MC68HC908Jx8/KL8, MC68HC08Jx8 Datasheet by NXP USA Inc.

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O : ' freescale'“ semiconductor
M68HC08
Microcontrollers
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MC68HC908JL8
MC68HC908JK8
MC68HC908KL8
MC68HC08JL8
MC68HC08JK8
Data Sheet
MC68HC908JL8
Rev. 3.1
3/2005
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 3
Freescale™ and the Freescale logo are trademarks of Freescale Semiconductor, Inc.
This product incorporates SuperFlash® technology licensed from SST.
© Freescale Semiconductor, Inc., 2005. All rights reserved.
MC68HC908JL8
MC68HC908JK8
MC68HC908KL8
MC68HC08JL8
MC68HC08JK8
Data Sheet
To provide the most up-to-date information, the revision of our documents on the World Wide Web will be
the most current. Your printed copy may be an earlier revision. To verify you have the latest information
available, refer to:
http://www.freescale.com
The following revision history table summarizes changes contained in this document. For your
convenience, the page number designators have been linked to the appropriate location.
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
4Freescale Semiconductor
Revision History
Date Revision
Level Description Page
Number(s)
Mar 2005 3.1 Added IRQ timing to Table 17-5 . Control Timing (5V) and Table 17-8 .
Control Timing (3V) 188, 190
Nov 2004 3
Chapter 9 Serial Communications Interface (SCI) — Corrected SCI
module clock source from OSCCLK to Bus Clock throughout. 121–206
Figure 13-2 . Keyboard Interrupt Block Diagram
Removed incorrect Schmitt trigger in block diagram. 168
14.7.2 Stop Mode — STOP_ICLKDIS bit does not affect stop mode
conditions for COP. Replaced section with new text. 176
Added Appendix A MC68HC08JL8 — ROM parts. 201
Added Appendix B MC68HC908KL8.207
Nov 2002 2 First general release.
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
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List of Chapters
Chapter 1 General Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Chapter 2 Memory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Chapter 3 Configuration and Mask Option Registers (CONFIG & MOR) . . . . . . . . . . . . . .41
Chapter 4 Central Processor Unit (CPU). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
Chapter 5 System Integration Module (SIM). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61
Chapter 6 Oscillator (OSC). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .79
Chapter 7 Monitor ROM (MON) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85
Chapter 8 Timer Interface Module (TIM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .105
Chapter 9 Serial Communications Interface (SCI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .121
Chapter 10 Analog-to-Digital Converter (ADC). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .145
Chapter 11 Input/Output (I/O) Ports. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .151
Chapter 12 External Interrupt (IRQ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .163
Chapter 13 Keyboard Interrupt Module (KBI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .167
Chapter 14 Computer Operating Properly (COP). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .173
Chapter 15 Low Voltage Inhibit (LVI). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .177
Chapter 16 Break Module (BREAK). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .179
Chapter 17 Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .185
Chapter 18 Mechanical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .195
Chapter 19 Ordering Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .199
Appendix A MC68HC08JL8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .201
Appendix B MC68HC908KL8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .207
List of Chapters
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Table of Contents
Chapter 1
General Description
1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
1.2 Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
1.3 MCU Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
1.4 Pin Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
1.5 Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Chapter 2
Memory
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
2.2 I/O Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
2.3 Monitor ROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
2.4 Random-Access Memory (RAM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
2.5 FLASH Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
2.6 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
2.7 FLASH Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
2.8 FLASH Page Erase Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
2.9 FLASH Mass Erase Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
2.10 FLASH Program Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
2.11 FLASH Block Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
2.12 FLASH Block Protect Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Chapter 3
Configuration and Mask Option Registers (CONFIG & MOR)
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
3.2 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
3.3 Configuration Register 1 (CONFIG1). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
3.4 Configuration Register 2 (CONFIG2). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
3.5 Mask Option Register (MOR). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Chapter 4
Central Processor Unit (CPU)
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
4.2 Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
4.3 CPU Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
4.3.1 Accumulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
4.3.2 Index Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
4.3.3 Stack Pointer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Table of Contents
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8Freescale Semiconductor
4.3.4 Program Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
4.3.5 Condition Code Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
4.4 Arithmetic/Logic Unit (ALU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
4.5 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
4.5.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
4.5.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
4.6 CPU During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
4.7 Instruction Set Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
4.8 Opcode Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Chapter 5
System Integration Module (SIM)
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
5.2 SIM Bus Clock Control and Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
5.2.1 Bus Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
5.2.2 Clock Start-Up from POR or LVI Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
5.2.3 Clocks in Stop Mode and Wait Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
5.3 Reset and System Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
5.3.1 External Pin Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
5.3.2 Active Resets from Internal Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
5.3.2.1 Power-On Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
5.3.2.2 Computer Operating Properly (COP) Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
5.3.2.3 Illegal Opcode Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
5.3.2.4 Illegal Address Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
5.3.2.5 Low-Voltage Inhibit (LVI) Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
5.4 SIM Counter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
5.4.1 SIM Counter During Power-On Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
5.4.2 SIM Counter During Stop Mode Recovery. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
5.4.3 SIM Counter and Reset States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
5.5 Exception Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
5.5.1 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
5.5.1.1 Hardware Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
5.5.1.2 SWI Instruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
5.5.2 Interrupt Status Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
5.5.2.1 Interrupt Status Register 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
5.5.2.2 Interrupt Status Register 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
5.5.2.3 Interrupt Status Register 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
5.5.3 Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
5.5.4 Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
5.5.5 Status Flag Protection in Break Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
5.6 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
5.6.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
5.6.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
5.7 SIM Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
5.7.1 Break Status Register (BSR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
5.7.2 Reset Status Register (RSR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
5.7.3 Break Flag Control Register (BFCR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
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Chapter 6
Oscillator (OSC)
6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
6.2 Oscillator Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
6.2.1 XTAL Oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
6.2.2 RC Oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
6.3 Internal Oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
6.4 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
6.4.1 Crystal Amplifier Input Pin (OSC1). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
6.4.2 Crystal Amplifier Output Pin (OSC2/RCCLK/PTA6/KBI6) . . . . . . . . . . . . . . . . . . . . . . . . . . 82
6.4.3 Oscillator Enable Signal (SIMOSCEN) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
6.4.4 XTAL Oscillator Clock (XTALCLK). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
6.4.5 RC Oscillator Clock (RCCLK) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
6.4.6 Oscillator Out 2 (2OSCOUT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
6.4.7 Oscillator Out (OSCOUT). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
6.4.8 Internal Oscillator Clock (ICLK) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
6.5 Low Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
6.5.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
6.5.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
6.6 Oscillator During Break Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Chapter 7
Monitor ROM (MON)
7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
7.2 Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
7.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
7.3.1 Entering Monitor Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
7.3.2 Baud Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
7.3.3 Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
7.3.4 Echoing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
7.3.5 Break Signal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
7.3.6 Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
7.4 Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
7.5 ROM-Resident Routines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
7.5.1 PRGRNGE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
7.5.2 ERARNGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
7.5.3 LDRNGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
7.5.4 MON_PRGRNGE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
7.5.5 MON_ERARNGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
7.5.6 MON_LDRNGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
7.5.7 EE_WRITE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
7.5.8 EE_READ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
Table of Contents
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
10 Freescale Semiconductor
Chapter 8
Timer Interface Module (TIM)
8.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
8.2 Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
8.3 Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
8.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
8.4.1 TIM Counter Prescaler. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
8.4.2 Input Capture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
8.4.3 Output Compare. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
8.4.3.1 Unbuffered Output Compare . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
8.4.3.2 Buffered Output Compare . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
8.4.4 Pulse Width Modulation (PWM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
8.4.4.1 Unbuffered PWM Signal Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
8.4.4.2 Buffered PWM Signal Generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
8.4.4.3 PWM Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
8.5 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
8.6 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
8.6.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
8.6.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
8.7 TIM During Break Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
8.8 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
8.8.1 TIM Clock Pin (ADC12/T2CLK) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
8.8.2 TIM Channel I/O Pins (PTD4/T1CH0, PTD5/T1CH1, PTE0/T2CH0, PTE1/T2CH1) . . . . . 113
8.9 I/O Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
8.9.1 TIM Status and Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
8.9.2 TIM Counter Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
8.9.3 TIM Counter Modulo Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
8.9.4 TIM Channel Status and Control Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
8.9.5 TIM Channel Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Chapter 9
Serial Communications Interface (SCI)
9.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
9.2 Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
9.3 Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
9.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
9.4.1 Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
9.4.2 Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
9.4.2.1 Character Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
9.4.2.2 Character Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
9.4.2.3 Break Characters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
9.4.2.4 Idle Characters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
9.4.2.5 Inversion of Transmitted Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
9.4.2.6 Transmitter Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
9.4.3 Receiver. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
9.4.3.1 Character Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
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9.4.3.2 Character Reception. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
9.4.3.3 Data Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
9.4.3.4 Framing Errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
9.4.3.5 Baud Rate Tolerance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
9.4.3.6 Receiver Wakeup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
9.4.3.7 Receiver Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
9.4.3.8 Error Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
9.5 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
9.5.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
9.5.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
9.6 SCI During Break Module Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
9.7 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
9.7.1 TxD (Transmit Data). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
9.7.2 RxD (Receive Data) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
9.8 I/O Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
9.8.1 SCI Control Register 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
9.8.2 SCI Control Register 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
9.8.3 SCI Control Register 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
9.8.4 SCI Status Register 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
9.8.5 SCI Status Register 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
9.8.6 SCI Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
9.8.7 SCI Baud Rate Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
Chapter 10
Analog-to-Digital Converter (ADC)
10.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
10.2 Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
10.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
10.3.1 ADC Port I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
10.3.2 Voltage Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
10.3.3 Conversion Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
10.3.4 Continuous Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
10.3.5 Accuracy and Precision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
10.4 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
10.5 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
10.5.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
10.5.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
10.6 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
10.6.1 ADC Voltage In (ADCVIN) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
10.7 I/O Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
10.7.1 ADC Status and Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
10.7.2 ADC Data Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
10.7.3 ADC Input Clock Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
Table of Contents
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Chapter 11
Input/Output (I/O) Ports
11.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
11.2 Port A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
11.2.1 Port A Data Register (PTA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
11.2.2 Data Direction Register A (DDRA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
11.2.3 Port A Input Pull-Up Enable Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
11.3 Port B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
11.3.1 Port B Data Register (PTB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
11.3.2 Data Direction Register B (DDRB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
11.4 Port D. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
11.4.1 Port D Data Register (PTD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
11.4.2 Data Direction Register D (DDRD). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
11.4.3 Port D Control Register (PDCR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
11.5 Port E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
11.5.1 Port E Data Register (PTE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
11.5.2 Data Direction Register E (DDRE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
Chapter 12
External Interrupt (IRQ)
12.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
12.2 Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
12.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
12.3.1 IRQ Pin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
12.4 IRQ Module During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
12.5 IRQ Status and Control Register (INTSCR). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
Chapter 13
Keyboard Interrupt Module (KBI)
13.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
13.2 Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
13.3 I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
13.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
13.4.1 Keyboard Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
13.5 Keyboard Interrupt Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
13.5.1 Keyboard Status and Control Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
13.5.2 Keyboard Interrupt Enable Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
13.6 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
13.6.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
13.6.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
13.7 Keyboard Module During Break Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
Chapter 14
Computer Operating Properly (COP)
14.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
14.2 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
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14.3 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
14.3.1 ICLK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
14.3.2 COPCTL Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
14.3.3 Power-On Reset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
14.3.4 Internal Reset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
14.3.5 Reset Vector Fetch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
14.3.6 COPD (COP Disable). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
14.3.7 COPRS (COP Rate Select) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
14.4 COP Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
14.5 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
14.6 Monitor Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
14.7 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
14.7.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176
14.7.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176
14.8 COP Module During Break Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176
Chapter 15
Low Voltage Inhibit (LVI)
15.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
15.2 Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
15.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
15.4 LVI Control Register (CONFIG2/CONFIG1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
15.5 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
15.5.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
15.5.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
Chapter 16
Break Module (BREAK)
16.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
16.2 Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
16.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
16.3.1 Flag Protection During Break Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
16.3.2 CPU During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
16.3.3 TIM During Break Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
16.3.4 COP During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
16.4 Break Module Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
16.4.1 Break Status and Control Register (BRKSCR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
16.4.2 Break Address Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
16.4.3 Break Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
16.4.4 Break Flag Control Register (BFCR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
16.5 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
16.5.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
16.5.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
Table of Contents
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14 Freescale Semiconductor
Chapter 17
Electrical Specifications
17.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
17.2 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
17.3 Functional Operating Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
17.4 Thermal Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
17.5 5V DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
17.6 5V Control Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
17.7 5V Oscillator Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
17.8 3V DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189
17.9 3V Control Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190
17.10 3V Oscillator Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
17.11 Typical Supply Currents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
17.12 Timer Interface Module Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
17.13 ADC Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
17.14 Memory Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
Chapter 18
Mechanical Specifications
18.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
18.2 20-Pin Plastic Dual In-Line Package (PDIP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
18.3 20-Pin Small Outline Integrated Circuit Package (SOIC). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
18.4 28-Pin Plastic Dual In-Line Package (PDIP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
18.5 28-Pin Small Outline Integrated Circuit Package (SOIC). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
18.6 32-Pin Shrink Dual In-Line Package (SDIP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
18.7 32-Pin Low-Profile Quad Flat Pack (LQFP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
Chapter 19
Ordering Information
19.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
19.2 MC Order Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
Appendix A
MC68HC08JL8
A.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
A.2 MCU Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
A.3 Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
A.4 Reserved Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202
A.5 Mask Option Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
A.6 Monitor ROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
A.7 Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
A.7.1 DC Electrical Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
A.8 Memory Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
A.9 MC68HC08JL8 Order Numbers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
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Appendix B
MC68HC908KL8
B.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207
B.2 MCU Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207
B.3 Pin Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207
B.4 Reserved Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
B.5 Reserved Vectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
B.6 MC68HC908KL8 Order Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
Table of Contents
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
16 Freescale Semiconductor
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 17
Chapter 1
General Description
1.1 Introduction
The MC68HC908JL8 is a member of the low-cost, high-performance M68HC08 Family of 8-bit
microcontroller units (MCUs). All MCUs in the family use the enhanced M68HC08 central processor unit
(CPU08) and are available with a variety of modules, memory sizes and types, and package types.
1.2 Features
Features of the MC68HC908JL8 include the following:
High-performance M68HC08 architecture
Fully upward-compatible object code with M6805, M146805, and M68HC05 Families
Low-power design; fully static with stop and wait modes
Maximum internal bus frequency:
8-MHz at 5V operating voltage
4-MHz at 3V operating voltage
Oscillator options:
Crystal or resonator
RC oscillator
8,192 bytes user program FLASH memory with security(1) feature
256 bytes of on-chip RAM
Two 16-bit, 2-channel timer interface modules (TIM1 and TIM2) with selectable input capture,
output compare, and PWM capability on each channel; external clock input option on TIM2
13-channel, 8-bit analog-to-digital converter (ADC)
Serial communications interface module (SCI)
26 general-purpose input/output (I/O) ports:
8 keyboard interrupt with internal pull-up
Table 1-1. Summary of Devices
Generic Part Description Pin Count
MC68HC908JL8 FLASH part 28 or 32
MC68HC908JK8 FLASH part 20
MC68HC08JL8 ROM part for MC68HC908JL8 28 or 32
MC68HC08JK8 ROM part for MC68HC908JK8 20
MC68HC908KL8 ADC-less MC68HC908JL8 28 or 32
1. No security feature is absolutely secure. However, Motorola’s strategy is to make reading or copying the FLASH difficult for
unauthorized users.
