
ADD opr16a  
ADD oprx16,X  
ADD oprx8,X  
ADD ,X  
CB hh ll  
DB ee ff  
EB ff  
Add without Carry  
A (A) + (M)  
IX1  
IX  
SP2  
SP1  
FB  
ADD oprx16,SP  
ADD oprx8,SP  
9EDB ee ff  
9EEB ff  
Add Immediate Value  
SP (SP) + (M)  
AIS #opr8i  
– IMM  
A7 ii  
2
(Signed) to Stack Pointer M is sign extended to a 16-bit value  
Add Immediate Value  
H:X (H:X) + (M)  
AIX #opr8i  
(Signed) to Index  
– IMM  
AF ii  
2
M is sign extended to a 16-bit value  
Register (H:X)  
AND #opr8i  
AND opr8a  
IMM  
DIR  
EXT  
A4 ii  
B4 dd  
2
3
4
4
3
3
5
4
AND opr16a  
AND oprx16,X  
AND oprx8,X  
AND ,X  
C4 hh ll  
D4 ee ff  
E4 ff  
IX2  
Logical AND  
A (A) & (M)  
0
IX1  
IX  
F4  
AND oprx16,SP  
AND oprx8,SP  
SP2  
SP1  
9ED4 ee ff  
9EE4 ff  
ASL opr8a  
ASLA  
DIR  
INH  
INH  
IX1  
IX  
38 dd  
48  
5
1
1
5
4
6
ASLX  
Arithmetic Shift Left  
(Same as LSL)  
58  
C
0
ASL oprx8,X  
ASL ,X  
68 ff  
78  
b7  
b0  
b0  
ASL oprx8,SP  
SP1  
9E68 ff  
ASR opr8a  
ASRA  
DIR  
INH  
INH  
IX1  
IX  
37 dd  
47  
5
1
1
5
4
6
ASRX  
57  
C
Arithmetic Shift Right  
ASR oprx8,X  
ASR ,X  
67 ff  
77  
b7  
ASR oprx8,SP  
SP1  
9E67 ff  
BCC rel  
Branch if Carry Bit Clear  
Branch if (C) = 0  
– REL  
24 rr  
3
DIR (b0)  
11 dd  
13 dd  
15 dd  
17 dd  
19 dd  
1B dd  
1D dd  
1F dd  
5
5
5
5
5
5
5
5
DIR (b1)  
DIR (b2)  
DIR (b3)  
DIR (b4)  
DIR (b5)  
DIR (b6)  
DIR (b7)  
BCLR n,opr8a  
Clear Bit n in Memory  
Mn 0  
Branch if Carry Bit Set  
(Same as BLO)  
BCS rel  
BEQ rel  
Branch if (C) = 1  
Branch if (Z) = 1  
– REL  
– REL  
25 rr  
27 rr  
3
3
Branch if Equal  
Branch if Greater Than or  
Equal To  
BGE rel  
Branch if (N V) = 0  
– REL  
– INH  
90 rr  
82  
3
(Signed Operands)  
Waits For and Processes BDM  
Commands Until GO, TRACE1, or  
TAGGO  
Enter Active Background  
if ENBDM = 1  
BGND  
5+  
Branch if Greater Than  
(Signed Operands)  
BGT rel  
Branch if (Z) | (N V) = 0  
– REL  
– REL  
92 rr  
28 rr  
3
3
Branch if Half Carry Bit  
Clear  
BHCC rel  
Branch if (H) = 0  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
85  
Central Processor Unit (CPU)  
Table 6-1 HCS08 Instruction Set Summary (Sheet 2 of 6)  
Effect  
on CCR  
Source  
Form  
Operation  
Description  
V H I N Z C  
Branch if Half Carry Bit  
Set  
BHCS rel  
Branch if (H) = 1  
Branch if (C) | (Z) = 0  
Branch if (C) = 0  
– REL  
– REL  
– REL  
– REL  
29 rr  
22 rr  
24 rr  
3
3
3
BHI rel  
Branch if Higher  
Branch if Higher or Same  
(Same as BCC)  
BHS rel  
BIH rel  
BIL rel  
Branch if IRQ Pin High  
Branch if IRQ Pin Low  
Branch if IRQ pin = 1  
Branch if IRQ pin = 0  
2F rr  
2E rr  
3
3
– – REL  
BIT #opr8i  
BIT opr8a  
IMM  
DIR  
EXT  
A5 ii  
B5 dd  
2
3
4
4
3
3
5
4
BIT opr16a  
BIT oprx16,X  
BIT oprx8,X  
BIT ,X  
C5 hh ll  
D5 ee ff  
E5 ff  
(A) & (M)  
(CCR Updated but Operands  
Not Changed)  
IX2  
Bit Test  
0
IX1  
IX  
F5  
BIT oprx16,SP  
BIT oprx8,SP  
SP2  
SP1  
9ED5 ee ff  
9EE5 ff  
Branch if Less Than  
or Equal To  
(Signed Operands)  
BLE rel  
Branch if (Z) | (N V) = 1  
– – REL  
93 rr  
3
Branch if Lower  
(Same as BCS)  
BLO rel  
BLS rel  
BLT rel  
Branch if (C) = 1  
Branch if (C) | (Z) = 1  
Branch if (N V ) = 1  
– REL  
25 rr  
23 rr  
91 rr  
3
3
3
Branch if Lower or Same  
– – REL  
– – REL  
Branch if Less Than  
(Signed Operands)  
Branch if Interrupt Mask  
Clear  
BMC rel  
BMI rel  
BMS rel  
Branch if (I) = 0  
Branch if (N) = 1  
Branch if (I) = 1  
– – REL  
– – REL  
– – REL  
2C rr  
2B rr  
2D rr  
3
3
3
Branch if Minus  
Branch if Interrupt Mask  
Set  
BNE rel  
BPL rel  
BRA rel  
Branch if Not Equal  
Branch if Plus  
Branch if (Z) = 0  
Branch if (N) = 0  
No Test  
– – REL  
– – REL  
– – REL  
26 rr  
2A rr  
20 rr  
3
3
3
Branch Always  
DIR (b0)  
01 dd rr  
03 dd rr  
05 dd rr  
07 dd rr  
09 dd rr  
0B dd rr  
0D dd rr  
0F dd rr  
5
5
5
5
5
5
5
5
DIR (b1)  
DIR (b2)  
DIR (b3)  
DIR (b4)  
DIR (b5)  
DIR (b6)  
DIR (b7)  
Branch if Bit n in Memory  
BRCLR n,opr8a,rel  
BRN rel  
Branch if (Mn) = 0  
Uses 3 Bus Cycles  
Branch if (Mn) = 1  
Clear  
Branch Never  
– REL  
21 rr  
3
DIR (b0)  
DIR (b1)  
DIR (b2)  
DIR (b3)  
DIR (b4)  
DIR (b5)  
DIR (b6)  
DIR (b7)  
00 dd rr  
02 dd rr  
04 dd rr  
06 dd rr  
08 dd rr  
0A dd rr  
0C dd rr  
0E dd rr  
5
5
5
5
5
5
5
5
Branch if Bit n in Memory  
Set  
BRSET n,opr8a,rel  
DIR (b0)  
DIR (b1)  
DIR (b2)  
DIR (b3)  
DIR (b4)  
DIR (b5)  
DIR (b6)  
DIR (b7)  
10 dd  
12 dd  
14 dd  
16 dd  
18 dd  
1A dd  
1C dd  
1E dd  
5
5
5
5
5
5
5
5
BSET n,opr8a  
BSR rel  
Set Bit n in Memory  
Mn 1  
PC (PC) + $0002  
push (PCL); SP (SP) – $0001  
push (PCH); SP (SP) – $0001  
PC (PC) + rel  
Branch to Subroutine  
– REL  
AD rr  
5
Freescale Semiconductor  
86  
MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
Table 6-1 HCS08 Instruction Set Summary (Sheet 3 of 6)  
Effect  
on CCR  
Source  
Form  
Operation  
Description  
V H I N Z C  
CBEQ opr8a,rel  
CBEQA #opr8i,rel  
CBEQX #opr8i,rel  
Branch if (A) = (M)  
Branch if (A) = (M)  
Branch if (X) = (M)  
Branch if (A) = (M)  
Branch if (A) = (M)  
Branch if (A) = (M)  
DIR  
IMM  
IMM  
IX1+  
IX+  
31 dd rr  
41 ii rr  
51 ii rr  
61 ff rr  
71 rr  
5
4
4
5
5
6
Compare and Branch if  
CBEQ oprx8,X+,rel Equal  
CBEQ ,X+,rel  
CBEQ oprx8,SP,rel  
SP1  
9E61 ff rr  
CLC  
CLI  
Clear Carry Bit  
C 0  
I 0  
0
0 INH  
– INH  
98  
9A  
1
1
Clear Interrupt Mask Bit  
CLR opr8a  
CLRA  
M $00  
A $00  
X $00  
H $00  
M $00  
M $00  
M $00  
DIR  
INH  
3F dd  
4F  
5
1
1
1
5
4
6
CLRX  
INH  
5F  
CLRH  
Clear  
0
0
1
– INH  
IX1  
8C  
CLR oprx8,X  
CLR ,X  
6F ff  
7F  
IX  
SP1  
CLR oprx8,SP  
9E6F ff  
CMP #opr8i  
CMP opr8a  
IMM  
DIR  
EXT  
IX2  
A1 ii  
B1 dd  
2
3
4
4
3
3
5
4
CMP opr16a  
CMP oprx16,X  
CMP oprx8,X  
CMP ,X  
C1 hh ll  
D1 ee ff  
E1 ff  
(A) – (M)  
(CCR Updated But Operands Not  
Changed)  
Compare Accumulator  
with Memory  
IX1  
IX  
SP2  
SP1  
F1  
CMP oprx16,SP  
CMP oprx8,SP  
9ED1 ee ff  
9EE1 ff  
COM opr8a  
COMA  
M (M)= $FF – (M)  
A (A) = $FF – (A)  
X (X) = $FF – (X)  
M (M) = $FF – (M)  
M (M) = $FF – (M)  
M (M) = $FF – (M)  
DIR  
INH  
33 dd  
43  
5
1
1
5
4
6
COMX  
Complement  
INH  
53  
0
1
COM oprx8,X  
COM ,X  
COM oprx8,SP  
(One’s Complement)  
IX1  
63 ff  
73  
9E63 ff  
IX  
SP1  
CPHX opr16a  
CPHX #opr16i  
CPHX opr8a  
EXT  
IMM  
DIR  
SP1  
3E hh ll  
65 jj kk  
75 dd  
6
3
5
6
(H:X) – (M:M + $0001)  
(CCR Updated But Operands Not  
Changed)  
Compare Index Register  
(H:X) with Memory  
CPHX oprx8,SP  
9EF3 ff  
CPX #opr8i  
CPX opr8a  
IMM  
DIR  
EXT  
IX2  
A3 ii  
B3 dd  
2
3
4
4
3
3
5
4
CPX opr16a  
CPX oprx16,X  
CPX oprx8,X  
CPX ,X  
C3 hh ll  
D3 ee ff  
E3 ff  
Compare X (Index  
Register Low) with  
Memory  
(X) – (M)  
(CCR Updated But Operands Not  
Changed)  
IX1  
IX  
SP2  
SP1  
F3  
CPX oprx16,SP  
CPX oprx8,SP  
9ED3 ee ff  
9EE3 ff  
Decimal Adjust  
DAA  
Accumulator After ADD or  
ADC of BCD Values  
(A)  
U
INH  
72  
1
10  
DBNZ opr8a,rel  
DBNZA rel  
DIR  
INH  
3B dd rr  
4B rr  
7
4
4
7
6
8
Decrement A, X, or M  
Branch if (result) 0  
DBNZX Affects X Not H  
DBNZX rel  
Decrement and Branch if  
Not Zero  
INH  
5B rr  
DBNZ oprx8,X,rel  
DBNZ ,X,rel  
IX1  
6B ff rr  
7B rr  
IX  
DBNZ oprx8,SP,rel  
SP1  
9E6B ff rr  
DEC opr8a  
DECA  
M (M) – $01  
A (A) – $01  
X (X) – $01  
M (M) – $01  
M (M) – $01  
M (M) – $01  
DIR  
INH  
INH  
3A dd  
4A  
5
1
1
5
4
6
DECX  
5A  
Decrement  
Divide  
DEC oprx8,X  
DEC ,X  
DEC oprx8,SP  
IX1  
IX  
6A ff  
7A  
9E6A ff  
SP1  
A (H:A)÷(X)  
DIV  
INH  
52  
6
H Remainder  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
87  
Central Processor Unit (CPU)  
Table 6-1 HCS08 Instruction Set Summary (Sheet 4 of 6)  
Effect  
on CCR  
Source  
Form  
Operation  
Description  
V H I N Z C  
EOR #opr8i  
IMM  
DIR  
EXT  
IX2  
A8 ii  
B8 dd  
2
3
4
4
3
3
5
4
EOR opr8a  
EOR opr16a  
EOR oprx16,X  
EOR oprx8,X  
EOR ,X  
EOR oprx16,SP  
EOR oprx8,SP  
C8 hh ll  
D8 ee ff  
E8 ff  
Exclusive OR  
Memory with  
Accumulator  
A (A M)  
0
IX1  
IX  
SP2  
SP1  
F8  
9ED8 ee ff  
9EE8 ff  
INC opr8a  
INCA  
M (M) + $01  
A (A) + $01  
X (X) + $01  
M (M) + $01  
M (M) + $01  
M (M) + $01  
DIR  
INH  
INH  
IX1  
IX  
3C dd  
4C  
5
1
1
5
4
6
INCX  
5C  
Increment  
INC oprx8,X  
INC ,X  
6C ff  
7C  
INC oprx8,SP  
SP1  
9E6C ff  
JMP opr8a  
JMP opr16a  
JMP oprx16,X  
JMP oprx8,X  
JMP ,X  
DIR  
BC dd  
CC hh ll  
DC ee ff  
EC ff  
3
4
4
3
3
EXT  
Jump  
PC Jump Address  
– IX2  
IX1  
IX  
FC  
JSR opr8a  
JSR opr16a  
JSR oprx16,X  
JSR oprx8,X  
JSR ,X  
DIR  
EXT  
– IX2  
IX1  
BD dd  
CD hh ll  
DD ee ff  
ED ff  
5
6
6
5
5
PC (PC) + n (n = 1, 2, or 3)  
Push (PCL); SP (SP) – $0001  
Push (PCH); SP (SP) – $0001  
PC Unconditional Address  
Jump to Subroutine  
IX  
FD  
LDA #opr8i  
LDA opr8a  
IMM  
DIR  
EXT  
A6 ii  
B6 dd  
2
3
4
4
3
3
5
4
LDA opr16a  
LDA oprx16,X  
LDA oprx8,X  
LDA ,X  
C6 hh ll  
D6 ee ff  
E6 ff  
Load Accumulator from  
Memory  
IX2  
A (M)  
H:X ← (M:M + $0001)  
X (M)  
0
0
0
IX1  
IX  
F6  
LDA oprx16,SP  
LDA oprx8,SP  
SP2  
SP1  
9ED6 ee ff  
9EE6 ff  
LDHX #opr16i  
LDHX opr8a  
LDHX opr16a  
LDHX ,X  
LDHX oprx16,X  
LDHX oprx8,X  
LDHX oprx8,SP  
IMM  
DIR  
EXT  
45 jj kk  
55 dd  
32 hh ll  
9EAE  
9EBE ee ff  
9ECE ff  
9EFE ff  
3
4
5
5
6
5
5
Load Index Register (H:X)  
from Memory  
IX  
IX2  
IX1  
SP1  
LDX #opr8i  
LDX opr8a  
IMM  
DIR  
EXT  
IX2  
AE ii  
BE dd  
2
3
4
4
3
3
5
4
LDX opr16a  
LDX oprx16,X  
LDX oprx8,X  
LDX ,X  
CE hh ll  
DE ee ff  
EE ff  
Load X (Index Register  
Low) from Memory  
IX1  
IX  
FE  
LDX oprx16,SP  
LDX oprx8,SP  
SP2  
SP1  
9EDE ee ff  
9EEE ff  
LSL opr8a  
LSLA  
DIR  
INH  
INH  
IX1  
IX  
38 dd  
48  
5
1
1
5
4
6
LSLX  
Logical Shift Left  
(Same as ASL)  
58  
C
0
LSL oprx8,X  
LSL ,X  
LSL oprx8,SP  
68 ff  
78  
9E68 ff  
b7  
b0  
b0  
SP1  
LSR opr8a  
LSRA  
DIR  
INH  
INH  
IX1  
IX  
34 dd  
44  
5
1
1
5
4
6
LSRX  
54  
0
C
Logical Shift Right  
0
LSR oprx8,X  
LSR ,X  
64 ff  
74  
b7  
LSR oprx8,SP  
SP1  
9E64 ff  
MOV opr8a,opr8a  
MOV opr8a,X+  
(M)  
(M)  
DIR/DIR  
DIR/IX+  
IMM/DIR  
IX+/DIR  
4E dd dd  
5E dd  
5
5
4
5
destination  
source  
Move  
0
MOV #opr8i,opr8a  
MOV ,X+,opr8a  
H:X (H:X) + $0001 in  
6E ii dd  
7E dd  
IX+/DIR and DIR/IX+ Modes  
MUL  
Unsigned multiply  
X:A (X) × (A)  
0
0 INH  
42  
5
Freescale Semiconductor  
88  
MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
Table 6-1 HCS08 Instruction Set Summary (Sheet 5 of 6)  
Effect  
on CCR  
Source  
Form  
Operation  
Description  
V H I N Z C  
NEG opr8a  
M – (M) = $00 – (M)  
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  
30 dd  
40  
5
1
1
5
4
6
NEGA  
NEGX  
Negate  
(Two’s Complement)  
50  
NEG oprx8,X  
NEG ,X  
60 ff  
70  
9E60 ff  
NEG oprx8,SP  
SP1  
NOP  
No Operation  
Uses 1 Bus Cycle  
INH  
9D  
1
Nibble Swap  
Accumulator  
NSA  
A (A[3:0]:A[7:4])  
INH  
62  
1
ORA #opr8i  
ORA opr8a  
IMM  
DIR  
EXT  
IX2  
AA ii  
BA dd  
2
3
4
4
3
3
5
4
ORA opr16a  
ORA oprx16,X  
ORA oprx8,X  
ORA ,X  
CA hh ll  
DA ee ff  
EA ff  
InclusiveORAccumulator  
and Memory  
A (A) | (M)  
0
IX1  
IX  
SP2  
SP1  
FA  
ORA oprx16,SP  
ORA oprx8,SP  
9EDA ee ff  
9EEA ff  
Push Accumulator onto  
Stack  
PSHA  
PSHH  
PSHX  
PULA  
PULH  
PULX  
Push (A); SP (SP) – $0001  
Push (H); SP (SP) – $0001  
Push (X); SP (SP) – $0001  
SP (SP + $0001); Pull (A)  
SP (SP + $0001); Pull (H)  
SP (SP + $0001); Pull (X)  
INH  
INH  
INH  
INH  
INH  
INH  
87  
8B  
89  
86  
8A  
88  
2
2
2
3
3
3
Push H (Index Register  
High) onto Stack  
Push X (Index Register  
Low) onto Stack  
Pull Accumulator from  
Stack  
Pull H (Index Register  
High) from Stack  
Pull X (Index Register  
Low) from Stack  
ROL opr8a  
ROLA  
DIR  
INH  
INH  
IX1  
IX  
39 dd  
49  
5
1
1
5
4
6
ROLX  
59  
C
Rotate Left through Carry  
ROL oprx8,X  
ROL ,X  
ROL oprx8,SP  
69 ff  
79  
9E69 ff  
b7  
b0  
SP1  
ROR opr8a  
RORA  
DIR  
INH  
INH  
IX1  
IX  
36 dd  
46  
5
1
1
5
4
6
RORX  
Rotate Right through  
Carry  
56  
C
ROR oprx8,X  
ROR ,X  
ROR oprx8,SP  
66 ff  
76  
9E66 ff  
b7  
b0  
SP1  
SP $FF  
RSP  
Reset Stack Pointer  
Return from Interrupt  
Return from Subroutine  
INH  
INH  
INH  
9C  
80  
81  
1
9
6
(High Byte Not Affected)  
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)  
SP SP + $0001; Pull (PCH)  
SP SP + $0001; Pull (PCL)  
RTI  
RTS  
SBC #opr8i  
SBC opr8a  
IMM  
DIR  
EXT  
IX2  
A2 ii  
B2 dd  
2
3
4
4
3
3
5
4
SBC opr16a  
SBC oprx16,X  
SBC oprx8,X  
SBC ,X  
C2 hh ll  
D2 ee ff  
E2 ff  
Subtract with Carry  
A (A) – (M) – (C)  
IX1  
IX  
F2  
SBC oprx16,SP  
SBC oprx8,SP  
SP2  
SP1  
9ED2 ee ff  
9EE2 ff  
SEC  
SEI  
Set Carry Bit  
C 1  
I 1  
1
INH  
INH  
99  
9B  
1
1
Set Interrupt Mask Bit  
1
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
89  
Central Processor Unit (CPU)  
Table 6-1 HCS08 Instruction Set Summary (Sheet 6 of 6)  
Effect  
on CCR  
Source  
Form  
Operation  
Description  
V H I N Z C  
STA opr8a  
DIR  
EXT  
IX2  
IX1  
IX  
SP2  
SP1  
B7 dd  
C7 hh ll  
D7 ee ff  
E7 ff  
3
4
4
3
2
5
4
STA opr16a  
STA oprx16,X  
STA oprx8,X  
STA ,X  
Store Accumulator in  
Memory  
M (A)  
0
F7  
STA oprx16,SP  
STA oprx8,SP  
9ED7 ee ff  
9EE7 ff  
STHX opr8a  
DIR  
EXT  
SP1  
35 dd  
96 hh ll  
9EFF ff  
4
5
5
STHX opr16a  
STHX oprx8,SP  
Store H:X (Index Reg.)  
(M:M + $0001) (H:X)  
0
Enable Interrupts:  
Stop Processing  
Refer to MCU  
STOP  
I bit 0; Stop Processing  
0
INH  
8E  
2+  
Documentation  
STX opr8a  
DIR  
EXT  
IX2  
IX1  
IX  
BF dd  
CF hh ll  
DF ee ff  
EF ff  
3
4
4
3
2
5
4
STX opr16a  
STX oprx16,X  
STX oprx8,X  
STX ,X  
Store X (Low 8 Bits of  
Index Register)  
in Memory  
M (X)  
0
FF  
STX oprx16,SP  
STX oprx8,SP  
SP2  
SP1  
9EDF ee ff  
9EEF ff  
SUB #opr8i  
SUB opr8a  
IMM  
DIR  
EXT  
IX2  
A0 ii  
B0 dd  
2
3
4
4
3
3
5
4
SUB opr16a  
SUB oprx16,X  
SUB oprx8,X  
SUB ,X  
C0 hh ll  
D0 ee ff  
E0 ff  
Subtract  
A (A) (M)  
IX1  
IX  
F0  
SUB oprx16,SP  
SUB oprx8,SP  
SP2  
SP1  
9ED0 ee ff  
9EE0 ff  
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;  
SWI  
Software Interrupt  
1
INH  
83  
11  
PCH Interrupt Vector High Byte  
PCL Interrupt Vector Low Byte  
Transfer Accumulator to  
CCR  
TAP  
TAX  
TPA  
CCR (A)  
X (A)  
INH  
INH  
INH  
84  
97  
85  
1
1
1
Transfer Accumulator to  
X (Index Register Low)  
Transfer CCR to  
Accumulator  
A (CCR)  
TST opr8a  
TSTA  
(M) – $00  
(A) – $00  
(X) – $00  
(M) – $00  
(M) – $00  
(M) – $00  
DIR  
INH  
INH  
IX1  
IX  
3D dd  
4D  
4
1
1
4
3
5
TSTX  
5D  
Test for Negative or Zero  
Transfer SP to Index Reg.  
0
TST oprx8,X  
TST ,X  
TST oprx8,SP  
6D ff  
7D  
9E6D ff  
SP1  
TSX  
TXA  
TXS  
WAIT  
H:X (SP) + $0001  
0
INH  
INH  
INH  
INH  
95  
9F  
94  
8F  
2
Transfer X (Index Reg.  
Low) to Accumulator  
A (X)  
1
Transfer Index Reg. to SP  
SP (H:X) – $0001  
I bit 0; Halt CPU  
2
Enable Interrupts; Wait  
for Interrupt  
2+  
NOTES:  