General Description
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
18 Freescale Semiconductor
11 LED drivers (sink)
–2 × 25mA open-drain I/O with pull-up
Resident routines for in-circuit programming and EEPROM emulation
System protection features:
Optional computer operating properly (COP) reset, driven by internal RC oscillator
Optional low-voltage detection with reset and selectable trip points for 3V and 5V operation
Illegal opcode detection with reset
Illegal address detection with reset
Master reset pin with internal pull-up and power-on reset
•IRQ
with schmitt-trigger input and programmable pull-up
20-pin dual in-line package (PDIP), 20-pin small outline integrated package (SOIC), 28-pin PDIP,
28-pin SOIC, 32-pin shrink dual in-line package (SDIP), and 32-pin low-profile quad flat pack
(LQFP)
Specific features of the MC68HC908JL8 in 28-pin packages are:
23 general-purpose I/Os only
7 keyboard interrupt with internal pull-up
10 LED drivers (sink)
12-channel ADC
Timer I/O pins on TIM1 only
Specific features of the MC68HC908JL8 in 20-pin packages are:
15 general-purpose I/Os only
1 keyboard interrupt with internal pull-up
4 LED drivers (sink)
10-channel ADC
Timer I/O pins on TIM1 only
Features of the CPU08 include the following:
Enhanced HC05 programming model
Extensive loop control functions
16 addressing modes (eight more than the HC05)
16-bit index register and stack pointer
Memory-to-memory data transfers
Fast 8 × 8 multiply instruction
Fast 16/8 divide instruction
Binary-coded decimal (BCD) instructions
Optimization for controller applications
Efficient C language support
1.3 MCU Block Diagram
Figure 1-1 shows the structure of the MC68HC908JL8.
MCU Block Diagram
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 19
Figure 1-1. MC68HC908JL8 Block Diagram
SYSTEM INTEGRATION
MODULE
ARITHMETIC/LOGIC
UNIT (ALU)
CPU
REGISTERS
M68HC08 CPU
CONTROL AND STATUS REGISTERS — 64 BYTES
EXTERNAL INTERRUPT
MODULE
INTERNAL BUS
* RST
* IRQ
POWER
VSS
2-CHANNEL TIMER INTERFACE
MODULE 1
KEYBOARD INTERRUPT
MODULE
8-BIT ANALOG-TO-DIGITAL
CONVERTER MODULE
VDD
ADC REFERENCE
DDRB
PORTB
PTB7/ADC7
PTB6/ADC6
PTB5/ADC5
PTB4/ADC4
PTB3/ADC3
PTB2/ADC2
PTB1/ADC1
PTB0/ADC0
DDRA
PORTA
PTA6/KBI6**¥
PTA5/KBI5**
PTA4/KBI4**
PTA3/KBI3**
PTA2/KBI2**
PTA1/KBI1**
PTA0/KBI0**
POWER-ON RESET
MODULE
* Pin contains integrated pull-up device.
** Pin contains programmable pull-up device.
LED direct sink pin.
OSC1
¥ OSC2/RCCLK
CRYSTAL OSCILLATOR
RC OSCILLATOR
DDRD
PORTD
PTD7/RxD**†‡
PTD6/TxD**†‡
PTD5/T1CH1
PTD4/T1CH0
PTD3/ADC8
PTD2/ADC9
PTD1/ADC10
PTD0/ADC11
BREAK
MODULE
COMPUTER OPERATING
PROPERLY MODULE
# Pins available on 32-pin packages only.
¥ Shared pin: OSC2/RCCLK/PTA6/KBI6.
PTA7/KBI7**
LOW-VOLTAGE INHIBIT
MODULE
SERIAL COMMUNICATIONS
INTERFACE MODULE
PTE
DDRE
PTE1/T2CH1
PTE0/T2CH0
INTERNAL OSCILLATOR
ADC12/T2CLK
2-CHANNEL TIMER INTERFACE
MODULE 2
USER FLASH — 8,192 BYTES
USER RAM — 256 BYTES
MONITOR ROM — 959 BYTES
USER FLASH VECTORS — 36 BYTES
#
##
#
##
#
## Pins available on 28-pin and 32-pin packages only.
25mA open-drain if output pin.
\ flflflflflflflfl 33333333 O UUUUUUUU EKKKKKKK 3 3333333333333333 u EEEEEEEEEEEEEEEE 3
General Description
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
20 Freescale Semiconductor
1.4 Pin Assignments
Figure 1-2. 32-Pin LQFP Pin Assignment
Figure 1-3. 32-Pin SDIP Pin Assignment
32
31
30
29
28
27
26
25
1
2
3
4
5
6
7
8
10
11
12
13
14
15
16
24
20
19
18
17
9
23
22
21
IRQ
PTA0/KBI0
VSS
OSC1
OSC2/RCCLK/PTA6/KBI6
PTA1/KBI1
VDD
PTA2/KBI2
PTA3/KBI3
PTB7/ADC7
PTB6/ADC6
PTB5/ADC5
ADC12/T2CLK
PTA7/KBI7
RST
PTA5/KBI5
PTD4/T1CH0
PTD5/T1CH1
PTD2/ADC9
PTA4/KBI4
PTD3/ADC8
PTB0/ADC0
PTB1/ADC1
PTD1/ADC10
PTB2/ADC2
PTB4/ADC4
PTD0/ADC11
PTB3/ADC3
PTD7/RxD
PTD6/TxD
PTE0/T2CH0
PTE1/T2CH1
1
2
3
4
5
6
7
32
31
30
29
28
27
26
25
24
23
22
12
13
14
21
20
19
8
9
10
11
ADC12/T2CLK
PTA7/KBI7
RST
PTA5/KBI5
PTD4/T1CH0
PTD5/T1CH1
PTD2/ADC9
PTA4/KBI4
PTD3/ADC8
PTB0/ADC0
PTB1/ADC1
PTD1/ADC10
PTB2/ADC2
PTB3/ADC3
IRQ
PTA0/KBI0
VSS
OSC1
OSC2/RCCLK/PTA6/KBI6
PTA1/KBI1
VDD
PTA2/KBI2
PTA3/KBI3
PTB7/ADC7
PTB6/ADC6
PTB5/ADC5
PTD7/RxD
PTD6/TxD
15
16
18
17
PTD0/ADC11
PTB4/ADC4
PTE0/T2CH0
PTE1/T2CH1
33333333333333 u i 3333:3333: EEEEEEEEEEEEEE u EEEEEEEEEE i
Pin Functions
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 21
Figure 1-4. 28-Pin PDIP/SOIC Pin Assignment
Figure 1-5. 20-Pin PDIP/SOIC Pin Assignment
1.5 Pin Functions
Description of the pin functions are provided in Table 1-2.
1
2
3
4
5
6
7
28
27
26
25
24
23
22
21
20
19
18
12
13
14
17
16
15
8
9
10
11
RST
PTA5/KBI5
PTD4/T1CH0
PTD5/T1CH1
PTD2/ADC9
PTA4/KBI4
PTD3/ADC8
PTB0/ADC0
PTB1/ADC1
PTD1/ADC10
PTB2/ADC2
PTB3/ADC3
PTD0/ADC11
PTB4/ADC4
IRQ
PTA0/KBI0
VSS
OSC1
OSC2/RCCLK/PTA6/KBI6
PTA1/KBI1
VDD
PTA2/KBI2
PTA3/KBI3
PTB7/ADC7
PTB6/ADC6
PTB5/ADC5
PTD7/RxD
PTD6/TxD
Pins not available on 28-pin packages
PTE0/T2CH0
PTE1/T2CH1
ADC12/T2CLK
PTA7/KBI7
Internal pads are unconnected.
Set these unused port I/Os to output low.
1
2
3
4
5
6
7
20
19
18
17
16
15
14
13
12
11
8
9
10
RST
PTD4/T1CH0
PTD5/T1CH1
PTD2/ADC9
PTD3/ADC8
PTB0/ADC0
PTB1/ADC1
PTB2/ADC2
PTB3/ADC3
PTB4/ADC4
IRQ
VSS
OSC1
OSC2/RCCLK/PTA6/KBI6
VDD
PTB7/ADC7
PTB6/ADC6
PTB5/ADC5
PTD7/RxD
PTD6/TxD
Pins not available on 20-pin packages
PTA0/KBI0 PTD0/ADC11
PTA1/KBI1 PTD1/ADC10
PTA2/KBI2
PTA3/KBI3 PTE0/T2CH0
PTA4/KBI4 PTE1/T2CH1
PTA5/KBI5
ADC12/T2CLK
PTA7/KBI7
Internal pads are unconnected.
Set these unused port I/Os to output low.
The 20-pin MC68HC908JL8 is designated MC68HC908JK8.
General Description
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
22 Freescale Semiconductor
Table 1-2. Pin Functions
PIN NAME PIN DESCRIPTION IN/OUT VOLTAGE
LEVEL
VDD Power supply. In 5V or 3V
VSS Power supply ground. Out 0V
RST Reset input, active low;
with internal pull-up and schmitt trigger input. In/Out VDD
IRQ
External IRQ pin; with programmable internal pull-up and schmitt
trigger input. In VDD
Used for monitor mode entry. In VDD to VTST
OSC1 Crystal or RC oscillator input. In VDD
OSC2/RCCLK
OSC2: crystal oscillator output; inverted OSC1 signal. Out VDD
RCCLK: RC oscillator clock output. Out VDD
Pin as PTA6/KBI6 (see PTA0–PTA7). In/Out VDD
ADC12/T2CLK
ADC12: channel-12 input of ADC. In VSS to VDD
T2CLK: external input clock for TIM2. In VDD
PTA0–PTA7
8-bit general purpose I/O port. In/Out VDD
Each pin has programmable internal pull-up when configured as
input. In VDD
Pins as keyboard interrupts, KBI0–KBI7. In VDD
PTA0–PTA5 and PTA7 have LED direct sink capability. Out VSS
PTA6 as OSC2/RCCLK. Out VDD
PTB0–PTB7
8-bit general purpose I/O port. In/Out VDD
Pins as ADC input channels, ADC0–ADC7. In VSS to VDD
PTD0–PTD7
8-bit general purpose I/O port;
with programmable internal pull-ups on PTD6–PTD7. In/Out VDD
PTD0–PTD3 as ADC input channels, ADC11–ADC8. Input VSS to VDD
PTD2–PTD3 and PTD6–PTD7 have LED direct sink capability Out VSS
PTD4 as T1CH0 of TIM1. In/Out VDD
PTD5 as T1CH1 of TIM1. In/Out VDD
PTD6–PTD7 have configurable 25mA open-drain output. Out VSS
PTD6 as TxD of SCI. Out VDD
PTD7 as RxD of SCI. In VDD
Pin Functions
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 23
NOTE
Devices in 28-pin packages, the following pins are not available:
PTA7/KBI7, PTE0/T2CH0, PTE1/T2CH1, and ADC12/T2CLK.
Devices in 20-pin packages, the following pins are not available:
PTA0/KBI0–PTA5/KBI5, PTD0/ADC11, PTD1/ADC10,
PTA7/KBI7, PTE0/T2CH0, PTE1/T2CH1, and ADC12/T2CLK.
PTE0–PTE1
2-bit general purpose I/O port. In/Out VDD
PTE0 as T2CH0 of TIM2. In/Out VDD
PTE1 as T2CH1 of TIM2. In/Out VDD
Table 1-2. Pin Functions (Continued)
PIN NAME PIN DESCRIPTION IN/OUT VOLTAGE
LEVEL
General Description
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
24 Freescale Semiconductor
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 25
Chapter 2
Memory
2.1 Introduction
The CPU08 can address 64-kbytes of memory space. The memory map, shown in Figure 2-1, includes:
8,192 bytes of user FLASH memory
36 bytes of user-defined vectors
959 bytes of monitor ROM
2.2 I/O Section
Addresses $0000–$003F, shown in Figure 2-2, contain most of the control, status, and data registers.
Additional I/O registers have the following addresses:
$FE00; Break Status Register, BSR
$FE01; Reset Status Register, RSR
•$FE02; Reserved
$FE03; Break Flag Control Register, BFCR
$FE04; Interrupt Status Register 1, INT1
$FE05; Interrupt Status Register 2, INT2
$FE06; Interrupt Status Register 3, INT3
•$FE07; Reserved
$FE08; FLASH Control Register, FLCR
•$FE09; Reserved
•$FE0A; Reserved
•$FE0B; Reserved
$FE0C; Break Address Register High, BRKH
$FE0D; Break Address Register Low, BRKL
$FE0E; Break Status and Control Register, BRKSCR
•$FE0F; Reserved
$FFCF; FLASH Block Protect Register, FLBPR (FLASH register)
$FFD0; Mask Option Register, MOR (FLASH register)
$FFFF; COP Control Register, COPCTL
2.3 Monitor ROM
The 959 bytes at addresses $FC00–$FDFF and $FE10–$FFCE are reserved ROM addresses that
contain the instructions for the monitor functions. (See Chapter 7 Monitor ROM (MON).)