1. Bus clock frequency is one-half of the CPU clock frequency.  
Freescale Semiconductor  
90  
MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
Table 6-2 Opcode Map (Sheet 1 of 2)  
Bit-Manipulation  
10  
Branch  
20  
Read-Modify-Write  
Control  
Register/Memory  
00  
5
5
3
30  
5
40  
1
50  
1
60  
5
70  
4
80  
9
90  
3
A0  
2
B0  
3
C0  
4
D0  
4
E0  
3
3
BRSET0 BSET0  
BRA  
NEG  
NEGA  
NEGX  
NEG  
NEG  
RTI  
BGE  
SUB  
SUB  
SUB  
SUB  
SUB  
3
01  
DIR  
5
2
11  
DIR  
5
2
21  
REL  
3
2
DIR  
5
1
INH  
4
1
INH  
4
2
IX1  
5
1
IX  
5
1
81  
INH  
6
2
91  
REL  
3
2
IMM  
2
2
DIR  
3
3
EXT  
4
3
IX2  
4
2
IX1  
3
IX  
3
31  
41  
51  
61  
71  
A1  
B1  
C1  
D1  
E1  
BRCLR0 BCLR0  
BRN  
CBEQ CBEQA CBEQX CBEQ  
CBEQ  
RTS  
BLT  
CMP  
CMP  
CMP  
CMP  
CMP  
CMP  
3
DIR  
5
2
DIR  
5
2
22  
REL  
3
3
DIR  
5
3
IMM  
5
3
IMM  
6
3
IX1+  
1
2
IX+  
1
1
82  
INH  
2
REL  
3
2
IMM  
2
2
DIR  
3
3
EXT  
4
3
IX2  
4
2
IX1  
3
1
IX  
3
02  
12  
32  
42  
52  
62  
72  
5+ 92  
A2  
B2  
C2  
D2  
E2  
F2  
BRSET1 BSET1  
BHI  
LDHX  
MUL  
DIV  
NSA  
DAA  
BGND  
BGT  
SBC  
SBC  
SBC  
SBC  
SBC  
SBC  
3
DIR  
5
2
DIR  
5
2
23  
REL  
3
3
EXT  
5
1
43  
INH  
1
1
53  
INH  
1
1
63  
INH  
5
1
73  
INH  
4
1
INH  
2
REL  
3
2
IMM  
2
2
DIR  
3
3
EXT  
4
3
IX2  
4
2
IX1  
3
1
IX  
3
03  
13  
33  
83  
11 93  
A3  
B3  
C3  
D3  
E3  
F3  
BRCLR1 BCLR1  
BLS  
COM  
COMA  
COMX  
COM  
COM  
SWI  
BLE  
CPX  
CPX  
CPX  
CPX  
CPX  
CPX  
3
DIR  
5
2
DIR  
5
2
24  
REL  
3
2
DIR  
5
1
INH  
1
INH  
2
IX1  
5
1
IX  
4
1
84  
INH  
1
2
94  
REL  
2
2
IMM  
2
2
DIR  
3
3
EXT  
4
3
IX2  
4
2
IX1  
3
1
IX  
3
04  
14  
34  
44  
1
54  
1
64  
74  
A4  
B4  
C4  
D4  
E4  
F4  
BRSET2 BSET2  
BCC  
LSR  
LSRA  
LSRX  
LSR  
LSR  
TAP  
TXS  
AND  
AND  
AND  
AND  
AND  
AND  
3
DIR  
5
2
DIR  
5
2
25  
REL  
3
2
35  
DIR  
4
1
INH  
3
1
INH  
4
2
65  
IX1  
3
1
75  
IX  
5
1
85  
INH  
1
1
95  
INH  
2
2
IMM  
2
2
DIR  
3
3
EXT  
4
3
IX2  
4
2
IX1  
3
1
IX  
3
05  
15  
45  
55  
A5  
B5  
C5  
D5  
E5  
F5  
BRCLR2 BCLR2  
BCS  
STHX  
LDHX  
LDHX  
CPHX  
CPHX  
TPA  
TSX  
BIT  
BIT  
BIT  
BIT  
BIT  
BIT  
LDA  
STA  
3
DIR  
5
2
DIR  
5
2
26  
REL  
3
2
DIR  
5
3
IMM  
1
2
DIR  
1
3
IMM  
5
2
DIR  
4
1
86  
INH  
3
1
96  
INH  
5
2
A6  
IMM  
2
2
B6  
DIR  
3
3
C6  
EXT  
4
3
D6  
IX2  
4
2
E6  
IX1  
3
1
F6  
IX  
3
06  
16  
36  
ROR  
46  
56  
66  
ROR  
76  
ROR  
BRSET3 BSET3  
BNE  
RORA  
RORX  
PULA  
STHX  
LDA  
LDA  
LDA  
LDA  
LDA  
3
07  
DIR  
5
2
17  
DIR  
5
2
27  
REL  
3
2
DIR  
5
1
INH  
1
INH  
2
IX1  
5
1
IX  
4
1
87  
INH  
2
3
97  
EXT  
1
2
A7  
IMM  
2
2
B7  
DIR  
3
3
C7  
EXT  
4
3
D7  
IX2  
4
2
E7  
IX1  
3
1
F7  
IX  
2
37  
47  
1
57  
1
67  
77  
BRCLR3 BCLR3  
BEQ  
ASR  
ASRA  
ASRX  
ASR  
ASR  
PSHA  
TAX  
AIS  
STA  
STA  
STA  
STA  
3
08  
DIR  
5
2
18  
DIR  
5
2
28  
REL  
3
2
DIR  
5
1
INH  
1
1
INH  
1
2
IX1  
5
1
IX  
4
1
88  
INH  
3
1
98  
INH  
1
2
A8  
IMM  
2
2
B8  
DIR  
3
3
C8  
EXT  
4
3
D8  
IX2  
4
2
E8  
IX1  
3
1
F8  
IX  
3
38  
48  
58  
68  
78  
BRSET4 BSET4  
BHCC  
LSL  
LSLA  
LSLX  
LSL  
LSL  
PULX  
CLC  
EOR  
EOR  
EOR  
EOR  
EOR  
EOR  
3
DIR  
5
2
DIR  
5
2
REL  
2
39  
DIR  
5
1
INH  
1
1
INH  
1
2
69  
IX1  
5
1
79  
IX  
4
1
INH  
2
1
99  
INH  
1
2
IMM  
2
2
DIR  
3
3
EXT  
4
3
IX2  
4
2
IX1  
3
1
IX  
3
09  
19  
29  
3
49  
59  
89  
A9  
B9  
C9  
D9  
E9  
F9  
BRCLR4 BCLR4  
BHCS  
ROL  
ROLA  
ROLX  
ROL  
ROL  
PSHX  
SEC  
ADC  
ADC  
ADC  
ADC  
ADC  
ADC  
3
DIR  
5
2
DIR  
5
2
REL  
3
2
DIR  
5
1
INH  
1
1
INH  
1
2
IX1  
5
1
IX  
4
1
INH  
3
1
INH  
1
2
IMM  
2
2
DIR  
3
3
EXT  
4
3
IX2  
4
2
IX1  
3
1
IX  
3
0A  
1A  
2A  
3A  
4A  
5A  
6A  
7A  
8A  
9A  
AA  
BA  
CA  
DA  
EA  
FA  
BRSET5 BSET5  
BPL  
DEC  
DECA  
DECX  
DEC  
DEC  
PULH  
CLI  
ORA  
ORA  
ORA  
ORA  
ORA  
ORA  
3
DIR  
5
2
DIR  
5
2
2B  
REL  
3
2
DIR  
7
1
INH  
1
INH  
2
IX1  
7
1
IX  
6
1
INH  
2
1
9B  
INH  
1
2
IMM  
2
2
DIR  
3
3
EXT  
4
3
IX2  
4
2
IX1  
3
1
IX  
3
0B  
1B  
3B  
4B  
4
5B  
4
6B  
7B  
8B  
AB  
BB  
CB  
DB  
EB  
FB  
BRCLR5 BCLR5  
BMI  
DBNZ  
DBNZA DBNZX  
DBNZ  
DBNZ  
PSHH  
SEI  
ADD  
ADD  
ADD  
ADD  
ADD  
ADD  
3
DIR  
5
2
DIR  
5
2
2C  
REL  
3
3
DIR  
5
2
INH  
1
2
INH  
1
3
IX1  
5
2
IX  
4
1
INH  
1
9C  
INH  
1
2
IMM  
2
DIR  
3
3
EXT  
4
3
IX2  
4
2
IX1  
3
1
IX  
3
0C  
1C  
3C  
4C  
5C  
6C  
7C  
8C  
1
BC  
CC  
DC  
EC  
FC  
BRSET6 BSET6  
BMC  
INC  
INCA  
INCX  
INC  
INC  
CLRH  
RSP  
JMP  
JMP  
JMP  
JMP  
JMP  
3
DIR  
5
2
DIR  
5
2
REL  
3
2
3D  
DIR  
4
1
INH  
1
1
INH  
1
2
6D  
IX1  
4
1
7D  
IX  
3
1
INH  
1
INH  
1
2
DIR  
5
3
EXT  
6
3
IX2  
6
2
IX1  
5
1
IX  
5
0D  
1D  
2D  
4D  
5D  
9D  
AD  
5
BD  
CD  
DD  
ED  
FD  
BRCLR6 BCLR6  
BMS  
TST  
TSTA  
TSTX  
TST  
TST  
NOP  
BSR  
JSR  
JSR  
JSR  
JSR  
JSR  
3
DIR  
5
2
DIR  
5
2
REL  
3
2
3E  
DIR  
6
1
INH  
5
1
INH  
5
2
6E  
IX1  
4
1
7E  
IX  
5
1
INH  
2
REL  
2
2
DIR  
3
3
EXT  
4
3
IX2  
4
2
IX1  
3
1
IX  
3
0E  
1E  
2E  
4E  
5E  
8E  
2+ 9E  
AE  
BE  
CE  
DE  
EE  
FE  
BRSET7 BSET7  
BIL  
CPHX  
MOV  
MOV  
MOV  
MOV  
STOP  
Page 2  
LDX  
LDX  
LDX  
LDX  
LDX  
LDX  
3
DIR  
5
2
DIR  
5
2
2F  
REL  
3
3
EXT  
3
DD  
1
2
DIX+  
1
3
IMD  
5
2
IX+D  
4
1
INH  
2
IMM  
2
2
DIR  
3
3
EXT  
4
3
IX2  
4
2
IX1  
3
1
FF  
IX  
2
0F  
1F  
3F  
5
4F  
5F  
6F  
7F  
1
8F  
2+ 9F  
1
AF  
BF  
STX  
CF  
STX  
DF  
STX  
EF  
STX  
BRCLR7 BCLR7  
BIH  
CLR  
CLRA  
CLRX  
CLR  
CLR  
WAIT  
TXA  
AIX  
STX  
3
DIR  
2
DIR  
2
REL  
2
DIR  
1
INH  
1
INH  
2
IX1  
IX  
1
INH  
1
INH  
2
IMM  
2
DIR  
3
EXT  
3
IX2  
2
IX1  
1
IX  
INH  
IMM  
DIR  
EXT  
DD  
Inherent  
REL  
IX  
Relative  
SP1  
SP2  
IX+  
Stack Pointer, 8-Bit Offset  
Stack Pointer, 16-Bit Offset  
Indexed, No Offset with  
Post Increment  
Indexed, 1-Byte Offset with  
Post Increment  
Immediate  
Direct  
Indexed, No Offset  
IX1  
IX2  
IMD  
Indexed, 8-Bit Offset  
Indexed, 16-Bit Offset  
IMM to DIR  
Extended  
DIR to DIR  
IX+D IX+ to DIR  
IX1+  
DIX+ DIR to IX+  
Opcode in  
F0  
3
HCS08 Cycles  
Instruction Mnemonic  
Addressing Mode  
Hexadecimal  
SUB  
Number of Bytes  
1
IX  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
91  
Central Processor Unit (CPU)  
Table 6-2 Opcode Map (Sheet 2 of 2)  
Bit-Manipulation  
Branch  
Read-Modify-Write  
9E60  
Control  
Register/Memory  
6
9ED0  
SUB  
5
9EE0  
4
NEG  
SUB  
3
SP1  
6
4
SP2  
5
3
SP1  
4
9E61  
9ED1  
9EE1  
CBEQ  
CMP  
CMP  
4
SP1  
4
SP2  
5
3
SP1  
4
9ED2  
9EE2  
SBC  
SBC  
4
SP2  
5
3
SP1  
4
6
9ED3  
9EE3  
6
CPX  
CPX  
SP1  
6
4
SP2  
5
3
SP1  
4
SP1  
9ED4  
9EE4  
LSR  
AND  
AND  
3
SP1  
4
SP2  
5
3
SP1  
4
9ED5  
9EE5  
BIT  
BIT  
4
SP2  
5
3
SP1  
4
9E66  
6
9ED6  
9EE6  
ROR  
LDA  
LDA  
3
SP1  
6
4
SP2  
5
3
SP1  
4
9E67  
9ED7  
9EE7  
ASR  
STA  
STA  
3
SP1  
6
4
SP2  
5
3
SP1  
4
9E68  
9ED8  
9EE8  
LSL  
EOR  
EOR  
3
SP1  
6
4
SP2  
5
3
SP1  
4
9E69  
9ED9  
9EE9  
ROL  
ADC  
ADC  
3
SP1  
6
4
SP2  
5
3
SP1  
4
9E6A  
9EDA  
9EEA  
DEC  
ORA  
ORA  
3
SP1  
8
4
SP2  
5
3
SP1  
4
9E6B  
9EDB  
9EEB  
DBNZ  
ADD  
ADD  
4
SP1  
4
SP2  
3
SP1  
9E6C  
6
INC  
3
SP1  
5
9E6D  
TST  
3
SP1  
5
9EBE  
6
5
5
4
5
LDHX  
IX  
4
IX2  
IX1  
SP1  
5
9E6F  
6
CLR  
STX  
STX  
STHX  
3
SP1  
4
SP2  
3
SP1  
3
SP1  
INH  
Inherent  
Immediate  
Direct  
REL  
IX  
Relative  
SP1  
SP2  
IX+  
Stack Pointer, 8-Bit Offset  
Stack Pointer, 16-Bit Offset  
Indexed, No Offset with  
Post Increment  
Indexed, 1-Byte Offset with  
Post Increment  
IMM  
DIR  
EXT  
DD  
Indexed, No Offset  
Indexed, 8-Bit Offset  
Indexed, 16-Bit Offset  
IMM to DIR  
IX1  
IX2  
IMD  
Extended  
DIR to DIR  
IX1+  
IX+D IX+ to DIR  
DIX+ DIR to IX+  
Note: All Sheet 2 Opcodes are Preceded by the Page 2 Prebyte (9E)  
Prebyte (9E) and Opcode in  
Hexadecimal  
9E60  
3
6
HCS08 Cycles  
Instruction Mnemonic  
Addressing Mode  
NEG  
Number of Bytes  
SP1  
Freescale Semiconductor  
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MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
Chapter 7 Carrier Modulator Timer (CMT) Module  
7.1 Introduction  
INTERNAL BUS  
DEBUG  
HCS08 CORE  
7
PTA7/KBI1P7–  
PTA1/KBI1P1  
BDC  
CPU  
NOTES1, 2, 6  
MODULE (DBG)  
PTA0/KBI1P0  
HCS08 SYSTEM CONTROL  
PTB7/TPM1CH1  
8-BIT KEYBOARD  
PTE6  
PTB5  
PTB4  
PTB3  
INTERRUPT MODULE (KBI1)  
RESETS AND INTERRUPTS  
MODES OF OPERATION  
POWER MANAGEMENT  
NOTES 1, 5  
4-BIT KEYBOARD  
PTB2  
PTB1/RxD1  
PTB0/TxD1  
INTERRUPT MODULE (KBI2)  
RTI  
COP  
LVD  
IRQ  
SERIAL COMMUNICATIONS  
INTERFACE MODULE (SCI1)  
PTC7/SS1  
PTC6/SPSCK1  
PTC5/MISO1  
PTC4/MOSI1  
PTC3/KBI2P3  
PTC2/KBI2P2  
PTC1/KBI2P1  
PTC0/KBI2P0  
USER FLASH  
NOTE 1  
(RC/RD/RE/RG60 = 63,364 BYTES)  
(RC/RD/RE/RG32 = 32,768 BYTES)  
(RC/RD/RE16 = 16,384 BYTES)  
(RC/RD/RE8 = 8192 BYTES)  
ANALOG COMPARATOR  
MODULE (ACMP1)  
2-CHANNEL TIMER/PWM  
MODULE (TPM1)  
PTD6/TPM1CH0  
PTD5/ACMP1+  
PTD4/ACMP1–  
PTD3  
USER RAM  
(RC/RD/RE/RG32/60 = 2048 BYTES)  
(RC/RD/RE8/16 = 1024 BYTES)  
NOTES  
1, 3, 4  
PTD2/IRQ  
PTD1/RESET  
PTD0/BKGD/MS  
SERIAL PERIPHERAL  
EXTAL  
XTAL  
INTERFACE MODULE (SPI1)  
LOW-POWER OSCILLATOR  
8
PTE7–PTE0 NOTE 1  
V
DD  
VOLTAGE  
REGULATOR  
V
CARRIER MODULATOR  
TIMER MODULE (CMT)  
SS  
IRO NOTE 5  
NOTES:  
1. Port pins are software configurable with pullup device if input port  
2. PTA0 does not have a clamp diode to VDD. PTA0 should not be driven above VDD  
.
3. IRQ pin contains software configurable pullup/pulldown device if IRQ enabled (IRQPE = 1)  
4. The RESET pin contains integrated pullup device enabled if reset enabled (RSTPE = 1)  
5. High current drive.  
6. Pins PTA[7:0] contain both pullup and pulldown devices. Pulldown available when KBI enabled (KBI1Pn = 1).  
Figure 7-1 MC9S08RC/RD/RE/RG Block Diagram  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
93  
Carrier Modulator Transmitter (CMT) Module  
7.2 Features  
The CMT consists of a carrier generator, modulator, and transmitter that drives the infrared out (IRO) pin.  
The features of this module include:  
Four modes of operation  
– Time with independent control of high and low times  
– Baseband  
– Frequency shift key (FSK)  
– Direct software control of IRO pin  
Extended space operation in time, baseband, and FSK modes  
Selectable input clock divide: 1, 2, 4, or 8  
Interrupt on end of cycle  
– Ability to disable IRO pin and use as timer interrupt  
7.3 CMT Block Diagram  
PRIMARY/SECONDARY SELECT  
MODULATOR  
OUT  
CARRIER  
OUT (f  
IRO  
PIN  
TRANSMITTER  
OUTPUT  
CARRIER  
CLOCK  
CONTROL  
)
CG  
MODULATOR  
CMTCLK  
GENERATOR  
CMTDIV  
CMT REGISTERS  
AND BUS INTERFACE  
BUS CLOCK  
INTERNAL BUS  
IIREQ  
Figure 7-2 Carrier Modulator Transmitter Module Block Diagram  
Freescale Semiconductor  
94  
MC9S08RC/RD/RE/RG  
 
SoC Guide — MC9S08RG60/D Rev 1.10  
7.4 Pin Description  
The IRO pin is the only pin associated with the CMT. The pin is driven by the transmitter output when the  
MCGEN bit in the CMTMSC register and the IROPEN bit in the CMTOC register are set. If the MCGEN  
bit is clear and the IROPEN bit is set, the pin is driven by the IROL bit in the CMTOC register. This  
enables user software to directly control the state of the IRO pin by writing to the IROL bit. If the IROPEN  
bit is clear, the pin is disabled and is not driven by the CMT module. This is so the CMT can be configured  
as a modulo timer for generating periodic interrupts without causing pin activity.  
7.5 Functional Description  
The CMT module consists of a carrier generator, a modulator, a transmitter output, and control registers.  
The block diagram is shown in Figure 7-2. When operating in time mode, the user independently defines  
the high and low times of the carrier signal to determine both period and duty cycle. The carrier generator  
resolution is 125 ns when operating with an 8 MHz internal bus frequency and the CMTDIV1 and  
CMTDIV0 bits in the CMTMSC register are both equal to 0. The carrier generator can generate signals  
with periods between 250 ns (4 MHz) and 127.5 µs (7.84 kHz) in steps of 125 ns. See Table 7-1.  
Table 7-1 Clock Divide  
Carrier  
Generator  
Resolution  
(µs)  
Min Carrier  
Generator  
Period  
Min  
Modulator  
Period  
(µs)  
Bus  
Clock  
(MHz)  
CMTDIV1:CMTDIV0  
(µs)  
8
8
8
8
0:0  
0:1  
1:0  
1:1  
0.125  
0.25  
0.5  
0.25  
0.5  
1.0  
2.0  
1.0  
2.0  
4.0  
8.0  
1.0  
The possible duty cycle options will depend upon the number of counts required to complete the carrier  
period. For example, a 1.6 MHz signal has a period of 625 ns and will therefore require 5 × 125 ns counts  
to generate. These counts may be split between high and low times, so the duty cycles available will be  
20 percent (one high, four low), 40 percent (two high, three low), 60 percent (three high, two low) and  
80 percent (four high, one low).  
For lower frequency signals with larger periods, higher resolution (as a percentage of the total period) duty  
cycles are possible.  
When the BASE bit in the CMT modulator status and control register (CMTMSC) is set, the carrier output  
(f ) to the modulator is held high continuously to allow for the generation of baseband protocols.  
CG  
A third mode allows the carrier generator to alternate between two sets of high and low times. When  
operating in FSK mode, the generator will toggle between the two sets when instructed by the modulator,  
allowing the user to dynamically switch between two carrier frequencies without CPU intervention.  
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Carrier Modulator Transmitter (CMT) Module  
The modulator provides a simple method to control protocol timing. The modulator has a minimum  
resolution of 1.0 µs with an 8 MHz internal bus clock. It can count bus clocks (to provide real-time control)  
or it can count carrier clocks (for self-clocked protocols). See 7.5.2 Modulator for more details.  
The transmitter output block controls the state of the infrared out pin (IRO). The modulator output is gated  
on to the IRO pin when the modulator/carrier generator is enabled.  
A summary of the possible modes is shown in Table 7-2.  
Table 7-2 CMT Modes of Operation  
MCGEN BASE  
FSK  
Bit  
EXSPC  
Bit  
Mode  
Comment  
(1)  
(2)  
(2)  
Bit  
Bit  
fCG controlled by primary high and low registers.  
fCG transmitted to IRO pin when modulator gate is open.  
Time  
1
1
0
1
0
x
0
0
fCG is always high. IRO pin high when modulator gate is open.  
Baseband  
fCG control alternates between primary high/low registers and  
FSK  
1
0
1
0
secondary high/low registers.  
fCG transmitted to IRO pin when modulator gate is open.  
Setting the EXSPC bit causes subsequent modulator cycles  
to be spaces (modulator out not asserted) for the duration of  
the modulator period (mark and space times).  
Extended  
Space  
1
0
x
x
x
x
1
x
IRO Latch  
IROL bit controls state of IRO pin.  
NOTES:  
1. To prevent spurious operation, initialize all data and control registers before beginning a transmission (MCGEN=1).  
2. These bits are not double buffered and should not be changed during a transmission (while MCGEN=1).  
7.5.1 Carrier Generator  
The carrier signal is generated by counting a register-selected number of input clocks (125 ns for an 8 MHz  
bus) for both the carrier high time and the carrier low time. The period is determined by the total number  
of clocks counted. The duty cycle is determined by the ratio of high time clocks to total clocks counted.  
The high and low time values are user programmable and are held in two registers.  
An alternate set of high/low count values is held in another set of registers to allow the generation of dual  
frequency FSK (frequency shift keying) protocols without CPU intervention.  
NOTE:  
Only non-zero data values are allowed. The carrier generator will not work if any  
of the count values are equal to zero.  
The MCGEN bit in the CMTMSC register must be set and the BASE bit must be cleared to enable carrier  
generator clocks. When the BASE bit is set, the carrier output to the modulator is held high continuously.  
The block diagram is shown in Figure 7-3.  
Freescale Semiconductor  
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MC9S08RC/RD/RE/RG  
 
SoC Guide — MC9S08RG60/D Rev 1.10  
CMTCGH2  
CMTCGH1  
=?  
CMTCLK  
BASE  
FSK  
CLK  
CLR  
8-BIT UP COUNTER  
PRIMARY/  
SECONDARY  
SELECT  
MCGEN  
CARRIER OUT (f  
)
CG  
=?  
CMTCGL1  
CMTCGL2  
Figure 7-3 Carrier Generator Block Diagram  
The high/low time counter is an 8-bit up counter. After each increment, the contents of the counter are  
compared with the appropriate high or low count value register. When the compare value is reached, the  
counter is reset to a value of $01, and the compare is redirected to the other count value register.  
Assuming that the high time count compare register is currently active, a valid compare will cause the  
carrier output to be driven low. The counter will continue to increment (starting at reset value of $01).  
When the value stored in the selected low count value register is reached, the counter will again be reset  
and the carrier output will be driven high.  
The cycle repeats, automatically generating a periodic signal that is directed to the modulator. The lowest  
frequency (maximum period) and highest frequency (minimum period) that can be generated are defined  
as:  
f
= fCMTCLK ÷ (2 x 1) Hz  
max  
8
f
= fCMTCLK ÷ (2 x (2 – 1)) Hz  
min  
In the general case, the carrier generator output frequency is:  
= fCMTCLK ÷ (Highcount + Lowcount) Hz  
f
CG  
Where:  
0 < Highcount < 256 and  
0 < Lowcount < 256  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
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Carrier Modulator Transmitter (CMT) Module  
The duty cycle of the carrier signal is controlled by varying the ratio of high time to low + high time. As  
the input clock period is fixed, the duty cycle resolution will be proportional to the number of counts  
required to generate the desired carrier period.  
Highcount  
Duty Cycle = ---------------------------------------------------------------  
Highcount + Lowcount  
7.5.2 Modulator  
The modulator has three main modes of operation:  
Gate the carrier onto the modulator output (time mode)  
Control the logic level of the modulator output (baseband mode)  
Count carrier periods and instruct the carrier generator to alternate between two carrier frequencies  
whenever a modulation period (mark + space counts) expires (FSK mode)  
The modulator includes a 17-bit down counter with underflow detection. The counter is loaded from the  
16-bit modulation mark period buffer registers, CMTCMD1 and CMTCMD2. The most significant bit is  
loaded with a logic zero and serves as a sign bit. When the counter holds a positive value, the modulator  
gate is open and the carrier signal is driven to the transmitter block.  
When the counter underflows, the modulator gate is closed and a 16-bit comparator is enabled that  
compares the logical complement of the value of the down-counter with the contents of the modulation  
space period register (which has been loaded from the registers CMTCMD3 and CMTCMD4).  
When a match is obtained the cycle repeats by opening the modulator gate, reloading the counter with the  
contents of CMTCMD1 and CMTCMD2, and reloading the modulation space period register with the  
contents of CMTCMD3 and CMTCMD4.  
If the contents of the modulation space period register are all zeroes, the match will be immediate and no  
space period will be generated (for instance, for FSK protocols that require successive bursts of different  
frequencies).  
The MCGEN bit in the CMTMSC register must be set to enable the modulator timer.  
Freescale Semiconductor  
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MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
16 BITS  
MODE  
CMTCMD1:CMTCMD2  
0
CMTCLOCK  
÷ 8  
CLOCK CONTROL  
.
17-BIT DOWN COUNTER *  
16  
CARRIER OUT (f  
)
CG  
LOAD  
MODULATOR  
OUT  
MODULATOR GATE  
EOC FLAG SET  
.
=?  
SYSTEM CONTROL  
MODULE INTERRUPT REQUEST  
PRIMARY/SECONDARY SELECT  
16  
SPACE PERIOD REGISTER *  
CMTCMD3:CMTCMD4  
16 BITS  
* DENOTES HIDDEN REGISTER  
Figure 7-4 Modulator Block Diagram  
7.5.2.1 Time Mode  
When the modulator operates in time mode (MCGEN bit is set, BASE bit is clear, and FSK bit is clear),  
the modulation mark period consists of an integer number of CMTCLK ÷ 8 clock periods. The modulation  
space period consists of zero or an integer number of CMTCLK ÷ 8 clock periods. With an 8 MHz bus and  
CMTDIV1:CMTDIV0 = 00, the modulator resolution is 1 µs and has a maximum mark and space period  
of about 65.535 ms each. See Figure 7-5 for an example of the time mode and baseband mode outputs.  
The mark and space time equations for time and baseband mode are:  
t
= (CMTCMD1:CMTCMD2 + 1) ÷ (fCMTCLK ÷ 8)  
= CMTCMD3:CMTCMD4 ÷ (fCMTCLK ÷ 8)  
mark  
t
space  
where CMTCMD1:CMTCMD2 and CMTCMD3:CMTCMD4 are the decimal values of the concatenated  
registers.  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
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Carrier Modulator Transmitter (CMT) Module  
CMTCLK ÷ 8  
(f  
CARRIER OUT  
)
CG  
MODULATOR GATE  
MARK  
SPACE  
MARK  
IRO PIN (TIME MODE)  
IRO PIN  
(BASEBAND MODE)  
Figure 7-5 Example CMT Output in Time and Baseband Modes  
7.5.2.2 Baseband Mode  
Baseband mode (MCGEN bit is set and BASE bit is set) is a derivative of time mode, where the mark and  
space period is based on (CMTCLK ÷ 8) counts. The mark and space calculations are the same as in time  
mode. In this mode the modulator output will be at a logic 1 for the duration of the mark period and at a  
logic 0 for the duration of a space period. See Figure 7-5 for an example of the output for both baseband  
and time modes. In the example, the carrier out frequency (f ) is generated with a high count of $01 and  
CG  
a low count of $02, which results in a divide of 3 of CMTCLK with a 33 percent duty cycle. The modulator  
down-counter was loaded with the value $0003 and the space period register with $0002.  
NOTE: The waveforms in Figure 7-5 and Figure 7-6 are for the purpose of conceptual  
illustration and are not meant to represent precise timing relationships between the  
signals shown.  
7.5.2.3 FSK Mode  
When the modulator operates in FSK mode (MCGEN bit is set, FSK bit is set, and BASE bit is clear), the  
modulation mark and space periods consist of an integer number of carrier clocks (space period can be 0).  
When the mark period expires, the space period is transparently started (as in time mode). The carrier  
generator toggles between primary and secondary data register values whenever the modulator space  
period expires.  
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MC9S08RC/RD/RE/RG  
 
 
 
SoC Guide — MC9S08RG60/D Rev 1.10  
The space period provides an interpulse gap (no carrier). If CMTCMD3:CMTCMD4 = $0000, then the  
modulator and carrier generator will switch between carrier frequencies without a gap or any carrier  
glitches (zero space).  
Using timing data for carrier burst and interpulse gap length calculated by the CPU, FSK mode can  
automatically generate a phase-coherent, dual-frequency FSK signal with programmable burst and  
interburst gaps.  
The mark and space time equations for FSK mode are:  
t
= (CMTCMD1:CMTCMD2 + 1) ÷ f  
= CMTCMD3:CMTCMD4 ÷ f  
mark  
CG  
t
space  
CG  
Where f is the frequency output from the carrier generator. The example in Figure 7-6 shows what the  
CG  
IRO pin output looks like in FSK mode with the following values: CMTCMD1:CMTCMD2 = $0003,  
CMTCMD3:CMTCMD4 = $0002, primary carrier high count = $01, primary carrier low count = $02,  
secondary carrier high count = $03, and secondary carrier low count = $01.  
(f  
)
CARRIER OUT  
CG  
SPACE1  
MARK1  
MARK2  
SPACE2  
MARK1  
MARK2  
SPACE1  
MODULATOR GATE  
IRO PIN  
Figure 7-6 Example CMT Output in FSK Mode  
7.5.3 Extended Space Operation  
In time, baseband, or FSK mode, the space period can be made longer than the maximum possible value  
of the space period register. Setting the EXSPC bit in the CMTMSC register will force the modulator to  
treat the next modulation period (beginning with the next load of the counter and space period register) as  
a space period equal in length to the mark and space counts combined. Subsequent modulation periods will  
consist entirely of these extended space periods with no mark periods. Clearing EXSPC will return the  
modulator to standard operation at the beginning of the next modulation period.  
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Carrier Modulator Transmitter (CMT) Module  
7.5.3.1 EXSPC Operation in Time Mode  
To calculate the length of an extended space in time or baseband modes, add the mark and space times and  
multiply by the number of modulation periods that EXSPC is set.  
t
= t  
+ (t  
+ t  
) x (number of modulation periods)  
exspace  
space  
mark  
space  
For an example of extended space operation, see Figure 7-7.  
NOTE: The EXSPC feature can be used to emulate a zero mark event.  
SET EXSPC  
CLEAR EXSPC  
Figure 7-7 Extended Space Operation  
7.5.3.2 EXSPC Operation in FSK Mode  
In FSK mode, the modulator continues to count carrier out clocks, alternating between the primary and  
secondary registers at the end of each modulation period.  
To calculate the length of an extended space in FSK mode, the user must know whether the EXSPC bit  
was set on a primary or secondary modulation period, as well as the total number of both primary and  
secondary modulation periods completed while the EXSPC bit is high. A status bit for the current  
modulation is not accessible to the CPU. If necessary, software should maintain tracking of the current  
modulation cycle (primary or secondary). The extended space period ends at the completion of the space  
period time of the modulation period during which the EXSPC bit is cleared.  
If the EXSPC bit was set during a primary modulation cycle, use the equation:  
t
= (t  
) + (t  
+ t  
) + (t  
+ t  
) +...  
space p  
exspace  
space p  
mark  
space s  
mark  
Where the subscripts p and s refer to mark and space times for the primary and secondary modulation  
cycles.  
If the EXSPC bit was set during a secondary modulation cycle, use the equation:  
t
= (t  
) + (t  
+ t  
) + (t  
+ t  
) +...  
space s  
exspace  
space s  
mark  
space p  
mark  
7.5.4 Transmitter  
The transmitter output block controls the state of the infrared out pin (IRO). The modulator output is gated  
on to the IRO pin when the modulator/carrier generator is enabled. When the modulator/carrier generator  
is disabled, the IRO pin is controlled by the state of the IRO latch.  
A polarity bit in the CMTOC register enables the IRO pin to be high true or low true.  
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SoC Guide — MC9S08RG60/D Rev 1.10  
7.5.5 CMT Interrupts  
The end of cycle flag (EOCF) is set when:  
The modulator is not currently active and the MCGEN bit is set to begin the initial CMT  
transmission  
At the end of each modulation cycle (when the counter is reloaded from CMTCMD1:CMTCMD2)  
while the MCGEN bit is set  
In the case where the MCGEN bit is cleared and then set before the end of the modulation cycle, the EOCF  
bit will not be set when the MCGEN is set, but will become set at the end of the current modulation cycle.  
When the MCGEN becomes disabled, the CMT module does not set the EOC flag at the end of the last  
modulation cycle.  
The EOCF bit is cleared by reading the CMT modulator status and control register (CMTMSC) followed  
by an access of CMTCMD2 or CMTCMD4.  
If the EOC interrupt enable (EOCIE) bit is high when the EOCF bit is set, the CMT module will generate  
an interrupt request. The EOCF bit must be cleared within the interrupt service routine to prevent another  
interrupt from being generated after exiting the interrupt service routine.  
The EOC interrupt is coincident with loading the down-counter with the contents of  
CMTCMD1:CMTCMD2 and loading the space period register with the contents of  
CMTCMD3:CMTCMD4. The EOC interrupt provides a means for the user to reload new mark/space  
values into the modulator data registers. Modulator data register updates will take effect at the end of the  
current modulation cycle. Note that the down-counter and space period register are updated at the end of  
every modulation cycle, regardless of interrupt handling and the state of the EOCF flag.  
7.5.6 Wait Mode Operation  
During wait mode the CMT, if enabled, will continue to operate normally. However, there will be no new  
codes or changes of pattern mode while in wait mode, because the CPU is not operating.  
7.5.7 Stop Mode Operation  
During all stop modes, clocks to the CMT module are halted.  
In stop1 and stop2 modes, all CMT register data is lost and must be re-initialized upon recovery from these  
two stop modes.  
No CMT module registers are affected in stop3 mode.  
Note, because the clocks are halted, the CMT will resume upon exit from stop (only in stop3 mode).  
Software should ensure stop2 or stop3 mode is not entered while the modulator is in operation to prevent  
the IRO pin from being asserted while in stop mode. This may require a time-out period from the time that  
the MCGEN bit is cleared to allow the last modulator cycle to complete.  
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Carrier Modulator Transmitter (CMT) Module  
7.5.8 Background Mode Operation  
When the microcontroller is in active background mode, the CMT temporarily suspends all counting until  
the microcontroller returns to normal user mode.  
7.6 CMT Registers and Control Bits  
The following registers control and monitor CMT operation:  
CMT carrier generator data registers (CMTCGH1, CMTCGL1, CMTCGH2, CMTCGL2)  
CMT output control register (CMTOC)  
CMT modulator status and control register (CMTMSC)  
CMT modulator period data registers (CMTCMD1, CMTCMD2, CMTCMD3, CMTCMD4)  
7.6.1 Carrier Generator Data Registers (CMTCGH1, CMTCGL1, CMTCGH2,  
and CMTCGL2)  
The carrier generator data registers contain the primary and secondary high and low values for generating  
the carrier output.  
Freescale Semiconductor  
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MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
CMTCGH1  
Read:  
Bit 7  
PH7  
U
6
PH6  
U
5
PH5  
U
4
PH4  
U
3
PH3  
U
2
PH2  
U
1
PH1  
U
Bit 0  
PH0  
U
Write:  
Reset:  
CMTCGL1  
Read:  
Bit 7  
PL7  
U
6
PL6  
U
5
PL5  
U
4
PL4  
U
3
PL3  
U
2
PL2  
U
1
PL1  
U
Bit 0  
PL0  
U
Write:  
Reset:  
CMTCGH2  
Read:  
Bit 7  
SH7  
U
6
SH6  
U
5
SH5  
U
4
SH4  
U
3
SH3  
U
2
SH2  
U
1
SH1  
U
Bit 0  
SH0  
U
Write:  
Reset:  
CMTCGL2  
Read:  
Bit 7  
SL7  
U
6
SL6  
U
5
SL5  
U
4
SL4  
U
3
SL3  
U
2
SL2  
U
1
SL1  
U
Bit 0  
SL0  
U
Write:  
Reset:  
U = Unaffected  
Figure 7-8 CMT Carrier Generator Data Registers  
(CMTCGH1, CMTCGL1, CMTCGH2, CMTCGL2)  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
105  
Carrier Modulator Transmitter (CMT) Module  
PH0–PH7 and PL0–PL7 — Primary Carrier High and Low Time Data Values  
When selected, these bits contain the number of input clocks required to generate the carrier high and  
low time periods. When operating in time mode (see 7.5.2.1 Time Mode), this register pair is always  
selected. When operating in FSK mode (see 7.5.2.3 FSK Mode), this register pair and the secondary  
register pair are alternatively selected under control of the modulator. The primary carrier high and low  
time values are undefined out of reset. These bits must be written to nonzero values before the carrier  
generator is enabled to avoid spurious results.  
SH0–SH7 and SL0–SL7 — Secondary Carrier High and Low Time Data Values  
When selected, these bits contain the number of input clocks required to generate the carrier high and  
low time periods. When operating in time mode (see 7.5.2.1 Time Mode), this register pair is never  
selected. When operating in FSK mode (see 7.5.2.3 FSK Mode), this register pair and the primary  
register pair are alternatively selected under control of the modulator. The secondary carrier high and  
low time values are undefined out of reset. These bits must be written to nonzero values before the  
carrier generator is enabled when operating in FSK mode.  