Memory
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
26 Freescale Semiconductor
$0000
$003F
I/O REGISTERS
64 BYTES
$0040
$005F
RESERVED
32 BYTES
$0060
$015F
RAM
256 BYTES
$0160
$DBFF
UNIMPLEMENTED
55,968 BYTES
$DC00
$FBFF
FLASH MEMORY
8,192 BYTES
$FC00
$FDFF
MONITOR ROM
512 BYTES
$FE00 BREAK STATUS REGISTER (BSR)
$FE01 RESET STATUS REGISTER (RSR)
$FE02 RESERVED
$FE03 BREAK FLAG CONTROL REGISTER (BFCR)
$FE04 INTERRUPT STATUS REGISTER 1 (INT1)
$FE05 INTERRUPT STATUS REGISTER 2 (INT2)
$FE06 INTERRUPT STATUS REGISTER 3 (INT3)
$FE07 RESERVED
$FE08 FLASH CONTROL REGISTER (FLCR)
$FE09
$FF0B
RESERVED
$FE0C BREAK ADDRESS HIGH REGISTER (BRKH)
$FE0D BREAK ADDRESS LOW REGISTER (BRKL)
$FE0E BREAK STATUS AND CONTROL REGISTER (BRKSCR)
$FE0F RESERVED
$FE10
$FFCE
MONITOR ROM
447 BYTES
$FFCF FLASH BLOCK PROTECT REGISTER (FLBPR)
$FFD0 MASK OPTION REGISTER (MOR)
$FFD1
$FFDB
RESERVED
11 BYTES
$FFDC
$FFFF
USER FLASH VECTORS
36 BYTES
Figure 2-1. Memory Map
Monitor ROM
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 27
Addr.Register Name Bit 7654321Bit 0
$0000 Port A Data Register (PTA)
Read: PTA7 PTA6 PTA5 PTA4 PTA3 PTA2 PTA1 PTA0
Write:
Reset: Unaffected by reset
$0001 Port B Data Register (PTB)
Read: PTB7 PTB6 PTB5 PTB4 PTB3 PTB2 PTB1 PTB0
Write:
Reset: Unaffected by reset
$0002 Unimplemented
Read:
Write:
$0003 Port D Data Register (PTD)
Read: PTD7 PTD6 PTD5 PTD4 PTD3 PTD2 PTD1 PTD0
Write:
Reset: Unaffected by reset
$0004 Data Direction Register A
(DDRA)
Read: DDRA7 DDRA6 DDRA5 DDRA4 DDRA3 DDRA2 DDRA1 DDRA0
Write:
Reset:00000000
$0005 Data Direction Register B
(DDRB)
Read: DDRB7 DDRB6 DDRB5 DDRB4 DDRB3 DDRB2 DDRB1 DDRB0
Write:
Reset:00000000
$0006 Unimplemented
Read:
Write:
$0007 Data Direction Register D
(DDRD)
Read: DDRD7 DDRD6 DDRD5 DDRD4 DDRD3 DDRD2 DDRD1 DDRD0
Write:
Reset:00000000
$0008 Port E Data Register
(PTE)
Read: PTE1 PTE0
Write:
Reset: Unaffected by reset
$0009 Unimplemented
Read:
Write:
$000A Port D Control Register
(PDCR)
Read: 0000
SLOWD7 SLOWD6 PTDPU7 PTDPU6
Write:
Reset: 00000000
$000B Unimplemented
Read:
Write:
$000C Data Direction Register E
(DDRE)
Read: DDRE1 DDRE0
Write:
Reset:00000000
$000D
Port A Input Pull-up
Enable Register
(PTAPUE)
Read: PTA6EN PTAPUE6 PTAPUE5 PTAPUE4 PTAPUE3 PTAPUE2 PTAPUE1 PTAPUE0
Write:
Reset: 00000000
$000E
PTA7 Input Pull-up
Enable Register
(PTA7PUE)
Read: PTAPUE7
Write:
Reset: 00000000
$000F
$0012
Unimplemented
Read:
Write:
U = Unaffected X = Indeterminate = Unimplemented R = Reserved
Figure 2-2. Control, Status, and Data Registers (Sheet 1 of 5)
HE. _” é
Memory
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
28 Freescale Semiconductor
$0013 SCI Control Register 1
(SCC1)
Read: LOOPS ENSCI TXINV M WAKE ILTY PEN PTY
Write:
Reset:00000000
$0014 SCI Control Register 2
(SCC2)
Read: SCTIE TCIE SCRIE ILIE TE RE RWU SBK
Write:
Reset:00000000
$0015 SCI Control Register 3
(SCC3)
Read: R8 T8 DMARE DMATE ORIE NEIE FEIE PEIE
Write:
Reset:UU000000
$0016 SCI Status Register 1 (SCS1)
Read: SCTE TC SCRF IDLE OR NF FE PE
Write:
Reset:11000000
$0017 SCI Status Register 2 (SCS2)
Read: BKF RPF
Write:
Reset:00000000
$0018 SCI Data Register
(SCDR)
Read: R7 R6 R5 R4 R3 R2 R1 R0
Write: T7 T6 T5 T4 T3 T2 T1 T0
Reset: Unaffected by reset
$0019 SCI Baud Rate Register
(SCBR)
Read: SCP1 SCP0 R SCR2 SCR1 SCR0
Write:
Reset:00000000
$001A
Keyboard Status and
Control Register
(KBSCR)
Read: 0000KEYF 0 IMASKK MODEK
Write: ACKK
Reset: 00000000
$001B
Keyboard Interrupt
Enable Register
(KBIER)
Read: KBIE7 KBIE6 KBIE5 KBIE4 KBIE3 KBIE2 KBIE1 KBIE0
Write:
Reset: 00000000
$001C Unimplemented
Read:
Write:
$001D
IRQ Status and Control
Register
(INTSCR)
Read:0000IRQF0
IMASK MODE
Write: ACK
Reset:00000000
$001E Configuration Register 2
(CONFIG2)
Read: IRQPUDRRLVIT1LVIT0RR
STOP_
ICLKDIS
Write:
Reset:0000*0*000
$001F Configuration Register 1
(CONFIG1)
Read: COPRS R R LVID R SSREC STOP COPD
Write:
Reset:00000000
† One-time writable register after each reset. * LVIT1 and LVIT0 reset to logic 0 by a power-on reset (POR) only.
$0020
TIM1 Status and Control
Register
(T1SC)
Read: TOF TOIE TSTOP 00
PS2 PS1 PS0
Write: 0 TRST
Reset: 00100000
$0021
TIM1 Counter Register
High
(T1CNTH)
Read: Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8
Write:
Reset: 00000000
Addr.Register Name Bit 7654321Bit 0
U = Unaffected X = Indeterminate = Unimplemented R = Reserved
Figure 2-2. Control, Status, and Data Registers (Sheet 2 of 5)
Monitor ROM
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 29
$0022
TIM1 Counter Register
Low
(T1CNTL)
Read: Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0
Write:
Reset: 00000000
$0023
TIM Counter Modulo
Register High
(TMODH)
Read: Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8
Write:
Reset: 11111111
$0024
TIM1 Counter Modulo
Register Low
(T1MODL)
Read: Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0
Write:
Reset: 11111111
$0025
TIM1 Channel 0 Status
and Control Register
(T1SC0)
Read: CH0F CH0IE MS0B MS0A ELS0B ELS0A TOV0 CH0MAX
Write: 0
Reset: 00000000
$0026
TIM1 Channel 0
Register High
(T1CH0H)
Read: Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8
Write:
Reset: Indeterminate after reset
$0027
TIM1 Channel 0
Register Low
(T1CH0L)
Read: Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0
Write:
Reset: Indeterminate after reset
$0028
TIM1 Channel 1 Status
and Control Register
(T1SC1)
Read: CH1F CH1IE 0MS1A ELS1B ELS1A TOV1 CH1MAX
Write: 0
Reset: 00000000
$0029
TIM1 Channel 1
Register High
(T1CH1H)
Read: Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8
Write:
Reset: Indeterminate after reset
$002A
TIM1 Channel 1
Register Low
(T1CH1L)
Read: Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0
Write:
Reset: Indeterminate after reset
$002B
$002F
Unimplemented
Read:
Write:
$0030
TIM2 Status and Control
Register
(T2SC)
Read: TOF TOIE TSTOP 00
PS2 PS1 PS0
Write: 0 TRST
Reset: 00100000
$0031
TIM2 Counter Register
High
(T2CNTH)
Read: Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8
Write:
Reset: 00000000
$0032
TIM2 Counter Register
Low
(T2CNTL)
Read: Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0
Write:
Reset: 00000000
$0033
TIM2 Counter Modulo
Register High
(T2MODH)
Read: Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8
Write:
Reset: 11111111
$0034
TIM2 Counter Modulo
Register Low
(T2MODL)
Read: Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0
Write:
Reset: 11111111
Addr.Register Name Bit 7654321Bit 0
U = Unaffected X = Indeterminate = Unimplemented R = Reserved
Figure 2-2. Control, Status, and Data Registers (Sheet 3 of 5)
H E w»
Memory
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
30 Freescale Semiconductor
$0035
TIM2 Channel 0 Status
and Control Register
(T2SC0)
Read: CH0F CH0IE MS0B MS0A ELS0B ELS0A TOV0 CH0MAX
Write: 0
Reset: 00000000
$0036
TIM2 Channel 0
Register High
(T2CH0H)
Read: Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8
Write:
Reset: Indeterminate after reset
$0037
TIM2 Channel 0
Register Low
(T2CH0L)
Read: Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0
Write:
Reset: Indeterminate after reset
$0038
TIM2 Channel 1 Status
and Control Register
(T2SC1)
Read: CH1F CH1IE 0MS1A ELS1B ELS1A TOV1 CH1MAX
Write: 0
Reset: 00000000
$0039
TIM2 Channel 1
Register High
(T2CH1H)
Read: Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8
Write:
Reset: Indeterminate after reset
$003A
TIM2 Channel 1
Register Low
(T2CH1L)
Read: Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0
Write:
Reset: Indeterminate after reset
$003B Unimplemented
Read:
Write:
$003C
ADC Status and Control
Register
(ADSCR)
Read: COCO AIEN ADCO ADCH4 ADCH3 ADCH2 ADCH1 ADCH0
Write:
Reset:00011111
$003D ADC Data Register
(ADR)
Read:AD7AD6AD5AD4AD3AD2AD1AD0
Write:
Reset: Indeterminate after reset
$003E ADC Input Clock Register
(ADICLK)
Read: ADIV2 ADIV1 ADIV0 00000
Write:
Reset:00000000
$003F Unimplemented
Read:
Write:
$FE00 Break Status Register (BSR)
Read: RRRRRR
SBSW R
Write: See note
Reset: 0
Note: Writing a logic 0 clears SBSW.
$FE01 Reset Status Register (RSR)
Read: POR PIN COP ILOP ILAD MODRST LVI 0
Write:
POR:10000000
$FE02 Reserved
Read: RRRRRRRR
Write:
$FE03
Break Flag Control
Register
(BFCR)
Read: BCFERRRRRRR
Write:
Reset: 0
Addr.Register Name Bit 7654321Bit 0
U = Unaffected X = Indeterminate = Unimplemented R = Reserved
Figure 2-2. Control, Status, and Data Registers (Sheet 4 of 5)
Monitor ROM
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 31
$FE04 Interrupt Status Register 1
(INT1)
Read: IF6 IF5 IF4 IF3 0 IF1 0 0
Write:RRRRRRRR
Reset:00000000
$FE05 Interrupt Status Register 2
(INT2)
Read: IF14 IF13 IF12 IF11 0 0 IF8 IF7
Write:RRRRRRRR
Reset:00000000
$FE06 Interrupt Status Register 3
(INT3)
Read:0000000IF15
Write:RRRRRRRR
Reset:00000000
$FE07 Reserved
Read: RRRRRRRR
Write:
$FE08 FLASH Control Register
(FLCR)
Read:0000
HVEN MASS ERASE PGM
Write:
Reset:00000000
$FE09
$FE0B
Reserved
Read: RRRRRRRR
Write:
$FE0C
Break Address High
Register
(BRKH)
Read: Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8
Write:
Reset:00000000
$FE0D
Break Address low
Register
(BRKL)
Read: Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0
Write:
Reset:00000000
$FE0E
Break Status and Control
Register
(BRKSCR)
Read: BRKE BRKA 000000
Write:
Reset:00000000
$FFCF
FLASH Block Protect
Register
(FLBPR)#
Read: BPR7 BPR6 BPR5 BPR4 BPR3 BPR2 BPR1 BPR0
Write:
Reset: Unaffected by reset; $FF when blank
$FFD0 Mask Option Register
(MOR)#
Read: OSCSELRRRRRRR
Write:
Reset: Unaffected by reset; $FF when blank
# Non-volatile FLASH registers; write by programming.
$FFFF COP Control Register
(COPCTL)
Read: Low byte of reset vector
Write: Writing clears COP counter (any value)
Reset: Unaffected by reset
Addr.Register Name Bit 7654321Bit 0
U = Unaffected X = Indeterminate = Unimplemented R = Reserved
Figure 2-2. Control, Status, and Data Registers (Sheet 5 of 5)
Memory
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
32 Freescale Semiconductor
.
Table 2-1. Vector Addresses
Vector Priority INT Flag Address Vector
Lowest
Highest
$FFD0
$FFDD
Not Used
IF15 $FFDE ADC Conversion Complete Vector (High)
$FFDF ADC Conversion Complete Vector (Low)
IF14 $FFE0 Keyboard Interrupt Vector (High)
$FFE1 Keyboard Interrupt Vector (Low)
IF13 $FFE2 SCI Transmit Vector (High)
$FFE3 SCI Transmit Vector (Low)
IF12 $FFE4 SCI Receive Vector (High)
$FFE5 SCI Receive Vector (Low)
IF11 $FFE6 SCI Error Vector (High)
$FFE7 SCI Error Vector (Low)
IF10
IF9
Not Used
IF8 $FFEC TIM2 Overflow Vector (High)
$FFED TIM2 Overflow Vector (Low)
IF7 $FFEE TIM2 Channel 1 Vector (High)
$FFEF TIM2 Channel 1 Vector (Low)
IF6 $FFF0 TIM2 Channel 0 Vector (High)
$FFF1 TIM2 Channel 0 Vector (Low)
IF5 $FFF2 TIM1 Overflow Vector (High)
$FFF3 TIM1 Overflow Vector (Low)
IF4 $FFF4 TIM1 Channel 1 Vector (High)
$FFF5 TIM1 Channel 1 Vector (Low)
IF3 $FFF6 TIM1 Channel 0 Vector (High)
$FFF7 TIM1 Channel 0 Vector (Low)
IF2 Not Used
IF1 $FFFA IRQ Vector (High)
$FFFB IRQ Vector (Low)
$FFFC SWI Vector (High)
$FFFD SWI Vector (Low)
$FFFE Reset Vector (High)
$FFFF Reset Vector (Low)
Random-Access Memory (RAM)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 33
2.4 Random-Access Memory (RAM)
Addresses $0060 through $015F are RAM locations. The location of the stack RAM is programmable.
The 16-bit stack pointer allows the stack to be anywhere in the 64-Kbyte memory space.
NOTE
For correct operation, the stack pointer must point only to RAM locations.
Within page zero are 160 bytes of RAM. Because the location of the stack RAM is programmable, all page
zero RAM locations can be used for I/O control and user data or code. When the stack pointer is moved
from its reset location at $00FF, direct addressing mode instructions can access efficiently all page zero
RAM locations. Page zero RAM, therefore, provides ideal locations for frequently accessed global
variables.
Before processing an interrupt, the CPU uses five bytes of the stack to save the contents of the CPU
registers.
NOTE
For M6805 compatibility, the H register is not stacked.
During a subroutine call, the CPU uses two bytes of the stack to store the return address. The stack
pointer decrements during pushes and increments during pulls.
NOTE
Be careful when using nested subroutines. The CPU may overwrite data in
the RAM during a subroutine or during the interrupt stacking operation.
2.5 FLASH Memory
This sub-section describes the operation of the embedded FLASH memory. The FLASH memory can be
read, programmed, and erased from a single external supply. The program and erase operations are
enabled through the use of an internal charge pump.
2.6 Functional Description
The FLASH memory consists of an array of 8,192 bytes for user memory plus a block of 36 bytes for user
interrupt vectors. An erased bit reads as logic 1 and a programmed bit reads as a logic 0. The FLASH
memory page size is defined as 64 bytes, and is the minimum size that can be erased in a page erase
operation. Program and erase operations are facilitated through control bits in FLASH control register
(FLCR).
The address ranges for the FLASH memory are:
$DC00–$FBFF; user memory; 12,288 bytes
$FFDC–$FFFF; user interrupt vectors; 36 bytes
Programming tools are available from Freescale. Contact your local Freescale representative for more
information.
NOTE
A security feature prevents viewing of the FLASH contents.(1)
1. No security feature is absolutely secure. However, Motorola’s strategy is to make reading or copying the FLASH difficult for
unauthorized users.
Memory
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
34 Freescale Semiconductor
2.7 FLASH Control Register
The FLASH control register (FCLR) controls FLASH program and erase operations.
HVEN — High Voltage Enable Bit
This read/write bit enables the charge pump to drive high voltages for program and erase operations
in the array. HVEN can only be set if either PGM = 1 or ERASE = 1 and the proper sequence for
program or erase is followed.
1 = High voltage enabled to array and charge pump on
0 = High voltage disabled to array and charge pump off
MASS — Mass Erase Control Bit
This read/write bit configures the memory for mass erase operation or page erase operation when the
ERASE bit is set.
1 = Mass erase operation selected
0 = Page erase operation selected
ERASE — Erase Control Bit
This read/write bit configures the memory for erase operation. ERASE is interlocked with the PGM bit
such that both bits cannot be equal to 1 or set to 1 at the same time.
1 = Erase operation selected
0 = Erase operation not selected
PGM — Program Control Bit
This read/write bit configures the memory for program operation. PGM is interlocked with the ERASE
bit such that both bits cannot be equal to 1 or set to 1 at the same time.
1 = Program operation selected
0 = Program operation not selected
2.8 FLASH Page Erase Operation
Use the following procedure to erase a page of FLASH memory. A page consists of 64 consecutive bytes
starting from addresses $XX00, $XX40, $XX80 or $XXC0. The 36-byte user interrupt vectors area also
forms a page. Any page within the 8,192 bytes user memory area ($DC00–$FBFF) can be erased alone.
The 36-byte user interrupt vectors cannot be erased by the page erase operation because of security
reasons. Mass erase is required to erase this page.