7.6.2 CMT Output Control Register (CMTOC)  
This register is used to control the IRO output of the CMT module.  
Bit 7  
IROL  
0
6
5
4
0
3
0
2
0
1
0
Bit 0  
0
Read:  
Write:  
Reset:  
CMTPOL IROPEN  
0
0
0
0
0
0
0
= Unimplemented  
Figure 7-9 CMT Output Control Register (CMTOC)  
IROL — IRO Latch Control  
Reading IROL reads the state of the IRO latch. Writing IROL changes the state of the IRO pin when  
the MCGEN bit is clear in the CMTMSC register and the IROPEN bit is set.  
CMTPOL — CMT Output Polarity  
The CMTPOL bit controls the polarity of the IRO pin output of the CMT.  
1 = IRO pin is active high  
0 = IRO pin is active low  
Freescale Semiconductor  
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SoC Guide — MC9S08RG60/D Rev 1.10  
IROPEN — IRO Pin Enable  
The IROPEN bit is used to enable and disable the IRO pin. When the pin is enabled, it is an output that  
drives out either the CMT transmitter output or the state of the IROL bit depending on whether the  
MCGEN bit in the CMTMSC register is set. Also, the state of the output is either inverted or not  
depending on the state of the CMTPOL bit. When the pin is disabled, it is in a high impedance state so  
it doesn’t draw any current. The pin is disabled during reset.  
1 = IRO pin enabled as output  
0 = IRO pin disabled  
7.6.3 CMT Modulator Status and Control Register (CMTMSC)  
The CMT modulator status and control register (CMTMSC) contains the modulator and carrier generator  
enable (MCGEN), end of cycle interrupt enable (EOCIE), FSK mode select (FSK), baseband enable  
(BASE), extended space (EXSPC), prescaler (CMTDIV1:CMTDIV0) bits, and the end of cycle (EOCF)  
status bit.  
Bit 7  
Read: EOCF  
Write:  
6
5
4
3
BASE  
0
2
FSK  
0
1
EOCIE  
0
Bit 0  
MCGEN  
0
CMTDIV1 CMTDIV0 EXSPC  
Reset:  
0
0
0
0
= Unimplemented  
Figure 7-10 CMT Modulator Status and Control Register (CMTMSC)  
EOCF — End of Cycle Status Flag  
The EOCF bit is set when:  
The modulator is not currently active and the MCGEN bit is set to begin the initial CMT  
transmission.  
At the end of each modulation cycle while the MCGEN bit is set. This is recognized when a match  
occurs between the contents of the space period register and the down-counter. At this time, the  
counter is initialized with the (possibly new) contents of the mark period buffer, CMTCMD1 and  
CMTCMD2. The space period register is loaded with the (possibly new) contents of the space  
period buffer, CMTCMD3 and CMTCMD4.  
This flag is cleared by a read of the CMTMSC register followed by an access of CMTCMD2 or  
CMTCMD4.  
In the case where the MCGEN bit is cleared and then set before the end of the modulation cycle, EOCF  
will not be set when MCGEN is set, but will be set at the end of the current modulation cycle.  
1 = End of modulator cycle has occurred  
0 = No end of modulation cycle occurrence since flag last cleared  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
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Carrier Modulator Transmitter (CMT) Module  
CMTDIV1:CMTDIV0 — CMT Clock Divide Prescaler  
The CMT clock divide prescaler causes the CMT to be clocked at the BUS CLOCK frequency, or the  
BUS CLOCK frequency divided by 1, 2, 4, or 8. Because these bits are not double buffered, they  
should not be changed during a transmission.  
Table 7-3 CMT Clock Divide Prescaler  
CMTDIV1:CMTDIV0  
CMT Clock Divide  
BUS CLOCK ÷ 1  
BUS CLOCK ÷ 2  
BUS CLOCK ÷ 4  
BUS CLOCK ÷ 8  
00  
01  
10  
11  
EXSPC — Extended Space Enable  
The EXSPC bit enables extended space operation.  
1 = Extended space enabled  
0 = Extended space disabled  
BASE — Baseband Enable  
When set, the BASE bit disables the carrier generator and forces the carrier output high for generation  
of baseband protocols. When BASE is clear, the carrier generator is enabled and the carrier output  
toggles at the frequency determined by values stored in the carrier data registers. See 7.5.2.2 Baseband  
Mode. This bit is cleared by reset. This bit is not double buffered and should not be written to during  
a transmission.  
1 = Baseband mode enabled  
0 = Baseband mode disabled  
FSK — FSK Mode Select  
The FSK bit enables FSK operation.  
1 = CMT operates in FSK mode  
0 = CMT operates in time or baseband mode  
EOCIE — End of Cycle Interrupt Enable  
A CPU interrupt will be requested when EOCF is set if EOCIE is high.  
1 = CPU interrupt enabled  
0 = CPU interrupt disabled  
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SoC Guide — MC9S08RG60/D Rev 1.10  
MCGEN — Modulator and Carrier Generator Enable  
Setting MCGEN will initialize the carrier generator and modulator and enable all clocks. After it is  
enabled, the carrier generator and modulator will function continuously. When MCGEN is cleared, the  
current modulator cycle will be allowed to expire before all carrier and modulator clocks are disabled  
(to save power) and the modulator output is forced low. To prevent spurious operation, the user should  
initialize all data and control registers before enabling the system.  
1 = Modulator and carrier generator enabled  
0 = Modulator and carrier generator disabled  
7.6.4 CMT Modulator Data Registers (CMTCMD1, CMTCMD2, CMTCMD3, and  
CMTCMD4)  
The modulator data registers control the mark and space periods of the modulator for all modes. The  
contents of these registers are transferred to the modulator down counter and space period register upon  
the completion of a modulation period.  
CMTCMD1  
Read:  
Bit 7  
6
5
4
3
2
1
Bit 0  
MB8  
MB15  
MB14  
MB13  
MB12  
MB11  
MB10  
MB9  
Write:  
Reset:  
Unaffected by Reset  
CMTCMD2  
Read:  
Bit 7  
MB7  
6
5
4
3
2
1
Bit 0  
MB0  
MB6  
MB5  
MB4  
MB3  
MB2  
MB1  
Write:  
Reset:  
Unaffected by Reset  
CMTCMD3  
Read:  
Bit 7  
6
5
4
3
2
1
Bit 0  
SB8  
SB15  
SB14  
SB13  
SB12  
SB11  
SB10  
SB9  
Write:  
Reset:  
Unaffected by Reset  
CMTCMD4  
Read:  
Bit 7  
SB7  
6
5
4
3
2
1
Bit 0  
SB0  
SB6  
SB5  
SB4  
SB3  
SB2  
SB1  
Write:  
Reset:  
Unaffected by Reset  
Figure 7-11 CMT Modulator Data Registers  
(CMTCMD1, CMTCMD2, CMTCMD3, and CMTCMD4)  
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Carrier Modulator Transmitter (CMT) Module  
Freescale Semiconductor  
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MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
Chapter 8 Parallel Input/Output  
8.1 Introduction  
This section explains software controls related to parallel input/output (I/O). The MC9S08RC/RD/RE/RG  
has five I/O ports that include a total of 39 general-purpose I/O pins (two of these pins are output only and  
one pin is input only). Not all of the ports are available in all packages. See Chapter 2 Pins and Connections  
for more information about the logic and hardware aspects of these pins.  
Many of these pins are shared with on-chip peripherals such as timer systems, external interrupts, or  
keyboard interrupts. When these other modules are not controlling the port pins, they revert to  
general-purpose I/O control. For each I/O pin, a port data bit provides access to input (read) and output  
(write) data. A data direction bit controls the direction of the pin and a pullup enable bit enables an internal  
pullup device (if the pin is configured as an input).  
NOTE: Not all general-purpose I/O pins are available on all packages. To avoid extra  
current drain from floating input pins, the user’s reset initialization routine in the  
application program should either enable on-chip pullup devices or change the  
direction of unconnected pins to outputs so the pins do not float.  
8.2 Features  
Parallel I/O features for the MC9S08RC/RD/RE/RG MCUs, depending on specific device and package  
choice, include:  
A total of 39 general-purpose I/O pins in five ports (two pins are output only, one is input only)  
High-current drivers on port B pins  
Hysteresis input buffers on all inputs  
Software-controlled pullups on each input pin  
Eight port A pins shared with KBI1  
Eight port B pins shared with SCI and TPMCH1  
Eight port C pins shared with KBI2 and SPI  
Seven port D pins shared with TPMCH0, ACMP, IRQ, RESET, and BKGD/MS  
Eight port E pins  
8.3 Pin Descriptions  
The MC9S08RC/RD/RE/RG has a total of 39 parallel I/O pins distributed between four 8-bit ports and one  
7-bit port. Not all pins are bonded out in all packages. Consult the pin assignment in the Pins and  
Connections section for available parallel I/O pins. All of these pins are available for general-purpose I/O  
when they are not used by other on-chip peripheral systems.  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
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Parallel Input/Output  
The following paragraphs discuss each port and the software controls that determine each pin’s use.  
8.3.1 Port A  
Port A  
Bit 7  
6
5
4
3
2
1
Bit 0  
PTA7/  
KBI1P7  
PTA6/  
KBI1P6  
PTA5/  
KBI1P5  
PTA4/  
KBI1P4  
PTA3/  
KBI1P3  
PTA2/  
KBI1P2  
PTA1/  
KBI1P1  
PTA0/  
KBI1P0  
MCU Pin:  
Figure 8-1 Port A Pin Names  
Port A is an 8-bit general-purpose I/O port shared with the KBI1 keyboard interrupt inputs. Bit 0 of port  
A is an input-only pin.  
Port A pins are available as general-purpose I/O pins controlled by the port A data (PTAD), data direction  
(PTADD), and pullup enable (PTAPE) registers. Refer to 8.4 Parallel I/O Controls for more information  
about general-purpose I/O control.  
Any of the port A pins can be configured as a KBI1 keyboard interrupt pin. Refer to the Keyboard Interrupt  
(KBI) Module section for more information about using port A pins as keyboard interrupt pins.  
8.3.2 Port B  
Port B  
Bit 7  
6
5
4
3
2
1
Bit 0  
PTB7/  
TPM1CH1  
PTB1/  
RxD1  
PTB0/  
TxD1  
MCU Pin:  
PTB6  
PTB5  
PTB4  
PTB3  
PTB2  
Figure 8-2 Port B Pin Names  
Port B is an 8-bit general-purpose I/O port with two pins shared with the SCI and one pin shared with the  
TPM. The port B output drivers are capable of high current drive.  
Port B pins are available as general-purpose I/O pins controlled by the port B data (PTBD), data direction  
(PTBDD), and pullup enable (PTBPE) registers. Refer to 8.4 Parallel I/O Controls for more information  
about general-purpose I/O control.  
When the SCI module is enabled, PTB0 and PTB1 function as the transmit (TxD1) and receive (RxD1)  
pins of the SCI. Refer to the Serial Communications Interface (SCI) Module section for more information  
about using PTB0 and PTB1 as SCI pins.  
The TPM can be configured to use PTB7 as either an input capture, output compare, or PWM pin. Refer  
to the Timer/PWM Module (TPM) Module section for more information about using PTB7 as a timer pin.  
Freescale Semiconductor  
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SoC Guide — MC9S08RG60/D Rev 1.10  
8.3.3 Port C  
Port C  
Bit 7  
6
5
3
3
2
1
Bit 0  
PTC7/  
SS1  
PTC6/ PTC5/  
SPSCK1 MISO1  
PTC4/  
MOSI1  
PTC3/  
KBI2P3  
PTC2/  
KBI2P2  
PTC1/  
KBI2P1  
PTC0/  
KBI2P0  
MCU Pin:  
Figure 8-3 Port C Pin Names  
Port C is an 8-bit general-purpose I/O port with four pins shared with the KBI2 keyboard interrupt inputs  
and four pins shared with the SPI.  
Port C pins are available as general-purpose I/O pins controlled by the port C data (PTCD), data direction  
(PTCDD), and pullup enable (PTCPE) registers. Refer to 8.4 Parallel I/O Controls for more information  
about general-purpose I/O control.  
When the SPI module is enabled, PTC7 serves as the SPI module’s slave select pin (SS1), PTC6 serves as  
the SPI clock pin (SPSCK1), PTC5 serves as the master-in slave-out pin (MISO1), and PTC4 serves as the  
master-out slave-in pin (MOSI1). Refer to the Serial Peripheral Interface (SPI) Module section for more  
information about using PTC7–PTC4 as SPI pins.  
Any of the port C pins PTC3-PTC0 can be configured as a KBI2 keyboard interrupt pin. Refer to the  
Keyboard Interrupt (KBI) Module section for more information about using port C pins as keyboard  
interrupt pins.  
8.3.4 Port D  
Port D  
Bit 7  
6
5
4
3
2
1
Bit 0  
PTD6/  
TPM1CH0  
PTD1/ PTD0/  
RESET BKGD/MS  
MCU Pin:  
PTD5  
PTD4  
PTD3  
PTD2  
Figure 8-4 Port D Pin Names  
Port D is an 7-bit general-purpose I/O port with one pin shared with the BKGD/MS function, one pin  
shared with the RESET function, one pin shared with the IRQ function, and one pin shared with the TPM.  
Port D pins are available as general-purpose I/O pins controlled by the port D data (PTDD), data direction  
(PTDDD), and pullup enable (PTDPE) registers. Refer to 8.4 Parallel I/O Controls for more information  
about general-purpose I/O control.  
The PTD0/BKGD/MS pin is configured for the BKGD/MS function during reset and following reset. The  
internal pullup for this pin is enabled when the BKGD/MS function is enabled, regardless of the PTDPE0  
bit. During reset, the BKGD/MS pin functions as a mode select pin. After the MCU is out of reset, the  
BKGD/MS pin becomes the background communications input/output pin. PTD0 can be configured to be  
a general-purpose output pin through software control. Refer to the Modes of Operation section, the  
Resets, Interrupts, and System Configuration section, and the Development Support section for more  
information about using this pin.  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
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Parallel Input/Output  
The PTD1/RESET pin is configured for the RESET function during reset and following reset.  
The TPM can be configured to use PTD6 as either an input capture, output compare, PWM, or external  
clock input pin. Refer to the Parallel Input/Output section for more information about using PTD6 as a  
timer pin.  
8.3.5 Port E  
Port E  
Bit 7  
6
5
4
3
2
1
Bit 0  
MCU Pin: PTE7  
PTE6  
PTE5  
PTE4  
PTE3  
PTE2  
PTE1  
PTE0  
Figure 8-5 Port E Pin Names  
Port E is an 8-bit general-purpose I/O port.  
Port E pins are available as general-purpose I/O pins controlled by the port E data (PTED), data direction  
(PTEDD), and pullup enable (PTEPE) registers. Refer to 8.4 Parallel I/O Controls for more information  
about general-purpose I/O control.  
8.4 Parallel I/O Controls  
Provided no on-chip peripheral is controlling a port pin, the pins operate as general-purpose I/O pins that  
are accessed and controlled by a data register (PTxD), a data direction register (PTxDD), and a pullup  
enable register (PTxPE) where x is A, B, C, D, or E.  
Reads of the data register return the pin value (if PTxDDn = 0) or the contents of the port data register (if  
PTxDDn = 1). Writes to the port data register are latched into the port register whether the pin is controlled  
by an on-chip peripheral or the pin is configured as an input. If the corresponding pin is not controlled by  
a peripheral and is configured as an output, this level will be driven out the port pin.  
8.4.1 Data Direction Control  
The data direction control bits determine whether the pin output driver is enabled, and they control what  
is read for port data register reads. Each port pin has a data direction control bit. When PTxDDn = 0, the  
corresponding pin is an input and reads of PTxD return the pin value. When PTxDDn = 1, the  
corresponding pin is an output and reads of PTxD return the last value written to the port data register.  
When a peripheral module or system function is in control of a port pin, the data direction control still  
controls what is returned for reads of the port data register, even though the peripheral system has  
overriding control of the actual pin direction.  
For the MC9S08RC/RD/RE/RG MCU, reads of PTD0/BKGD/MS and PTD1/RESET will return the value  
on the output pin.  
It is a good programming practice to write to the port data register before changing the direction of a port  
pin to become an output. This ensures that the pin will not be driven with an old data value that happened  
to be in the port data register.  
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8.4.2 Internal Pullup Control  
An internal pullup device can be enabled for each port pin that is configured as an input (PTxDDn = 0).  
The pullup device is available for a peripheral module to use, provided the peripheral is enabled and is an  
input function as long as the PTxDDn = 0.  
NOTE: The voltage measured on the pulled up PTA0 pin will be less than V . The internal  
DD  
gates connected to this pin are pulled all the way to V . All other pins with  
DD  
enabled pullup resistors will have an unloaded measurement of V  
.
DD  
8.5 Stop Modes  
Depending on the stop mode, I/O functions differently as the result of executing a STOP instruction. An  
explanation of I/O behavior for the various stop modes follows:  
When the MCU enters stop1 mode, all internal registers, including general-purpose I/O control and  
data registers, are powered down. All of the general-purpose I/O pins assume their reset state:  
output buffers and pullups turned off. Upon exit from stop1, all I/O must be initialized as if the  
MCU had been reset.  
When the MCU enters stop2 mode, the internal registers are powered down as in stop1 but the I/O  
pin states are latched and held. For example, a port pin that is an output driving low continues to  
function as an output driving low even though its associated data direction and output data registers  
are powered down internally. Upon exit from stop2, the pins continue to hold their states until a 1  
is written to the PPDACK bit. To avoid discontinuity in the pin state following exit from stop2, the  
user must restore the port control and data registers to the values they held befor4e entering stop2.  
These values can be stored in RAM before entering stop2 because the RAM is maintained during  
stop2.  
In stop3 mode, all I/O is maintained because internal logic circuity stays powered up. Upon  
recovery, normal I/O function is available to the user.  
8.6 Parallel I/O Registers and Control Bits  
This section provides information about all registers and control bits associated with the parallel I/O ports.  
Refer to tables in the Memory section for the absolute address assignments for all parallel I/O registers.  
This section refers to registers and control bits only by their names. A Freescale-provided equate or header  
file normally is used to translate these names into the appropriate absolute addresses.  
8.6.1 Port A Registers (PTAD, PTAPE, and PTADD)  
Port A pins used as general-purpose I/O pins are controlled by the port A data (PTAD), data direction  
(PTADD), and pullup enable (PTAPE) registers.  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
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Parallel Input/Output  
PTAD  
Bit 7  
PTAD7  
0
6
PTAD6  
0
5
PTAD5  
0
4
PTAD4  
0
3
PTAD3  
0
2
PTAD2  
0
1
PTAD1  
0
Bit 0  
PTAD0  
0
Read:  
Write:  
Reset:  
PTAPE  
PTADD  
Read:  
Write:  
Reset:  
PTAPE7 PTAPE6 PTAPE5 PTAPE4 PTAPE3 PTAPE2 PTAPE1 PTAPE0  
0
0
0
0
0
0
0
0
Read:  
Write:  
Reset:  
PTADD7 PTADD6 PTADD5 PTADD4 PTADD3 PTADD2 PTADD1 PTADD0  
0
0
0
0
0
0
0
0
Figure 8-6 Port A Registers  
PTADn — Port A Data Register Bit n (n = 0–7)  
For port A pins that are inputs, reads of this register return the logic level on the pin. For port A pins  
that are configured as outputs, reads of this register 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.  
PTAPEn — Pullup Enable for Port A Bit n (n = 0–7)  
For port A pins that are inputs, these read/write control bits determine whether internal pullup devices  
are enabled provided the corresponding PTADDn is a logic 0. For port A pins that are configured as  
outputs, these bits are ignored and the internal pullup devices are disabled. When any of bits 7 through  
4 of port A are enabled as KBI inputs and are configured to detect rising edges/high levels, the pullup  
enable bits enable pulldown rather than pullup devices.  
1 = Internal pullup device enabled.  
0 = Internal pullup device disabled.  
PTADDn — Data Direction for Port A Bit n (n = 0–7)  
These read/write bits control the direction of port A pins and what is read for PTAD reads.  
1 = Output driver enabled for port A bit n and PTAD reads return the contents of PTADn.  
0 = Input (output driver disabled) and reads return the pin value.  
Freescale Semiconductor  
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SoC Guide — MC9S08RG60/D Rev 1.10  
8.6.2 Port B Registers (PTBD, PTBPE, and PTBDD)  
Port B pins used as general-purpose I/O pins are controlled by the port B data (PTBD), data direction  
(PTBDD), and pullup enable (PTBPE) registers.  
PTBD  
Bit 7  
PTBD7  
0
6
PTBD6  
0
5
PTBD5  
0
4
PTBD4  
0
3
PTBD3  
0
2
PTBD2  
0
1
PTBD1  
0
Bit 0  
PTBD0  
0
Read:  
Write:  
Reset:  
PTBPE  
PTBDD  
Read:  
Write:  
Reset:  
PTBPE7 PTBPE6 PTBPE5 PTBPE4 PTBPE3 PTBPE2 PTBPE1 PTBPE0  
0
0
0
0
0
0
0
0
Read:  
Write:  
Reset:  
PTBDD7 PTBDD6 PTBDD5 PTBDD4 PTBDD3 PTBDD2 PTBDD1 PTBDD0  
0
0
0
0
0
0
0
0
Figure 8-7 Port B Registers  
PTBDn — Port B Data Register Bit n (n = 0–7)  
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 on the corresponding pins because reset  
also configures all port pins as high-impedance inputs with pullups disabled.  
PTBPEn — Pullup Enable for Port B Bit n (n = 0–7)  
For port B pins that are inputs, these read/write control bits determine whether internal pullup devices  
are enabled. For port B pins that are configured as outputs, these bits are ignored and the internal pullup  
devices are disabled.  
1 = Internal pullup device enabled.  
0 = Internal pullup device disabled.  
PTBDDn — Data Direction for Port B Bit n (n = 0–7)  
These read/write bits control the direction of port B pins and what is read for PTBD reads.  
1 = Output driver enabled for port B bit n and PTBD reads return the contents of PTBDn.  
0 = Input (output driver disabled) and reads return the pin value.  
Freescale Semiconductor  
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Parallel Input/Output  
8.6.3 Port C Registers (PTCD, PTCPE, and PTCDD)  
Port C pins used as general-purpose I/O pins are controlled by the port C data (PTCD), data direction  
(PTCDD), and pullup enable (PTCPE) registers.  
PTCD  
Bit 7  
PTCD7  
0
6
PTCD6  
0
5
PTCD5  
0
4
PTCD4  
0
3
PTCD3  
0
2
PTCD2  
0
1
PTCD1  
0
Bit 0  
PTCD0  
0
Read:  
Write:  
Reset:  
PTCPE  
PTCDD  
Read:  
Write:  
Reset:  
PTCPE7 PTCPE6 PTCPE5 PTCPE4 PTCPE3 PTCPE2 PTCPE1 PTCPE0  
0
0
0
0
0
0
0
0
Read:  
Write:  
Reset:  
PTCDD7 PTCDD6 PTCDD5 PTCDD4 PTCDD3 PTCDD2 PTCDD1 PTCDD0  
0
0
0
0
0
0
0
0
Figure 8-8 Port C Registers  
PTCDn — Port C Data Register Bit n (n = 0–7)  
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.  
PTCPEn — Pullup Enable for Port C Bit n (n = 0–7)  
For port C pins that are inputs, these read/write control bits determine whether internal pullup devices  
are enabled. For port C pins that are configured as outputs, these bits are ignored and the internal pullup  
devices are disabled.  
1 = Internal pullup device enabled.  
0 = Internal pullup device disabled.  
PTCDDn — Data Direction for Port C Bit n (n = 0–7)  
These read/write bits control the direction of port C pins and what is read for PTCD reads.  
1 = Output driver enabled for port C bit n and PTCD reads return the contents of PTCDn.  
0 = Input (output driver disabled) and reads return the pin value.  
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8.6.4 Port D Registers (PTDD, PTDPE, and PTDDD)  
Port D pins used as general-purpose I/O pins are controlled by the port D data (PTDD), data direction  
(PTDDD), and pullup enable (PTDPE) registers.  
PTDD  
Bit 7  
0
6
PTDD6  
0
5
PTDD5  
0
4
PTDD4  
0
3
PTDD3  
0
2
PTDD2  
0
1
PTDD1  
0
Bit 0  
PTDD0  
0
Read:  
Write:  
Reset:  
0
0
0
0
0
PTDPE  
PTDDD  
Read:  
Write:  
Reset:  
PTDPE6 PTDPE5 PTDPE4 PTDPE3 PTDPE2 PTDPE1 PTDPE0  
0
0
0
0
0
0
0
Read:  
Write:  
Reset:  
PTDDD6 PTDDD5 PTDDD4 PTDDD3 PTDDD2 PTDDD1 PTDDD0  
0
0
0
0
0
0
0
= Unimplemented or Reserved  
Figure 8-9 Port D Registers  
PTDDn — Port D Data Register Bit n (n = 0–7)  
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.  
PTDPEn — Pullup Enable for Port D Bit n (n = 0–7)  
For port D pins that are inputs, these read/write control bits determine whether internal pullup devices  
are enabled. For port D pins that are configured as outputs, these bits are ignored and the internal pullup  
devices are disabled.  
1 = Internal pullup device enabled.  
0 = Internal pullup device disabled.  
PTDDDn — Data Direction for Port D Bit n (n = 0–7)  
These read/write bits control the direction of port D pins and what is read for PTDD reads.  
1 = Output driver enabled for port D bit n and PTDD reads return the contents of PTDDn.  
0 = Input (output driver disabled) and reads return the pin value.  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
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Parallel Input/Output  
8.6.5 Port E Registers (PTED, PTEPE, and PTEDD)  
Port E pins used as general-purpose I/O pins are controlled by the port E data (PTED), data direction  
(PTEDD), and pullup enable (PTEPE) registers.  
PTED  
Bit 7  
PTED7  
0
6
PTED6  
0
5
PTED5  
0
4
PTED4  
0
3
PTED3  
0
2
PTED2  
0
1
PTED1  
0
Bit 0  
PTED0  
0
Read:  
Write:  
Reset:  
PTEPE  
PTEDD  
Read:  
Write:  
Reset:  
PTEPE7 PTEPE6 PTEPE5 PTEPE4 PTEPE3 PTEPE2 PTEPE1 PTEPE0  
0
0
0
0
0
0
0
0
Read:  
Write:  
Reset:  
PTEDD7 PTEDD6 PTEDD5 PTEDD4 PTEDD3 PTEDD2 PTEDD1 PTEDD0  
0
0
0
0
0
0
0
0
Figure 8-10 Port E Registers  
PTEDn — Port E Data Register Bit n (n = 0–7)  
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.  
PTEPEn — Pullup Enable for Port E Bit n (n = 0–7)  
For port E pins that are inputs, these read/write control bits determine whether internal pullup devices  
are enabled. For port E pins that are configured as outputs, these bits are ignored and the internal pullup  
devices are disabled.  
1 = Internal pullup device enabled.  
0 = Internal pullup device disabled.  
PTEDDn — Data Direction for Port E Bit n (n = 0–7)  
These read/write bits control the direction of port E pins and what is read for PTED reads.  
1 = Output driver enabled for port E bit n and PTED reads return the contents of PTEDn.  
0 = Input (output driver disabled) and reads return the pin value.  
Freescale Semiconductor  
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SoC Guide — MC9S08RG60/D Rev 1.10  
Chapter 9 Keyboard Interrupt (KBI) Module  
9.1 Introduction  
The MC9S08RC/RD/RE/RG has two KBI modules. One has eight keyboard interrupt inputs that share  
port A pins. The other KBI module has four inputs that are shared on the upper four pins of port C. See the  
Pins and Connections section for more information about the logic and hardware aspects of these pins.  
Port A is an 8-bit port that is shared between the KBI1 keyboard interrupt inputs and general-purpose I/O.  
The eight KBI1PEn control bits in the KBI1PE register allow selection of any combination of port A pins  
to be assigned as KBI1 inputs. Any pins that are enabled as KBI1 inputs will be forced to act as inputs and  
the remaining port A pins are available as general-purpose I/O pins controlled by the port A data (PTAD),  
data direction (PTADD) and pullup enable (PTAPE) registers. The eight PTAPEn control bits in the  
PTAPE register allow the user to select whether an internal pullup device is enabled on each port A pin  
that is configured as a port input or a KBI1 input.  
KBI1 inputs can be configured for edge-only sensitivity or edge-and-level sensitivity. Bits 3 through 0 of  
port A are falling-edge/low-level sensitive and bits 7 through 4 can be configured for  
rising-edge/high-level or for falling-edge/low-level sensitivity.  
Port C is an 8-bit port with its lower four pins shared between the KBI2 keyboard interrupt inputs and  
general-purpose I/O. The four KBI2PEn control bits in the KBI2PE register allow selection of any  
combination of the lower four port C pins to be assigned as KBI2 inputs. Any pins that are enabled as KBI2  
inputs will be forced to act as inputs and the remaining port C pins are available as general-purpose I/O  
pins controlled by the port C data (PTCD), data direction (PTCDD) and pullup enable (PTCPE) registers.  
The eight PTCPEn control bits in the PTCPE register allow the user to select whether an internal pullup  
device is enabled on each port C pin that is configured as a port input or a KBI2 input.  
Any enabled keyboard interrupt can be used to wake the MCU from wait, standby (stop3), partial  
power-down (stop2) or power-down modes (stop1). In either stop1 or stop2 mode, an input functions as a  
falling edge/low-level wakeup, therefore it should be configured to use falling-edge sensing if the MCU  
will be used in stop1 or stop2 modes.  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
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Keyboard Interrupt (KBI) Module  
INTERNAL BUS  
DEBUG  
HCS08 CORE  
7
PTA7/KBI1P7–  
PTA1/KBI1P1  
BDC  
CPU  
NOTES1, 2  
MODULE (DBG)  
PTA0/KBI1P0  
HCS08 SYSTEM CONTROL  
PTB7/TPM1CH1  
8-BIT KEYBOARD  
INTERRUPT MODULE (KBI1)  
PTE6  
PTB5  
PTB4  
PTB3  
RESETS AND INTERRUPTS  
MODES OF OPERATION  
POWER MANAGEMENT  
NOTES 1, 5  
4-BIT KEYBOARD  
INTERRUPT MODULE (KBI2)  
PTB2  
PTB1/RxD1  
PTB0/TxD1  
RTI  
COP  
LVD  
IRQ  
SERIAL COMMUNICATIONS  
INTERFACE MODULE (SCI1)  
PTC7/SS1  
PTC6/SPSCK1  
PTC5/MISO1  
PTC4/MOSI1  
PTC3/KBI2P3  
PTC2/KBI2P2  
PTC1/KBI2P1  
PTC0/KBI2P0  
USER FLASH  
NOTE 1  
(RC/RD/RE/RG60 = 63,364 BYTES)  
(RC/RD/RE/RG32 = 32,768 BYTES)  
(RC/RD/RE16 = 16,384 BYTES)  
(RC/RD/RE8 = 8192 BYTES)  
ANALOG COMPARATOR  
MODULE (ACMP1)  
2-CHANNEL TIMER/PWM  
MODULE (TPM1)  
PTD6/TPM1CH0  
PTD5/ACMP1+  
PTD4/ACMP1–  
PTD3  
USER RAM  
(RC/RD/RE/RG32/60 = 2048 BYTES)  
(RC/RD/RE8/16 = 1024 BYTES)  
NOTES  
1, 3, 4  
PTD2/IRQ  
PTD1/RESET  
PTD0/BKGD/MS  
SERIAL PERIPHERAL  
EXTAL  
XTAL  
INTERFACE MODULE (SPI1)  
LOW-POWER OSCILLATOR  
8
PTE7–PTE0 NOTE 1  
V
DD  
VOLTAGE  
REGULATOR  
V
CARRIER MODULATOR  
TIMER MODULE (CMT)  
SS  
IRO NOTE 5  
NOTES:  
1. Port pins are software configurable with pullup device if input port  
2. PTA0 does not have a clamp diode to VDD. PTA0 should not be driven above VDD  
.