1. Set the ERASE bit and clear the MASS bit in the FLASH control register.
2. Read the FLASH block protect register.
3. Write any data to any FLASH address within the page address range desired.
4. Wait for a time, tnvs (10µs).
5. Set the HVEN bit.
6. Wait for a time terase (4ms).
Address: $FE08
Bit 7654321Bit 0
Read:0000
HVEN MASS ERASE PGM
Write:
Reset:00000000
Figure 2-3. FLASH Control Register (FLCR)
FLASH Mass Erase Operation
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 35
7. Clear the ERASE bit.
8. Wait for a time, tnvh (5µs).
9. Clear the HVEN bit.
10. After time, trcv (1µs), the memory can be accessed in read mode again.
NOTE
Programming and erasing of FLASH locations cannot be performed by
code being executed from the FLASH memory. While these operations
must be performed in the order as shown, but other unrelated operations
may occur between the steps.
2.9 FLASH Mass Erase Operation
Use the following procedure to erase the entire FLASH memory:
1. Set both the ERASE bit and the MASS bit in the FLASH control register.
2. Read the FLASH block protect register.
3. Write any data to any FLASH location within the FLASH memory address range.
4. Wait for a time, tnvs (10µs).
5. Set the HVEN bit.
6. Wait for a time tmerase (4ms).
7. Clear the ERASE bit.
8. Wait for a time, tnvh1 (100µs).
9. Clear the HVEN bit.
10. After time, trcv (1µs), the memory can be accessed in read mode again.
NOTE
Programming and erasing of FLASH locations cannot be performed by
code being executed from the FLASH memory. While these operations
must be performed in the order as shown, but other unrelated operations
may occur between the steps.
2.10 FLASH Program Operation
Programming of the FLASH memory is done on a row basis. A row consists of 32 consecutive bytes
starting from addresses $XX00, $XX20, $XX40, $XX60, $XX80, $XXA0, $XXC0 or $XXE0. Use this
step-by-step procedure to program a row of FLASH memory:
(Figure 2-4 shows a flowchart of the programming algorithm.)
1. Set the PGM bit. This configures the memory for program operation and enables the latching of
address and data for programming.
2. Read the FLASH block protect register.
3. Write any data to any FLASH location within the address range of the row to be programmed.
4. Wait for a time, tnvs (10µs).
5. Set the HVEN bit.
6. Wait for a time, tpgs (5µs).
7. Write data to the FLASH address to be programmed.
Memory
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
36 Freescale Semiconductor
8. Wait for time, tprog (30µs).
9. Repeat steps 7 and 8 until all bytes within the row are programmed.
10. Clear the PGM bit.
11. Wait for time, tnvh (5µs).
12. Clear the HVEN bit.
13. After time, trcv (1µs), the memory can be accessed in read mode again.
This program sequence is repeated throughout the memory until all data is programmed.
NOTE
The time between each FLASH address change (step 7 to step 7), or the
time between the last FLASH addressed programmed to clearing the PGM
bit (step 7 to step 10), must not exceed the maximum programming time,
tprog max.
NOTE
Programming and erasing of FLASH locations cannot be performed by
code being executed from the FLASH memory. While these operations
must be performed in the order shown, other unrelated operations may
occur between the steps.
FLASH Program Operation
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 37
Figure 2-4. FLASH Programming Flowchart
Set HVEN bit
Read the FLASH block protect register
Write any data to any FLASH location
within the address range of the row to
Wait for a time, tnvs
Set PGM bit
Wait for a time, tpgs
Write data to the FLASH address
to be programmed
Wait for a time, tprog
Clear PGM bit
Wait for a time, tnvh
Clear HVEN bit
Wait for a time, trcv
Completed
programming
this row?
Y
N
End of programming
The time between each FLASH address change (step 7 to step 7), or
must not exceed the maximum programming
time, tprog max.
the time between the last FLASH address programmed
to clearing PGM bit (step 7 to step 10)
NOTE:
1
2
3
4
5
6
7
8
10
11
12
13
Algorithm for programming
a row (32 bytes) of FLASH memory
This row program algorithm assumes the row/s
to be programmed are initially erased.
be programmed
Memory
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38 Freescale Semiconductor
2.11 FLASH Block Protection
Due to the ability of the on-board charge pump to erase and program the FLASH memory in the target
application, provision is made to protect blocks of memory from unintentional erase or program operations
due to system malfunction. This protection is done by use of a FLASH block protect register (FLBPR).
The FLBPR determines the range of the FLASH memory which is to be protected. The range of the
protected area starts from a location defined by FLBPR and ends to the bottom of the FLASH memory
($FFFF). When the memory is protected, the HVEN bit cannot be set in either erase or program
operations.
NOTE
In performing a program or erase operation, the FLASH block protect register must be read after setting
the PGM or ERASE bit and before asserting the HVEN bit
When the FLBPR is program with all 0’s, the entire memory is protected from being programmed and
erased. When all the bits are erased
(all 1’s), the entire memory is accessible for program and erase.
When bits within the FLBPR are programmed, they lock a block of memory, address ranges as shown in
2.12 FLASH Block Protect Register. Once the FLBPR is programmed with a value other than $FF, any
erase or program of the FLBPR or the protected block of FLASH memory is prohibited. The FLBPR itself
can be erased or programmed only with an external voltage, VTST, present on the IRQ pin. This voltage
also allows entry from reset into the monitor mode.
2.12 FLASH Block Protect Register
The FLASH block protect register (FLBPR) is implemented as a byte within the FLASH memory, and
therefore can only be written during a programming sequence of the FLASH memory. The value in this
register determines the starting location of the protected range within the FLASH memory.
BPR[7:0] — FLASH Block Protect Bits
BPR[7:0] represent bits [13:6] of a 16-bit memory address. Bits [15:14] are logic 1’s and bits [5:0] are
logic 0’s.
Address: $FFCF
Bit 7654321Bit 0
Read:
BPR7 BPR6 BPR5 BPR4 BPR3 BPR2 BPR1 BPR0
Write:
Reset: Unaffected by reset; $FF when blank
Non-volatile FLASH register; write by programming.
Figure 2-5. FLASH Block Protect Register (FLBPR)
16-bit memory address
Start address of FLASH block protect 1 1 000000
BPR[7:0]
FLASH Block Protect Register
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 39
The resultant 16-bit address is used for specifying the start address of the FLASH memory for block
protection. The FLASH is protected from this start address to the end of FLASH memory, at $FFFF.
With this mechanism, the protect start address can be XX00, XX40, XX80, or XXC0 (at page
boundaries — 64 bytes) within the FLASH memory.
Examples of protect start address:
BPR[7:0] Start of Address of Protect Range (1)
1. The end address of the protected range is always $FFFF.
$00–$70 The entire FLASH memory is protected.
$71
(0111 0001)$DC40 (1101 1100 0100 0000)
$72
(0111 0010)$DC80 (1101 1100 1000 0000)
$73
(0111 0011)$DCC0 (1101 1100 1100 0000)
and so on...
$FD
(1111 1101)$FF40 (1111 1111 0100 0000)
$FE
(1111 1110)$FF80 (1111 1111 1000 0000)
$FF The entire FLASH memory is not protected.
Memory
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
40 Freescale Semiconductor
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 41
Chapter 3
Configuration and Mask Option Registers (CONFIG & MOR)
3.1 Introduction
This section describes the configuration registers, CONFIG1 and CONFIG2; and the mask option register
(MOR).
The configuration registers enable or disable these options:
Computer operating properly module (COP)
COP timeout period (213–24 or 218–24 ICLK cycles)
Internal oscillator during stop mode
Low voltage inhibit (LVI) module
LVI module voltage trip point selection
•STOP instruction
Stop mode recovery time (32 or 4096 ICLK cycles)
Pull-up on IRQ pin
The mask option register selects the oscillator option:
Crystal or RC
3.2 Functional Description
The configuration registers are used in the initialization of various options. The configuration registers can
be written once after each reset. All of the configuration register bits are cleared during reset. Since the
various options affect the operation of the MCU, it is recommended that these registers be written
immediately after reset. The configuration registers are located at $001E and $001F. The configuration
registers may be read at anytime.
NOTE
The options except LVIT[1:0] are one-time writable by the user after each
reset. The LVIT[1:0] bits are one-time writable by the user only after each
POR (power-on reset). The CONFIG registers are not in the FLASH
memory but are special registers containing one-time writable latches after
each reset. Upon a reset, the CONFIG registers default to predetermined
settings as shown in Figure 3-1 and Figure 3-2.
The mask option register (MOR) is used to select the oscillator option for the MCU: crystal oscillator or
RC oscillator. The MOR is implemented as a byte in FLASH memory. Hence, writing to the MOR requires
programming the byte.
Configuration and Mask Option Registers (CONFIG & MOR)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
42 Freescale Semiconductor
3.3 Configuration Register 1 (CONFIG1)
COPRS — COP Rate Select Bit
COPRS selects the COP time-out period. Reset clears COPRS.
(See Chapter 14 Computer Operating Properly (COP).)
1 = COP timeout period is (213 – 24) ICLK cycles
0 = COP timeout period is (218 – 24) ICLK cycles
LVID — Low Voltage Inhibit Disable Bit
LVID disables the LVI module. Reset clears LVID.
(See Chapter 15 Low Voltage Inhibit (LVI).)
1 = Low voltage inhibit disabled
0 = Low voltage inhibit enabled
SSREC — Short Stop Recovery Bit
SSREC enables the CPU to exit stop mode with a delay of
32 ICLK cycles instead of a 4096 ICLK cycle delay.
1 = Stop mode recovery after 32 ICLK cycles
0 = Stop mode recovery after 4096 ICLK cycles
NOTE
Exiting stop mode by pulling reset will result in the long stop recovery.
If using an external crystal, do not set the SSREC bit.
STOP — STOP Instruction Enable Bit
STOP enables the STOP instruction.
1 = STOP instruction enabled
0 = STOP instruction treated as illegal opcode
COPD — COP Disable Bit
COPD disables the COP module. Reset clears COPD.
(See Chapter 14 Computer Operating Properly (COP).)
1 = COP module disabled
0 = COP module enabled
Address: $001F
Bit 7654321Bit 0
Read:
COPRS R R LVID R SSREC STOP COPD
Write:
Reset:00000000
R=Reserved
Figure 3-1. Configuration Register 1 (CONFIG1)
Configuration Register 2 (CONFIG2)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 43
3.4 Configuration Register 2 (CONFIG2)
IRQPUD — IRQ Pin Pull-Up Disable Bit
IRQPUD disconnects the internal pull-up on the IRQ pin.
1 = Internal pull-up is disconnected
0 = Internal pull-up is connected between IRQ pin and VDD
LVIT1, LVIT0 — LVI Trip Voltage Selection Bits
Detail description of trip voltage selection is given in Chapter 15 Low Voltage Inhibit (LVI).
STOP_ICLKDIS — Internal Oscillator Stop Mode Disable Bit
Setting STOP_ICLKDIS disables the internal oscillator during stop mode. When this bit is cleared, the
internal oscillator continues to operate in stop mode. Reset clears this bit.
1 = Internal oscillator disabled during stop mode
0 = Internal oscillator enabled during stop mode
3.5 Mask Option Register (MOR)
The mask option register (MOR) is implemented as a byte within the FLASH memory, and therefore can
only be written during a programming sequence of the FLASH memory. This register is read after a
power-on reset to determine the type of oscillator selected. (See Chapter 6 Oscillator (OSC).)
OSCSEL — Oscillator Select Bit
OSCSEL selects the oscillator type for the MCU. The erased or unprogrammed state of this bit is
logic 1, selecting the crystal oscillator option. This bit is unaffected by reset.
1 = Crystal oscillator
0 = RC oscillator
Address: $001E
Bit 7654321Bit 0
Read:
IRQPUD R R LVIT1 LVIT0 R R STOP_
ICLKDIS
Write:
Reset:000
Not affected Not affected 000
POR:00000000
R=Reserved
One-time writable register after each reset. LVIT1 and LVIT0 reset to logic 0 by a power-on reset (POR) only.
Figure 3-2. Configuration Register 2 (CONFIG2)
Address: $FFD0
Bit 7654321Bit 0
Read:
OSCSELRRRRRRR
Write:
Erased:11111111
Reset: Unaffected by reset
Non-volatile FLASH register; write by programming.
R=Reserved
Figure 3-3. Mask Option Register (MOR)
Configuration and Mask Option Registers (CONFIG & MOR)
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44 Freescale Semiconductor
Bits 6–0 — Should be left as logic 1’s.
NOTE
When Crystal oscillator is selected, the OSC2/RCCLK/PTA6/KBI6 pin is
used as OSC2; other functions such as PTA6/KBI6 will not be available.
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 45
Chapter 4
Central Processor Unit (CPU)
4.1 Introduction
The M68HC08 CPU (central processor unit) is an enhanced and fully object-code-compatible version of
the M68HC05 CPU. The CPU08 Reference Manual (Freescale document order number CPU08RM/AD)
contains a description of the CPU instruction set, addressing modes, and architecture.
4.2 Features
Object code fully upward-compatible with M68HC05 Family
16-bit stack pointer with stack manipulation instructions
16-Bit Index Register with X-Register Manipulation Instructions
8-MHz CPU Internal Bus Frequency
64-Kbyte Program/Data Memory Space
16 Addressing Modes
Memory-to-Memory Data Moves without Using Accumulator
Fast 8-Bit by 8-Bit Multiply and 16-Bit by 8-Bit Divide Instructions
Enhanced Binary-Coded Decimal (BCD) Data Handling
Modular Architecture with Expandable Internal Bus Definition for Extension of Addressing Range
beyond 64 Kbytes
Low-Power Stop and Wait Modes
géééa
Central Processor Unit (CPU)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
46 Freescale Semiconductor
4.3 CPU Registers
Figure 4-1 shows the five CPU registers. CPU registers are not part of the memory map.
Figure 4-1. CPU Registers
4.3.1 Accumulator
The accumulator is a general-purpose 8-bit register. The CPU uses the accumulator to hold operands and
the results of arithmetic/logic operations.
4.3.2 Index Register
The 16-bit index register allows indexed addressing of a 64-Kbyte memory space. H is the upper byte of
the index register, and X is the lower byte. H:X is the concatenated 16-bit index register.
In the indexed addressing modes, the CPU uses the contents of the index register to determine the
conditional address of the operand.
The index register can serve also as a temporary data storage location.
Bit 7654321Bit 0
Read:
Write:
Reset: Unaffected by reset
Figure 4-2. Accumulator (A)
ACCUMULATOR (A)
INDEX REGISTER (H:X)
STACK POINTER (SP)
PROGRAM COUNTER (PC)
CONDITION CODE REGISTER (CCR)
CARRY/BORROW FLAG
ZERO FLAG
NEGATIVE FLAG
INTERRUPT MASK
HALF-CARRY FLAG
TWO’S COMPLEMENT OVERFLOW FLAG
V11HINZC
H X
0
0
0
0
7
15
15
15
70
CPU Registers
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 47
4.3.3 Stack Pointer
The stack pointer is a 16-bit register that contains the address of the next location on the stack. During a
reset, the stack pointer is preset to $00FF. The reset stack pointer (RSP) instruction sets the least
significant byte to $FF and does not affect the most significant byte. The stack pointer decrements as data
is pushed onto the stack and increments as data is pulled from the stack.
In the stack pointer 8-bit offset and 16-bit offset addressing modes, the stack pointer can function as an
index register to access data on the stack. The CPU uses the contents of the stack pointer to determine
the conditional address of the operand.