3. IRQ pin contains software configurable pullup/pulldown device if IRQ enabled (IRQPE = 1)  
4. The RESET pin contains integrated pullup device enabled if reset enabled (RSTPE = 1)  
5. High current drive  
6. Pins PTA[7:0] contain both pullup and pulldown devices. Pulldown available when KBI enabled (KBI1Pn = 1).  
Figure 9-1 MC9S08RC/RD/RE/RG Block Diagram  
Freescale Semiconductor  
122  
MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
9.2 KBI Block Diagram  
Figure 9-2 shows the block diagram for a KBI module.  
KBIxP0  
KBIPE0  
BUSCLK  
KBACK  
RESET  
KBIxP3  
V
KBIPE3  
KBIPE4  
DD  
KBF  
CLR  
D
Q
1
0
SYNCHRONIZER  
STOP BYPASS  
CK  
KBIxP4  
S
KEYBOARD  
INTERRUPT FF  
STOP  
KEYBOARD  
INTERRUPT  
REQUEST  
KBEDG4  
KBIMOD  
1
0
KBIE  
KBIxPn  
S
KBIPEn  
KBEDGn  
Figure 9-2 KBI Block Diagram  
The KBI module allows up to eight pins to act as additional interrupt sources. Four of these pins allow  
falling-edge sensing while the other four can be configured for either rising-edge sensing or falling-edge  
sensing. The sensing mode for all eight pins can also be modified to detect edges and levels instead of only  
edges.  
9.3 Keyboard Interrupt (KBI) Module  
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 up the  
MCU from stop or wait low-power modes.  
9.3.1 Pin Enables  
The KBIPEn control bits in the KBIxPE register allow a user to enable (KBIPEn = 1) any combination of  
KBI-related port pins to be connected to the KBI module. Pins corresponding to 0s in KBIxPE are  
general-purpose I/O pins that are not associated with the KBI module.  
9.3.2 Edge and Level Sensitivity  
Synchronous logic is used to detect edges. Prior to detecting an edge, enabled keyboard inputs in a KBI  
module must be at the deasserted logic level.  
Freescale Semiconductor  
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Keyboard Interrupt (KBI) Module  
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.  
The KBIMOD control bit can be set to reconfigure the detection logic so that it detects edges and levels.  
In KBIMOD = 1 mode, the KBF status flag becomes set when an edge is detected (when one or more  
enabled pins change from the deasserted to the asserted level while all other enabled pins remain at their  
deasserted levels), but the flag is continuously set (and cannot be cleared) as long as any enabled keyboard  
input pin remains at the asserted level. When the MCU enters stop mode, the synchronous edge-detection  
logic is bypassed (because clocks are stopped). In stop mode, KBI inputs act as asynchronous  
level-sensitive inputs so they can wake the MCU from stop mode.  
9.3.3 KBI Interrupt Controls  
The KBF status flag becomes set (1) when an edge event has been detected on any KBI input pin. If  
KBIE = 1 in the KBIxSC register, a hardware interrupt will be requested whenever KBF = 1. The KBF  
flag is cleared by writing a 1 to the keyboard acknowledge (KBACK) bit.  
When KBIMOD = 0 (selecting edge-only operation), KBF is always cleared by writing 1 to KBACK.  
When KBIMOD = 1 (selecting edge-and-level operation), KBF cannot be cleared as long as any keyboard  
input is at its asserted level.  
9.4 KBI Registers and Control Bits  
This section provides information about all registers and control bits associated with the KBI modules.  
Refer to the direct-page register summary in the Memory section of this data sheet for the absolute address  
assignments for all KBI 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 MCU systems have more than one KBI, so register names include placeholder characters to identify  
which KBI is being referenced. For example, KBIxSC refers to the KBIx status and control register and  
KBI2SC is the status and control register for KBI2.  
9.4.1 KBI x Status and Control Register (KBIxSC)  
Bit 7  
6
5
4
3
2
1
KBIE  
0
Bit 0  
KBIMOD  
0
Read:  
Write:  
Reset:  
KBF  
0
KBACK  
0
KBEDG7 KBEDG6 KBEDG5 KBEDG4  
0
0
0
0
0
= Unimplemented or Reserved  
Figure 9-3 KBI x Status and Control Register (KBIxSC)  
Freescale Semiconductor  
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MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
KBEDGn — Keyboard Edge Select for KBI Port Bit n (n = 7–4)  
Each of these read/write bits selects the polarity of the edges and/or levels that are recognized as trigger  
events on the corresponding KBI port pin when it is configured as a keyboard interrupt input  
(KBIPEn = 1). Also see the KBIMOD control bit, which determines whether the pin is sensitive to  
edges-only or edges and levels.  
1 = Rising edges/high levels.  
0 = Falling edges/low levels.  
KBF — Keyboard Interrupt Flag  
This read-only status flag is set whenever the selected edge event has been detected on any of the  
enabled KBI port pins. This flag is cleared by writing a logic 1 to the KBACK control bit. The flag will  
remain set if KBIMOD = 1 to select edge-and-level operation and any enabled KBI port pin remains  
at the asserted level.  
1 = KBI interrupt pending.  
0 = No KBI interrupt pending.  
KBF can be used as a software pollable flag (KBIE = 0) or it can generate a hardware interrupt request  
to the CPU (KBIE = 1).  
KBACK — Keyboard Interrupt Acknowledge  
This write-only bit (reads always return 0) is used to clear the KBF status flag by writing a logic 1 to  
KBACK. When KBIMOD = 1 to select edge-and-level operation and any enabled KBI port pin  
remains at the asserted level, KBF is being continuously set so writing 1 to KBACK does not clear the  
KBF flag.  
KBIE — Keyboard Interrupt Enable  
This read/write control bit determines whether hardware interrupts are generated when the KBF status  
flag equals 1. When KBIE = 0, no hardware interrupts are generated, but KBF can still be used for  
software polling.  
1 = KBI hardware interrupt requested when KBF = 1.  
0 = KBF does not generate hardware interrupts (use polling).  
KBIMOD — Keyboard Detection Mode  
This read/write control bit selects either edge-only detection or edge-and-level detection. KBI port bits  
3 through 0 can detect falling edges-only or falling edges and low levels.  
KBI port bits 7 through 4 can be configured to detect either:  
Rising edges-only or rising edges and high levels (KBEDGn = 1)  
Falling edges-only or falling edges and low levels (KBEDGn = 0)  
1 = Edge-and-level detection.  
0 = Edge-only detection.  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
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Keyboard Interrupt (KBI) Module  
9.4.2 KBI x Pin Enable Register (KBIxPE)  
Bit 7  
6
5
4
3
2
1
Bit 0  
Read:  
Write:  
Reset:  
KBIPE7 KBIPE6 KBIPE5 KBIPE4 KBIPE3 KBIPE2 KBIPE1 KBIPE0  
0
0
0
0
0
0
0
0
Figure 9-4 KBI x Pin Enable Register (KBIxPE)  
KBIPEn — Keyboard Pin Enable for KBI Port Bit n (n = 7–0)  
Each of these read/write bits selects whether the associated KBI port pin is enabled as a keyboard  
interrupt input or functions as a general-purpose I/O pin.  
1 = Bit n of KBI port enabled as a keyboard interrupt input  
0 = Bit n of KBI port is a general-purpose I/O pin not associated with the KBI.  
Freescale Semiconductor  
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Chapter 10 Timer/PWM Module (TPM) Module  
10.1 Introduction  
The MC9S08RC/RD/RE/RG includes a timer/PWM (TPM) module that supports traditional input capture,  
output compare, or buffered edge-aligned pulse-width modulation (PWM) on each channel. A control bit  
in the TPM configures both channels in the timer to operate as center-aligned PWM functions. Timing  
functions in the TPM 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. The MC9S08RC/RD/RE/RG devices do not have a separate fixed internal  
clock source (XCLK). If the XCLK source is selected using the CLKSA and CLKSB control bits (see  
Table 10-1), the TPM will use the BUSCLK.  
10.2 Features  
Timer system features include:  
Two separate channels:  
– Each channel may be input capture, output compare, or buffered 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  
The TPM may be configured for buffered, center-aligned pulse-width modulation (CPWM) on both  
channels  
Clock source to prescaler for the TPM is selectable between the bus clock or an external pin:  
– Prescale taps for divide by 1, 2, 4, 8, 16, 32, 64, or 128  
– External clock input shared with TPM1CH0 timer channel pin  
16-bit modulus register to control counter range  
Timer system enable  
One interrupt per channel plus terminal count interrupt  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
127  
Timer/PWM Module (TPM) Module  
INTERNAL BUS  
DEBUG  
HCS08 CORE  
7
PTA7/KBI1P7–  
PTA1/KBI1P1  
NOTES1, 2  
BDC  
CPU  
MODULE (DBG)  
PTA0/KBI1P0  
HCS08 SYSTEM CONTROL  
PTB7/TPM1CH1  
PTE6  
8-BIT KEYBOARD  
INTERRUPT MODULE (KBI1)  
RESETS AND INTERRUPTS  
MODES OF OPERATION  
POWER MANAGEMENT  
PTB5  
PTB4  
PTB3  
PTB2  
NOTES 1, 5  
4-BIT KEYBOARD  
INTERRUPT MODULE (KBI2)  
PTB1/RxD1  
PTB0/TxD1  
RTI  
COP  
LVD  
IRQ  
SERIAL COMMUNICATIONS  
INTERFACE MODULE (SCI1)  
PTC7/SS1  
PTC6/SPSCK1  
PTC5/MISO1  
PTC4/MOSI1  
PTC3/KBI2P3  
PTC2/KBI2P2  
PTC1/KBI2P1  
PTC0/KBI2P0  
USER FLASH  
NOTE 1  
(RC/RD/RE/RG60 = 63,364 BYTES)  
(RC/RD/RE/RG32 = 32,768 BYTES)  
(RC/RD/RE16 = 16,384 BYTES)  
(RC/RD/RE8 = 8192 BYTES)  
ANALOG COMPARATOR  
MODULE (ACMP1)  
2-CHANNEL TIMER/PWM  
MODULE (TPM1)  
PTD6/TPM1CH0  
PTD5/ACMP1+  
PTD4/ACMP1–  
PTD3  
USER RAM  
(RC/RD/RE/RG32/60 = 2048 BYTES)  
(RC/RD/RE8/16 = 1024 BYTES)  
NOTES  
1, 3, 4  
PTD2/IRQ  
PTD1/RESET  
PTD0/BKGD/MS  
SERIAL PERIPHERAL  
EXTAL  
XTAL  
INTERFACE MODULE (SPI1)  
LOW-POWER OSCILLATOR  
8
PTE7–PTE0 NOTE 1  
V
DD  
VOLTAGE  
REGULATOR  
V
CARRIER MODULATOR  
TIMER MODULE (CMT)  
SS  
IRO NOTE 5  
NOTES:  
1. Port pins are software configurable with pullup device if input port  
2. PTA0 does not have a clamp diode to VDD. PTA0 should not be driven above VDD  
.
3. IRQ pin contains software configurable pullup/pulldown device if IRQ enabled (IRQPE = 1)  
4. The RESET pin contains integrated pullup device enabled if reset enabled (RSTPE = 1)  
5. High current drive  
6. Pins PTA[7:0] contain both pullup and pulldown devices. Pulldown available when KBI enabled (KBI1Pn = 1).  
Figure 10-1 MC9S08RC/RD/RE/RG Block Diagram Highlighting TPM Block and Pins  
Freescale Semiconductor  
128  
MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
10.3 TPM Block Diagram  
The TPM uses one input/output (I/O) pin per channel, TPM1CHn where x is the TPM number (for  
example, 1 or 2) and n is the channel number (for example, 0–4). The TPM shares its I/O pins with  
general-purpose I/O port pins (refer to the Pins and Connections section for more information).  
Figure 10-2 shows the structure of a TPM. Some MCUs include more than one TPM, with various  
numbers of channels.  
BUSCLK  
XCLK  
CLOCK SOURCE  
SELECT  
PRESCALE AND SELECT  
DIVIDE BY  
OFF, BUS, XCLK, EXT  
1, 2, 4, 8, 16, 32, 64, or 128  
SYNC  
TPM1) EXT CLK  
CPWMS  
PS2  
PS1  
PS0  
CLKSB  
CLKSA  
MAIN 16-BIT COUNTER  
TOF  
TOIE  
INTERRUPT  
LOGIC  
COUNTER RESET  
16-BIT COMPARATOR  
TPM1MODH:TPM1MODL  
ELS0B ELS0A  
CHANNEL 0  
PORT  
LOGIC  
TPM1CH0  
16-BIT COMPARATOR  
TPM1C0VH:TPM1C0VL  
16-BIT LATCH  
CH0F  
INTERRUPT  
LOGIC  
CH0IE  
MS0B MS0A  
ELS1B ELS1A  
CHANNEL 1  
TPM1CH1  
PORT  
LOGIC  
16-BIT COMPARATOR  
CH1F  
TPM1C1VH:TPM1C1VL  
16-BIT LATCH  
INTERRUPT  
LOGIC  
CH1IE  
MS1B MS1A  
ELSnB ELSnA  
CHANNEL n  
16-BIT COMPARATOR  
TPM1CnVH:TPM1CnVL  
16-BIT LATCH  
TPM1CHn  
PORT  
LOGIC  
CHnF  
INTERRUPT  
LOGIC  
CHnIE  
MSnA  
MSnB  
Figure 10-2 TPM Block Diagram  
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The central component of the TPM is the 16-bit counter that can operate as a free-running counter, a  
modulo counter, or an up-/down-counter when the TPM is configured for center-aligned PWM. 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,  
TPM1MODH:TPM1MODL, control the modulo value of the counter. (The values $0000 or $FFFF  
effectively make the counter free running.) Software can read the counter value at any time without  
affecting the counting sequence. Any write to either byte of the TPM1CNT counter resets the counter  
regardless of the data value written.  
All TPM channels are programmable independently as input capture, output compare, or buffered  
edge-aligned PWM channels.  
10.4 Pin Descriptions  
Table 10-1 shows the MCU pins related to the TPM modules. When TPM1CH0 is used as an external  
clock input, the associated TPM channel 0 can not use the pin. (Channel 0 can still be used in output  
compare mode as a software timer.) When any of the pins associated with the timer is configured as a timer  
input, a passive pullup can be enabled. After reset, the TPM modules are disabled and all pins default to  
general-purpose inputs with the passive pullups disabled.  
10.4.1 External TPM Clock Sources  
When control bits CLKSB:CLKSA in the timer status and control register are set to 1:1, the prescaler and  
consequently the 16-bit counter for TPM1 are driven by an external clock source connected to the  
TPM1CH0 pin. A synchronizer is needed between the external clock and the rest of the TPM. This  
synchronizer is clocked by the bus clock so the frequency of the external source must be less than one-half  
the frequency of the bus rate clock. The upper frequency limit for this external clock source is specified to  
be one-fourth the bus frequency to conservatively accommodate duty cycle and phase-locked loop (PLL)  
or frequency-locked loop (FLL) frequency jitter effects.  
When the TPM is using the channel 0 pin for an external clock, the corresponding ELS0B:ELS0A control  
bits should be set to 0:0 so channel 0 is not trying to use the same pin.  
10.4.2 TPM1CHn — TPM1 Channel n I/O Pins  
Each TPM channel is associated with an I/O pin on the MCU. The function of this pin depends on the  
configuration of the channel. In some cases, no pin function is needed so the pin reverts to being controlled  
by general-purpose I/O controls. When a timer has control of a port pin, the port data and data direction  
registers do not affect the related pin(s). See the Pins and Connections section for additional information  
about shared pin functions.  
10.5 Functional Description  
All TPM functions are associated with a main 16-bit counter that allows flexible selection of the clock  
source and prescale divisor. A 16-bit modulo register also is associated with the main 16-bit counter in the  
TPM. Each TPM channel is optionally associated with an MCU pin and a maskable interrupt function.  
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The TPM has center-aligned PWM capabilities controlled by the CPWMS control bit in TPM1SC. When  
CPWMS is set to 1, timer counter TPM1CNT changes to an up-/down-counter and all channels in the  
associated TPM act as center-aligned PWM channels. When CPWMS = 0, each channel can  
independently be configured to operate in input capture, output compare, or buffered edge-aligned PWM  
mode.  
The following sections describe the main 16-bit 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 activity depend on the operating mode, these topics are covered in the associated mode  
sections.  
10.5.1 Counter  
All timer functions are based on the main 16-bit counter (TPM1CNTH:TPM1CNTL). This section  
discusses selection of the clock source, up-counting vs. up-/down-counting, end-of-count overflow, and  
manual counter reset.  
After any MCU reset, CLKSB:CLKSA = 0:0 so no clock source is selected and the TPM is inactive.  
Normally, CLKSB:CLKSA would be set to 0:1 so the bus clock drives the timer counter. The clock source  
for each of the TPM can be independently selected to be off, the bus clock (BUSCLK), the fixed system  
clock (XCLK), or an external input through the TPM1CH0 pin. The maximum frequency allowed for the  
external clock option is one-fourth the bus rate. Refer to 10.7.1 Timer x Status and Control Register  
(TPM1SC) and Table 10-1 for more information about clock source selection.  
When the microcontroller is in active background mode, the TPM temporarily suspends all counting until  
the microcontroller returns to normal user operating mode. During stop mode, all TPM clocks are stopped;  
therefore, the TPM is effectively disabled until clocks resume. During wait mode, the TPM continues to  
operate normally.  
The main 16-bit 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 main 16-bit counter counts from $0000 through its terminal count and then continues  
with $0000. The terminal count is $FFFF or a modulus value in TPM1MODH:TPM1MODL.  
When center-aligned PWM operation is specified, the counter counts upward from $0000 through its  
terminal count and then counts downward to $0000 where it returns to up-counting. Both $0000 and the  
terminal count value (value in TPM1MODH:TPM1MODL) are normal length counts (one timer clock  
period long).  
An interrupt flag and enable are associated with the main 16-bit counter. The timer overflow flag (TOF) is  
a software-accessible indication that the timer counter has overflowed. The enable signal selects between  
software polling (TOIE = 0) where no hardware interrupt is generated, or interrupt-driven operation  
(TOIE = 1) where a static hardware interrupt is automatically generated whenever the TOF flag is 1.  
The conditions that cause TOF to become set depend on the counting mode (up or up/down). In  
up-counting mode, the main 16-bit counter counts from $0000 through $FFFF and overflows to $0000 on  
the next counting clock. TOF becomes set at the transition from $FFFF to $0000. When a modulus limit  
is set, TOF becomes set at the transition from the value set in the modulus register to $0000. When the  
main 16-bit counter is operating in up-/down-counting mode, the TOF flag gets set as the counter changes  
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direction at the transition from the value set in the modulus register and the next lower count value. This  
corresponds to the end of a PWM period. (The $0000 count value corresponds to the center of a period.)  
Because the HCS08 MCU is an 8-bit architecture, a coherency mechanism is built into the timer counter  
for read operations. Whenever either byte of the counter is read (TPM1CNTH or TPM1CNTL), both bytes  
are captured into a buffer so when the other byte is read, the value will represent the other byte of the count  
at the time the first byte was read. The counter continues to count normally, but no new value can be read  
from either byte until both bytes of the old count have been read.  
The main timer counter can be reset manually at any time by writing any value to either byte of the timer  
count TPM1CNTH or TPM1CNTL. Resetting the counter in this manner also resets the coherency  
mechanism in case only one byte of the counter was read before resetting the count.  
10.5.2 Channel Mode Selection  
Provided CPWMS = 0 (center-aligned PWM operation is not specified), the MSnB and MSnA control bits  
in the channel n status and control registers determine the basic mode of operation for the corresponding  
channel. Choices include input capture, output compare, and buffered edge-aligned PWM.  
10.5.2.1 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 (TPM1CnVH:TPM1CnVL). Rising edges, falling edges, or any edge may  
be chosen as the active edge that triggers an input capture.  
When either byte of the 16-bit capture register is read, both bytes are latched into a buffer to support  
coherent 16-bit accesses regardless of order. The coherency sequence can be manually reset by writing to  
the channel status/control register (TPM1CnSC).  
An input capture event sets a flag bit (CHnF) that can optionally generate a CPU interrupt request.  
10.5.2.2 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 the channel value registers of an  
output compare channel, the TPM can set, clear, or toggle the channel pin.  
In output compare mode, values are transferred to the corresponding timer channel value registers only  
after both 8-bit bytes of a 16-bit register have been written. This coherency sequence can be manually reset  
by writing to the channel status/control register (TPM1CnSC).  
An output compare event sets a flag bit (CHnF) that can optionally generate a CPU interrupt request.  
10.5.2.3 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 setting in the modulus register  
(TPM1MODH:TPM1MODL). The duty cycle is determined by the setting in the timer channel value  
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register (TPM1CnVH:TPM1CnVL). The polarity of this PWM signal is determined by the setting in the  
ELSnA control bit. Duty cycle cases of 0 percent and 100 percent are possible.  
As Figure 10-3 shows, the output compare value in the TPM channel registers determines the pulse width  
(duty cycle) of the PWM signal. The time between the modulus overflow and the output compare is the  
pulse width. If ELSnA = 0, the counter overflow forces the PWM signal high and the output compare  
forces the PWM signal low. If ELSnA = 1, the counter overflow forces the PWM signal low and the output  
compare forces the PWM signal high.  
OVERFLOW  
OVERFLOW  
OVERFLOW  
PERIOD  
PULSE  
WIDTH  
TPM1CHn  
OUTPUT  
COMPARE  
OUTPUT  
COMPARE  
OUTPUT  
COMPARE  
Figure 10-3 PWM Period and Pulse Width (ELSnA = 0)  
When the channel value register is set to $0000, the duty cycle is 0 percent. By setting the timer channel  
value register (TPM1CnVH:TPM1CnVL) to a value greater than the modulus setting, 100 percent duty  
cycle can be achieved. This implies that the modulus setting must be less than $FFFF to get 100 percent  
duty cycle.  
Because the HCS08 is a family of 8-bit MCUs, the settings in the timer channel registers are buffered to  
ensure coherent 16-bit updates and to avoid unexpected PWM pulse widths. Writes to either register,  
TPM1CnVH or TPM1CnVL, write to buffer registers. In edge-PWM mode, values are transferred to the  
corresponding timer channel registers only after both 8-bit bytes of a 16-bit register have been written and  
the value in the TPM1CNTH:TPM1CNTL counter is $0000. (The new duty cycle does not take effect until  
the next full period.)  
10.5.3 Center-Aligned PWM Mode  
This type of PWM output uses the up-/down-counting mode of the timer counter (CPWMS = 1). The  
output compare value in TPM1CnVH:TPM1CnVL determines the pulse width (duty cycle) of the PWM  
signal and the period is determined by the value in TPM1MODH:TPM1MODL.  
TPM1MODH:TPM1MODL should be kept in the range of $0001 to $7FFF because values outside this  
range can produce ambiguous results. ELSnA will determine the polarity of the CPWM output.  
Equation 1: pulse width = 2 x (TPM1CnVH:TPM1CnVL)  
Equation 2: period = 2 x (TPM1MODH:TPM1MODL);  
for TPM1MODH:TPM1MODL = $0001–$7FFF  
If the channel value register TPM1CnVH:TPM1CnVL is zero or negative (bit 15 set), the duty cycle will  
be 0 percent. If TPM1CnVH:TPM1CnVL is a positive value (bit 15 clear) and is greater than the (nonzero)  
modulus setting, the duty cycle will be 100 percent because the duty cycle compare will never occur. This  
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implies the usable range of periods set by the modulus register is $0001 through $7FFE ($7FFF if  
generation of 100 percent duty cycle is not necessary). This is not a significant limitation because the  
resulting period is much longer than required for normal applications.  
TPM1MODH:TPM1MODL = $0000 is a special case that should not be used with center-aligned PWM  
mode. When CPWMS = 0, this case corresponds to the counter running free from $0000 through $FFFF,  
but when CPWMS = 1 the counter needs a valid match to the modulus register somewhere other than at  
$0000 in order to change directions from up-counting to down-counting.  
Figure 10-4 shows the output compare value in the TPM channel registers (multiplied by 2), which  
determines the pulse width (duty cycle) of the CPWM signal. If ELSnA = 0, the compare match while  
counting up forces the CPWM output signal low and a compare match while counting down forces the  
output high. The counter counts up until it reaches the modulo setting in TPM1MODH:TPM1MODL, then  
counts down until it reaches zero. This sets the period equal to two times TPM1MODH:TPM1MODL.  
COUNT = 0  
OUTPUT  
COMPARE  
(COUNT UP)  
OUTPUT  
COMPARE  
(COUNT DOWN)  
COUNT =  
TPM1MODH:TPM1MODL  
COUNT =  
TPM1MODH:TPM1MODL  
TPM1CHn  
PULSE WIDTH  
2 x TPM1CnVH:TPM1CnVL  
PERIOD  
2 x TPM1MODH:TPM1MODL  
Figure 10-4 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.  
Because the HCS08 is a family of 8-bit MCUs, the settings in 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,  
TPM1MODH, TPM1MODL, TPM1CnVH, and TPM1CnVL, actually write to buffer registers. Values are  
transferred to the corresponding timer channel registers only after both 8-bit bytes of a 16-bit register have  
been written and the timer counter overflows (reverses direction from up-counting to down-counting at the  
end of the terminal count in the modulus register). This TPM1CNT overflow requirement only applies to  
PWM channels, not output compares.  
Optionally, when TPM1CNTH:TPM1CNTL = TPM1MODH:TPM1MODL, the TPM can generate a TOF  
interrupt at the end of this count. The user can choose to reload any number of the PWM buffers, and they  
will all update simultaneously at the start of a new period.  
Writing to TPM1SC cancels any values written to TPM1MODH and/or TPM1MODL and resets the  
coherency mechanism for the modulo registers. Writing to TPM1CnSC cancels any values written to the  
channel value registers and resets the coherency mechanism for TPM1CnVH:TPM1CnVL.  
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10.6 TPM Interrupts  
The TPM generates an optional interrupt for the main counter overflow and an interrupt for each channel.  
The meaning of channel interrupts depends on the mode of operation for each channel. 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. See the Resets,  
Interrupts, and System Configuration section for absolute interrupt vector addresses, priority, and local  
interrupt mask control bits.  
For each interrupt source in the TPM, a flag bit is set on recognition of the interrupt condition such as timer  
overflow, channel input capture, or output compare events. This flag may be read (polled) by software to  
verify that the action has occurred, or an associated enable bit (TOIE or CHnIE) can be set to enable  
hardware interrupt generation. While the interrupt enable bit is set, a static interrupt will be generated  
whenever the associated interrupt flag equals 1. It is the responsibility of user software to perform a  
sequence of steps to clear the interrupt flag before returning from the interrupt service routine.  
10.6.1 Clearing Timer Interrupt Flags  
TPM interrupt flags are cleared by a 2-step process that includes a read of the flag bit while it is set (1)  
followed by a write of 0 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.  
10.6.2 Timer Overflow Interrupt Description  
The conditions that cause TOF to become set depend on the counting mode (up or up/down). In  
up-counting mode, the 16-bit timer counter counts from $0000 through $FFFF and overflows to $0000 on  
the next counting clock. TOF becomes set at the transition from $FFFF to $0000. When a modulus limit  
is set, TOF becomes set at the transition from the value set in the modulus register to $0000. When the  
counter is operating in up-/down-counting mode, the TOF flag gets set as the counter changes direction at  
the transition from the value set in the modulus register and the next lower count value. This corresponds  
to the end of a PWM period. (The $0000 count value corresponds to the center of a period.)  
10.6.3 Channel Event Interrupt Description  
The meaning of channel interrupts depends on the current mode of the channel (input capture, output  
compare, edge-aligned PWM, or center-aligned PWM).  
When a channel is configured as an input capture channel, the ELSnB:ELSnA control bits select rising  
edges, falling edges, any edge, or no edge (off) 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 2-step sequence described in  
10.6.1 Clearing Timer Interrupt Flags.  
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 2-step  
sequence described in 10.6.1 Clearing Timer Interrupt Flags.  
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10.6.4 PWM End-of-Duty-Cycle Events  
For channels that are configured for PWM operation, there are two possibilities:  
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, which are the times when the timer counter matches the  
channel value register.  
The flag is cleared by the 2-step sequence described in 10.6.1 Clearing Timer Interrupt Flags.  
10.7 TPM Registers and Control Bits  
The TPM includes:  
An 8-bit status and control register (TPM1SC)  
A 16-bit counter (TPM1CNTH:TPM1CNTL)  
A 16-bit modulo register (TPM1MODH:TPM1MODL)  
Each timer channel has:  
An 8-bit status and control register (TPM1CnSC)  
A 16-bit channel value register (TPM1CnVH:TPM1CnVL)  
Refer to the direct-page register summary in the Memory section of this data sheet for the absolute address  
assignments for all TPM 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 MCU systems have more than one TPM, so register names include placeholder characters to identify  
which TPM and which channel is being referenced. For example, TPMxCnSC refers to timer (TPM) x,  
channel n and TPM1C2SC is the status and control register for timer 1, channel 2.  
10.7.1 Timer x Status and Control Register (TPM1SC)  
TPM1SC contains the overflow status flag and control bits that are used to configure the interrupt enable,  
TPM configuration, clock source, and prescale divisor. These controls relate to all channels within this  
timer module.  
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Bit 7  
TOF  
6
TOIE  
0
5
4
3
CLKSA  
0
2
PS2  
0
1
PS1  
0
Bit 0  
PS0  
0
Read:  
Write:  
Reset:  
CPWMS CLKSB  
0
0
0
= Unimplemented or Reserved  
Figure 10-5 Timer x Status and Control Register (TPM1SC)  
TOF — Timer Overflow Flag  
This flag is set when the TPM counter changes to $0000 after reaching the modulo value programmed  
in the TPM counter modulo registers. When the TPM is configured for CPWM, TOF is set after the  
counter has reached the value in the modulo register, at the transition to the next lower count value.  
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 complete, the sequence is  
reset so TOF would remain set after the clear sequence was completed for the earlier TOF. Reset clears  
the TOF bit. Writing a logic 1 to TOF has no effect.  
1 = TPM counter has overflowed.  
0 = TPM counter has not reached modulo value or overflow.  
TOIE — Timer Overflow Interrupt Enable  
This read/write bit enables TPM overflow interrupts. If TOIE is set, an interrupt is generated when  
TOF equals 1. Reset clears TOIE.  
1 = TOF interrupts enabled.  
0 = TOF interrupts inhibited (use software polling).  
CPWMS — Center-Aligned PWM Select  
This read/write bit selects CPWM operating mode. Reset clears this bit so 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 the CPWMS bit.  
1 = All TPM1 channels operate in center-aligned PWM mode.  
0 = All TPM1 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.  
CLKSB:CLKSA — Clock Source Select  
As shown in Table 10-1, this 2-bit field is used to disable the TPM system or select one of three clock  
sources to drive the counter prescaler. The external source and the crystal source are synchronized to  
the bus clock by an on-chip synchronization circuit.  
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Table 10-1 TPM Clock Source Selection  
CLKSB:CLKSA  
TPM Clock Source to Prescaler Input  
No clock selected (TPM disabled)  
0:0  
0:1  
1:0  
Bus rate clock (BUSCLK)  
Fixed system clock (XCLK)  
External source (TPM1 Ext Clk)12  
1:1  
1
The maximum frequency that is allowed as an external clock is one-fourth of the bus  
frequency.  
2
When the TPM1CH0 pin is selected as the TPM clock source, the corresponding  
ELS0B:ELS0A control bits should be set to 0:0 so channel 0 does not try to use the same pin  
for a conflicting function.  
PS2:PS1:PS0 — Prescale Divisor Select  
This 3-bit field selects one of eight divisors for the TPM clock input as shown in Table 10-2. This  
prescaler is located after any clock source synchronization or clock source selection, so it affects  
whatever clock source is selected to drive the TPM system.  