NOTE
The location of the stack is arbitrary and may be relocated anywhere in
RAM. Moving the SP out of page 0 ($0000 to $00FF) frees direct address
(page 0) space. For correct operation, the stack pointer must point only to
RAM locations.
4.3.4 Program Counter
The program counter is a 16-bit register that contains the address of the next instruction or operand to be
fetched.
Normally, the program counter automatically increments to the next sequential memory location every
time an instruction or operand is fetched. Jump, branch, and interrupt operations load the program
counter with an address other than that of the next sequential location.
During reset, the program counter is loaded with the reset vector address located at $FFFE and $FFFF.
The vector address is the address of the first instruction to be executed after exiting the reset state.
Bit
15 1413121110987654321Bit 0
Read:
Write:
Reset:00000000XXXXXXXX
X = Indeterminate
Figure 4-3. Index Register (H:X)
Bit
15 1413121110987654321Bit 0
Read:
Write:
Reset:0000000011111111
Figure 4-4. Stack Pointer (SP)
Central Processor Unit (CPU)
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48 Freescale Semiconductor
4.3.5 Condition Code Register
The 8-bit condition code register contains the interrupt mask 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 register.
V — 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 flags to determine the appropriate correction factor.
1 = Carry between bits 3 and 4
0 = No carry between bits 3 and 4
I — Interrupt Mask
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 interrupt vector is fetched.
1 = Interrupts disabled
0 = Interrupts enabled
NOTE
To maintain M6805 Family compatibility, the upper byte of the index
register (H) is not stacked automatically. If the interrupt service routine
modifies H, then the user must stack and unstack H using the PSHH and
PULH instructions.
Bit
15 1413121110987654321Bit 0
Read:
Write:
Reset: Loaded with Vector from $FFFE and $FFFF
Figure 4-5. Program Counter (PC)
Bit 7654321Bit 0
Read:
V11HINZC
Write:
Reset:X11X1XXX
X = Indeterminate
Figure 4-6. Condition Code Register (CCR)
Arithmetic/Logic Unit (ALU)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 49
After the I bit is cleared, the highest-priority interrupt request is serviced first.
A return-from-interrupt (RTI) instruction pulls the CPU registers from the stack and restores the
interrupt mask from the stack. After any reset, the interrupt mask is set and can be cleared only by the
clear interrupt mask software instruction (CLI).
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.
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.
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
4.4 Arithmetic/Logic Unit (ALU)
The ALU performs the arithmetic and logic operations defined by the instruction set.
Refer to the CPU08 Reference Manual (Freescale document order number CPU08RM/AD) for a
description of the instructions and addressing modes and more detail about the architecture of the CPU.
4.5 Low-Power Modes
The WAIT and STOP instructions put the MCU in low power-consumption standby modes.
4.5.1 Wait Mode
The WAIT instruction:
Clears the interrupt mask (I bit) in the condition code register, enabling interrupts. After exit from
wait mode by interrupt, the I bit remains clear. After exit by reset, the I bit is set.
Disables the CPU clock
4.5.2 Stop Mode
The STOP instruction:
Clears the interrupt mask (I bit) in the condition code register, enabling external interrupts. After
exit from stop mode by external interrupt, the I bit remains clear. After exit by reset, the I bit is set.
Disables the CPU clock
After exiting stop mode, the CPU clock begins running after the oscillator stabilization delay.
3.08
Central Processor Unit (CPU)
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50 Freescale Semiconductor
4.6 CPU During Break Interrupts
If a break module is present on the MCU, the CPU starts a break interrupt by:
Loading the instruction register with the SWI instruction
Loading the program counter with $FFFC:$FFFD or with $FEFC:$FEFD in monitor mode
The break interrupt begins after completion of the CPU instruction in progress. If the break address
register match occurs on the last cycle of a CPU instruction, the break interrupt begins immediately.
A return-from-interrupt instruction (RTI) in the break routine ends the break interrupt and returns the MCU
to normal operation if the break interrupt has been deasserted.
4.7 Instruction Set Summary
Table 4-1 provides a summary of the M68HC08 instruction set.
4.8 Opcode Map
The opcode map is provided in Table 4-2.
Table 4-1. Instruction Set Summary
Source
Form Operation Description
Effect on
CCR
Address
Mode
Opcode
Operand
Cycles
VH I NZC
ADC #opr
ADC opr
ADC opr
ADC opr,X
ADC opr,X
ADC ,X
ADC opr,SP
ADC opr,SP
Add with Carry A (A) + (M) + (C) RRRRR
IMM
DIR
EXT
IX2
IX1
IX
SP1
SP2
A9
B9
C9
D9
E9
F9
9EE9
9ED9
ii
dd
hh ll
ee ff
ff
ff
ee ff
2
3
4
4
3
2
4
5
ADD #opr
ADD opr
ADD opr
ADD opr,X
ADD opr,X
ADD ,X
ADD opr,SP
ADD opr,SP
Add without Carry A (A) + (M) RRRRR
IMM
DIR
EXT
IX2
IX1
IX
SP1
SP2
AB
BB
CB
DB
EB
FB
9EEB
9EDB
ii
dd
hh ll
ee ff
ff
ff
ee ff
2
3
4
4
3
2
4
5
AIS #opr Add Immediate Value (Signed) to SP SP (SP) + (16 « M) ––––––IMM A7 ii 2
AIX #opr Add Immediate Value (Signed) to H:X H:X (H:X) + (16 « M) ––––––IMM AF ii 2
mu_u>u WE
Opcode Map
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 51
AND #opr
AND opr
AND opr
AND opr,X
AND opr,X
AND ,X
AND opr,SP
AND opr,SP
Logical AND A (A) & (M) 0 RR
IMM
DIR
EXT
IX2
IX1
IX
SP1
SP2
A4
B4
C4
D4
E4
F4
9EE4
9ED4
ii
dd
hh ll
ee ff
ff
ff
ee ff
2
3
4
4
3
2
4
5
ASL opr
ASLA
ASLX
ASL opr,X
ASL ,X
ASL opr,SP
Arithmetic Shift Left
(Same as LSL) R––RRR
DIR
INH
INH
IX1
IX
SP1
38
48
58
68
78
9E68
dd
ff
ff
4
1
1
4
3
5
ASR opr
ASRA
ASRX
ASR opr,X
ASR opr,X
ASR opr,SP
Arithmetic Shift Right R––RRR
DIR
INH
INH
IX1
IX
SP1
37
47
57
67
77
9E67
dd
ff
ff
4
1
1
4
3
5
BCC rel Branch if Carry Bit Clear PC (PC) + 2 + rel ? (C) = 0 ––––––REL 24 rr 3
BCLR n, opr Clear Bit n in M Mn 0 ––––––
DIR (b0)
DIR (b1)
DIR (b2)
DIR (b3)
DIR (b4)
DIR (b5)
DIR (b6)
DIR (b7)
11
13
15
17
19
1B
1D
1F
dd
dd
dd
dd
dd
dd
dd
dd
4
4
4
4
4
4
4
4
BCS rel Branch if Carry Bit Set (Same as BLO) PC (PC) + 2 + rel ? (C) = 1 ––––––REL 25 rr 3
BEQ rel Branch if Equal PC (PC) + 2 + rel ? (Z) = 1 ––––––REL 27 rr 3
BGE opr Branch if Greater Than or Equal To
(Signed Operands) PC (PC) + 2 + rel ? (N V) = 0 ––––––REL 90 rr 3
BGT opr Branch if Greater Than (Signed
Operands) PC (PC) + 2 +rel ? (Z) | (N V)=0––––––REL 92 rr 3
BHCC rel Branch if Half Carry Bit Clear PC (PC) + 2 + rel ? (H) = 0 ––––––REL 28 rr 3
BHCS rel Branch if Half Carry Bit Set PC (PC) + 2 + rel ? (H) = 1 ––––––REL 29 rr 3
BHI rel Branch if Higher PC (PC) + 2 + rel ? (C) | (Z) = 0 ––––––REL 22 rr 3
BHS rel Branch if Higher or Same
(Same as BCC) PC (PC) + 2 + rel ? (C) = 0 ––––––REL 24 rr 3
BIH rel Branch if IRQ Pin High PC (PC) + 2 + rel ? IRQ = 1 ––––––REL 2F rr 3
BIL rel Branch if IRQ Pin Low PC (PC) + 2 + rel ? IRQ = 0 ––––––REL 2E rr 3
Table 4-1. Instruction Set Summary
Source
Form Operation Description
Effect on
CCR
Address
Mode
Opcode
Operand
Cycles
VH I NZC
C
b0
b7
0
b0
b7
C
mu_u>u
Central Processor Unit (CPU)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
52 Freescale Semiconductor
BIT #opr
BIT opr
BIT opr
BIT opr,X
BIT opr,X
BIT ,X
BIT opr,SP
BIT opr,SP
Bit Test (A) & (M) 0 RR
IMM
DIR
EXT
IX2
IX1
IX
SP1
SP2
A5
B5
C5
D5
E5
F5
9EE5
9ED5
ii
dd
hh ll
ee ff
ff
ff
ee ff
2
3
4
4
3
2
4
5
BLE opr Branch if Less Than or Equal To
(Signed Operands) PC (PC) + 2 + rel ? (Z) | (N V)=1––––––REL 93 rr 3
BLO rel Branch if Lower (Same as BCS) PC (PC) + 2 + rel ? (C) = 1 ––––––REL 25 rr 3
BLS rel Branch if Lower or Same PC (PC) + 2 + rel ? (C) | (Z) = 1 ––––––REL 23 rr 3
BLT opr Branch if Less Than (Signed Operands) PC (PC) + 2 + rel ? (N V) = 1 ––––––REL 91 rr 3
BMC rel Branch if Interrupt Mask Clear PC (PC) + 2 + rel ? (I) = 0 ––––––REL 2C rr 3
BMI rel Branch if Minus PC (PC) + 2 + rel ? (N) = 1 ––––––REL 2B rr 3
BMS rel Branch if Interrupt Mask Set PC (PC) + 2 + rel ? (I) = 1 ––––––REL 2D rr 3
BNE rel Branch if Not Equal PC (PC) + 2 + rel ? (Z) = 0 ––––––REL 26 rr 3
BPL rel Branch if Plus PC (PC) + 2 + rel ? (N) = 0 ––––––REL 2A rr 3
BRA rel Branch Always PC (PC) + 2 + rel ––––––REL 20 rr 3
BRCLR n,opr,rel Branch if Bit n in M Clear PC (PC) + 3 + rel ? (Mn) = 0 R
DIR (b0)
DIR (b1)
DIR (b2)
DIR (b3)
DIR (b4)
DIR (b5)
DIR (b6)
DIR (b7)
01
03
05
07
09
0B
0D
0F
dd rr
dd rr
dd rr
dd rr
dd rr
dd rr
dd rr
dd rr
5
5
5
5
5
5
5
5
BRN rel Branch Never PC (PC) + 2 ––––––REL 21 rr 3
BRSET n,opr,rel Branch if Bit n in M Set PC (PC) + 3 + rel ? (Mn) = 1 R
DIR (b0)
DIR (b1)
DIR (b2)
DIR (b3)
DIR (b4)
DIR (b5)
DIR (b6)
DIR (b7)
00
02
04
06
08
0A
0C
0E
dd rr
dd rr
dd rr
dd rr
dd rr
dd rr
dd rr
dd rr
5
5
5
5
5
5
5
5
BSET n,opr Set Bit n in M Mn 1 ––––––
DIR (b0)
DIR (b1)
DIR (b2)
DIR (b3)
DIR (b4)
DIR (b5)
DIR (b6)
DIR (b7)
10
12
14
16
18
1A
1C
1E
dd
dd
dd
dd
dd
dd
dd
dd
4
4
4
4
4
4
4
4
Table 4-1. Instruction Set Summary
Source
Form Operation Description
Effect on
CCR
Address
Mode
Opcode
Operand
Cycles
VH I NZC
mu_u>u
Opcode Map
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 53
BSR rel Branch to Subroutine
PC (PC) + 2; push (PCL)
SP (SP) – 1; push (PCH)
SP (SP) – 1
PC (PC) + rel
––––––REL AD rr 4
CBEQ opr,rel
CBEQA #opr,rel
CBEQX #opr,rel
CBEQ opr,X+,rel
CBEQ X+,rel
CBEQ opr,SP,rel
Compare and Branch if Equal
PC (PC) + 3 + rel ? (A) – (M) = $00
PC (PC) + 3 + rel ? (A) – (M) = $00
PC (PC) + 3 + rel ? (X) – (M) = $00
PC (PC) + 3 + rel ? (A) – (M) = $00
PC (PC) + 2 + rel ? (A) – (M) = $00
PC (PC) + 4 + rel ? (A) – (M) = $00
––––––
DIR
IMM
IMM
IX1+
IX+
SP1
31
41
51
61
71
9E61
dd rr
ii rr
ii rr
ff rr
rr
ff rr
5
4
4
5
4
6
CLC Clear Carry Bit C 0 –––––0INH 98 1
CLI Clear Interrupt Mask I 0 ––0–––INH 9A 2
CLR opr
CLRA
CLRX
CLRH
CLR opr,X
CLR ,X
CLR opr,SP
Clear
M $00
A $00
X $00
H $00
M $00
M $00
M $00
0––01–
DIR
INH
INH
INH
IX1
IX
SP1
3F
4F
5F
8C
6F
7F
9E6F
dd
ff
ff
3
1
1
1
3
2
4
CMP #opr
CMP opr
CMP opr
CMP opr,X
CMP opr,X
CMP ,X
CMP opr,SP
CMP opr,SP
Compare A with M (A) – (M) R––RRR
IMM
DIR
EXT
IX2
IX1
IX
SP1
SP2
A1
B1
C1
D1
E1
F1
9EE1
9ED1
ii
dd
hh ll
ee ff
ff
ff
ee ff
2
3
4
4
3
2
4
5
COM opr
COMA
COMX
COM opr,X
COM ,X
COM opr,SP
Complement (One’s Complement)
M (M) = $FF – (M)
A (A) = $FF – (M)
X (X) = $FF – (M)
M (M) = $FF – (M)
M (M) = $FF – (M)
M (M) = $FF – (M)
0––RR1
DIR
INH
INH
IX1
IX
SP1
33
43
53
63
73
9E63
dd
ff
ff
4
1
1
4
3
5
CPHX #opr
CPHX opr Compare H:X with M (H:X) – (M:M + 1) R––RRR
IMM
DIR
65
75
ii ii+1
dd
3
4
CPX #opr
CPX opr
CPX opr
CPX ,X
CPX opr,X
CPX opr,X
CPX opr,SP
CPX opr,SP
Compare X with M (X) – (M) R––RRR
IMM
DIR
EXT
IX2
IX1
IX
SP1
SP2
A3
B3
C3
D3
E3
F3
9EE3
9ED3
ii
dd
hh ll
ee ff
ff
ff
ee ff
2
3
4
4
3
2
4
5
DAA Decimal Adjust A (A)10 U–RRRINH 72 2
Table 4-1. Instruction Set Summary