Table 10-2 Prescale Divisor Selection  
PS2:PS1:PS0  
0:0:0  
TPM Clock Source Divided-By  
1
2
0:0:1  
0:1:0  
4
0:1:1  
8
1:0:0  
16  
32  
64  
128  
1:0:1  
1:1:0  
1:1:1  
10.7.2 Timer x Counter Registers (TPM1CNTH:TPM1CNTL)  
The two read-only TPM counter registers contain the high and low bytes of the value in the TPM counter.  
Reading either byte (TPM1CNTH or TPM1CNTL) latches the contents of both bytes into a buffer where  
they remain latched until the other byte is read. This allows coherent 16-bit reads in either order. The  
coherency mechanism is automatically restarted by an MCU reset, a write of any value to TPM1CNTH or  
TPM1CNTL, or any write to the timer status/control register (TPM1SC).  
Reset clears the TPM counter registers.  
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Bit 7  
Read: Bit 15  
Write:  
6
5
4
3
2
1
9
Bit 0  
Bit 8  
14  
13  
12  
11  
10  
Any write to TPM1CNTH clears the 16-bit counter.  
Reset:  
0
0
0
0
0
0
0
0
Figure 10-6 Timer x Counter Register High (TPM1CNTH)  
Bit 7  
Bit 7  
6
6
5
5
4
4
3
3
2
2
1
1
Bit 0  
Bit 0  
Read:  
Write:  
Reset:  
Any write to TPM1CNTL clears the 16-bit counter.  
0
0
0
0
0
0
0
0
Figure 10-7 Timer x Counter Register Low (TPM1CNTL)  
When background mode is active, the timer counter and the coherency mechanism are frozen such that the  
buffer latches remain in the state they were in when the background mode became active even if one or  
both bytes of the counter are read while background mode is active.  
10.7.3 Timer x Counter Modulo Registers (TPM1MODH:TPM1MODL)  
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 $0000 at the next clock  
(CPWMS = 0) or starts counting down (CPWMS = 1), and the overflow flag (TOF) becomes set. Writing  
to TPM1MODH or TPM1MODL inhibits the TOF bit and overflow interrupts until the other byte is  
written. Reset sets the TPM counter modulo registers to $0000, which results in a free-running timer  
counter (modulo disabled).  
Bit 7  
Bit 15  
0
6
14  
0
5
13  
0
4
12  
0
3
11  
0
3
10  
0
2
9
0
Bit 0  
Bit 8  
0
Read:  
Write:  
Reset:  
Figure 10-8 Timer x Counter Modulo Register High (TPM1MODH)  
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Bit 7  
Bit 7  
0
6
6
0
5
5
0
4
4
0
3
3
0
2
2
0
1
1
0
Bit 0  
Bit 0  
0
Read:  
Write:  
Reset:  
Figure 10-9 Timer x Counter Modulo Register Low (TPM1MODL)  
It is good practice to wait for an overflow interrupt so both bytes of the modulo register can be written well  
before a new overflow. An alternative approach is to reset the TPM counter before writing to the TPM  
modulo registers to avoid confusion about when the first counter overflow will occur.  
10.7.4 Timer x Channel n Status and Control Register (TPM1CnSC)  
TPM1CnSC contains the channel interrupt status flag and control bits that are used to configure the  
interrupt enable, channel configuration, and pin function.  
Bit 7  
CHnF  
0
6
CHnIE  
0
5
MSnB  
0
4
MSnA  
0
3
ELSnB  
0
2
ELSnA  
0
1
0
Bit 0  
0
Read:  
Write:  
Reset:  
0
0
= Unimplemented or Reserved  
Figure 10-10 Timer x Channel n Status and Control Register (TPM1CnSC)  
CHnF — Channel n Flag  
When channel n is configured for input capture, this flag bit is set when an active edge occurs on the  
channel n pin. When channel n is an output compare or edge-aligned PWM channel, CHnF is set when  
the value in the TPM counter registers matches the value in the TPM channel n value registers. This  
flag is seldom used with center-aligned PWMs because it is set every time the counter matches the  
channel value register, which correspond to both edges of the active duty cycle period.  
A corresponding interrupt is requested when CHnF is set and interrupts are enabled (CHnIE = 1). Clear  
CHnF by reading TPM1CnSC while CHnF is set and then writing a logic 0 to CHnF. If another  
interrupt request occurs before the clearing sequence is complete, the sequence is reset so CHnF would  
remain set after the clear sequence was completed for the earlier CHnF. This is done so a CHnF  
interrupt request cannot be lost by clearing a previous CHnF.  
Reset clears the CHnF bit. Writing a logic 1 to CHnF has no effect.  
1 = Input capture or output compare event occurred on channel n.  
0 = No input capture or output compare event occurred on channel n.  
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CHnIE — Channel n Interrupt Enable  
This read/write bit enables interrupts from channel n. Reset clears the CHnIE bit.  
1 = Channel n interrupt requests enabled.  
0 = Channel n interrupt requests disabled (use software polling).  
MSnB — Mode Select B for TPM Channel n  
When CPWMS = 0, MSnB = 1 configures TPM channel n for edge-aligned PWM mode. For a  
summary of channel mode and setup controls, refer to Table 10-3.  
MSnA — Mode Select A for TPM Channel n  
When CPWMS = 0 and MSnB = 0, MSnA configures TPM channel n for input capture mode or output  
compare mode. Refer to Table 10-3 for a summary of channel mode and setup controls.  
Table 10-3 Mode, Edge, and Level Selection  
CPWMS  
MSnB:MSnA  
ELSnB:ELSnA  
Mode  
Configuration  
Pin not used for TPM channel; use as an external clock for the TPM or  
revert to general-purpose I/O  
X
XX  
00  
01  
10  
11  
01  
10  
11  
10  
X1  
10  
X1  
Capture on rising edge only  
00  
01  
Input capture  
Capture on falling edge only  
Capture on rising or falling edge  
Toggle output on compare  
0
Output compare  
Clear output on compare  
Set output on compare  
High-true pulses (clear output on compare)  
Low-true pulses (set output on compare)  
High-true pulses (clear output on compare-up)  
Low-true pulses (set output on compare-up)  
Edge-aligned  
PWM  
1X  
XX  
Center-aligned  
PWM  
1
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. Typically, a program would clear  
status flags after changing channel configuration bits and before enabling channel interrupts or using the  
status flags to avoid any unexpected behavior.  
ELSnB:ELSnA — Edge/Level Select Bits  
Depending on the operating mode for the timer channel as set by CPWMS:MSnB:MSnA and shown  
in Table 10-3, these bits select the polarity of the input edge that triggers an input capture event, select  
the level that will be driven in response to an output compare match, or select the polarity of the PWM  
output.  
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Setting ELSnB:ELSnA to 0:0 configures the related timer pin as a general-purpose I/O pin unrelated  
to any timer channel functions. This function is typically used to temporarily disable an input capture  
channel or to make the timer pin available as a general-purpose I/O pin when the associated timer  
channel is set up as a software timer that does not require the use of a pin. This is also the setting  
required for channel 0 when the TPM1CH0 pin is used as an external clock input.  
10.7.5 Timer x Channel Value Registers (TPM1CnVH:TPM1CnVL)  
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 value registers are cleared  
by reset.  
Bit 7  
Bit 15  
0
6
14  
0
5
13  
0
4
12  
0
3
11  
0
2
10  
0
1
9
0
Bit 0  
Bit 8  
0
Read:  
Write:  
Reset:  
Figure 10-11 Timer x Channel Value Register High (TPM1CnVH)  
Bit 7  
Bit 7  
0
6
6
0
5
5
0
4
4
0
3
3
0
2
2
0
1
1
0
Bit 0  
Bit 0  
0
Read:  
Write:  
Reset:  
Figure 10-12 Timer x Channel Value Register Low (TPM1CnVL)  
In input capture mode, reading either byte (TPM1CnVH or TPM1CnVL) latches the contents of both bytes  
into a buffer where they remain latched until the other byte is read. This latching mechanism also resets  
(becomes unlatched) when the TPM1CnSC register is written.  
In output compare or PWM modes, writing to either byte (TPM1CnVH or TPM1CnVL) latches the value  
into a buffer. When both bytes have been written, they are transferred as a coherent 16-bit value into the  
timer channel value registers. This latching mechanism may be manually reset by writing to the  
TPM1CnSC register.  
This latching mechanism allows coherent 16-bit writes in either order, which is friendly to various  
compiler implementations.  
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Chapter 11 Serial Communications Interface (SCI) Module  
The MC9S08RDxx, MC9S08RExx, and MC9S08RGxx devices include a serial communications interface  
(SCI) module, which is sometimes called a universal asynchronous receiver/transmitters (UART). The  
SCI module shares pins with PTB0 and PTB1 port pins. When the SCI is enabled, the pins are controlled  
by the SCI module.  
INTERNAL BUS  
HCS08 CORE  
7
PTA7/KBI1P7–  
PTA1/KBI1P1  
NOTES1, 2  
BDC  
CPU  
DEBUG  
MODULE (DBG)  
PTA0/KBI1P0  
HCS08 SYSTEM CONTROL  
PTB7/TPM1CH1  
8-BIT KEYBOARD  
PTE6  
PTB5  
PTB4  
PTB3  
INTERRUPT MODULE (KBI1)  
RESETS AND INTERRUPTS  
MODES OF OPERATION  
POWER MANAGEMENT  
NOTES 1, 5  
4-BIT KEYBOARD  
PTB2  
PTB1/RxD1  
PTB0/TxD1  
INTERRUPT MODULE (KBI2)  
RTI  
COP  
LVD  
IRQ  
SERIAL COMMUNICATIONS  
INTERFACE MODULE (SCI1)  
PTC7/SS1  
PTC6/SPSCK1  
PTC5/MISO1  
PTC4/MOSI1  
PTC3/KBI2P3  
PTC2/KBI2P2  
PTC1/KBI2P1  
PTC0/KBI2P0  
USER FLASH  
NOTE 1  
(RC/RD/RE/RG60 = 63,364 BYTES)  
(RC/RD/RE/RG32 = 32,768 BYTES)  
(RC/RD/RE16 = 16,384 BYTES)  
(RC/RD/RE8 = 8192 BYTES)  
ANALOG COMPARATOR  
MODULE (ACMP1)  
2-CHANNEL TIMER/PWM  
MODULE (TPM1)  
PTD6/TPM1CH0  
PTD5/ACMP1+  
PTD4/ACMP1–  
PTD3  
USER RAM  
(RC/RD/RE/RG32/60 = 2048 BYTES)  
(RC/RD/RE8/16 = 1024 BYTES)  
NOTES  
1, 3, 4  
PTD2/IRQ  
PTD1/RESET  
PTD0/BKGD/MS  
SERIAL PERIPHERAL  
EXTAL  
XTAL  
INTERFACE MODULE (SPI1)  
LOW-POWER OSCILLATOR  
8
PTE7–PTE0 NOTE 1  
V
DD  
VOLTAGE  
REGULATOR  
V
CARRIER MODULATOR  
TIMER MODULE (CMT)  
SS  
IRO NOTE 5  
NOTES:  
1. Port pins are software configurable with pullup device if input port  
2. PTA0 does not have a clamp diode to VDD. PTA0 should not be driven above VDD  
.
3. IRQ pin contains software configurable pullup/pulldown device if IRQ enabled (IRQPE = 1)  
4. The RESET pin contains integrated pullup device enabled if reset enabled (RSTPE = 1)  
5. High current drive  
6. Pins PTA[7:0] contain both pullup and pulldown devices. Pulldown available when KBI enabled (KBI1Pn = 1).  
Figure 11-1 MC9S08RC/RD/RE/RG Block Diagram Highlighting SCI Block and Pins  
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11.1 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  
Hardware parity generation and checking  
Programmable 8-bit or 9-bit character length  
Receiver wakeup by idle-line or address-mark  
11.2 SCI System 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.  
11.3 Baud Rate Generation  
As shown in Figure 11-2, the clock source for the SCI baud rate generator is the bus-rate clock.  
MODULO DIVIDE BY  
(1 THROUGH 8191)  
DIVIDE BY  
16  
Tx BAUD RATE  
BUSCLK  
SBR12:SBR0  
Rx SAMPLING CLOCK  
(16 × BAUD RATE)  
BAUD RATE GENERATOR  
OFF IF [SBR12:SBR0] = 0  
BUSCLK  
[SBR12:SBR0] × 16  
BAUD RATE =  
Figure 11-2 SCI Baud Rate Generation  
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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 MC9S08RC/RD/RE/RG resynchronizes to bit boundaries on every high-to-low transition, but 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.  
11.4 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.  
11.4.1 Transmitter Block Diagram  
Figure 11-3 shows the transmitter portion of the SCI.  
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INTERNAL BUS  
(WRITE-ONLY)  
LOOPS  
RSRC  
SCID – Tx BUFFER  
LOOP  
TO RECEIVE  
DATA IN  
CONTROL  
M
11-BIT TRANSMIT SHIFT REGISTER  
TO TxD1 PIN  
H
8
7
6
5
4
3
2
1
0
L
1 × BAUD  
RATE CLOCK  
SHIFT DIRECTION  
T8  
PE  
PT  
PARITY  
GENERATION  
SCI CONTROLS TxD1  
TxD1 DIRECTION  
ENABLE  
TE  
TO TxD1  
TRANSMIT CONTROL  
PIN LOGIC  
SBK  
TXDIR  
TDRE  
TIE  
Tx INTERRUPT  
REQUEST  
TC  
TCIE  
Figure 11-3 SCI Transmitter Block Diagram  
The transmitter is enabled by setting the TE bit in SCI1C2. This queues a preamble character that is one  
full character frame of logic high. The transmitter then remains idle (TxD1 pin remains high) until data is  
available in the transmit data buffer. Programs store data into the transmit data buffer by writing to the SCI  
data register (SCI1D).  
The central element of the SCI transmitter is the transmit shift register that is either 10 or 11 bits long  
depending on the setting in the M control bit. For the remainder of this section, we will assume M = 0,  
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 SCI1D.  
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If no new character is waiting in the transmit data buffer after a stop bit is shifted out the TxD1 pin, the  
transmitter sets the transmit complete flag and enters an idle mode, with TxD1 high, waiting for more  
characters to transmit.  
Writing 0 to TE does not immediately release the pin to be a general-purpose I/O pin. Any transmit activity  
that is in progress must first be completed. This includes data characters in progress, queued idle  
characters, and queued break characters.  
11.4.2 Send Break and Queued Idle  
The SBK control bit in SCI1C2 is used to send break characters that were originally used to gain the  
attention of old teletype receivers. Break characters are a full character time of logic 0 (including a 0 where  
the stop bit would be normally). 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 is still 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 will be  
received as 0s in all eight (or nine) data bits and a framing error (FE = 1).  
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 = 0, the SCI transmitter never actually releases control of the TxD1 pin.  
If there is a possibility of the shifter finishing while TE = 0, set the general-purpose I/O controls so the pin  
that is shared with TxD1 is an output driving a logic 1. This ensures that the TxD1 line will look like a  
normal idle line even if the SCI loses control of the port pin between writing 0 and then 1 to TE.  
11.5 Receiver Functional Description  
In this section, the receiver block diagram (Figure 11-4) 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.  
11.5.1 Receiver Block Diagram  
Figure 11-4 shows the receiver portion of the SCI.  
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INTERNAL BUS  
(READ-ONLY)  
SCID – Rx BUFFER  
DIVIDE  
16 × BAUD  
RATE CLOCK  
BY 16  
M
11-BIT RECEIVE SHIFT REGISTER  
H
8
7
6
5
4
3
2
1
0
L
DATA RECOVERY  
FROM RxD1 PIN  
SHIFT DIRECTION  
LOOPS  
RSRC  
WAKE  
SINGLE-WIRE  
LOOP CONTROL  
WAKEUP  
LOGIC  
RWU  
ILT  
FROM  
TRANSMITTER  
RDRF  
RIE  
Rx INTERRUPT  
REQUEST  
IDLE  
ILIE  
OR  
ORIE  
FE  
FEIE  
ERROR INTERRUPT  
REQUEST  
NF  
NEIE  
PE  
PT  
PARITY  
CHECKING  
PF  
PEIE  
Figure 11-4 SCI Receiver Block Diagram  
The receiver is enabled by setting the RE bit in SCI1C2. 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 11.7.1 8- and 9-Bit Data Modes. For the remainder of this discussion, we assume the SCI is configured  
for normal 8-bit data mode.  
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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  
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 SCI1D. The RDRF flag is cleared automatically by a 2-step sequence (which is  
normally satisfied in the course of the user’s program that handles receive data). Refer to 11.6 Interrupts  
and Status Flags for more details about flag clearing.  
11.5.2 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 RxD1 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 is used to  
divide 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) will be set when the received character is transferred to the receive  
data buffer.  
The falling edge detection logic continuously looks for falling edges, and 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 is still set.  
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11.5.3 Receiver Wakeup Operation  
Receiver wakeup is a hardware mechanism that allows an SCI receiver to ignore the characters in a  
message that is 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 SCI1C2. When RWU = 1, it  
inhibits setting of the status flags associated with the receiver, thus eliminating the software overhead for  
handling the unimportant message characters. At the end of a message, or at the beginning of the next  
message, all receivers automatically force RWU to 0 so all receivers wake up in time to look at the first  
character(s) of the next message.  
11.5.3.1 Idle-Line Wakeup  
When WAKE = 0, 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). The idle-line type (ILT) control bit selects one  
of two ways to detect an idle line. When ILT = 0, 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 = 1, the  
idle bit counter doesn’t 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.  
11.5.3.2 Address-Mark Wakeup  
When WAKE = 1, 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 in M = 0 mode and ninth bit in M = 1 mode).  
11.6 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 and IDLE events, and a third vector is  
used for OR, NF, FE, and PF error conditions. Each of these eight interrupt sources can be separately  
masked by local interrupt enable masks. The flags can still 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 optionally can 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 SCI1D. If the transmit interrupt enable (TIE) bit is set, a hardware interrupt will be  
requested whenever TDRE = 1. Transmit complete (TC) indicates that the transmitter is finished  
transmitting all data, preamble, and break characters and is idle with TxD1 high. 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 will be requested whenever TC = 1. Instead of hardware  
interrupts, software polling may be used to monitor the TDRE and TC status flags if the corresponding  
TIE or TCIE local interrupt masks are 0s.  
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When a program detects that the receive data register is full (RDRF = 1), it gets the data from the receive  
data register by reading SCI1D. The RDRF flag is cleared by reading SCI1S1 while RDRF = 1 and then  
reading SCI1D.  
When polling is used, this sequence is naturally satisfied in the normal course of the user program. If  
hardware interrupts are used, SCI1S1 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 RxD1 line  
remains idle for an extended period of time. IDLE is cleared by reading SCI1S1 while IDLE = 1 and then  
reading SCI1D. 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) — get 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 gets set instead and the data and any associated NF, FE, or PF  
condition is lost.  
11.7 Additional SCI Functions  
The following sections describe additional SCI functions.  
11.7.1 8- 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 SCI1C1. 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 SCI1C3. For the receiver, the ninth bit is  
held in R8 in SCI1C3.  
For coherent writes to the transmit data buffer, write to the T8 bit before writing to SCI1D. For coherent  
reads of the receive data buffer, read R8 before reading SCI1D because reading or writing SCI1D is the  
final step in automatic clearing mechanisms for SCI flags.  
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 SCI1D to the shifter.  
9-bit data mode typically is used in conjunction 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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11.8 Stop Mode Operation  
During all stop modes, clocks to the SCI module are halted.  
In stop1 and stop2 modes, all SCI register data is lost and must be re-initialized upon recovery from these  
two stop modes.  
No SCI module registers are affected in stop3 mode.  
Note, because the clocks are halted, the SCI module will resume 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.  
11.8.1 Loop Mode  
When LOOPS = 1, 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 RxD1 pin is not used by the SCI, so it reverts to a  
general-purpose port I/O pin.  
11.8.2 Single-Wire Operation  
When LOOPS = 1, the RSRC bit in the same register chooses between loop mode (RSRC = 0) or  
single-wire mode (RSRC = 1). Single-wire mode is used to implement a half-duplex serial connection.  
The receiver is internally connected to the transmitter output and to the TxD1 pin. The RxD1 pin is not  
used and reverts to a general-purpose port I/O pin.  
In single-wire mode, the TXDIR bit in SCI1C3 controls the direction of serial data on the TxD1 pin. When  
TXDIR = 0, the TxD1 pin is an input to the SCI receiver and the transmitter is temporarily disconnected  
from the TxD1 pin so an external device can send serial data to the receiver. When TXDIR = 1, the TxD1  
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.  
11.9 SCI Registers and Control Bits  
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 the Memory section of this data sheet for 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.  
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11.9.1 SCI Baud Rate Registers (SCI1BDH, SCI1BDL)  
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 SCI1BDH to buffer the high half of the new value and then write  
to SCI1BDL. The working value in SCI1BDH does not change until SCI1BDL is written.  
SCI1BDL 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 SCI1C2 are written to 1).  
Bit 7  
0
6
0
5
0
4
SBR12  
0
3
SBR11  
0
2
SBR10  
0
1
SBR9  
0
Bit 0  
SBR8  
0
Read:  
Write:  
Reset:  
0
0
0
= Unimplemented or Reserved  
Figure 11-5 SCI Baud Rate Register (SCI1BDH)  
Bit 7  
SBR7  
0
6
SBR6  
0
5
SBR5  
0
4
SBR4  
0
3
SBR3  
0
2
SBR2  
1
1
SBR1  
0
Bit 0  
SBR0  
0
Read:  
Write:  
Reset:  
= Unimplemented or Reserved  
Figure 11-6 SCI Baud Rate Register (SCI1BDL)  
SBR12:SBR0 — Baud Rate Modulo Divisor  
These 13 bits are referred to collectively as BR, and they set the modulo divide rate for the SCI baud  
rate generator. When BR = 0, the SCI baud rate generator is disabled to reduce supply current. When  
BR = 1 to 8191, the SCI baud rate = BUSCLK/(16×BR).  
11.9.2 SCI Control Register 1 (SCI1C1)  
This read/write register is used to control various optional features of the SCI system.  
Bit 7  
6
5
RSRC  
0
4
M
0
3
WAKE  
0
2
ILT  
0
1
PE  
0
Bit 0  
PT  
0
Read:  
Write:  
Reset:  
LOOPS SCISWAI  
0
0
Figure 11-7 SCI Control Register 1 (SCI1C1)  
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LOOPS — Loop Mode Select  
Selects between loop back modes and normal 2-pin full-duplex modes. When LOOPS = 1, the  
transmitter output is internally connected to the receiver input.  
1 = Loop mode or single-wire mode where transmitter outputs are internally connected to receiver  
input. (See RSRC bit.) RxD1 pin is not used by SCI.  
0 = Normal operation — RxD1 and TxD1 use separate pins.  
SCISWAI — SCI Stops in Wait Mode  
1 = SCI clocks freeze while CPU is 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.  
RSRC — Receiver Source Select  
This bit has no meaning or effect unless the LOOPS bit is set to 1. When LOOPS = 1, the receiver input  
is internally connected to the TxD1 pin and RSRC determines whether this connection is also  
connected to the transmitter output.  
1 = Single-wire SCI mode where the TxD1 pin is connected to the transmitter output and receiver  
input.  
0 = Provided LOOPS = 1, RSRC = 0 selects internal loop back mode and the SCI does not use the  
RxD1 or TxD1 pins.  
M — 9-Bit or 8-Bit Mode Select  
1 = Receiver and transmitter use 9-bit data characters  
start + 8 data bits (LSB first) + 9th data bit + stop.  
0 = Normal — start + 8 data bits (LSB first) + stop.  
WAKE — Receiver Wakeup Method Select  
Refer to 11.5.3 Receiver Wakeup Operation for more information.  
1 = Address-mark wakeup.  
0 = Idle-line wakeup.  
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 the logic high level by the idle line detection logic. Refer to 11.5.3.1 Idle-Line  
Wakeup for more information.  
1 = Idle character bit count starts after stop bit.  
0 = Idle character bit count starts after start bit.  
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.  
1 = Parity enabled.  
0 = No hardware parity generation or checking.  
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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.  
1 = Odd parity.  
0 = Even parity.  
11.9.3 SCI Control Register 2 (SCI1C2)  
This register can be read or written at any time.  
Bit 7  
TIE  
0
6
TCIE  
0
5
RIE  
0
4
ILIE  
0
3
TE  
0
2
RE  
0
1
RWU  
0
Bit 0  
SBK  
0
Read:  
Write:  
Reset:  
Figure 11-8 SCI Control Register 2 (SCI1C2)  
TIE — Transmit Interrupt Enable (for TDRE)  
1 = Hardware interrupt requested when TDRE flag is 1.  
0 = Hardware interrupts from TDRE disabled (use polling).  
TCIE — Transmission Complete Interrupt Enable (for TC)  
1 = Hardware interrupt requested when TC flag is 1.  
0 = Hardware interrupts from TC disabled (use polling).  
RIE — Receiver Interrupt Enable (for RDRF)  
1 = Hardware interrupt requested when RDRF flag is 1.  
0 = Hardware interrupts from RDRF disabled (use polling).  
ILIE — Idle Line Interrupt Enable (for IDLE)  
1 = Hardware interrupt requested when IDLE flag is 1.  
0 = Hardware interrupts from IDLE disabled (use polling).  
TE — Transmitter Enable  
1 = Transmitter on.  
0 = Transmitter off.  
TE must be 1 in order to use the SCI transmitter. Normally, when TE = 1, the SCI forces the TxD1 pin  
to act as an output for the SCI system. If LOOPS = 1 and RSRC = 0, the TxD1 pin reverts to being a  
port B general-purpose I/O pin even if TE = 1.  
When the SCI is configured for single-wire operation (LOOPS = RSRC = 1), TXDIR controls the  
direction of traffic on the single SCI communication line (TxD1 pin).  
TE also can be used to queue an idle character by writing TE = 0 then TE = 1 while a transmission is  
in progress. Refer to 11.4.2 Send Break and Queued Idle for more details.  
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When TE is written to 0, the transmitter keeps control of the port TxD1 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.  
RE — Receiver Enable  
When the SCI receiver is off, the RxD1 pin reverts to being a general-purpose port I/O pin.  
1 = Receiver on.  
0 = Receiver off.  
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 either 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 11.5.3 Receiver Wakeup Operation for more  
details.  
1 = SCI receiver in standby waiting for wakeup condition.  
0 = Normal SCI receiver operation.  
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 bit times of logic 0 are queued as long as SBK = 1. 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 11.4.2 Send Break and Queued Idle for  
more details.  
1 = Queue break character(s) to be sent.  
0 = Normal transmitter operation.  
11.9.4 SCI Status Register 1 (SCI1S1)  
This register has eight read-only status flags. Writes have no effect. Special software sequences (that do  
not involve writing to this register) are used to clear these status flags.  
Bit 7  
Read: TDRE  
Write:  
6
5
4
3
2
1
Bit 0  
PF  
TC  
RDRF  
IDLE  
OR  
NF  
FE  
Reset:  
1
1
0
0
0
0
0
0
= Unimplemented or Reserved  
Figure 11-9 SCI Status Register 1 (SCI1S1)  
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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 SCI1S1 with  
TDRE = 1 and then write to the SCI data register (SCI1D).  
1 = Transmit data register (buffer) empty.  
0 = Transmit data register (buffer) full.  
TC — Transmission Complete Flag  
TC is set out of reset and when TDRE = 1 and no data, preamble, or break character is being  
transmitted.  
1 = Transmitter idle (transmission activity complete).  
0 = Transmitter active (sending data, a preamble, or a break).  
TC is cleared automatically by reading SCI1S1 with TC = 1 and then doing one of the following:  
Write to the SCI data register (SCI1D) to transmit new data  
Queue a preamble by changing TE from 0 to 1  
Queue a break character by writing 1 to SBK in SCI1C2  
RDRF — Receive Data Register Full Flag  
RDRF becomes set when a character transfers from the receive shifter into the receive data register  
(SCI1D). To clear RDRF, read SCI1S1 with RDRF = 1 and then read the SCI data register (SCI1D).  
1 = Receive data register full.  
0 = Receive data register empty.  
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 = 0, 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 = 1, the receiver doesn’t start counting idle bit times until after the stop bit. So 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 SCI1S1 with IDLE = 1 and then read the SCI data register (SCI1D). After IDLE  
has been cleared, it cannot become set again until after a new character has been received and RDRF  
has been set. IDLE will be set only once even if the receive line remains idle for an extended period.  
1 = Idle line was detected.  
0 = No idle line detected.  
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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 SCI1D yet. In this case, the new character  
(and all associated error information) is lost because there is no room to move it into SCI1D. To clear  
OR, read SCI1S1 with OR = 1 and then read the SCI data register (SCI1D).  
1 = Receive overrun (new SCI data lost).  
0 = No overrun.  
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 will be set at the same time as the flag RDRF gets  
set for the character. To clear NF, read SCI1S1 and then read the SCI data register (SCI1D).  
1 = Noise detected in the received character in SCI1D.  
0 = No noise detected.  
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 SCI1S1  
with FE = 1 and then read the SCI data register (SCI1D).  
1 = Framing error.  
0 = No framing error detected. This does not guarantee the framing is correct.  
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 SCI1S1 and then read the  
SCI data register (SCI1D).  
1 = Parity error.  
0 = No parity error.  
11.9.5 SCI Status Register 2 (SCI1S2)  
This register has one read-only status flag. Writes have no effect.  
Bit 7  
0
6
0
5
0
4
0
3
0
2
0
1
0
Bit 0  
RAF  
Read:  
Write:  
Reset:  
0
0
0
0
0
0
0
0
= Unimplemented or Reserved  
Figure 11-10 SCI Status Register 2 (SCI1S2)  
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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.  
1 = SCI receiver active (RxD1 input not idle).  
0 = SCI receiver idle waiting for a start bit.  
11.9.6 SCI Control Register 3 (SCI1C3)  
Bit 7  
R8  
6
T8  
0
5
TXDIR  
0
4
0
3
ORIE  
0
2
NEIE  
0
1
FEIE  
0
Bit 0  
PEIE  
0
Read:  
Write:  
Reset:  
0
0
= Unimplemented or Reserved  
Figure 11-11 SCI Control Register 3 (SCI1C3)  
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 SCI1D register. When reading 9-bit data, read R8 before  
reading SCI1D because reading SCI1D completes automatic flag clearing sequences that could allow  
R8 and SCI1D to be overwritten with new data.  
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 SCI1D register. When writing 9-bit data, the entire 9-bit value  
is transferred to the SCI shift register after SCI1D is written so T8 should be written (if it needs to  
change from its previous value) before SCI1D 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 SCI1D  
is written.  
TXDIR — TxD1 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 TxD1 pin.  
1 = TxD1 pin is an output in single-wire mode.  
0 = TxD1 pin is an input in single-wire mode.  
ORIE — Overrun Interrupt Enable  
This bit enables the overrun flag (OR) to generate hardware interrupt requests.  
1 = Hardware interrupt requested when OR = 1.  
0 = OR interrupts disabled (use polling).  
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NEIE — Noise Error Interrupt Enable  
This bit enables the noise flag (NF) to generate hardware interrupt requests.  
1 = Hardware interrupt requested when NF = 1.  
0 = NF interrupts disabled (use polling).  
FEIE — Framing Error Interrupt Enable  
This bit enables the framing error flag (FE) to generate hardware interrupt requests.  
1 = Hardware interrupt requested when FE = 1.  
0 = FE interrupts disabled (use polling).  
PEIE — Parity Error Interrupt Enable  
This bit enables the parity error flag (PF) to generate hardware interrupt requests.  
1 = Hardware interrupt requested when PF = 1.  
0 = PF interrupts disabled (use polling).  
11.9.7 SCI Data Register (SCI1D)  
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.  
Bit 7  
R7  
T7  
0
6
R6  
T6  
0
5
R5  
T5  
0
4
R4  
T4  
0
3
R3  
T3  
0
2
R2  
T2  
0
1
R1  
T1  
0
Bit 0  
R0  
T0  
0
Read:  
Write:  
Reset:  
Figure 11-12 SCI Data Register (SCI1D)  
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Chapter 12 Serial Peripheral Interface (SPI) Module  
The SPI is only available on the MC9S08RGxx versions of this family of microcontrollers. The SPI pins  
are shared with PTC4-PTC7 port pins. When the SPI is enabled these pins are controlled by the SPI  
module.  