Source
Form Operation Description
Effect on
CCR
Address
Mode
Opcode
Operand
Cycles
VH I NZC
mu_u>u
Central Processor Unit (CPU)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
54 Freescale Semiconductor
DBNZ opr,rel
DBNZA rel
DBNZX rel
DBNZ opr,X,rel
DBNZ X,rel
DBNZ opr,SP,rel
Decrement and Branch if Not Zero
A (A)–1 or M (M)1 or X (X)1
PC (PC) + 3 + rel ? (result) 0
PC (PC) + 2 + rel ? (result) 0
PC (PC) + 2 + rel ? (result) 0
PC (PC) + 3 + rel ? (result) 0
PC (PC) + 2 + rel ? (result) 0
PC (PC) + 4 + rel ? (result) 0
––––––
DIR
INH
INH
IX1
IX
SP1
3B
4B
5B
6B
7B
9E6B
dd rr
rr
rr
ff rr
rr
ff rr
5
3
3
5
4
6
DEC opr
DECA
DECX
DEC opr,X
DEC ,X
DEC opr,SP
Decrement
M (M) – 1
A (A) – 1
X (X) – 1
M (M) – 1
M (M) – 1
M (M) – 1
R––RR
DIR
INH
INH
IX1
IX
SP1
3A
4A
5A
6A
7A
9E6A
dd
ff
ff
4
1
1
4
3
5
DIV Divide A (H:A)/(X)
H Remainder ––––RRINH 52 7
EOR #opr
EOR opr
EOR opr
EOR opr,X
EOR opr,X
EOR ,X
EOR opr,SP
EOR opr,SP
Exclusive OR M with A A (A M) 0 RR
IMM
DIR
EXT
IX2
IX1
IX
SP1
SP2
A8
B8
C8
D8
E8
F8
9EE8
9ED8
ii
dd
hh ll
ee ff
ff
ff
ee ff
2
3
4
4
3
2
4
5
INC opr
INCA
INCX
INC opr,X
INC ,X
INC opr,SP
Increment
M (M) + 1
A (A) + 1
X (X) + 1
M (M) + 1
M (M) + 1
M (M) + 1
R––RR
DIR
INH
INH
IX1
IX
SP1
3C
4C
5C
6C
7C
9E6C
dd
ff
ff
4
1
1
4
3
5
JMP opr
JMP opr
JMP opr,X
JMP opr,X
JMP ,X
Jump PC Jump Address ––––––
DIR
EXT
IX2
IX1
IX
BC
CC
DC
EC
FC
dd
hh ll
ee ff
ff
2
3
4
3
2
JSR opr
JSR opr
JSR opr,X
JSR opr,X
JSR ,X
Jump to Subroutine
PC (PC) + n (n = 1, 2, or 3)
Push (PCL); SP (SP) – 1
Push (PCH); SP (SP) – 1
PC Unconditional Address
––––––
DIR
EXT
IX2
IX1
IX
BD
CD
DD
ED
FD
dd
hh ll
ee ff
ff
4
5
6
5
4
LDA #opr
LDA opr
LDA opr
LDA opr,X
LDA opr,X
LDA ,X
LDA opr,SP
LDA opr,SP
Load A from M A (M) 0 RR
IMM
DIR
EXT
IX2
IX1
IX
SP1
SP2
A6
B6
C6
D6
E6
F6
9EE6
9ED6
ii
dd
hh ll
ee ff
ff
ff
ee ff
2
3
4
4
3
2
4
5
LDHX #opr
LDHX opr Load H:X from M H:X (M:M + 1) 0 RRIMM
DIR
45
55
ii jj
dd
3
4
Table 4-1. Instruction Set Summary
Source
Form Operation Description
Effect on
CCR
Address
Mode
Opcode
Operand
Cycles
VH I NZC
mu_u>u D
Opcode Map
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 55
LDX #opr
LDX opr
LDX opr
LDX opr,X
LDX opr,X
LDX ,X
LDX opr,SP
LDX opr,SP
Load X from M X (M) 0 RR
IMM
DIR
EXT
IX2
IX1
IX
SP1
SP2
AE
BE
CE
DE
EE
FE
9EEE
9EDE
ii
dd
hh ll
ee ff
ff
ff
ee ff
2
3
4
4
3
2
4
5
LSL opr
LSLA
LSLX
LSL opr,X
LSL ,X
LSL opr,SP
Logical Shift Left
(Same as ASL) R––RRR
DIR
INH
INH
IX1
IX
SP1
38
48
58
68
78
9E68
dd
ff
ff
4
1
1
4
3
5
LSR opr
LSRA
LSRX
LSR opr,X
LSR ,X
LSR opr,SP
Logical Shift Right R––0RR
DIR
INH
INH
IX1
IX
SP1
34
44
54
64
74
9E64
dd
ff
ff
4
1
1
4
3
5
MOV opr,opr
MOV opr,X+
MOV #opr,opr
MOV X+,opr
Move
(M)Destination (M)Source
H:X (H:X) + 1 (IX+D, DIX+)
0––RR
DD
DIX+
IMD
IX+D
4E
5E
6E
7E
dd dd
dd
ii dd
dd
5
4
4
4
MUL Unsigned multiply X:A (X) × (A) –0–––0INH 42 5
NEG opr
NEGA
NEGX
NEG opr,X
NEG ,X
NEG opr,SP
Negate (Two’s Complement)
M –(M) = $00 – (M)
A –(A) = $00 – (A)
X –(X) = $00 – (X)
M –(M) = $00 – (M)
M –(M) = $00 – (M)
R––RRR
DIR
INH
INH
IX1
IX
SP1
30
40
50
60
70
9E60
dd
ff
ff
4
1
1
4
3
5
NOP No Operation None ––––––INH 9D 1
NSA Nibble Swap A A (A[3:0]:A[7:4]) ––––––INH 62 3
ORA #opr
ORA opr
ORA opr
ORA opr,X
ORA opr,X
ORA ,X
ORA opr,SP
ORA opr,SP
Inclusive OR A and M A (A) | (M) 0 RR
IMM
DIR
EXT
IX2
IX1
IX
SP1
SP2
AA
BA
CA
DA
EA
FA
9EEA
9EDA
ii
dd
hh ll
ee ff
ff
ff
ee ff
2
3
4
4
3
2
4
5
PSHA Push A onto Stack Push (A); SP (SP) 1 ––––––INH 87 2
PSHH Push H onto Stack Push (H); SP (SP) 1 ––––––INH 8B 2
PSHX Push X onto Stack Push (X); SP (SP) 1 ––––––INH 89 2
PULA Pull A from Stack SP (SP + 1); Pull (A)––––––INH 86 2
Table 4-1. Instruction Set Summary
Source
Form Operation Description
Effect on
CCR
Address
Mode
Opcode
Operand
Cycles
VH I NZC
C
b0
b7
0
b0
b7
C0
Cycles
Central Processor Unit (CPU)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
56 Freescale Semiconductor
PULH Pull H from Stack SP (SP + 1); Pull (H)––––––INH 8A 2
PULX Pull X from Stack SP (SP + 1); Pull (X)––––––INH 88 2
ROL opr
ROLA
ROLX
ROL opr,X
ROL ,X
ROL opr,SP
Rotate Left through Carry R––RRR
DIR
INH
INH
IX1
IX
SP1
39
49
59
69
79
9E69
dd
ff
ff
4
1
1
4
3
5
ROR opr
RORA
RORX
ROR opr,X
ROR ,X
ROR opr,SP
Rotate Right through Carry R––RRR
DIR
INH
INH
IX1
IX
SP1
36
46
56
66
76
9E66
dd
ff
ff
4
1
1
4
3
5
RSP Reset Stack Pointer SP $FF ––––––INH 9C 1
RTI Return from Interrupt
SP (SP) + 1; Pull (CCR)
SP (SP) + 1; Pull (A)
SP (SP) + 1; Pull (X)
SP (SP) + 1; Pull (PCH)
SP (SP) + 1; Pull (PCL)
RRRRRRINH 80 7
RTS Return from Subroutine SP SP + 1; Pull (PCH)
SP SP + 1; Pull (PCL) ––––––INH 81 4
SBC #opr
SBC opr
SBC opr
SBC opr,X
SBC opr,X
SBC ,X
SBC opr,SP
SBC opr,SP
Subtract with Carry A (A) – (M) – (C) R––RRR
IMM
DIR
EXT
IX2
IX1
IX
SP1
SP2
A2
B2
C2
D2
E2
F2
9EE2
9ED2
ii
dd
hh ll
ee ff
ff
ff
ee ff
2
3
4
4
3
2
4
5
SEC Set Carry Bit C 1 –––––1INH 99 1
SEI Set Interrupt Mask I 1 ––1–––INH 9B 2
STA opr
STA opr
STA opr,X
STA opr,X
STA ,X
STA opr,SP
STA opr,SP
Store A in M M (A) 0 – RR
DIR
EXT
IX2
IX1
IX
SP1
SP2
B7
C7
D7
E7
F7
9EE7
9ED7
dd
hh ll
ee ff
ff
ff
ee ff
3
4
4
3
2
4
5
STHX opr Store H:X in M (M:M + 1) (H:X) 0 RR– DIR 35 dd 4
STOP Enable IRQ Pin; Stop Oscillator I 0; Stop Oscillator ––0–––INH 8E 1
Table 4-1. Instruction Set Summary
Source
Form Operation Description
Effect on
CCR
Address
Mode
Opcode
Operand
Cycles
VH I NZC
C
b0
b7
b0
b7
C
mu_u>u
Opcode Map
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 57
STX opr
STX opr
STX opr,X
STX opr,X
STX ,X
STX opr,SP
STX opr,SP
Store X in M M (X) 0 – RR
DIR
EXT
IX2
IX1
IX
SP1
SP2
BF
CF
DF
EF
FF
9EEF
9EDF
dd
hh ll
ee ff
ff
ff
ee ff
3
4
4
3
2
4
5
SUB #opr
SUB opr
SUB opr
SUB opr,X
SUB opr,X
SUB ,X
SUB opr,SP
SUB opr,SP
Subtract A (A) – (M) R––RRR
IMM
DIR
EXT
IX2
IX1
IX
SP1
SP2
A0
B0
C0
D0
E0
F0
9EE0
9ED0
ii
dd
hh ll
ee ff
ff
ff
ee ff
2
3
4
4
3
2
4
5
SWI Software Interrupt
PC (PC) + 1; Push (PCL)
SP (SP) – 1; Push (PCH)
SP (SP) – 1; Push (X)
SP (SP) – 1; Push (A)
SP (SP) – 1; Push (CCR)
SP (SP) – 1; I 1
PCH Interrupt Vector High Byte
PCL Interrupt Vector Low Byte
––1–––INH 83 9
TAP Transfer A to CCR CCR (A) RRRRRRINH 84 2
TAX Transfer A to X X (A) ––––––INH 97 1
TPA Transfer CCR to A A (CCR) ––––––INH 85 1
TST opr
TSTA
TSTX
TST opr,X
TST ,X
TST opr,SP
Test for Negative or Zero (A) – $00 or (X) – $00 or (M) – $00 0 RR
DIR
INH
INH
IX1
IX
SP1
3D
4D
5D
6D
7D
9E6D
dd
ff
ff
3
1
1
3
2
4
TSX Transfer SP to H:X H:X (SP) + 1 ––––––INH 95 2
TXA Transfer X to A A (X) ––––––INH 9F 1
TXS Transfer H:X to SP (SP) (H:X) 1 ––––––INH 94 2
Table 4-1. Instruction Set Summary
Source
Form Operation Description
Effect on
CCR
Address
Mode
Opcode
Operand
Cycles
VH I NZC
3.05
Central Processor Unit (CPU)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
58 Freescale Semiconductor
A Accumulator nAny bit
C Carry/borrow bit opr Operand (one or two bytes)
CCR Condition code register PC Program counter
dd Direct address of operand PCH Program counter high byte
dd rr Direct address of operand and relative offset of branch instruction PCL Program counter low byte
DD Direct to direct addressing mode REL Relative addressing mode
DIR Direct addressing mode rel Relative program counter offset byte
DIX+ Direct to indexed with post increment addressing mode rr Relative program counter offset byte
ee ff High and low bytes of offset in indexed, 16-bit offset addressing SP1 Stack pointer, 8-bit offset addressing mode
EXT Extended addressing mode SP2 Stack pointer 16-bit offset addressing mode
ff Offset byte in indexed, 8-bit offset addressing SP Stack pointer
H Half-carry bit U Undefined
H Index register high byte V Overflow bit
hh ll High and low bytes of operand address in extended addressing X Index register low byte
I Interrupt mask Z Zero bit
ii Immediate operand byte & Logical AND
IMD Immediate source to direct destination addressing mode | Logical OR
IMM Immediate addressing mode Logical EXCLUSIVE OR
INH Inherent addressing mode ( ) Contents of
IX Indexed, no offset addressing mode –( ) Negation (two’s complement)
IX+ Indexed, no offset, post increment addressing mode # Immediate value
IX+D Indexed with post increment to direct addressing mode «Sign extend
IX1 Indexed, 8-bit offset addressing mode Loaded with
IX1+ Indexed, 8-bit offset, post increment addressing mode ? If
IX2 Indexed, 16-bit offset addressing mode : Concatenated with
M Memory location RSet or cleared
N Negative bit Not affected
Table 4-1. Instruction Set Summary
Source
Form Operation Description
Effect on
CCR
Address
Mode
Opcode
Operand
Cycles
VH I NZC
MSE LSE MSE LEE
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 59
Opcode Map
Table 4-2. Opcode Map
Bit Manipulation Branch Read-Modify-Write Control Register/Memory
DIR DIR REL DIR INH INH IX1 SP1 IX INH INH IMM DIR EXT IX2 SP2 IX1 SP1 IX
01234569E6789ABCD9EDE9EEF
0
5
BRSET0
3DIR
4
BSET0
2DIR
3
BRA
2REL
4
NEG
2DIR
1
NEGA
1INH
1
NEGX
1INH
4
NEG
2IX1
5
NEG
3SP1
3
NEG
1IX
7
RTI
1INH
3
BGE
2REL
2
SUB
2IMM
3
SUB
2DIR
4
SUB
3EXT
4
SUB
3IX2
5
SUB
4SP2
3
SUB
2IX1
4
SUB
3SP1
2
SUB
1IX
1
5
BRCLR0
3DIR
4
BCLR0
2DIR
3
BRN
2REL
5
CBEQ
3DIR
4
CBEQA
3IMM
4
CBEQX
3IMM
5
CBEQ
3IX1+
6
CBEQ
4SP1
4
CBEQ
2IX+
4
RTS
1INH
3
BLT
2REL
2
CMP
2IMM
3
CMP
2DIR
4
CMP
3EXT
4
CMP
3IX2
5
CMP
4SP2
3
CMP
2IX1
4
CMP
3SP1
2
CMP
1IX
2
5
BRSET1
3DIR
4
BSET1
2DIR
3
BHI
2REL
5
MUL
1INH
7
DIV
1INH
3
NSA
1INH
2
DAA
1INH
3
BGT
2REL
2
SBC
2IMM
3
SBC
2DIR
4
SBC
3EXT
4
SBC
3IX2
5
SBC
4SP2
3
SBC
2IX1
4
SBC
3SP1
2
SBC
1IX
3
5
BRCLR1
3DIR
4
BCLR1
2DIR
3
BLS
2REL
4
COM
2DIR
1
COMA
1INH
1
COMX
1INH
4
COM
2IX1
5
COM
3SP1
3
COM
1IX
9
SWI
1INH
3
BLE
2REL
2
CPX
2IMM
3
CPX
2DIR
4
CPX
3EXT
4
CPX
3IX2
5
CPX
4SP2
3
CPX
2IX1
4
CPX
3SP1
2
CPX
1IX
4
5
BRSET2
3DIR
4
BSET2
2DIR
3
BCC
2REL
4
LSR
2DIR
1
LSRA
1INH
1
LSRX
1INH
4
LSR
2IX1
5
LSR
3SP1
3
LSR
1IX
2
TA P
1INH
2
TXS
1INH
2
AND
2IMM
3
AND
2DIR
4
AND
3EXT
4
AND
3IX2
5
AND
4SP2
3
AND
2IX1
4
AND
3SP1
2
AND
1IX
5
5
BRCLR2
3DIR
4
BCLR2
2DIR
3
BCS
2REL
4
STHX
2DIR
3
LDHX
3IMM
4
LDHX
2DIR
3
CPHX
3IMM
4
CPHX
2DIR
1
TPA
1INH
2
TSX
1INH
2
BIT
2IMM
3
BIT
2DIR
4
BIT
3EXT
4
BIT
3IX2
5
BIT
4SP2
3
BIT
2IX1
4
BIT
3SP1
2
BIT
1IX
6
5
BRSET3
3DIR
4
BSET3
2DIR
3
BNE
2REL
4
ROR
2DIR
1
RORA
1INH
1
RORX
1INH
4
ROR
2IX1
5
ROR
3SP1
3
ROR
1IX
2
PULA
1INH
2
LDA
2IMM
3
LDA
2DIR
4
LDA
3EXT
4
LDA
3IX2
5
LDA
4SP2
3
LDA
2IX1
4
LDA
3SP1
2
LDA
1IX
7
5
BRCLR3
3DIR
4
BCLR3
2DIR
3
BEQ
2REL
4
ASR
2DIR
1
ASRA
1INH
1
ASRX
1INH
4
ASR
2IX1
5
ASR
3SP1
3
ASR
1IX
2
PSHA
1INH
1
TA X
1INH
2
AIS
2IMM
3
STA
2DIR
4
STA
3EXT
4
STA
3IX2
5
STA
4SP2
3
STA
2IX1
4
STA
3SP1
2
STA
1IX
8
5
BRSET4
3DIR
4
BSET4
2DIR
3
BHCC
2REL
4
LSL
2DIR
1
LSLA
1INH
1
LSLX
1INH
4
LSL
2IX1
5
LSL
3SP1
3
LSL
1IX
2
PULX
1INH
1
CLC
1INH
2
EOR
2IMM
3
EOR
2DIR
4
EOR
3EXT
4
EOR
3IX2
5
EOR
4SP2
3
EOR
2IX1
4
EOR
3SP1
2
EOR
1IX
9
5
BRCLR4
3DIR
4
BCLR4
2DIR
3
BHCS
2REL
4
ROL
2DIR
1
ROLA
1INH
1
ROLX
1INH
4
ROL
2IX1
5
ROL
3SP1
3
ROL
1IX
2
PSHX
1INH
1
SEC
1INH
2
ADC
2IMM
3
ADC
2DIR
4
ADC
3EXT
4
ADC
3IX2
5
ADC
4SP2
3
ADC
2IX1
4
ADC
3SP1
2
ADC
1IX
A
5
BRSET5
3DIR
4
BSET5
2DIR
3
BPL
2REL
4
DEC
2DIR
1
DECA
1INH
1
DECX
1INH
4
DEC
2IX1
5
DEC
3SP1
3
DEC
1IX
2
PULH
1INH
2
CLI
1INH
2
ORA
2IMM
3
ORA
2DIR
4
ORA
3EXT
4
ORA
3IX2
5
ORA
4SP2
3
ORA
2IX1
4
ORA
3SP1
2
ORA
1IX
B
5
BRCLR5
3DIR
4
BCLR5
2DIR
3
BMI
2REL
5
DBNZ
3DIR
3
DBNZA
2INH
3
DBNZX
2INH
5
DBNZ
3IX1
6
DBNZ
4SP1
4
DBNZ
2IX
2
PSHH
1INH
2
SEI
1INH
2
ADD
2IMM
3
ADD
2DIR
4
ADD
3EXT
4
ADD
3IX2
5
ADD
4SP2
3
ADD
2IX1
4
ADD
3SP1
2
ADD
1IX
C
5
BRSET6
3DIR
4
BSET6
2DIR
3
BMC
2REL
4
INC
2DIR
1
INCA
1INH
1
INCX
1INH
4
INC
2IX1
5
INC
3SP1
3
INC
1IX
1
CLRH
1INH
1
RSP
1INH
2
JMP
2DIR
3
JMP
3EXT
4
JMP
3IX2
3
JMP
2IX1
2
JMP
1IX
D
5
BRCLR6
3DIR
4
BCLR6
2DIR
3
BMS
2REL
3
TST
2DIR
1
TSTA
1INH
1
TSTX
1INH
3
TST
2IX1
4
TST
3SP1
2
TST
1IX
1
NOP
1INH
4
BSR
2REL
4
JSR
2DIR
5
JSR
3EXT
6
JSR
3IX2
5
JSR
2IX1
4
JSR
1IX
E
5
BRSET7
3DIR
4
BSET7
2DIR
3
BIL
2REL
5
MOV
3DD
4
MOV
2DIX+
4
MOV
3IMD
4
MOV
2IX+D
1
STOP
1INH *
2
LDX
2IMM
3
LDX
2DIR
4
LDX
3EXT
4
LDX
3IX2
5
LDX
4SP2
3
LDX
2IX1
4
LDX
3SP1
2
LDX
1IX
F
5
BRCLR7
3DIR
4
BCLR7
2DIR
3
BIH
2REL
3
CLR
2DIR
1
CLRA
1INH
1
CLRX
1INH
3
CLR
2IX1
4
CLR
3SP1
2
CLR
1IX
1
WAIT
1INH
1
TXA
1INH
2
AIX
2IMM
3
STX
2DIR
4
STX
3EXT
4
STX
3IX2
5
STX
4SP2
3
STX
2IX1
4
STX
3SP1
2
STX
1IX
INH Inherent REL Relative SP1 Stack Pointer, 8-Bit Offset
IMM Immediate IX Indexed, No Offset SP2 Stack Pointer, 16-Bit Offset
DIR Direct IX1 Indexed, 8-Bit Offset IX+ Indexed, No Offset with
EXT Extended IX2 Indexed, 16-Bit Offset Post Increment
DD Direct-Direct IMD Immediate-Direct IX1+ Indexed, 1-Byte Offset with
IX+D Indexed-Direct DIX+ Direct-Indexed Post Increment
*Pre-byte for stack pointer indexed instructions
0 High Byte of Opcode in Hexadecimal
Low Byte of Opcode in Hexadecimal 0
5
BRSET0
3DIR
Cycles
Opcode Mnemonic
Number of Bytes / Addressing Mode
MSB
LSB
MSB
LSB
Central Processor Unit (CPU)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
60 Freescale Semiconductor
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 61
Chapter 5
System Integration Module (SIM)
5.1 Introduction
This section describes the system integration module (SIM), which supports up to 24 external and/or
internal interrupts. Together with the CPU, the SIM controls all MCU activities. A block diagram of the SIM
is shown in Figure 5-1. Figure 5-2 is a summary of the SIM I/O registers. The SIM is a system state
controller that coordinates CPU and exception timing.
The SIM is responsible for:
Bus clock generation and control for CPU and peripherals
– Stop/wait/reset/break entry and recovery
Internal clock control
Master reset control, including power-on reset (POR) and COP timeout
Interrupt control:
Acknowledge timing
Arbitration control timing
Vector address generation
CPU enable/disable timing
Modular architecture expandable to 128 interrupt sources
Table 5-1 shows the internal signal names used in this section.
Table 5-1. Signal Name Conventions
Signal Name Description
ICLK Internal oscillator clock
OSCOUT The XTAL or RC frequency divided by two. This signal is again divided by two in the SIM
to generate the internal bus clocks. (Bus clock = OSCOUT ÷ 2)
IAB Internal address bus
IDB Internal data bus
PORRST Signal from the power-on reset module to the SIM
IRST Internal reset signal
R/W Read/write signal
COUNTER PW LOG‘C
System Integration Module (SIM)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
62 Freescale Semiconductor
Figure 5-1. SIM Block Diagram
Addr.Register Name Bit 7654321Bit 0
$FE00 Break Status Register (BSR)
Read: RRRRRR
SBSW R
Write: NOTE
Reset:00000000
Note: Writing a logic 0 clears SBSW.
$FE01 Reset Status Register (RSR)
Read: POR PIN COP ILOP ILAD MODRST LVI 0
Write:
POR:10000000
$FE02 Reserved
Read: RRRRRRRR
Write:
Reset:
$FE03
Break Flag Control
Register
(BFCR)
Read: BCFERRRRRRR
Write:
Reset: 0
Figure 5-2. SIM I/O Register Summary
STOP/WAIT
CLOCK
CONTROL CLOCK GENERATORS
POR CONTROL
RESET PIN CONTROL
SIM RESET STATUS REGISTER
INTERRUPT CONTROL
AND PRIORITY DECODE
MODULE STOP
MODULE WAIT
CPU STOP (FROM CPU)
CPU WAIT (FROM CPU)
SIMOSCEN (TO OSCILLATOR)
OSCOUT (FROM OSCILLATOR)
INTERNAL CLOCKS
MASTER
RESET
CONTROL
RESET
PIN LOGIC
ILLEGAL OPCODE (FROM CPU)
ILLEGAL ADDRESS (FROM ADDRESS
MAP DECODERS)
COP TIMEOUT (FROM COP MODULE)
INTERRUPT SOURCES
CPU INTERFACE
RESET
CONTROL
SIM
COUNTER COP CLOCK
ICLK (FROM OSCILLATOR)
÷2
USB RESET (FROM USB MODULE)
VDD
INTERNAL
PULL-UP
SIM Bus Clock Control and Generation
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 63
5.2 SIM Bus Clock Control and Generation
The bus clock generator provides system clock signals for the CPU and peripherals on the MCU. The
system clocks are generated from an incoming clock, OSCOUT, as shown in Figure 5-3.
Figure 5-3. SIM Clock Signals
5.2.1 Bus Timing
In user mode, the internal bus frequency is the oscillator frequency divided by four.
5.2.2 Clock Start-Up from POR or LVI Reset
When the power-on reset module or the low-voltage inhibit module generates a reset, the clocks to the
CPU and peripherals are inactive and held in an inactive phase until after the 4096 ICLK cycle POR
timeout has completed. The RST pin is driven low by the SIM during this entire period. The IBUS clocks
start upon completion of the timeout.
5.2.3 Clocks in Stop Mode and Wait Mode
Upon exit from stop mode by an interrupt, break, or reset, the SIM allows ICLK to clock the SIM counter.
The CPU and peripheral clocks do not become active until after the stop delay time-out. This time-out is
selectable as 4096 or 32 ICLK cycles. (See 5.6.2 Stop Mode.)
In wait mode, the CPU clocks are inactive. The SIM also produces two sets of clocks for other modules.
Refer to the wait mode subsection of each module to see if the module is active or inactive in wait mode.
Some modules can be programmed to be active in wait mode.
$FE04 Interrupt Status Register 1
(INT1)
Read: IF6 IF5 IF4 IF3 0 IF1 0 0
Write:RRRRRRRR
Reset:00000000
$FE05 Interrupt Status Register 2
(INT2)
Read: IF14 IF13 IF12 IF11 0 0 IF8 IF7
Write:RRRRRRRR
Reset:00000000
$FE06 Interrupt Status Register 3
(INT3)
Read:0000000IF15
Write:RRRRRRRR
Reset:00000000
= Unimplemented R = Reserved
Figure 5-2. SIM I/O Register Summary
÷ 2BUS CLOCK
GENERATORS
SIM
SIM COUNTER
From
OSCILLATOR
From
OSCILLATOR
OSCOUT
ICLK
OSCOUT is OSC frequency divided by 2
WW \_1 I01010)1.1010101019101010)101010101019101010101.1031WWWWWM----
System Integration Module (SIM)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
64 Freescale Semiconductor
5.3 Reset and System Initialization
The MCU has these reset sources:
Power-on reset module (POR)
External reset pin (RST)
Computer operating properly module (COP)
Low-voltage inhibit module (LVI)
Illegal opcode
Illegal address
All of these resets produce the vector $FFFE–$FFFF ($FEFE–$FEFF in Monitor mode) and assert the
internal reset signal (IRST). IRST causes all registers to be returned to their default values and all
modules to be returned to their reset states.
An internal reset clears the SIM counter (see 5.4 SIM Counter), but an external reset does not. Each of
the resets sets a corresponding bit in the reset status register (RSR). (See 5.7 SIM Registers.)
5.3.1 External Pin Reset
The RST pin circuits include an internal pull-up device. Pulling the asynchronous RST pin low halts all
processing. The PIN bit of the reset status register (RSR) is set as long as RST is held low for a minimum
of 67 ICLK cycles, assuming that the POR was not the source of the reset. See Table 5-2 for details.
Figure 5-4 shows the relative timing.
Figure 5-4. External Reset Timing
5.3.2 Active Resets from Internal Sources
All internal reset sources actively pull the RST pin low for 32 ICLK cycles to allow resetting of external
peripherals. The internal reset signal IRST continues to be asserted for an additional 32 cycles
(Figure 5-5). An internal reset can be caused by an illegal address, illegal opcode, COP time-out, or POR.
(See Figure 5-6 . Sources of Internal Reset.) Note that for POR resets, the SIM cycles through 4096 ICLK
cycles during which the SIM forces the RST pin low. The internal reset signal then follows the sequence
from the falling edge of RST shown in Figure 5-5.
Table 5-2. PIN Bit Set Timing
Reset Type Number of Cycles Required to Set PIN
POR 4163 (4096 + 64 + 3)
All others 67 (64 + 3)
RST
IAB PC VECT H VECT L
ICLK
+ H7 4H I—\ I—\ H I—\ u I—\ I—\ f Io)10m10101to)lob:to)10101to)lob:mo:to)lob:mo:alomcoblolmlololcotolobmqo—
Reset and System Initialization
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 65
Figure 5-5. Internal Reset Timing
The COP reset is asynchronous to the bus clock.
Figure 5-6. Sources of Internal Reset
The active reset feature allows the part to issue a reset to peripherals and other chips within a system
built around the MCU.
5.3.2.1 Power-On Reset
When power is first applied to the MCU, the power-on reset module (POR) generates a pulse to indicate
that power-on has occurred. The external reset pin (RST) is held low while the SIM counter counts out
4096 ICLK cycles. Sixty-four ICLK cycles later, the CPU and memories are released from reset to allow
the reset vector sequence to occur.
At power-on, the following events occur:
A POR pulse is generated.
The internal reset signal is asserted.
The SIM enables OSCOUT.
Internal clocks to the CPU and modules are held inactive for 4096 ICLK cycles to allow stabilization
of the oscillator.
•The RST
pin is driven low during the oscillator stabilization time.
The POR bit of the reset status register (RSR) is set and all other bits in the register are cleared.
IRST
RST RST PULLED LOW BY MCU
IAB
32 CYCLES 32 CYCLES
VECTOR HIGH
ICLK
ILLEGAL ADDRESS RST
ILLEGAL OPCODE RST
COPRST
POR
LVI
INTERNAL RESET
WWWW J «H J, H JJWWMW 4ww guuuu i —ss—ss—fl X X
System Integration Module (SIM)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
66 Freescale Semiconductor
Figure 5-7. POR Recovery
5.3.2.2 Computer Operating Properly (COP) Reset
An input to the SIM is reserved for the COP reset signal. The overflow of the COP counter causes an
internal reset and sets the COP bit in the reset status register (RSR). The SIM actively pulls down the
RST pin for all internal reset sources.
To prevent a COP module time-out, write any value to location $FFFF. Writing to location $FFFF clears
the COP counter and stages 12 through 5 of the SIM counter. The SIM counter output, which occurs at
least every (212 – 24) ICLK cycles, drives the COP counter. The COP should be serviced as soon as
possible out of reset to guarantee the maximum amount of time before the first time-out.
The COP module is disabled if the RST pin or the IRQ pin is held at VTST while the MCU is in monitor
mode. The COP module can be disabled only through combinational logic conditioned with the high
voltage signal on the RST or the IRQ pin. This prevents the COP from becoming disabled as a result of
external noise. During a break state, VTST on the RST pin disables the COP module.