INTERNAL BUS  
HCS08 CORE  
7
PTA7/KBI1P7–  
PTA1/KBI1P1  
NOTES1, 2  
BDC  
CPU  
DEBUG  
MODULE (DBG)  
PTA0/KBI1P0  
HCS08 SYSTEM CONTROL  
PTB7/TPM1CH1  
8-BIT KEYBOARD  
PTE6  
PTB5  
PTB4  
PTB3  
INTERRUPT MODULE (KBI1)  
RESETS AND INTERRUPTS  
MODES OF OPERATION  
POWER MANAGEMENT  
NOTES 1, 5  
4-BIT KEYBOARD  
PTB2  
PTB1/RxD1  
PTB0/TxD1  
INTERRUPT MODULE (KBI2)  
RTI  
COP  
LVD  
IRQ  
SERIAL COMMUNICATIONS  
INTERFACE MODULE (SCI1)  
PTC7/SS1  
PTC6/SPSCK1  
PTC5/MISO1  
PTC4/MOSI1  
PTC3/KBI2P3  
PTC2/KBI2P2  
PTC1/KBI2P1  
PTC0/KBI2P0  
USER FLASH  
NOTE 1  
(RC/RD/RE/RG60 = 63,364 BYTES)  
(RC/RD/RE/RG32 = 32,768 BYTES)  
(RC/RD/RE16 = 16,384 BYTES)  
(RC/RD/RE8 = 8192 BYTES)  
ANALOG COMPARATOR  
MODULE (ACMP1)  
2-CHANNEL TIMER/PWM  
MODULE (TPM1)  
PTD6/TPM1CH0  
PTD5/ACMP1+  
PTD4/ACMP1–  
PTD3  
USER RAM  
(RC/RD/RE/RG32/60 = 2048 BYTES)  
(RC/RD/RE8/16 = 1024 BYTES)  
NOTES  
1, 3, 4  
PTD2/IRQ  
PTD1/RESET  
PTD0/BKGD/MS  
SERIAL PERIPHERAL  
INTERFACE MODULE (SPI1)  
EXTAL  
XTAL  
LOW-POWER OSCILLATOR  
8
PTE7–PTE0 NOTE 1  
V
DD  
VOLTAGE  
REGULATOR  
V
CARRIER MODULATOR  
TIMER MODULE (CMT)  
SS  
IRO NOTE 5  
NOTES:  
1. Port pins are software configurable with pullup device if input port  
2. PTA0 does not have a clamp diode to VDD. PTA0 should not be driven above VDD  
.
3. IRQ pin contains software configurable pullup/pulldown device if IRQ enabled (IRQPE = 1)  
4. The RESET pin contains integrated pullup device enabled if reset enabled (RSTPE = 1)  
5. High current drive  
6. Pins PTA[7:0] contain both pullup and pulldown devices. Pulldown available when KBI enabled (KBI1Pn = 1).  
Figure 12-1 MC9S08RC/RD/RE/RG Block Diagram Highlighting SPI Block and Pins  
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12.1 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  
12.2 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.  
12.2.1 SPI System Block Diagram  
Figure 12-2 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 MOSI1 pin) to  
the slave while simultaneously shifting data in (on the MISO1 pin) from the slave. The transfer effectively  
exchanges the data that was in the SPI shift registers of the two SPI systems. The SPSCK1 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 (SS1 pin). In this system, the master device has configured its SS1 pin as an optional  
slave select output.  
SLAVE  
MASTER  
MOSI1  
MISO1  
MOSI1  
MISO1  
SPI SHIFTER  
SPI SHIFTER  
7
6
5
4
3
2
1
0
7
6
5
4
3
2
1
0
SPSCK1  
SS1  
SPSCK1  
SS1  
CLOCK  
GENERATOR  
Figure 12-2 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 12-2 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.  
12.2.2 SPI Module Block Diagram  
Figure 12-3 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 SPI1D) 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 SPI1D). 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 SPSCK1 pin, the shifter output  
is routed to MOSI1, and the shifter input is routed from the MISO1 pin.  
When the SPI is configured as a slave, the SPSCK1 pin is routed to the clock input of the SPI, the shifter  
output is routed to MISO1, and the shifter input is routed from the MOSI1 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
S
MOSI1  
(MOMI)  
SPE  
Tx BUFFER (WRITE SPI1D)  
ENABLE  
M
S
MISO1  
(SISO)  
SPI SYSTEM  
SHIFT  
OUT  
SHIFT  
IN  
SPI SHIFT REGISTER  
SPC0  
Rx BUFFER (READ SPI1D)  
BIDIROE  
SHIFT  
SHIFT  
Rx BUFFER  
FULL  
Tx BUFFER  
EMPTY  
LSBFE  
DIRECTION  
CLOCK  
MASTER CLOCK  
SLAVE CLOCK  
M
S
BUS RATE  
CLOCK  
CLOCK  
LOGIC  
SPIBR  
SPSCK1  
CLOCK GENERATOR  
MASTER/SLAVE  
MODE SELECT  
MASTER/  
SLAVE  
MSTR  
MODFEN  
SSOE  
MODE FAULT  
DETECTION  
SS1  
SPTEF  
SPTIE  
SPRF  
SPI  
INTERRUPT  
REQUEST  
MODF  
SPIE  
Figure 12-3 SPI Module Block Diagram  
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12.2.3 SPI Baud Rate Generation  
As shown in Figure 12-4, 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 (SPR2:SPR1:SPR0) divide the output of the prescaler stage by 2, 4, 8, 16, 32, 64, 128, or 256  
to get the internal SPI master mode bit-rate clock.  
PRESCALER  
CLOCK RATE DIVIDER  
MASTER  
SPI  
BIT RATE  
DIVIDE BY  
DIVIDE BY  
BUS CLOCK  
1, 2, 3, 4, 5, 6, 7, or 8  
2, 4, 8, 16, 32, 64, 128, or 256  
SPPR2:SPPR1:SPPR0  
SPR2:SPR1:SPR0  
Figure 12-4 SPI Baud Rate Generation  
12.3 Functional Description  
An SPI transfer is initiated by checking for the SPI transmit buffer empty flag (SPTEF = 1) and then  
writing a byte of data to the SPI data register (SPI1D) in the master SPI device. When the SPI shift register  
is available, this byte of data is moved from the transmit data buffer to the shifter, SPTEF is set to indicate  
there is room in the buffer to queue another transmit character if desired, and the SPI serial transfer starts.  
During the SPI transfer, data is sampled (read) on the MISO1 pin at one SPSCK edge and shifted, changing  
the bit value on the MOSI1 pin, one-half SPSCK cycle later. After eight SPSCK cycles, the data that was  
in the shift register of the master has been shifted out the MOSI1 pin to the slave while eight bits of data  
were shifted in the MISO1 pin into the master’s shift register. At the end of this transfer, the received data  
byte is moved from the shifter into the receive data buffer and SPRF is set to indicate the data can be read  
by reading SPI1D. If another byte of data is waiting in the transmit buffer at the end of a transfer, it is  
moved into the shifter, SPTEF is set, and a new transfer is started.  
Normally, SPI data is transferred most significant bit (MSB) first. If the least significant bit first enable  
(LSBFE) bit is set, SPI data is shifted LSB first.  
When the SPI is configured as a slave, its SS1 pin must be driven low before a transfer starts and SS1 must  
stay low throughout the transfer. If a clock format where CPHA = 0 is selected, SS1 must be driven to a  
logic 1 between successive transfers. If CPHA = 1, SS1 may remain low between successive transfers. See  
12.3.1 SPI Clock Formats for more details.  
Because the transmitter and receiver are double buffered, a second byte, in addition to the byte currently  
being shifted out, can be queued into the transmit data buffer, and a previously received character can be  
in the receive data buffer while a new character is being shifted in. The SPTEF flag indicates when the  
transmit buffer has room for a new character. The SPRF flag indicates when a received character is  
available in the receive data buffer. The received character must be read out of the receive buffer (read  
SPI1D) before the next transfer is finished or a receive overrun error results.  
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In the case of a receive overrun, the new data is lost because the receive buffer still held the previous  
character and was not ready to accept the new data. There is no indication for such an overrun condition  
so the application system designer must ensure that previous data has been read from the receive buffer  
before a new transfer is initiated.  
12.3.1 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 12-5 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
SPSCK  
(CPOL = 0)  
SPSCK  
(CPOL = 1)  
SAMPLE IN  
(MISO OR MOSI)  
MOSI  
(MASTER OUT)  
MSB FIRST  
LSB FIRST  
BIT 7  
BIT 0  
BIT 6  
BIT 1  
...  
...  
BIT 2  
BIT 5  
BIT 1  
BIT 6  
BIT 0  
BIT 7  
MISO  
(SLAVE OUT)  
SS OUT  
(MASTER)  
SS IN  
(SLAVE)  
Figure 12-5 SPI Clock Formats (CPHA = 1)  
When CPHA = 1, the slave begins to drive its MISO output when SS1 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 12-6 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 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
SPSCK  
(CPOL = 0)  
SPSCK  
(CPOL = 1)  
SAMPLE IN  
(MISO OR MOSI)  
MOSI  
(MASTER OUT)  
MSB FIRST  
LSB FIRST  
BIT 7  
BIT 0  
BIT 6  
BIT 1  
...  
...  
BIT 2  
BIT 5  
BIT 1  
BIT 6  
BIT 0  
BIT 7  
MISO  
(SLAVE OUT)  
SS OUT  
(MASTER)  
SS IN  
(SLAVE)  
Figure 12-6 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 SS1 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.  
12.3.2 SPI Pin Controls  
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.  
12.3.2.1 SPSCK1 — 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.  
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12.3.2.2 MOSI1 — 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.  
12.3.2.3 MISO1 — 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.  
12.3.2.4 SS1 — 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).  
12.3.3 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).  
12.3.4 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 SS1 pin (provided the SS1 pin is configured as the mode fault input signal). The SS1 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 SS1 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.  
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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 SPSCK1, MOSI1, and MISO1 (if not bidirectional mode) are  
disabled.  
MODF is cleared by reading it while it is set, then writing to the SPI control register 1 (SPI1C1). User  
software should verify the error condition has been corrected before changing the SPI back to master  
mode.  
12.4 SPI Registers and Control Bits  
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 the Memory section of this data sheet 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.  
12.4.1 SPI Control Register 1 (SPI1C1)  
This read/write register includes the SPI enable control, interrupt enables, and configuration options.  
Bit 7  
SPIE  
0
6
SPE  
0
5
SPTIE  
0
4
MSTR  
0
3
CPOL  
0
2
CPHA  
1
1
SSOE  
0
Bit 0  
LSBFE  
0
Read:  
Write:  
Reset:  
Figure 12-7 SPI Control Register 1 (SPI1C1)  
SPIE — SPI Interrupt Enable (for SPRF and MODF)  
This is the interrupt enable for SPI receive buffer full (SPRF) and mode fault (MODF) events.  
1 = When SPRF or MODF is 1, request a hardware interrupt.  
0 = Interrupts from SPRF and MODF inhibited (use polling).  
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.  
1 = SPI system enabled.  
0 = SPI system inactive.  
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SPTIE — SPI Transmit Interrupt Enable  
This is the interrupt enable bit for SPI transmit buffer empty (SPTEF).  
1 = When SPTEF is 1, hardware interrupt requested.  
0 = Interrupts from SPTEF inhibited (use polling).  
MSTR — Master/Slave Mode Select  
1 = SPI module configured as a master SPI device.  
0 = SPI module configured as a slave SPI device.  
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 12.3.1 SPI Clock Formats for more details.  
1 = Active-low SPI clock (idles high).  
0 = Active-high SPI clock (idles low).  
CPHA — Clock Phase  
This bit selects one of two clock formats for different kinds of synchronous serial peripheral devices.  
Refer to 12.3.1 SPI Clock Formats for more details.  
1 = First edge on SPSCK occurs at the start of the first cycle of an 8-cycle data transfer.  
0 = First edge on SPSCK occurs at the middle of the first cycle of an 8-cycle data transfer.  
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 SS1 pin as shown in Table 12-1.  
Table 12-1 SS1 Pin Function  
MODFEN  
SSOE  
Master Mode  
General-purpose I/O (not SPI)  
General-purpose I/O (not SPI)  
SS input for mode fault  
Slave Mode  
0
0
1
1
0
1
0
1
Slave select input  
Slave select input  
Slave select input  
Slave select input  
Automatic SS output  
LSBFE — LSB First (Shifter Direction)  
1 = SPI serial data transfers start with least significant bit.  
0 = SPI serial data transfers start with most significant bit.  
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12.4.2 SPI Control Register 2 (SPI1C2)  
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.  
Bit 7  
0
6
0
5
0
4
3
2
0
1
SPISWAI  
0
Bit 0  
SPC0  
0
Read:  
Write:  
Reset:  
MODFEN BIDIROE  
0
0
0
0
0
0
= Unimplemented or Reserved  
Figure 12-8 SPI Control Register 2 (SPI1C2)  
MODFEN — Master Mode-Fault Function Enable  
When the SPI is configured for slave mode, this bit has no meaning or effect. (The SS1 pin is the slave  
select input.) In master mode, this bit determines how the SS1 pin is used (refer to Table 12-1 for more  
details).  
1 = Mode fault function enabled, master SS1 pin acts as the mode fault input or the slave select  
output.  
0 = Mode fault function disabled, master SS1 pin reverts to general-purpose I/O not controlled by  
SPI.  
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 MOSI1 (MOMI) or MISO1 (SISO) pin,  
respectively, as the single SPI data I/O pin. When SPC0 = 0, BIDIROE has no meaning or effect.  
1 = SPI I/O pin enabled as an output.  
0 = Output driver disabled so SPI data I/O pin acts as an input.  
SPISWAI — SPI Stop in Wait Mode  
1 = SPI clocks stop when the MCU enters wait mode.  
0 = SPI clocks continue to operate in wait mode.  
SPC0 — SPI Pin Control 0  
The SPC0 bit chooses single-wire bidirectional mode. If MSTR = 0 (slave mode), the SPI uses the  
MISO1 (SISO) pin for bidirectional SPI data transfers. If MSTR = 1 (master mode), the SPI uses the  
MOSI1 (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.  
1 = SPI configured for single-wire bidirectional operation.  
0 = SPI uses separate pins for data input and data output.  
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12.4.3 SPI Baud Rate Register (SPI1BR)  
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.  
Bit 7  
0
6
SPPR2  
0
5
SPPR1  
0
4
SPPR0  
0
3
0
2
SPR2  
0
1
SPR1  
0
Bit 0  
SPR0  
0
Read:  
Write:  
Reset:  
0
0
= Unimplemented or Reserved  
Figure 12-9 SPI Baud Rate Register (SPI1BR)  
SPPR2:SPPR1:SPPR0 — SPI Baud Rate Prescale Divisor  
This 3-bit field selects one of eight divisors for the SPI baud rate prescaler as shown in Table 12-2. 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 12-4).  
Table 12-2 SPI Baud Rate Prescaler Divisor  
SPPR2:SPPR1:SPPR0  
Prescaler Divisor  
0:0:0  
0:0:1  
0:1:0  
0:1:1  
1:0:0  
1:0:1  
1:1:0  
1:1:1  
1
2
3
4
5
6
7
8
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SPR2:SPR1:SPR0 — SPI Baud Rate Divisor  
This 3-bit field selects one of eight divisors for the SPI baud rate divider as shown in Table 12-3. The  
input to this divider comes from the SPI baud rate prescaler (see Figure 12-4). The output of this  
divider is the SPI bit rate clock for master mode.  
Table 12-3 SPI Baud Rate Divisor  
SPR2:SPR1:SPR0  
Rate Divisor  
0:0:0  
0:0:1  
0:1:0  
0:1:1  
1:0:0  
1:0:1  
1:1:0  
1:1:1  
2
4
8
16  
32  
64  
128  
256  
12.4.4 SPI Status Register (SPI1S)  
This register has three read-only status bits. Bits 6, 3, 2, 1, and 0 are not implemented and always read 0s.  
Writes have no meaning or effect.  
Bit 7  
Read: SPRF  
Write:  
6
0
5
4
3
0
2
0
1
0
Bit 0  
0
SPTEF  
MODF  
Reset:  
0
0
1
0
0
0
0
0
= Unimplemented or Reserved  
Figure 12-10 SPI Status Register (SPI1S)  
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 (SPI1D). SPRF is cleared by reading SPRF while it is set, then reading the SPI data  
register.  
1 = Data available in the receive data buffer.  
0 = No data available in the receive data buffer.  
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SPTEF — SPI Transmit Buffer Empty Flag  
This bit is set when there is room in the transmit data buffer. It is cleared by reading SPI1S with SPTEF  
set, followed by writing a data value to the transmit buffer at SPI1D. SPI1S must be read with  
SPTEF = 1 before writing data to SPI1D or the SPI1D write will be ignored. SPTEF generates an  
SPTEF CPU interrupt request if the SPTIE bit in the SPI1C1 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 SPI1D 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.  
1 = SPI transmit buffer empty.  
0 = SPI transmit buffer not empty.  
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 SS1 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 (SPI1C1).  
1 = Mode fault error detected.  
0 = No mode fault error.  
12.4.5 SPI Data Register (SPI1D)  
Bit 7  
Bit 7  
0
6
6
0
5
5
0
4
4
0
3
3
0
2
2
0
1
1
0
Bit 0  
Bit 0  
0
Read:  
Write:  
Reset:  
Figure 12-11 SPI Data Register (SPI1D)  
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 SPI1D 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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Chapter 13 Analog Comparator (ACMP) Module  
The 32- and 44-pin LQFP packages of the MC9S08RCxx, MC9S08RExx, and MC9S08RGxx devices  
include an analog comparator. This comparator has two inputs or can optionally use an internal bandgap  
reference. The comparator inputs are shared with PTD4 and PTD5 port I/O pins.  
INTERNAL BUS  
HCS08 CORE  
7
CPU  
BDC  
INT  
PTA7/KBI1P7–  
PTA1/KBI1P1  
NOTES1, 2  
DEBUG  
MODULE (DBG)  
PTA0/KBI1P0  
BKP  
HCS08 SYSTEM CONTROL  
PTB7/TPM1CH1  
8-BIT KEYBOARD  
PTE6  
PTB5  
PTB4  
PTB3  
INTERRUPT MODULE (KBI1)  
RESETS AND INTERRUPTS  
MODES OF OPERATION  
POWER MANAGEMENT  
NOTES 1, 5  
4-BIT KEYBOARD  
PTB2  
PTB1/RxD1  
PTB0/TxD1  
INTERRUPT MODULE (KBI2)  
RTI  
COP  
LVD  
IRQ  
SERIAL COMMUNICATIONS  
INTERFACE MODULE (SCI1)  
PTC7/SS1  
PTC6/SPSCK1  
PTC5/MISO1  
PTC4/MOSI1  
PTC3/KBI2P3  
PTC2/KBI2P2  
PTC1/KBI2P1  
PTC0/KBI2P0  
USER FLASH  
NOTE 1  
(RC/RD/RE/RG60 = 63,364 BYTES)  
(RC/RD/RE/RG32 = 32,768 BYTES)  
(RC/RD/RE16 = 16,384 BYTES)  
(RC/RD/RE8 = 8192 BYTES)  
ANALOG COMPARATOR  
MODULE (ACMP1)  
2-CHANNEL TIMER/PWM  
MODULE (TPM1)  
PTD6/TPM1CH0  
PTD5/ACMP1+  
PTD4/ACMP1–  
PTD3  
USER RAM  
(RC/RD/RE/RG32/60 = 2048 BYTES)  
(RC/RD/RE8/16 = 1024 BYTES)  
NOTES  
1, 3, 4  
PTD2/IRQ  
PTD1/RESET  
PTD0/BKGD/MS  
SERIAL PERIPHERAL  
EXTAL  
XTAL  
INTERFACE MODULE (SPI1)  
LOW-POWER OSCILLATOR  
8
PTE7–PTE0 NOTE 1  
V
DD  
VOLTAGE  
REGULATOR  
V
CARRIER MODULATOR  
TIMER MODULE (CMT)  
SS  
IRO NOTE 5  
NOTES:  
1. Port pins are software configurable with pullup device if input port  
2. PTA0 does not have a clamp diode to VDD. PTA0 should not be driven above VDD  
.
3. IRQ pin contains software configurable pullup/pulldown device if IRQ enabled (IRQPE = 1)  
4. The RESET pin contains integrated pullup device enabled if reset enabled (RSTPE = 1)  
5. High current drive  
6. Pins PTA[7:0] contain both pullup and pulldown devices. Pulldown available when KBI enabled (KBIPn = 1).  
Figure 13-1 MC9S08RC/RD/RE/RG Block Diagram Highlighting ACMP Block and Pins  
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13.1 Features  
The ACMP has the following features:  
Full rail-to-rail supply operation.  
Less than 40 mV of input offset.  
Selectable interrupt on rising edge, falling edge, or either rising or falling edge of comparator  
output.  
Option to compare to fixed internal bandgap reference voltage.  
13.2 Block Diagram  
The block diagram for the analog comparator module is shown below.  
INTERNAL BUS  
INTERNAL  
REFERENCE  
ACBGS  
ACPE  
ACIE  
ACF  
AC IRQ  
STATUS & CONTROL  
REGISTER  
ACMP1+  
+
INTERRUPT  
CONTROL  
ACMP1–  
Figure 13-2 Analog Comparator Module Block Diagram  
13.3 Pin Description  
The ACMP has two analog input pins: ACMP1– and ACMP1+. Each of these pins can accept an input  
voltage that varies across the full operating voltage range of the MCU. When the ACMP1+ is configured  
to use the internal bandgap reference, ACMP1+ is available to be as general-purpose I/O. As shown in the  
block diagram, the ACMP1+ pin is connected to the comparator non-inverting input if ACBGS is equal to  
logic 0, and the ACMP1– pin is connected to the inverting input of the comparator.  
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13.4 Functional Description  
The analog comparator can be used to compare two analog input voltages applied to ACMP1– and  
ACMP1+; or it can be used to compare an analog input voltage applied to ACMP1– with an internal  
bandgap reference voltage. The ACBGS bit is used to select the mode of operation. The comparator output  
is high when the non-inverting input is greater than the inverting input, and is low when the non-inverting  
input is less than the inverting input. The ACMOD0 and ACMOD1 bits are used to select the condition  
that will cause the ACF bit to be set. The ACF bit can be set on a rising edge of the comparator output, a  
falling edge of the comparator output, or either a rising or a falling edge. The comparator output can be  
read directly through the ACO bit.  
13.4.1 Interrupts  
The ACMP module is capable of generating an interrupt on a compare event. The interrupt request is  
asserted when both the ACIE bit and the ACF bit are set. The interrupt is deasserted by clearing either the  
ACIE bit or the ACF bit. The ACIE bit is cleared by writing a 0 and the ACF bit is cleared by writing a 1.  
13.4.2 Wait Mode Operation  
During wait mode the ACMP, if enabled, will continue to operate normally. Also, if enabled, the interrupt  
can wake up the MCU.  
13.4.3 Stop Mode Operation  
During stop mode, clocks to the ACMP module are halted. The ACMP comparator circuit will enter a low  
power state. No compare operation will occur while in stop mode.  
In stop1 and stop2 modes, the ACMP module will be in its reset state when the MCU recovers from the  
stop condition and must be re-initialized.  
In stop3 mode, control and status register information is maintained and upon recovery normal ACMP  
function is available to the user.  
13.4.4 Background Mode Operation  
When the microcontroller is in active background mode, the ACMP will continue to operate normally.  
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13.5 ACMP Status and Control Register (ACMP1SC)  
Bit 7  
ACME  
0
6
ACBGS  
0
5
ACF  
0
4
ACIE  
0
3
2
0
1
Bit 0  
Read:  
Write:  
Reset:  
ACO  
ACMOD1 ACMOD0  
0
0
0
0
= Unimplemented  
Figure 13-3 ACMP Status and Control Register (ACMP1SC)  
ACME — Analog Comparator Module Enable  
The ACME bit enables the analog comparator module. When the module is not enabled, it remains in  
a low-power state.  
1 = Analog comparator enabled  
0 = Analog comparator disabled  
ACBGS — Analog Comparator Bandgap Select  
The ACBGS bit is used to select the internal bandgap as the comparator reference.  
1 = Internal bandgap reference selected as comparator non-inverting input  
0 = External pin ACMP1+ selected as comparator non-inverting input  
ACF — Analog Comparator Flag  
The ACF bit is set when a compare event occurs. Compare events are defined by the ACMOD0 and  
ACMOD1 bits. The ACF bit is cleared by writing a 1 to the bit.  
1 = Compare event has occurred.  
0 = Compare event has not occurred.  
ACIE — Analog Comparator Interrupt Enable  
The ACIE bit enables the interrupt from the ACMP. When this bit is set, an interrupt will be asserted  
when the ACF bit is set.  
1 = Interrupt enabled  
0 = Interrupt disabled  
ACO — Analog Comparator Output  
Reading the ACO bit will return the current value of the analog comparator output. The register bit is  
reset to 0 and will read as 0 when the analog comparator module is disabled (ACME = 0).  
ACMOD1:ACMOD0 — Analog Comparator Modes  
The ACMOD1 and ACMOD0 bits select the flag setting mode that controls the type of compare event  
that sets the ACF bit.  
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Table 13-1 Analog Comparator Modes  
ACMOD1:ACMOD0  
Flag Setting Mode  
00 or 10  
01  
Comparator output falling edge  
Comparator output rising edge  
Comparator output either rising  
or falling edge  
11  
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Chapter 14 Development Support  
14.1 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 (not even in test  
modes). Debug is done through commands fed into the target MCU via 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.  
The alternate BDC clock source for the MC9S08RC/RD/RE/RG devices is the oscillator output  
(OSCOUT).  
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14.2 Features  
Features of the background debug controller (BDC) 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  
Features of the debug module (DBG) include:  
Two trigger comparators:  
– Two address + read/write (R/W) or  
– One full address + data + R/W  
Flexible 8-word by 16-bit FIFO (first-in, first-out) buffer for capture information:  
– Change-of-flow addresses or  
– Event-only data  
Two types of breakpoints:  
– Tag breakpoints for instruction opcodes  
– Force breakpoints for any address access  
Nine trigger modes:  
– A-only  
– A OR B  
– A then B  
– A AND B data (full mode)  
– A AND NOT B data (full mode)  
– Event-only B (store data)  
– A then event-only B (store data)  
– Inside range (A address B)  
– Outside range (address < A or address > B)  
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14.3 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 V . An open-drain connection to reset allows the host to force a target system reset,  
DD  
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 V can be used to allow the pod to use  
DD  
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.  
2
GND  
BKGD  
1
NO CONNECT 3  
NO CONNECT 5  
4 RESET  
6 V  
DD  
Figure 14-1 BDM Tool Connector  
14.3.1 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  
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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 14.3.2  
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 14.3.2 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 development system is connected, it can pull both BKGD and  
RESET low, release RESET to select active background mode rather than normal operating mode, then  
release BKGD. It is not necessary to reset the target MCU to communicate with it through the background  
debug interface.  
14.3.2 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  
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.  
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Figure 14-2 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  
EARLIEST START  
OF NEXT BIT  
SYNCHRONIZATION  
UNCERTAINTY  
TARGET SENSES BIT LEVEL  
PERCEIVED START  
OF BIT TIME  
Figure 14-2 BDC Host-to-Target Serial Bit Timing  
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Figure 14-3 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  
HIGH-IMPEDANCE  
TO BKGD PIN  
TARGET MCU  
SPEEDUP PULSE  
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 14-3 BDC Target-to-Host Serial Bit Timing (Logic 1)  
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Figure 14-4 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 14-4 BDM Target-to-Host Serial Bit Timing (Logic 0)  
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14.3.3 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 14-1 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 14-1 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)  
/
d
=
=
=
=
=
=
=
=
=
=
separates parts of the command  
delay 16 target BDC clock cycles  
AAAA  
RD  
a 16-bit address in the host-to-target direction  
8 bits of read data in the target-to-host direction  
8 bits of write data in the host-to-target direction  
16 bits of read data in the target-to-host direction  
16 bits of write data in the host-to-target direction  
the contents of BDCSCR in the target-to-host direction (STATUS)  
8 bits of write data for BDCSCR in the host-to-target direction (CONTROL)  
WD  
RD16  
WD16  
SS  
CC  
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 14-1 BDC Command Summary  
Command  
Mnemonic  
Active BDM/  
Non-intrusive  
Coding  
Structure  
Description  
Request a timed reference pulse to determine  
target BDC communication speed  
n/a(1)  
D5/d  
D6/d  
90/d  
SYNC  
Non-intrusive  
Non-intrusive  
Non-intrusive  
Non-intrusive  
Enable acknowledge protocol. Refer to  
Freescale document HCS08RMv1/D.  
ACK_ENABLE  
ACK_DISABLE  
BACKGROUND  
Disable acknowledge protocol. Refer to  
Freescale document HCS08RMv1/D.  
Enter active background mode if enabled  
(ignore if ENBDM bit equals 0)  
READ_STATUS  
WRITE_CONTROL  
READ_BYTE  
Non-intrusive  
Non-intrusive  
Non-intrusive  
Non-intrusive  
E4/SS  
C4/CC  
Read BDC status from BDCSCR  
Write BDC controls in BDCSCR  
Read a byte from target memory  
Read a byte and report status  
E0/AAAA/d/RD  
READ_BYTE_WS  
E1/AAAA/d/SS/RD  
Re-read byte from address just read and  
report status  
READ_LAST  
Non-intrusive  
E8/SS/RD  
WRITE_BYTE  
WRITE_BYTE_WS  
READ_BKPT  
Non-intrusive  
Non-intrusive  
Non-intrusive  
Non-intrusive  
C0/AAAA/WD/d  
C1/AAAA/WD/d/SS  
E2/RBKP  
Write a byte to target memory  
Write a byte and report status  
Read BDCBKPT breakpoint register  
Write BDCBKPT breakpoint register  
WRITE_BKPT  
C2/WBKP  
Go to execute the user application program  
starting at the address currently in the PC  
GO  
Active BDM  
Active BDM  
Active BDM  
08/d  
10/d  
18/d  
Trace 1 user instruction at the address in the  
PC, then return to active background mode  
TRACE1  
TAGGO  
Same as GO but enable external tagging  
(HCS08 devices have no external tagging pin)  
READ_A  
Active BDM  
Active BDM  
Active BDM  
Active BDM  
Active BDM  
68/d/RD  
Read accumulator (A)  
READ_CCR  
READ_PC  
READ_HX  
READ_SP  
69/d/RD  
Read condition code register (CCR)  
Read program counter (PC)  
Read H and X register pair (H:X)  
Read stack pointer (SP)  
6B/d/RD16  
6C/d/RD16  
6F/d/RD16  
Increment H:X by one then read memory byte  
located at H:X  
READ_NEXT  
Active BDM  
Active BDM  
70/d/RD  
Increment H:X by one then read memory byte  
located at H:X. Report status and data.  
READ_NEXT_WS  
71/d/SS/RD  
WRITE_A  
Active BDM  
Active BDM  
Active BDM  
Active BDM  
Active BDM  
48/WD/d  
Write accumulator (A)  
WRITE_CCR  
WRITE_PC  
WRITE_HX  
WRITE_SP  
49/WD/d  
Write condition code register (CCR)  
Write program counter (PC)  
Write H and X register pair (H:X)  
Write stack pointer (SP)  
4B/WD16/d  
4C/WD16/d  
4F/WD16/d  
Increment H:X by one, then write memory byte  
located at H:X  
WRITE_NEXT  
Active BDM  
Active BDM  
50/WD/d  
Increment H:X by one, then write memory byte  
located at H:X. Also report status.  
WRITE_NEXT_WS  
51/WD/d/SS  
NOTES:  
1. 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.  
14.3.4 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.  
The on-chip debug module (DBG) includes circuitry for two additional hardware breakpoints that are  
more flexible than the simple breakpoint in the BDC module.  
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14.4 On-Chip Debug System (DBG)  
Because HCS08 devices do not have external address and data buses, the most important functions of an  
in-circuit emulator have been built onto the chip with the MCU. The debug system consists of an 8-stage  
FIFO that can store address or data bus information, and a flexible trigger system to decide when to capture  
bus information and what information to capture. The system relies on the single-wire background debug  
system to access debug control registers and to read results out of the eight stage FIFO.  
The debug module includes control and status registers that are accessible in the user’s memory map.  
These registers are located in the high register space to avoid using valuable direct page memory space.  
Most of the debug module’s functions are used during development, and user programs rarely access any  
of the control and status registers for the debug module. The one exception is that the debug system can  
provide the means to implement a form of ROM patching. This topic is discussed in greater detail in 14.4.6  
Hardware Breakpoints.  
14.4.1 Comparators A and B  
Two 16-bit comparators (A and B) can optionally be qualified with the R/W signal and an opcode tracking  
circuit. Separate control bits allow you to ignore R/W for each comparator. The opcode tracking circuitry  
optionally allows you to specify that a trigger will occur only if the opcode at the specified address is  
actually executed as opposed to only being read from memory into the instruction queue. The comparators  
are also capable of magnitude comparisons to support the inside range and outside range trigger modes.  
Comparators are disabled temporarily during all BDC accesses.  
The A comparator is always associated with the 16-bit CPU address. The B comparator compares to the  
CPU address or the 8-bit CPU data bus, depending on the trigger mode selected. Because the CPU data  
bus is separated into a read data bus and a write data bus, the RWAEN and RWA control bits have an  
additional purpose, in full address plus data comparisons they are used to decide which of these buses to  
use in the comparator B data bus comparisons. If RWAEN = 1 (enabled) and RWA = 0 (write), the CPU’s  
write data bus is used. Otherwise, the CPU’s read data bus is used.  
The currently selected trigger mode determines what the debugger logic does when a comparator detects  
a qualified match condition. A match can cause:  
Generation of a breakpoint to the CPU  
Storage of data bus values into the FIFO  
Starting to store change-of-flow addresses into the FIFO (begin type trace)  
Stopping the storage of change-of-flow addresses into the FIFO (end type trace)  
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14.4.2 Bus Capture Information and FIFO Operation  
The usual way to use the FIFO is to setup the trigger mode and other control options, then arm the  
debugger. When the FIFO has filled or the debugger has stopped storing data into the FIFO, you would  
read the information out of it in the order it was stored into the FIFO. Status bits indicate the number of  
words of valid information that are in the FIFO as data is stored into it. If a trace run is manually halted by  
writing 0 to ARM before the FIFO is full (CNT = 1:0:0:0), the information is shifted by one position and  
the host must perform ((8 – CNT) – 1) dummy reads of the FIFO to advance it to the first significant entry  
in the FIFO.  
In most trigger modes, the information stored in the FIFO consists of 16-bit change-of-flow addresses. In  
these cases, read DBGFH then DBGFL to get one coherent word of information out of the FIFO. Reading  
DBGFL (the low-order byte of the FIFO data port) causes the FIFO to shift so the next word of information  
is available at the FIFO data port. In the event-only trigger modes (see 14.4.5 Trigger Modes), 8-bit data  
information is stored into the FIFO. In these cases, the high-order half of the FIFO (DBGFH) is not used  
and data is read out of the FIFO by simply reading DBGFL. Each time DBGFL is read, the FIFO is shifted  
so the next data value is available through the FIFO data port at DBGFL.  
In trigger modes where the FIFO is storing change-of-flow addresses, there is a delay between CPU  
addresses and the input side of the FIFO. Because of this delay, if the trigger event itself is a  
change-of-flow address or a change-of-flow address appears during the next two bus cycles after a trigger  
event starts the FIFO, it will not be saved into the FIFO. In the case of an end-trace, if the trigger event is  
a change-of-flow, it will be saved as the last change-of-flow entry for that debug run.  
The FIFO can also be used to generate a profile of executed instruction addresses when the debugger is  
not armed. When ARM = 0, reading DBGFL causes the address of the most-recently fetched opcode to be  
saved in the FIFO. To use the profiling feature, a host debugger would read addresses out of the FIFO by  
reading DBGFH then DBGFL at regular periodic intervals. The first eight values would be discarded  
because they correspond to the eight DBGFL reads needed to initially fill the FIFO. Additional periodic  
reads of DBGFH and DBGFL return delayed information about executed instructions so the host debugger  
can develop a profile of executed instruction addresses.  
14.4.3 Change-of-Flow Information  
To minimize the amount of information stored in the FIFO, only information related to instructions that  
cause a change to the normal sequential execution of instructions is stored. With knowledge of the source  
and object code program stored in the target system, an external debugger system can reconstruct the path  
of execution through many instructions from the change-of-flow information stored in the FIFO.  
For conditional branch instructions where the branch is taken (branch condition was true), the source  
address is stored (the address of the conditional branch opcode). Because BRA and BRN instructions are  
not conditional, these events do not cause change-of-flow information to be stored in the FIFO.  
Indirect JMP and JSR instructions use the current contents of the H:X index register pair to determine the  
destination address, so the debug system stores the run-time destination address for any indirect JMP or  
JSR. For interrupts, RTI, or RTS, the destination address is stored in the FIFO as change-of-flow  
information.  
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14.4.4 Tag vs. Force Breakpoints and Triggers  
Tagging is a term that refers to identifying an instruction opcode as it is fetched into the instruction queue,  
but not taking any other action until and unless that instruction is actually executed by the CPU. This  
distinction is important because any change-of-flow from a jump, branch, subroutine call, or interrupt  
causes some instructions that have been fetched into the instruction queue to be thrown away without being  
executed.  
A force-type breakpoint waits for the current instruction to finish and then acts upon the breakpoint  
request. The usual action in response to a breakpoint is to go to active background mode rather than  
continuing to the next instruction in the user application program.  
The tag vs. force terminology is used in two contexts within the debug module. The first context refers to  
breakpoint requests from the debug module to the CPU. The second refers to match signals from the  
comparators to the debugger control logic. When a tag-type break request is sent to the CPU, a signal is  
entered into the instruction queue along with the opcode so that if/when this opcode ever executes, the  
CPU will effectively replace the tagged opcode with a BGND opcode so the CPU goes to active  
background mode rather than executing the tagged instruction. When the TRGSEL control bit in the  
DBGT register is set to select tag-type operation, the output from comparator A or B is qualified by a block  
of logic in the debug module that tracks opcodes and only produces a trigger to the debugger if the opcode  
at the compare address is actually executed. There is separate opcode tracking logic for each comparator  
so more than one compare event can be tracked through the instruction queue at a time.  
14.4.5 Trigger Modes  
The trigger mode controls the overall behavior of a debug run. The 4-bit TRG field in the DBGT register  
selects one of nine trigger modes. When TRGSEL = 1 in the DBGT register, the output of the comparator  
must propagate through an opcode tracking circuit before triggering FIFO actions. The BEGIN bit in  
DBGT chooses whether the FIFO begins storing data when the qualified trigger is detected (begin trace),  
or the FIFO stores data in a circular fashion from the time it is armed until the qualified trigger is detected  
(end trigger).  
A debug run is started by writing a 1 to the ARM bit in the DBGC register, which sets the ARMF flag and  
clears the AF and BF flags and the CNT bits in DBGS. A begin-trace debug run ends when the FIFO gets  
full. An end-trace run ends when the selected trigger event occurs. Any debug run can be stopped manually  
by writing a 0 to the ARM bit or DBGEN bit in DBGC.  
In all trigger modes except event-only modes, the FIFO stores change-of-flow addresses. In event-only  
trigger modes, the FIFO stores data in the low-order eight bits of the FIFO.  
The BEGIN control bit is ignored in event-only trigger modes and all such debug runs are begin type  
traces. When TRGSEL = 1 to select opcode fetch triggers, it is not necessary to use R/W in comparisons  
because opcode tags would only apply to opcode fetches that are always read cycles. It would also be  
unusual to specify TRGSEL = 1 while using a full mode trigger because the opcode value is normally  
known at a particular address.  
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The following trigger mode descriptions only state the primary comparator conditions that lead to a  
trigger. Either comparator can usually be further qualified with R/W by setting RWAEN (RWBEN) and  
the corresponding RWA (RWB) value to be matched against R/W. The signal from the comparator with  
optional R/W qualification is used to request a CPU breakpoint if BRKEN = 1 and TAG determines  
whether the CPU request will be a tag request or a force request.  
A-Only — Trigger when the address matches the value in comparator A  
A OR B — Trigger when the address matches either the value in comparator A or the value in  
comparator B  
A Then B — Trigger when the address matches the value in comparator B but only after the address for  
another cycle matched the value in comparator A. There can be any number of cycles after the A match  
and before the B match.  
A AND B Data (Full Mode) — This is called a full mode because address, data, and R/W (optionally)  
must match within the same bus cycle to cause a trigger event. Comparator A checks address, the low byte  
of comparator B checks data, and R/W is checked against RWA if RWAEN = 1. The high-order half of  
comparator B is not used.  
In full trigger modes it is not useful to specify a tag-type CPU breakpoint (BRKEN = TAG = 1), but if you  
do, the comparator B data match is ignored for the purpose of issuing the tag request to the CPU and the  
CPU breakpoint is issued when the comparator A address matches.  
A AND NOT B Data (Full Mode) — Address must match comparator A, data must not match the low  
half of comparator B, and R/W must match RWA if RWAEN = 1. All three conditions must be met within  
the same bus cycle to cause a trigger.  
In full trigger modes it is not useful to specify a tag-type CPU breakpoint (BRKEN = TAG = 1), but if you  
do, the comparator B data match is ignored for the purpose of issuing the tag request to the CPU and the  
CPU breakpoint is issued when the comparator A address matches.  
Event-Only B (Store Data) — Trigger events occur each time the address matches the value in  
comparator B. Trigger events cause the data to be captured into the FIFO. The debug run ends when the  
FIFO becomes full.  
A Then Event-Only B (Store Data) — After the address has matched the value in comparator A, a trigger  
event occurs each time the address matches the value in comparator B. Trigger events cause the data to be  
captured into the FIFO. The debug run ends when the FIFO becomes full.  
Inside Range (A Address B) — A trigger occurs when the address is greater than or equal to the value  
in comparator A and less than or equal to the value in comparator B at the same time.  
Outside Range (Address < A or Address > B) — A trigger occurs when the address is either less than  
the value in comparator A or greater than the value in comparator B.  
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14.4.6 Hardware Breakpoints  
The BRKEN control bit in the DBGC register may be set to 1 to allow any of the trigger conditions  
described in 14.4.5 Trigger Modes to be used to generate a hardware breakpoint request to the CPU. The  
TAG bit in DBGC controls whether the breakpoint request will be treated as a tag-type breakpoint or a  
force-type breakpoint. A tag breakpoint causes the current opcode to be marked as it enters the instruction  
queue. If a tagged opcode reaches the end of the pipe, the CPU executes a BGND instruction to go to active  
background mode rather than executing the tagged opcode. A force-type breakpoint causes the CPU to  
finish the current instruction and then go to active background mode.  
If the background mode has not been enabled (ENBDM = 1) by a serial WRITE_CONTROL command  
through the BKGD pin, the CPU will execute an SWI instruction instead of going to active background  
mode.  
14.5 Registers and Control Bits  
This section contains the descriptions of the BDC and DBG registers and control bits.  
Refer to the high-page register summary in the Memory section of this data sheet for the absolute address  
assignments for all DBG 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.  
14.5.1 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.  
14.5.1.1 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.  
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Bit 7  
6
5
4
3
2
1
Bit 0  
DVF  
Read:  
Write:  
BDMACT  
WS  
WSF  
ENBDM  
BKPTEN  
FTS  
CLKSW  
Normal Reset:  
0
1
0
1
0
0
0
0
0
1
0
0
0
0
0
0
Reset in Active BDM:  
= Unimplemented or Reserved  
Figure 14-5 BDC Status and Control Register (BDCSCR)  
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.  
1 = BDM can be made active to allow active background mode commands.  
0 = BDM cannot be made active (non-intrusive commands still allowed).  
BDMACT — Background Mode Active Status  
This is a read-only status bit.  
1 = BDM active and waiting for serial commands.  
0 = BDM not active (user application program running).  
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.  
1 = BDC breakpoint enabled.  
0 = BDC breakpoint disabled.  
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.  
1 = Breakpoint match forces active background mode at next instruction boundary (address need  
not be an opcode).  
0 = Tag opcode at breakpoint address and enter active background mode if CPU attempts to execute  
that instruction.  
CLKSW — Select Source for BDC Communications Clock  
CLKSW defaults to 0, which selects the alternate BDC clock source.  
1 = MCU bus clock.  
0 = Alternate BDC clock source.  
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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.  
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.  
0 = Target CPU is running user application code or in active background mode (was not in wait or  
stop mode when background became active).  
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.)  
1 = Memory access command failed because the CPU entered wait or stop mode.  
0 = Memory access did not conflict with a wait or stop instruction.  
DVF — Data Valid Failure Status  
This status bit is not used in the MC9S08RC/RD/RE/RG because it does not have any slow access  
memory.  
1 = Memory access command failed because CPU was not finished with a slow memory access.  
0 = Memory access did not conflict with a slow memory access.  
14.5.1.2 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 14.3.4 BDC Hardware Breakpoint.  
14.5.2 System Background Debug Force Reset Register (SBDFR)  
This register contains a single write-only control bit. A serial active 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 $00.  
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Bit 7  
0
6
0
5
0
4
0
3
0
2
0
1
0
Bit 0  
0
Read:  
(1)  
Write:  
BDFR  
Reset:  
0
0
0
1
0
0
0
0
= Unimplemented or Reserved  
NOTES:  
1. BDFR is writable only through serial active background mode debug commands, not from user programs.  
Figure 14-6 System Background Debug Force Reset Register (SBDFR)  
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 logic 1 to this bit forces an MCU reset. This bit cannot be written  
from a user program.  
14.5.3 DBG Registers and Control Bits  
The debug module includes nine bytes of register space for three 16-bit registers and three 8-bit control  
and status registers. These registers are located in the high register space of the normal memory map so  
they are accessible to normal application programs. These registers are rarely if ever accessed by normal  
user application programs with the possible exception of a ROM patching mechanism that uses the  
breakpoint logic.  
14.5.3.1 Debug Comparator A High Register (DBGCAH)  
This register contains compare value bits for the high-order eight bits of comparator A. This register is  
forced to $00 at reset and can be read at any time or written at any time unless ARM = 1.  
14.5.3.2 Debug Comparator A Low Register (DBGCAL)  
This register contains compare value bits for the low-order eight bits of comparator A. This register is  
forced to $00 at reset and can be read at any time or written at any time unless ARM = 1.  
14.5.3.3 Debug Comparator B High Register (DBGCBH)  
This register contains compare value bits for the high-order eight bits of comparator B. This register is  
forced to $00 at reset and can be read at any time or written at any time unless ARM = 1.  
14.5.3.4 Debug Comparator B Low Register (DBGCBL)  
This register contains compare value bits for the low-order eight bits of comparator B. This register is  
forced to $00 at reset and can be read at any time or written at any time unless ARM = 1.  
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14.5.3.5 Debug FIFO High Register (DBGFH)  
This register provides read-only access to the high-order eight bits of the FIFO. Writes to this register have  
no meaning or effect. In the event-only trigger modes, the FIFO only stores data into the low-order byte  
of each FIFO word, so this register is not used and will read $00.  
Reading DBGFH does not cause the FIFO to shift to the next word. When reading 16-bit words out of the  
FIFO, read DBGFH before reading DBGFL because reading DBGFL causes the FIFO to advance to the  
next word of information.  
14.5.3.6 Debug FIFO Low Register (DBGFL)  
This register provides read-only access to the low-order eight bits of the FIFO. Writes to this register have  
no meaning or effect.  
Reading DBGFL causes the FIFO to shift to the next available word of information. When the debug  
module is operating in event-only modes, only 8-bit data is stored into the FIFO (high-order half of each  
FIFO word is unused). When reading 8-bit words out of the FIFO, simply read DBGFL repeatedly to get  
successive bytes of data from the FIFO. It isn’t necessary to read DBGFH in this case.  
Do not attempt to read data from the FIFO while it is still armed (after arming but before the FIFO is filled  
or ARMF is cleared) because the FIFO is prevented from advancing during reads of DBGFL. This can  
interfere with normal sequencing of reads from the FIFO.  
Reading DBGFL while the debugger is not armed causes the address of the most-recently fetched opcode  
to be stored to the last location in the FIFO. By reading DBGFH then DBGFL periodically, external host  
software can develop a profile of program execution. After eight reads from the FIFO, the ninth read will  
return the information that was stored as a result of the first read. To use the profiling feature, read the  
FIFO eight times without using the data to prime the sequence and then begin using the data to get a  
delayed picture of what addresses were being executed. The information stored into the FIFO on reads of  
DBGFL (while the FIFO is not armed) is the address of the most-recently fetched opcode.  
14.5.3.7 Debug Control Register (DBGC)  
This register can be read or written at any time.  
Bit 7  
DBGEN  
0
6
ARM  
0
5
TAG  
0
4
BRKEN  
0
3
RWA  
0
2
RWAEN  
0
1
RWB  
0
Bit 0  
RWBEN  
0
Read:  
Write:  
Reset:  
Figure 14-7 Debug Control Register (DBGC)  
DBGEN — Debug Module Enable  
Used to enable the debug module. DBGEN cannot be set to 1 if the MCU is secure.  
1 = DBG enabled.  
0 = DBG disabled.  
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ARM — Arm Control  
Controls whether the debugger is comparing and storing information in the FIFO. A write is used to  
set this bit (and the ARMF bit) and completion of a debug run automatically clears it. Any debug run  
can be manually stopped by writing 0 to ARM or to DBGEN.  
1 = Debugger armed.  
0 = Debugger not armed.  
TAG — Tag/Force Select  
Controls whether break requests to the CPU will be tag or force type requests. If BRKEN = 0, this bit  
has no meaning or effect.  
1 = CPU breaks requested as tag type requests.  
0 = CPU breaks requested as force type requests.  
BRKEN — Break Enable  
Controls whether a trigger event will generate a break request to the CPU. Trigger events can cause  
information to be stored in the FIFO without generating a break request to the CPU. For an end trace,  
CPU break requests are issued to the CPU when the comparator(s) and R/W meet the trigger  
requirements. For a begin trace, CPU break requests are issued when the FIFO becomes full. TRGSEL  
does not affect the timing of CPU break requests.  
1 = Triggers cause a break request to the CPU.  
0 = CPU break requests not enabled.  
RWA — R/W Comparison Value for Comparator A  
When RWAEN = 1, this bit determines whether a read or a write access qualifies comparator A. When  
RWAEN = 0, RWA and the R/W signal do not affect comparator A.  
1 = Comparator A can only match on a read cycle.  
0 = Comparator A can only match on a write cycle.  
RWAEN — Enable R/W for Comparator A  
Controls whether the level of R/W is considered for a comparator A match.  
1 = R/W is used in comparison A.  
0 = R/W is not used in comparison A.  
RWB — R/W Comparison Value for Comparator B  
When RWBEN = 1, this bit determines whether a read or a write access qualifies comparator B. When  
RWBEN = 0, RWB and the R/W signal do not affect comparator B.  
1 = Comparator B can match only on a read cycle.  
0 = Comparator B can match only on a write cycle.  
RWBEN — Enable R/W for Comparator B  
Controls whether the level of R/W is considered for a comparator B match.  
1 = R/W is used in comparison B.  
0 = R/W is not used in comparison B.  
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14.5.3.8 Debug Trigger Register (DBGT)  
This register can be read any time, but may be written only if ARM = 0, except bits 4 and 5 are hard-wired  
to 0s.  
Bit 7  
TRGSEL  
0
6
BEGIN  
0
5
0
4
0
3
TRG3  
0
2
TRG2  
0
1
TRG1  
0
Bit 0  
TRG0  
0
Read:  
Write:  
Reset:  
0
0
= Unimplemented or Reserved  
Figure 14-8 Debug Trigger Register (DBGT)  
TRGSEL — Trigger Type  
Controls whether the match outputs from comparators A and B are qualified with the opcode tracking  
logic in the debug module. If TRGSEL is set, a match signal from comparator A or B must propagate  
through the opcode tracking logic and a trigger event is only signalled to the FIFO logic if the opcode  
at the match address is actually executed.  
1 = Trigger if opcode at compare address is executed (tag).  
0 = Trigger on access to compare address (force).  
BEGIN — Begin/End Trigger Select  
Controls whether the FIFO starts filling at a trigger or fills in a circular manner until a trigger ends the  
capture of information. In event-only trigger modes, this bit is ignored and all debug runs are assumed  
to be begin traces.  
1 = Trigger initiates data storage (begin trace).  
0 = Data stored in FIFO until trigger (end trace).  
TRG3:TRG2:TRG1:TRG0 — Select Trigger Mode  
Selects one of nine triggering modes  
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Development Support  
Table 14-2 Trigger Mode Selection  
TRG[3:0]  
Triggering Mode  
0000  
0001  
A-only  
A OR B  
A Then B  
0010  
0011  
Event-only B (store data)  
0100  
A then event-only B (store data)  
A AND B data (full mode)  
0101  
0110  
A AND NOT B data (full mode)  
Inside range: A address B  
Outside range: address < A or address > B  
No trigger  
0111  
1000  
1001 – 1111  
14.5.3.9 Debug Status Register (DBGS)  
This is a read-only status register.  
Bit 7  
AF  
6
5
4
0
3
2
1
Bit 0  
Read:  
Write:  
Reset:  
BF  
ARMF  
CNT3  
CNT2  
CNT1  
CNT0  
0
0
0
0
0
0
0
0
= Unimplemented or Reserved  
Figure 14-9 Debug Status Register (DBGS)  
AF — Trigger Match A Flag  
AF is cleared at the start of a debug run and indicates whether a trigger match A condition was met  
since arming.  
1 = Comparator A match.  
0 = Comparator A has not matched.  
BF — Trigger Match B Flag  
BF is cleared at the start of a debug run and indicates whether a trigger match B condition was met  
since arming.  
1 = Comparator B match.  
0 = Comparator B has not matched.  
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SoC Guide — MC9S08RG60/D Rev 1.10  
ARMF — Arm Flag  
While DBGEN = 1, this status bit is a read-only image of the ARM bit in DBGC. This bit is set by  
writing 1 to the ARM control bit in DBGC (while DBGEN = 1) and is automatically cleared at the end  
of a debug run. A debug run is completed when the FIFO is full (begin trace) or when a trigger event  
is detected (end trace). A debug run can also be ended manually by writing 0 to the ARM or DBGEN  
bits in DBGC.  
1 = Debugger armed.  
0 = Debugger not armed.  
CNT3:CNT2:CNT1:CNT0 — FIFO Valid Count  
These bits are cleared at the start of a debug run and indicate the number of words of valid data in the  
FIFO at the end of a debug run. The value in CNT does not decrement as data is read out of the FIFO.  
The external debug host is responsible for keeping track of the count as information is read out of the  
FIFO.  
Table 14-3 CNT Status Bits  
CNT[3:0]  
0000  
Valid Words in FIFO  
No valid data  
0001  
1
2
3
4
5
6
7
8
0010  
0011  
0100  
0101  
0110  
0111  
1000  
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Development Support  
Freescale Semiconductor  
206  
MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
Appendix C Electrical Characteristics  
C.1 Introduction  
This section contains electrical and timing specifications.  
C.2 Absolute Maximum Ratings  
Absolute maximum ratings are stress ratings only, and functional operation at the maxima is not  
guaranteed. Stress beyond the limits specified in Table C-1 may affect device reliability or cause  
permanent damage to the device. For functional operating conditions, refer to the remaining tables in this  
section.  
This device contains circuitry protecting against damage due to high static voltage or electrical fields;  
however, it is advised that normal precautions be taken to avoid application of any voltages higher than  
maximum-rated voltages to this high-impedance circuit. Reliability of operation is enhanced if unused  
inputs are tied to an appropriate logic voltage level (for instance, either V or V ) or the programmable  
SS  
DD  
pull-up resistor associated with the pin is enabled.  
Table C-1 Absolute Maximum Ratings  
Rating  
Symbol  
VDD  
Value  
Unit  
V
Supply voltage  
–0.3 to +3.8  
120  
Maximum current into VDD  
IDD  
mA  
V
VIn  
–0.3 to VDD + 0.3  
Digital input voltage  
Instantaneous maximum current  
ID  
± 25  
mA  
Single pin limit (applies to all port pins)(1) (2) (3)  
Storage temperature range  
NOTES:  
,
,
Tstg  
–55 to 150  
°C  
1. Input must be current limited to the value specified. To determine the value of the required  
current-limiting resistor, calculate resistance values for positive (VDD) and negative (VSS  
)
clamp voltages, then use the larger of the two resistance values.  
2. All functional non-supply pins are internally clamped to VSS and VDD  
.
3. Power supply must maintain regulation within operating VDD range during instantaneous  
and operating maximum current conditions. If positive injection current (VIn > VDD) is  
greater than IDD, the injection current may flow out of VDD and could result in external  
power supply going out of regulation. Ensure external VDD load will shunt current greater  
than maximum injection current. This will be the greatest risk when the MCU is not  
consuming power. Examples are: if no system clock is present, or if the clock rate is very  
low (which would reduce overall power consumption).  
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MC9S08RC/RD/RE/RG  
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Electrical Characteristics  
C.3 Thermal Characteristics  
This section provides information about operating temperature range, power dissipation, and package  
thermal resistance. Power dissipation on I/O pins is usually small compared to the power dissipation in  
on-chip logic and voltage regulator circuits and it is user-determined rather than being controlled by the  
MCU design. In order to take P into account in power calculations, determine the difference between  
I/O  
actual pin voltage and V or V and multiply by the pin current for each I/O pin. Except in cases of  
SS  
DD  
unusually high pin current (heavy loads), the difference between pin voltage and V or V will be very  
SS  
DD  
small.  
Table C-2 Thermal Characteristics  
Rating  
Symbol  
Value  
Unit  
TL to TH  
–40 to 85  
TA  
Operating temperature range (packaged)  
°C  
Thermal resistance  
28-pin PDIP  
28-pin SOIC  
32-pin LQFP  
44-pin LQFP  
θJA  
75  
70  
72  
70  
°C/W  
The average chip-junction temperature (T ) in °C can be obtained from:  
J
Equation 1 T = T + (P × θ )  
J
A
D
JA  
where:  
T = Ambient temperature, °C  
A
θ
= Package thermal resistance, junction-to-ambient, °C/W  
JA  
P = P + P  
D
int  
I/O  
P
P
= I × V , Watts — chip internal power  
= Power dissipation on input and output pins — user determined  
int  
I/O  
DD DD  
For most applications, P << P and can be neglected. An approximate relationship between P and T  
J
I/O  
int  
D
(if P is neglected) is:  
I/O  
Equation 2 P = K ÷ (T + 273°C)  
D
J
Solving equations 1 and 2 for K gives:  
2
Equation 3 K = P × (T + 273°C) + θ × (P )  
D
A
JA  
D
where K is a constant pertaining to the particular part. K can be determined from equation 3 by measuring  
P (at equilibrium) for a known T . Using this value of K, the values of P and T can be obtained by  
D
A
D
J
solving equations 1 and 2 iteratively for any value of T .  
A
Freescale Semiconductor  
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MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
C.4 Electrostatic Discharge (ESD) Protection Characteristics  
Although damage from static discharge is much less common on these devices than on early CMOS  
circuits, normal handling precautions should be used to avoid exposure to static discharge. Qualification  
tests are performed to ensure that these devices can withstand exposure to reasonable levels of static  
without suffering any permanent damage. All ESD testing is in conformity with CDF-AEC-Q00 Stress  
Test Qualification for Automotive Grade Integrated Circuits. (http://www.aecouncil.com/) A device is  
considered to have failed if, after exposure to ESD pulses, the device no longer meets the device  
specification requirements. Complete dc parametric and functional testing is performed per the applicable  
device data sheet at room temperature followed by hot temperature, unless specified otherwise in the  
device data sheet.  
Table C-3 ESD Protection Characteristics  
Parameter  
Symbol  
Value  
Unit  
ESD Target for Machine Model (MM)  
MM circuit description  
VTHMM  
200  
V
ESD Target for Human Body Model (HBM)  
HBM circuit description  
VTHHBM  
2000  
V
C.5 DC Characteristics  
This section includes information about power supply requirements, I/O pin characteristics, and power  
supply current in various operating modes.  
Table C-4 DC Characteristics (Temperature Range = 0 to 70°C Ambient)  
Parameter  
Symbol  
VLVD  
Min  
1.82  
0.8  
Typical  
1.875  
0.9  
Max  
1.90  
1.0  
Unit  
Low-voltage detection threshold  
V
V
V
VPOR  
Power on reset (POR) voltage  
Maximum low-voltage safe state re-arm(1)  
NOTES:  
VREARM  
1.90  
2.24  
2.60  
1. If SAFE bit is set, VDD must be above re-arm voltage to allow MCU to accept interrupts, refer to 5.6 Low-Voltage Detect  
(LVD) System.  
Table C-5 DC Characteristics (Temperature Range = –40 to 85°C Ambient)  
Parameter  
Symbol  
Min  
Typical  
Max  
Unit  
Supply voltage (run, wait and stop modes.)  
0 < fBus < 8 MHz  
VDD  
V
1.8  
3.6  
(1), (2)  
VRAM  
V
V
Minimum RAM retention supply voltage applied to VDD  
VPOR  
Low-voltage detection threshold  
(VDD falling)  
VLVD  
1.82  
1.92  
1.88  
1.96  
1.93  
2.01  
(VDD rising)  
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MC9S08RC/RD/RE/RG  
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Electrical Characteristics  
Table C-5 DC Characteristics (Continued)(Temperature Range = –40 to 85°C Ambient)  
Parameter  
Symbol  
Min  
Typical  
Max  
Unit  
Low-voltage warning threshold  
(VDD falling)  
(VDD rising)  
VLVW  
2.07  
2.16  
2.13  
2.21  
2.18  
2.26  
V
VPOR  
VREARM  
VIH  
Power on reset (POR) voltage  
0.85  
1.0  
1.2  
3.0  
V
Maximum low-voltage safe state re-arm(3)  
V
Input high voltage (VDD > 2.3 V) (all digital inputs)  
0.70 × VDD  
0.85 × VDD  
V
V
Input high voltage (1.8 V VDD 2.3 V) (all digital inputs)  
VIH  
0.35 ×  
VDD  
Input low voltage (VDD > 2.3 V) (all digital inputs)  
VIL  
V
Input low voltage (1.8 V VDD 2.3 V)  
(all digital inputs)  
0.30 ×  
VIL  
Vhys  
|IIn|  
V
V
VDD  
0.06 × VDD  
Input hysteresis (all digital inputs)  
Input leakage current (Per pin)  
0.025  
0.025  
1.0  
µA  
V
In = VDD or VSS, all input only pins  
High impedance (off-state) leakage current (per pin)  
In = VDD or VSS, all input/output  
|IOZ  
|
1.0  
µA  
V
Internal pullup resistors(4) (5)  
Internal pulldown resistor (IRQ)  
Output high voltage (VDD 1.8 V)  
RPU  
RPD  
17.5  
17.5  
52.5  
52.5  
kΩ  
kΩ  
VDD – 0.5  
I
= –2 mA (ports A, C, D and E)  
OH  
VOH  
Output high voltage (port B and IRO)  
V
I
I
I
= –10 mA (VDD 2.7 V)  
= –6 mA (VDD 2.3 V)  
= –3 mA (VDD 1.8 V)  
OH  
OH  
OH  
VDD – 0.5  
Maximum total IOH for all port pins  
|IOHT|  
60  
mA  
Output low voltage (VDD 1.8 V)  
I
= 2.0 mA (ports A, C, D and E)  
0.5  
OL  
Output low voltage (port B)  
I
= 10.0 mA (VDD 2.7 V)  
= 6 mA (VDD 2.3 V)  
= 3 mA (VDD 1.8 V)  
0.5  
0.5  
0.5  
OL  
V
I
I
OL  
OL  
VOL  
Output low voltage (IRO)  
I
= 16 mA (VDD 2.7 V)  
=TBD mA (VDD 2.3 V)  
= TBD mA (VDD 1.8 V)  
OL  
1.2  
1.2  
1.2  
I
OL  
OL  
I
Maximum total IOL for all port pins  
IOLT  
|IIC|  
CIn  
60  
mA  
dc injection current(2), (6), (7), (8),, (9)  
VIN < VSS, VIN > VDD  
Single pin limit  
Total MCU limit, includes sum of all stressed pins  
0.2  
5
mA  
mA  
Input capacitance (all non-supply pins)  
7
pF  
Freescale Semiconductor  
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MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
NOTES:  
1. RAM will retain data down to POR voltage. RAM data not guaranteed to be valid following a POR.  
2. This parameter is characterized and not tested on each device.  
3. If SAFE bit is set, VDD must be above re-arm voltage to allow MCU to accept interrupts, refer to 5.6 Low-Voltage Detect  
(LVD) System.  
4. Measurement condition for pull resistors: VIn = VSS for pullup and VIn = VDD for pulldown.  
5. The PTA0 pullup resistor may not pull up to the specified minimum VIH. However, all ports are functionally tested to  
guarantee that a logic 1 will be read on any port input when the pullup is enabled and no dc load is present on the pin. In  
addition, the test checks that the pin is pulled up from VSS to a logic 1 within 20 µs with a nominal capacitance of 75 pF.  
6. All functional non-supply pins are internally clamped to VSS and VDD  
.
7. Input must be current limited to the value specified. To determine the value of the required current-limiting resistor,  
calculate resistance values for positive and negative clamp voltages, then use the larger of the two values.  
8. Power supply must maintain regulation within operating VDD range during instantaneous and operating maximum current  
conditions. If positive injection current (VIn > VDD) is greater than IDD, the injection current may flow out of VDD and could  
result in external power supply going out of regulation. Ensure external VDD load will shunt current greater than maximum  
injection current. This will be the greatest risk when the MCU is not consuming power. Examples are: if no system clock  
is present, or if clock rate is very low (which would reduce overall power consumption).  
9. PTA0 does not have a clamp diode to VDD. Do not drive PTA0 above VDD  
.
PULLUP RESISTOR TYPICALS  
40  
PULLDOWN RESISTOR TYPICALS  
85°C  
40  
85°C  
25°C  
25°C  
–40°C  
–40°C  
35  
35  
30  
30  
25  
25  
20  
20  
1.8  
2
2.2 2.4 2.6 2.8  
(V)  
3
3.2 3.4 3.6  
1.8  
2.3  
2.8  
(V)  
3.3  
3.6  
V
DD  
V
DD  
Figure C-1 Pullup and Pulldown Typical Resistor Values (V = 3.0 V)  
DD  
TYPICAL V VS V  
OL  
TYPICAL V VS I AT V = 3.0 V  
DD  
DD  
OL  
OL  
1
0.4  
0.3  
0.2  
0.1  
85°C  
25°C  
85°C  
25°C  
0.8  
0.6  
0.4  
0.2  
–40°C  
–40°C  
I
= 10 mA  
OL  
I
= 6 mA  
OL  
I
= 3 mA  
OL  
0
0
0
10  
20  
30  
1
2
3
4
V
(V)  
DD  
I
(mA)  
OL  
Figure C-2 Typical Low-Side Driver (Sink) Characteristics (Port B and IRO)  
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Electrical Characteristics  
TYPICAL V VS I AT V = 3.0 V  
DD  
TYPICAL V VS V  
OL  
OL  
OL  
DD  
0.2  
0.15  
0.1  
1.2  
1
85°C  
25°C  
–40°C  
0.8  
0.6  
0.4  
0.2  
0
85°C,  
25°C,  
I
I
= 2 mA  
= 2 mA  
I = 2 mA  
OL  
0.05  
0
OL  
OL  
–40°C,  
1
2
3
4
0
5
10  
(mA)  
15  
20  
V
(V)  
DD  
I
OL  
Figure C-3 Typical Low-Side Driver (Sink) Characteristics (Ports A, C, D and E)  
TYPICAL V – V VS V AT SPEC I  
OH  
DD  
OH  
DD  
0.4  
0.3  
0.2  
0.1  
85°C  
25°C  
TYPICAL V – V VS I AT V = 3.0 V  
OH  
DD  
OH  
DD  
0.8  
0.6  
0.4  
0.2  
0
85°C  
25°C  
–40°C  
–40°C  
I
= –10 mA  
OH  
I
= –6 mA  
OH  
I
= –3 mA  
2
OH  
0
–5  
–10  
–15  
–20  
–25  
–30  
0
I
(mA)  
OH  
1
3
4
V
(V)  
DD  
Figure C-4 Typical High-Side Driver (Source) Characteristics (Port B and IRO)  
TYPICAL V – V VS I AT V = 3.0 V  
OH  
TYPICAL V – V VS V AT SPEC I  
DD  
DD  
OH  
DD  
DD  
OH  
OH  
1.2  
1
0.25  
0.2  
0.15  
0.1  
0.05  
0
85°C  
25°C  
85°C,  
25°C,  
I
I
= 2 mA  
= 2 mA  
I = 2 mA  
OH  
OH  
OH  
–40°C  
–40°C,  
0.8  
0.6  
0.4  
0.2  
0
0
–5  
–10  
–15  
–20  
1
2
3
4
V
(V)  
DD  
I
(mA))  
OH  
Figure C-5 Typical High-Side (Source) Characteristics (Ports A, C, D and E)  
Freescale Semiconductor  
212  
MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
C.6 Supply Current Characteristics  
Table C-6 Supply Current Characteristics  
V
Temp.  
(°C)  
DD  
(1)  
(2)  
Parameter  
Symbol  
Max  
Typical  
(V)  
1.525 mA  
1.525 mA  
70  
85  
3
2
3
2
3
2
3
2
3
2
500 µA  
450 µA  
3.8 mA  
2.6 mA  
100 nA  
100 nA  
500 nA  
500 nA  
600 nA  
500 nA  
Run supply current(3) measured at  
(CPU clock = 2 MHz, fBus = 1 MHz)  
RIDD  
1.475 mA  
1.475 mA  
70  
85  
4.8 mA  
4.8 mA  
70  
85  
Run supply current(3) measured at  
(CPU clock = 16 MHz, fBus = 8 MHz)  
RIDD  
3.6 mA  
3.6 mA  
70  
85  
350 nA  
736 nA  
70  
85  
Stop1 mode supply current  
Stop2 mode supply current  
S1IDD  
S2IDD  
S3IDD  
150 nA  
450 nA  
70  
85  
1.20 µA  
1.90 µA  
70  
85  
1.00 µA  
1.70 µA  
70  
85  
2.65 µA  
4.65 µA  
70  
85  
Stop3 mode supply current  
2.30 µA  
4.30 µA  
70  
85  
3
2
3
2
300 nA  
300 nA  
70 µA  
RTI adder from stop2 or stop3  
Adder for LVD reset enabled in stop3  
60 µA  
NOTES:  
1. 3 V values are 100% tested; 2 V values are characterized but not tested.  
2. Typicals are measured at 25°C.  
3. Does not include any dc loads on port pins  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
213  
Electrical Characteristics  
C.7 Analog Comparator (ACMP) Electricals  
Table C-7 ACMP Electrical Specifications (Temp Range = -40 to 85° C Ambient)  
Characteristic  
Symbol  
VAIN  
Min  
Typical  
Max  
Unit  
V
VSS – 0.3  
VDD  
Analog input voltage  
VAIO  
Analog input offset voltage  
40  
1
mV  
µs  
tAINIT  
VBG  
Analog Comparator initialization delay  
Analog Comparator bandgap reference voltage  
1.208  
1.218  
1.228  
V
C.8 Oscillator Characteristics  
OSC  
EXTAL  
XTAL  
R
F
Crystal or Resonator  
C
1
C
2
Table C-8 OSC Electrical Specifications (Temperature Range = -40 to 85°C Ambient)  
(1)  
Characteristic  
Symbol  
Min  
Max  
Unit  
Typ  
fOSC  
Frequency  
1
16  
MHz  
C1  
C2  
(2)  
Load Capacitors  
RF  
1
MΩ  
Feedback resistor  
NOTES:  
1. Data in typical column was characterized at 3.0 V, 25°C or is typical recommended value.  
2. See crystal or resonator manufacturer’s recommendation.  
Freescale Semiconductor  
214  
MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
C.9 AC Characteristics  
This section describes ac timing characteristics for each peripheral system.  
C.9.1 Control Timing  
Table C-9 Control Timing  
Parameter  
Symbol  
fBus  
Min  
dc  
Typical  
Max  
8
Unit  
MHz  
Hz  
ns  
Bus frequency (tcyc = 1/fBus  
)
Real time interrupt internal oscillator  
External reset pulse width(1)  
fRTI  
700  
1300  
textrst  
trstdrv  
tMSSU  
tMSH  
1.5 tcyc  
34 tcyc  
Reset low drive(2)  
ns  
Active background debug mode latch setup time  
Active background debug mode latch hold time  
25  
25  
ns  
ns  
IRQ pulse width(3)  
tILIH  
1.5 tcyc  
ns  
Port rise and fall time (load = 50 pF)(4)  
tRise, tFall  
3
ns  
NOTES:  
1. This is the shortest pulse that is guaranteed to be recognized as a reset pin request. Shorter pulses are not guaranteed  
to override reset requests from internal sources.  
2. When any reset is initiated, internal circuitry drives the reset pin low for about 34 cycles of fBus and then samples the  
level on the reset pin about 38 cycles later to distinguish external reset requests from internal requests.  
3. This is the minimum pulse width that is guaranteed to pass through the pin synchronization circuitry. Shorter pulses may  
or may not be recognized. In stop mode, the synchronizer is bypassed so shorter pulses can be recognized in that case.  
4. Timing is shown with respect to 20% VDD and 80% VDD levels. Temperature range –40°C to 85°C.  
t
extrst  
RESET PIN  
Figure C-6 Reset Timing  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
215  
Electrical Characteristics  
BKGD/MS  
RESET  
t
MSH  
t
MSSU  
Figure C-7 Active Background Debug Mode Latch Timing  
t
ILIH  
IRQ  
Figure C-8 IRQ Timing  
C.9.2 Timer/PWM (TPM) Module Timing  
Synchronizer circuits determine the shortest input pulses that can be recognized or the fastest clock that  
can be used as the optional external source to the timer counter. These synchronizers operate from the  
current bus rate clock.  
Table C-10 TPM Input Timing  
Function  
External clock frequency  
External clock period  
Symbol  
fTPMext  
tTPMext  
tclkh  
Min  
dc  
Max  
Unit  
MHz  
tcyc  
fBus/4  
4
tcyc  
External clock high time  
External clock low time  
Input capture pulse width  
1.5  
1.5  
1.5  
tclkl  
tcyc  
tICPW  
tcyc  
t
Text  
t
clkh  
TPM1CHn  
t
clkl  
Figure C-9 Timer External Clock  
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MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
t
ICPW  
TPM1CHn  
TPM1CHn  
t
ICPW  
Figure C-10 Timer Input Capture Pulse  
C.9.3 SPI Timing  
Table C-11 and Figure C-11 through Figure C-14 describe the timing requirements for the SPI system.  
Table C-11 SPI Timing  
No.  
Function  
Symbol  
Min  
/2048  
Max  
Unit  
Operating frequency  
Master  
f
f
f
f
/2  
/4  
Hz  
op  
Bus  
Bus  
Bus  
Slave  
dc  
SPSCK period  
Master  
Slave  
1
2
3
4
5
6
t
2
4
2048  
t
t
SPSCK  
cyc  
cyc  
Enable lead time  
Master  
Slave  
t
1/2  
1
t
t
Lead  
SPSCK  
t
cyc  
Enable lag time  
Master  
Slave  
t
1/2  
1
Lag  
SPSCK  
t
cyc  
Clock (SPSCK) high or low time  
Master  
Slave  
t
t
t
– 30  
– 30  
1024 t  
ns  
ns  
WSPSCK  
cyc  
cyc  
cyc  
Data setup time (inputs)  
Master  
Slave  
t
15  
15  
ns  
ns  
SU  
Data hold time (inputs)  
Master  
Slave  
t
0
25  
ns  
ns  
HI  
7
8
Slave access time  
t
1
1
t
a
cyc  
cyc  
Slave MISO disable time  
t
t
dis  
Data valid (after SPSCK edge)  
9
Master  
Slave  
t
25  
25  
ns  
ns  
v
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Electrical Characteristics  
No.  
Table C-11 SPI Timing (Continued)  
Function  
Symbol  
Min  
Max  
Unit  
Data hold time (outputs)  
Master  
Slave  
10  
11  
12  
t
0
0
ns  
ns  
HO  
Rise time  
Input  
Output  
t
t
t
t
– 25  
cyc  
25  
ns  
ns  
RI  
RO  
Fall time  
Input  
Output  
t
t
– 25  
ns  
ns  
FI  
cyc  
25  
FO  
1
SS  
(OUTPUT)  
1
2
11  
12  
3
SPSCK  
(CPOL = 0)  
4
(OUTPUT)  
4
SPSCK  
(CPOL = 1)  
(OUTPUT)  
5
6
MISO  
(INPUT)  
2
BIT 6 . . . 1  
MSB IN  
LSB IN  
9
9
10  
MOSI  
(OUTPUT)  
2
BIT 6 . . . 1  
LSB OUT  
MSB OUT  
NOTES:  
1. SS output mode (DDS7 = 1, SSOE = 1).  
2. LSBF = 0. For LSBF = 1, bit order is LSB, bit 1, ..., bit 6, MSB.  
Figure C-11 SPI Master Timing (CPHA = 0)  
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SoC Guide — MC9S08RG60/D Rev 1.10  
(1)  
SS  
(OUTPUT)  
1
2
11  
12  
3
12  
11  
SPSCK  
(CPOL = 0)  
(OUTPUT)  
4
4
SPSCK  
(CPOL = 1)  
(OUTPUT)  
5
6
MISO  
(INPUT)  
(2)  
MSB IN  
BIT 6 . . . 1  
10  
BIT 6 . . . 1  
LSB IN  
9
MOSI  
(OUTPUT)  
(2)  
PORT DATA  
MASTER LSB OUT  
PORT DATA  
MASTER MSB OUT  
NOTES:  
1. SS output mode (DDS7 = 1, SSOE = 1).  
2. LSBF = 0. For LSBF = 1, bit order is LSB, bit 1, ..., bit 6, MSB.  
Figure C-12 SPI Master Timing (CPHA =1)  
SS  
(INPUT)  
11  
12  
3
1
12  
11  
SPSCK  
(CPOL = 0)  
(INPUT)  
2
4
4
SPSCK  
(CPOL = 1)  
(INPUT)  
8
7
10  
9
10  
MISO  
(OUTPUT)  
SEE  
NOTE  
BIT 6 . . . 1  
SLAVE LSB OUT  
MSB OUT  
6
SLAVE  
5
MOSI  
(INPUT)  
BIT 6 . . . 1  
MSB IN  
LSB IN  
NOTE:  
1. Not defined but normally MSB of character just received  
Figure C-13 SPI Slave Timing (CPHA = 0)  
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Electrical Characteristics  
SS  
(INPUT)  
1
3
12  
2
11  
SPSCK  
(CPOL = 0)  
(INPUT)  
4
4
11  
12  
SPSCK  
(CPOL = 1)  
(INPUT)  
9
10  
8
MISO  
(OUTPUT)  
SEE  
BIT 6 . . . 1  
SLAVE LSB OUT  
LSB IN  
SLAVE MSB OUT  
NOTE  
5
6
7
MOSI  
(INPUT)  
MSB IN  
BIT 6 . . . 1  
NOTE:  
1. Not defined but normally LSB of character just received  
Figure C-14 SPI Slave Timing (CPHA = 1)  
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SoC Guide — MC9S08RG60/D Rev 1.10  
C.10 FLASH Specifications  
This section provides details about program/erase times and program-erase endurance for the FLASH  
memory.  
Program and erase operations do not require any special power sources other than the normal V supply.  
DD  
For more detailed information about program/erase operations, see the Memory section.  
Table C-12 FLASH Characteristics  
Characteristic  
Symbol  
Min  
Typical  
Max  
Unit  
Vprog/erase  
Supply voltage for program/erase  
2.05  
3.6  
V
Supply voltage for read operation  
0 < fBus < 8 MHz  
VRead  
V
1.8  
150  
5
3.6  
200  
6.67  
Internal FCLK frequency(1)  
fFCLK  
tFcyc  
tprog  
kHz  
µs  
Internal FCLK period (1/FCLK)  
Byte program time (random location)(2)  
Byte program time (burst mode)(2)  
Page erase time(2)  
tFcyc  
tFcyc  
tFcyc  
tFcyc  
9
4
tBurst  
tPage  
tMass  
4000  
20,000  
Mass erase time(2)  
Program/erase endurance(3)  
10,000  
15  
cycles  
years  
TL to TH = –40°C to + 85°C  
T = 25°C  
100,000  
100  
Data retention(4)  
tD_ret  
NOTES:  
1. The frequency of this clock is controlled by a software setting.  
2. These values are hardware state machine controlled. User code does not need to count cycles. This  
information supplied for calculating approximate time to program and erase.  
3. Typical endurance for FLASH was evaluated for this product family on the 9S12Dx64. For additional  
information on how Freescale Semiconductor defines typical endurance, please refer to Engineering  
Bulletin EB619/D, Typical Endurance for Nonvolatile Memory.  
4. Typical data retention values are based on intrinsic capability of the technology measured at high  
temperature and de-rated to 25°C using the Arrhenius equation. For additional information on how  
Freescale Semiconductor defines typical data retention, please refer to Engineering Bulletin EB618/D,  
Typical Data Retention for Nonvolatile Memory.  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
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Electrical Characteristics  
Freescale Semiconductor  
222  
MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
Appendix D Ordering Information and Mechanical  
Drawings  
D.1 Ordering Information  
This section contains ordering numbers for MC9S08RC/RD/RE/RG devices. See below for an example of  
the device numbering system.  
Table 14-4 Orderable Part Numbers  
FLASH  
Memory  
Available Package Type  
(Part Number Suffix)  
MC Order Number  
RAM  
ACMP  
SCI  
SPI  
MC9S08RG32(C)FJ  
MC9S08RG32(C)FG  
MC9S08RG60(C)FJ  
MC9S08RG60(C)FG  
MC9S08RE8(C)FJ  
MC9S08RE8(C)FG  
MC9S08RE16(C)FJ  
MC9S08RE16(C)FG  
MC9S08RE32(C)FJ  
MC9S08RE32(C)FG  
MC9S08RE60(C)FJ  
MC9S08RE60(C)FG  
MC9S08RD8(C)PE  
MC9S08RD8(C)DWE  
MC9S08RD8(C)FJ  
MC9S08RD8(C)FG  
MC9S08RD16(C)PE  
MC9S08RD16(C)DWE  
MC9S08RD16(C)FJ  
MC9S08RD16(C)FG  
MC9S08RD32(C)PE  
MC9S08RD32(C)DWE  
MC9S08RD32(C)FJ  
32K  
32K  
60K  
60K  
8K  
2K  
2K  
2K  
2K  
1K  
1K  
1K  
1K  
2K  
2K  
2K  
2K  
1K  
1K  
1K  
1K  
1K  
1K  
1K  
1K  
2K  
2K  
2K  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
No  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
No  
No  
No  
No  
No  
No  
No  
No  
No  
No  
No  
No  
No  
No  
No  
No  
No  
No  
No  
32 LQFP (FJ)  
44 LQFP (FG)  
32 LQFP (FJ)  
44 LQFP (FG)  
32 LQFP (FJ)  
44 LQFP (FG)  
32 LQFP (FJ)  
44 LQFP (FG)  
32 LQFP (FJ)  
44 LQFP (FG)  
32 LQFP (FJ)  
44 LQFP (FG)  
28 PDIP (P)  
8K  
16K  
16K  
32K  
32K  
60K  
60K  
8K  
8K  
No  
28 SOIC (DW)  
32 LQFP (FJ)  
44 LQFP (FG)  
28 PDIP (P)  
8K  
No  
8K  
No  
16K  
16K  
16K  
16K  
32K  
32K  
32K  
No  
No  
28 SOIC (DW)  
32 LQFP (FJ)  
44 LQFP (FG)  
28 PDIP (P)  
No  
No  
No  
No  
28 SOIC (DW)  
32 LQFP (FJ)  
No  
Freescale Semiconductor  
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223  
Ordering Information and Mechanical Drawings  
Table 14-4 Orderable Part Numbers (Continued)  
FLASH  
Memory  
Available Package Type  
(Part Number Suffix)  
MC Order Number  
RAM  
ACMP  
SCI  
SPI  
MC9S08RD32(C)FG  
MC9S08RD60(C)PE  
MC9S08RD60(C)DWE  
MC9S08RD60(C)FJ  
MC9S08RD60(C)FG  
MC9S08RC8(C)FJ  
MC9S08RC8(C)FG  
MC9S08RC16(C)FJ  
MC9S08RC16(C)FG  
MC9S08RC32(C)FJ  
MC9S08RC32(C)FG  
MC9S08RC60(C)FJ  
MC9S08RC60(C)FG  
32K  
60K  
60K  
60K  
60K  
8K  
2K  
2K  
2K  
2K  
2K  
1K  
1K  
1K  
1K  
2K  
2K  
2K  
2K  
No  
No  
Yes  
Yes  
Yes  
Yes  
Yes  
No  
No  
No  
No  
No  
No  
No  
No  
No  
No  
No  
No  
No  
No  
No  
No  
No  
No  
No  
No  
No  
44 LQFP (FG)  
28 PDIP (P)  
No  
28 SOIC (DW)  
32 LQFP (FJ)  
44 LQFP (FG)  
32 LQFP (FJ)  
44 LQFP (FG)  
32 LQFP (FJ)  
44 LQFP (FG)  
32 LQFP (FJ)  
44 LQFP (FG)  
32 LQFP (FJ)  
44 LQFP (FG)  
No  
No  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
8K  
16K  
16K  
32K  
32K  
60K  
60K  
Package designators:  
DW =28-pin Small Outline Integrated Circuit (SOIC)  
P = 28-pin Plastic Dual In-Line Package (PDIP)  
FG = 44-pin Low Quad Flat Package (LQFP)  
FJ = 32-pin Low Quad Flat Package (LQFP)  
MC 9 S08 RG60 (C) XX E  
Indicates lead-free packag  
Package designator  
Status  
Memory  
Type  
Temperature range  
designator  
C = –40 thru 85°C  
Blank = 0 thru 70°C  
Core  
Family  
D.2 Mechanical Drawings  
This appendix contains mechanical specification for MC9S08RC/RD/RE/RG MCU.  
Freescale Semiconductor  
224  
MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
D.2.1 28-Pin SOIC Package Drawing  
D
NOTES:  
A
1. DIMENSIONS ARE IN MILLIMETERS.  
2. INTERPRET DIMENSIONS AND TOLERANCES PER  
ASME Y14.5M, 1994.  
28  
15  
3. DIMENSIONS D AND E DO NOT INCLUDE MOLD  
PROTRUSIONS.  
4. MAXIMUM MOLD PROTRUSION 0.015 PER SIDE.  
5. DIMENSION B DOES NOT INCLUDE DAMBAR PRO-  
TRUSION. ALLOWABLE DAMBAR PROTRUSION  
SHALL BE 0.13 TOTAL IN EXCESS OF B DIMENSION  
AT MAXIMUM MATERIAL CONDITION.  
1
14  
MILLIMETERS  
B
PIN 1 IDENT  
DIM MIN  
2.35  
A1 0.13  
MAX  
2.65  
0.29  
0.49  
0.32  
A
B
C
D
E
e
H
L
q
0.35  
0.23  
17.80 18.05  
7.40 7.60  
1.27 BSC  
10.05 10.55  
L
0.10  
e
0.41  
0
0.90  
8
C
_
_
SEATING  
PLANE  
B
C
q
M
S
S
0.025  
C A  
B
CASE 751F-05  
ISSUE F  
DATE 05/27/97  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
225  
Ordering Information and Mechanical Drawings  
D.2.2 28-Pin PDIP Package Drawing  
Freescale Semiconductor  
226  
MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
D.2.3 32-Pin LQFP Package Drawing  
4X  
A
A1  
0.20 (0.008) AB T-U  
Z
32  
25  
1
-U-  
-T-  
B
V
AE  
P
B1  
DETAIL Y  
V1  
17  
8
AE  
DETAIL Y  
9
4X  
-Z-  
0.20 (0.008) AC T-U  
Z
9
NOTES:  
1. DIMENSIONING AND TOLERANCING PER ANSI  
Y14.5M, 1982.  
S1  
S
2. CONTROLLING DIMENSION: MILLIMETER.  
3. DATUM PLANE -AB- IS LOCATED AT BOTTOM OF LEAD  
AND IS COINCIDENT WITH THE LEAD WHERE THE  
LEAD EXITS THE PLASTIC BODY AT THE BOTTOM OF  
THE PARTING LINE.  
DETAIL AD  
4. DATUMS -T-, -U-, AND -Z- TO BE DETERMINED AT  
DATUM PLANE -AB-.  
G
5. DIMENSIONS S AND V TO BE DETERMINED AT  
SEATING PLANE -AC-.  
-AB-  
-AC-  
6. DIMENSIONS A AND B DO NOT INCLUDE MOLD  
PROTRUSION. ALLOWABLE PROTRUSION IS 0.250  
(0.010) PER SIDE. DIMENSIONS A AND B DO INCLUDE  
MOLD MISMATCH AND ARE DETERMINED AT DATUM  
PLANE -AB-.  
SEATING  
PLANE  
0.10 (0.004) AC  
BASE  
METAL  
7. DIMENSION D DOES NOT INCLUDE DAMBAR  
PROTRUSION. DAMBAR PROTRUSION SHALL NOT  
CAUSE THE D DIMENSION TO EXCEED 0.520 (0.020).  
8. MINIMUM SOLDER PLATE THICKNESS SHALL BE  
0.0076 (0.0003).  
N
9. EXACT SHAPE OF EACH CORNER MAY VARY FROM  
DEPICTION.  
F
D
8X M  
MILLIMETERS  
DIM MIN MAX  
7.000 BSC  
INCHES  
MIN MAX  
0.276 BSC  
0.138 BSC  
0.276 BSC  
0.138 BSC  
R
J
A
A1  
B
3.500 BSC  
7.000 BSC  
3.500 BSC  
SECTION AE-AE  
E
C
B1  
C
1.400  
1.600  
0.450  
1.450  
0.400  
0.055  
0.063  
0.018  
0.057  
0.016  
D
E
F
0.300  
1.350  
0.300  
0.012  
0.053  
0.012  
W
G
H
J
0.800 BSC  
0.031 BSC  
Q
H
K
X
0.050  
0.090  
0.500  
0.150  
0.200  
0.700  
0.002  
0.004  
0.020  
0.006  
0.008  
0.028  
K
_
_
M
N
P
12 REF  
0.090 0.160  
0.400 BSC  
12 REF  
0.004 0.006  
0.016 BSC  
DETAIL AD  
Q
R
1_  
0.150  
5_  
0.250  
1_  
0.006  
5 _  
0.010  
S
9.000 BSC  
0.354 BSC  
S1  
V
V1  
W
X
4.500 BSC  
9.000 BSC  
4.500 BSC  
0.200 REF  
1.000 REF  
0.177 BSC  
0.354 BSC  
0.177 BSC  
0.008 REF  
0.039 REF  
CASE 873A-02  
ISSUE A  
DATE 12/16/93  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
227  
Ordering Information and Mechanical Drawings  
D.2.4 44-Pin LQFP Package Drawing  
PLATING  
BASE METAL  
-X-  
X=L, M, N  
4X 11 TIPS  
0.2 (0.008) T L-M N  
4X  
0.2 (0.008) H L-M N  
F
44  
34  
33  
J
U
C
L
1
AB  
AB  
40X  
G
D
M
S
S
N
0.20 (0.008)  
T L-M  
3X VIEW Y  
-L-  
-M-  
SECTION AB-AB  
ROTATED 90 CLOCKWISE  
VIEW Y  
°
B
V
NOTES:  
1. DIMENSIONING AND TOLERANCING PER ANSI  
Y14.5M, 1982.  
2. CONTROLLING DIMENSION: MILLIMETER.  
3. DATUM PLANE -H- IS LOCATED AT BOTTOM OF LEAD  
AND IS COINCIDENT WITH THE LEAD WHERE THE  
LEAD EXITS THE PLASTIC BODY AT THE BOTTOM OF  
THE PARTING LINE.  
B1  
V1  
11  
23  
22  
12  
4. DATUMS -L-, -M- AND -N- TO BE DETERMINED AT  
DATUM PLANE -H-.  
5. DIMENSIONS S AND V TO BE DETERMINED AT  
SEATING PLANE -T-.  
-N-  
A1  
S1  
6. DIMENSIONS A AND B DO NOT INCLUDE MOLD  
PROTRUSION. ALLOWABLE PROTRUSION IS 0.25  
(0.010) PER SIDE. DIMENSIONS A AND B DO INCLUDE  
MOLD MISMATCH AND ARE DETERMINED AT DATUM  
PLANE -H-.  
A
S
7. DIMENSION D DOES NOT INCLUDE DAMBAR  
PROTRUSION. DAMBAR PROTRUSION SHALL NOT  
CAUSE THE D DIMENSION TO EXCEED 0.53 (0.021).  
MINIMUM SPACE BETWEEN PROTRUSION AND  
ADJACENT LEAD OR PROTRUSION 0.07 (0.003).  
4X (q2)  
VIEW AA  
0.1 (0.004) T  
C
-H-  
-T-  
SEATING  
PLANE  
MILLIMETERS  
DIM MIN MAX  
10.00 BSC  
INCHES  
MIN MAX  
0.394 BSC  
0.197 BSC  
0.394 BSC  
0.197 BSC  
A
A1  
B
5.00 BSC  
10.00 BSC  
5.00 BSC  
4X (q3)  
C2  
B2  
C
---  
0.05  
1.35  
0.30  
0.45  
0.30  
1.60  
---  
0.15 0.002  
1.45 0.053  
0.45 0.012  
0.75 0.018  
0.40 0.012  
0.063  
C1  
C2  
D
E
F
0.006  
0.057  
0.018  
0.030  
0.016  
S
0.05 (0.002)  
(W)  
G
J
K
0.80 BSC  
0.09  
0.50 REF  
0.031 BSC  
0.20 0.004  
0.008  
q1  
0.020 REF  
2X R R1  
R1  
S
S1  
U
0.09  
12.00 BSC  
6.00 BSC  
0.09 0.16 0.004  
0.20 0.004  
0.008  
0.25 (0.010)  
0.472 BSC  
0.236 BSC  
0.006  
GAGE PLANE  
V
12.00 BSC  
6.00 BSC  
0.20 REF  
1.00 REF  
0.472 BSC  
0.236 BSC  
0.008 REF  
0.039 REF  
V1  
W
Z
(K)  
E
(Z)  
q
C1  
q
0
0
7
---  
0
0
7
°
---  
°
°
°
°
°
q1  
q2  
q3  
12 REF  
12 REF  
°
12 REF  
12 REF  
°
VIEW AA  
°
°
CASE 824D-02  
ISSUE A  
DATE 08/09/95  
Freescale Semiconductor  
228  
MC9S08RC/RD/RE/RG  
SoC Guide — MC9S08RG60/D Rev 1.10  
SoC Guide End Sheet  
need need more than 13 words type on blank page or will turn page landscape in pdf file??  
turned white so this would not show up on customer page.  
Freescale Semiconductor  
MC9S08RC/RD/RE/RG  
229  
FINAL PAGE OF  
230  
PAGES  
Freescale Semiconductor  
230  
MC9S08RC/RD/RE/RG  
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MC9S08RG60/D  
Rev 1.10  

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