5.3.2.3 Illegal Opcode Reset
The SIM decodes signals from the CPU to detect illegal instructions. An illegal instruction sets the ILOP
bit in the reset status register (RSR) and causes a reset.
If the stop enable bit, STOP, in the mask option register is logic zero, the SIM treats the STOP instruction
as an illegal opcode and causes an illegal opcode reset. The SIM actively pulls down the RST pin for all
internal reset sources.
5.3.2.4 Illegal Address Reset
An opcode fetch from an unmapped address generates an illegal address reset. The SIM verifies that the
CPU is fetching an opcode prior to asserting the ILAD bit in the reset status register (RSR) and resetting
the MCU. A data fetch from an unmapped address does not generate a reset. The SIM actively pulls down
the RST pin for all internal reset sources.
5.3.2.5 Low-Voltage Inhibit (LVI) Reset
The low-voltage inhibit module (LVI) asserts its output to the SIM when the VDD voltage falls to the LVI
trip voltage VTRIP. The LVI bit in the reset status register (RSR) is set, and the external reset pin (RST) is
PORRST
OSC1
ICLK
OSCOUT
RST
IAB
4096
CYCLES
32
CYCLES
32
CYCLES
$FFFE $FFFF
SIM Counter
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 67
held low while the SIM counter counts out 4096 ICLK cycles. Sixty-four ICLK cycles later, the CPU and
memories are released from reset to allow the reset vector sequence to occur. The SIM actively pulls
down the RST pin for all internal reset sources.
5.4 SIM Counter
The SIM counter is used by the power-on reset module (POR) and in stop mode recovery to allow the
oscillator time to stabilize before enabling the internal bus (IBUS) clocks. The SIM counter also serves as
a prescaler for the computer operating properly module (COP). The SIM counter uses 12 stages for
counting, followed by a 13th stage that triggers a reset of SIM counters and supplies the clock for the COP
module. The SIM counter is clocked by the falling edge of ICLK.
5.4.1 SIM Counter During Power-On Reset
The power-on reset module (POR) detects power applied to the MCU. At power-on, the POR circuit
asserts the signal PORRST. Once the SIM is initialized, it enables the oscillator to drive the bus clock
state machine.
5.4.2 SIM Counter During Stop Mode Recovery
The SIM counter also is used for stop mode recovery. The STOP instruction clears the SIM counter. After
an interrupt, break, or reset, the SIM senses the state of the short stop recovery bit, SSREC, in the mask
option register. If the SSREC bit is a logic one, then the stop recovery is reduced from the normal delay
of 4096 ICLK cycles down to 32 ICLK cycles. This is ideal for applications using canned oscillators that
do not require long start-up times from stop mode. External crystal applications should use the full stop
recovery time, that is, with SSREC cleared in the configuration register 1 (CONFIG1).
5.4.3 SIM Counter and Reset States
External reset has no effect on the SIM counter. (See 5.6.2 Stop Mode for details.) The SIM counter is
free-running after all reset states. (See 5.3.2 Active Resets from Internal Sources for counter control and
internal reset recovery sequences.)
5.5 Exception Control
Normal, sequential program execution can be changed in three different ways:
• Interrupts
Maskable hardware CPU interrupts
Non-maskable software interrupt instruction (SWI)
• Reset
Break interrupts
5.5.1 Interrupts
An interrupt temporarily changes the sequence of program execution to respond to a particular event.
Figure 5-8 flow charts the handling of system interrupts.
Interrupts are latched, and arbitration is performed in the SIM at the start of interrupt processing. The
arbitration result is a constant that the CPU uses to determine which vector to fetch. Once an interrupt is
latched by the SIM, no other interrupt can take precedence, regardless of priority, until the latched
interrupt is serviced (or the I bit is cleared).
VES
System Integration Module (SIM)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
68 Freescale Semiconductor
Figure 5-8. Interrupt Processing
NO
NO
NO
YES
NO
NO
YES
NO
YES
YES
(As many interrupts as exist on chip)
I BIT SET?
FROM RESET
BREAK INTERRUPT?
I BIT SET?
IRQ
INTERRUPT?
TIMER 1
INTERRUPT?
SWI
INSTRUCTION?
RTI
INSTRUCTION?
FETCH NEXT
INSTRUCTION
UNSTACK CPU REGISTERS.
STACK CPU REGISTERS.
SET I BIT.
LOAD PC WITH INTERRUPT VECTOR.
EXECUTE INSTRUCTION.
YES
YES
Exception Control
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 69
At the beginning of an interrupt, the CPU saves the CPU register contents on the stack and sets the
interrupt mask (I bit) to prevent additional interrupts. At the end of an interrupt, the RTI instruction recovers
the CPU register contents from the stack so that normal processing can resume. Figure 5-9 shows
interrupt entry timing.
Figure 5-10 shows interrupt recovery timing.
Figure 5-9. Interrupt Entry
Figure 5-10. Interrupt Recovery
5.5.1.1 Hardware Interrupts
A hardware interrupt does not stop the current instruction. Processing of a hardware interrupt begins after
completion of the current instruction. When the current instruction is complete, the SIM checks all pending
hardware interrupts. If interrupts are not masked (I bit clear in the condition code register), and if the
corresponding interrupt enable bit is set, the SIM proceeds with interrupt processing; otherwise, the next
instruction is fetched and executed.
If more than one interrupt is pending at the end of an instruction execution, the highest priority interrupt is
serviced first. Figure 5-11 demonstrates what happens when two interrupts are pending. If an interrupt is
pending upon exit from the original interrupt service routine, the pending interrupt is serviced before the
LDA instruction is executed.
MODULE
IDB
R/W
INTERRUPT
DUMMY SP SP – 1 SP – 2 SP – 3 SP – 4 VECT H VECT L START ADDR
IAB
DUMMY PC – 1[7:0] PC – 1[15:8] X A CCR V DATA H V DATA L OPCODE
I BIT
MODULE
IDB
R/W
INTERRUPT
SP – 4 SP – 3 SP – 2 SP – 1 SP PC PC + 1
IAB
CCR A X PC – 1[15:8] PC – 1[7:0] OPCODE OPERAND
I BIT
System Integration Module (SIM)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
70 Freescale Semiconductor
Figure 5-11. Interrupt Recognition Example
The LDA opcode is prefetched by both the INT1 and INT2 RTI instructions. However, in the case of the
INT1 RTI prefetch, this is a redundant operation.
NOTE
To maintain compatibility with the M6805 Family, the H register is not
pushed on the stack during interrupt entry. If the interrupt service routine
modifies the H register or uses the indexed addressing mode, software
should save the H register and then restore it prior to exiting the routine.
5.5.1.2 SWI Instruction
The SWI instruction is a non-maskable instruction that causes an interrupt regardless of the state of the
interrupt mask (I bit) in the condition code register.
NOTE
A software interrupt pushes PC onto the stack. A software interrupt does
not push PC – 1, as a hardware interrupt does.
5.5.2 Interrupt Status Registers
The flags in the interrupt status registers identify maskable interrupt sources. Table 5-3 summarizes the
interrupt sources and the interrupt status register flags that they set. The interrupt status registers can be
useful for debugging.
CLI
LDA
INT1
PULH
RTI
INT2
BACKGROUND ROUTINE#$FF
PSHH
INT1 INTERRUPT SERVICE ROUTINE
PULH
RTI
PSHH
INT2 INTERRUPT SERVICE ROUTINE
Exception Control
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 71
5.5.2.1 Interrupt Status Register 1
IF1, IF3 to IF6 — Interrupt Flags
These flags indicate the presence of interrupt requests from the sources shown in Table 5-3.
1 = Interrupt request present
0 = No interrupt request present
Bit 0, 1, and 3 — Always read 0
Table 5-3. Interrupt Sources
Priority Source Flag Mask (1) INT Flag Vector Address
Highest Reset $FFFE–$FFFF
SWI Instruction $FFFC–$FFFD
IRQ Pin IRQF IMASK IF1 $FFFA–$FFFB
Timer 1 Channel 0 Interrupt CH0F CH0IE IF3 $FFF6–$FFF7
Timer 1 Channel 1 Interrupt CH1F CH1IE IF4 $FFF4–$FFF5
Timer 1 Overflow Interrupt TOF TOIE IF5 $FFF2–$FFF3
Timer 2 Channel 0 Interrupt CH0F CH0IE IF6 $FFF0–$FFF1
Timer 2 Channel 1 Interrupt CH1F CH1IE IF7 $FFEE–$FFEF
Timer 2 Overflow Interrupt TOF TOIE IF8 $FFEC–$FFED
SCI Error
OR
NF
FE
PE
ORIE
NEIE
FEIE
PEIE
IF11 $FFE6–$FFE7
SCI Receive SCRF
IDLE
SCRIE
ILIE IF12 $FFE4–$FFE5
SCI Transmit SCTE
TC
SCTIE
TCIE IF13 $FFE2–$FFE3
Keyboard Interrupt KEYF IMASKK IF14 $FFE0–$FFE1
Lowest ADC Conversion Complete Interrupt COCO AIEN IF15 $FFDE–$FFDF
1. The I bit in the condition code register is a global mask for all interrupts sources except the SWI instruction.
Address: $FE04
Bit 7654321Bit 0
Read: IF6 IF5 IF4 IF3 0 IF1 0 0
Write:RRRRRRRR
Reset:00000000
R= Reserved
Figure 5-12. Interrupt Status Register 1 (INT1)
System Integration Module (SIM)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
72 Freescale Semiconductor
5.5.2.2 Interrupt Status Register 2
IF7, IF8, IF11 to F14 — Interrupt Flags
This flag indicates the presence of interrupt requests from the sources shown in Table 5-3.
1 = Interrupt request present
0 = No interrupt request present
Bit 2 and 3 — Always read 0
5.5.2.3 Interrupt Status Register 3
IF15 — Interrupt Flags
These flags indicate the presence of interrupt requests from the sources shown in Table 5-3.
1 = Interrupt request present
0 = No interrupt request present
Bit 1 to 7 — Always read 0
5.5.3 Reset
All reset sources always have equal and highest priority and cannot be arbitrated.
5.5.4 Break Interrupts
The break module can stop normal program flow at a software-programmable break point by asserting its
break interrupt output. (See Chapter 16 Break Module (BREAK).) The SIM puts the CPU into the break
state by forcing it to the SWI vector location. Refer to the break interrupt subsection of each module to
see how each module is affected by the break state.
Address: $FE05
Bit 7654321Bit 0
Read: IF14 IF13 IF12 IF11 0 0 IF8 IF7
Write:RRRRRRRR
Reset:00000000
R= Reserved
Figure 5-13. Interrupt Status Register 2 (INT2)
Address: $FE06
Bit 7654321Bit 0
Read:0000000IF15
Write:RRRRRRRR
Reset:00000000
R= Reserved
Figure 5-14. Interrupt Status Register 3 (INT3)
Low-Power Modes
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 73
5.5.5 Status Flag Protection in Break Mode
The SIM controls whether status flags contained in other modules can be cleared during break mode. The
user can select whether flags are protected from being cleared by properly initializing the break clear flag
enable bit (BCFE) in the break flag control register (BFCR).
Protecting flags in break mode ensures that set flags will not be cleared while in break mode. This
protection allows registers to be freely read and written during break mode without losing status flag
information.
Setting the BCFE bit enables the clearing mechanisms. Once cleared in break mode, a flag remains
cleared even when break mode is exited. Status flags with a two-step clearing mechanism — for example,
a read of one register followed by the read or write of another — are protected, even when the first step
is accomplished prior to entering break mode. Upon leaving break mode, execution of the second step
will clear the flag as normal.
5.6 Low-Power Modes
Executing the WAIT or STOP instruction puts the MCU in a low-power-consumption mode for standby
situations. The SIM holds the CPU in a non-clocked state. The operation of each of these modes is
described below. Both STOP and WAIT clear the interrupt mask (I) in the condition code register, allowing
interrupts to occur.
5.6.1 Wait Mode
In wait mode, the CPU clocks are inactive while the peripheral clocks continue to run. Figure 5-15 shows
the timing for wait mode entry.
A module that is active during wait mode can wake up the CPU with an interrupt if the interrupt is enabled.
Stacking for the interrupt begins one cycle after the WAIT instruction during which the interrupt occurred.
In wait mode, the CPU clocks are inactive. Refer to the wait mode subsection of each module to see if the
module is active or inactive in wait mode. Some modules can be programmed to be active in wait mode.
Wait mode can also be exited by a reset or break. A break interrupt during wait mode sets the SIM break
stop/wait bit, SBSW, in the break status register (BSR). If the COP disable bit, COPD, in the mask option
register is logic zero, then the computer operating properly module (COP) is enabled and remains active
in wait mode.
Figure 5-15. Wait Mode Entry Timing
Figure 5-16 and Figure 5-17 show the timing for WAIT recovery.
WAIT ADDR + 1 SAME SAMEIAB
IDB PREVIOUS DATA NEXT OPCODE SAME
WAIT ADDR
SAME
R/W
NOTE: Previous data can be operand data or the WAIT opcode, depending on the
last instruction.
System Integration Module (SIM)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
74 Freescale Semiconductor
Figure 5-16. Wait Recovery from Interrupt or Break
Figure 5-17. Wait Recovery from Internal Reset
5.6.2 Stop Mode
In stop mode, the SIM counter is reset and the system clocks are disabled. An interrupt request from a
module can cause an exit from stop mode. Stacking for interrupts begins after the selected stop recovery
time has elapsed. Reset or break also causes an exit from stop mode.
The SIM disables the oscillator signals (OSCOUT) in stop mode, stopping the CPU and peripherals. Stop
recovery time is selectable using the SSREC bit in the configuration register 1 (CONFIG1). If SSREC is
set, stop recovery is reduced from the normal delay of 4096 ICLK cycles down to 32. This is ideal for
applications using canned oscillators that do not require long start-up times from stop mode.
NOTE
External crystal applications should use the full stop recovery time by
clearing the SSREC bit.
A break interrupt during stop mode sets the SIM break stop/wait bit (SBSW) in the break status register
(BSR).
The SIM counter is held in reset from the execution of the STOP instruction until the beginning of stop
recovery. It is then used to time the recovery period. Figure 5-18 shows stop mode entry timing.
NOTE
To minimize stop current, all pins configured as inputs should be driven to
a logic 1 or logic 0.
$6E0C$6E0B $00FF $00FE $00FD $00FC
$A6 $A6 $01 $0B $6E$A6
IAB
IDB
EXITSTOPWAIT
NOTE: EXITSTOPWAIT = RST pin OR CPU interrupt OR break interrupt
IAB
IDB
RST
$A6 $A6
$6E0B RST VCT H RST VCT L
$A6
ICLK
32
Cycles
32
Cycles
SIM Registers
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 75
Figure 5-18. Stop Mode Entry Timing
Figure 5-19. Stop Mode Recovery from Interrupt or Break
5.7 SIM Registers
The SIM has three memory mapped registers.
Break Status Register (BSR)
Reset Status Register (RSR)
Break Flag Control Register (BFCR)
5.7.1 Break Status Register (BSR)
The break status register contains a flag to indicate that a break caused an exit from stop or wait mode.
Address: $FE00
Bit 7654321Bit 0
Read:
RRRRRR
SBSW
R
Write: Note(1)
Reset:00000000
R = Reserved 1. Writing a logic zero clears SBSW.
Figure 5-20. Break Status Register (BSR)
STOP ADDR + 1 SAME SAMEIAB
IDB PREVIOUS DATA NEXT OPCODE SAME
STOP ADDR
SAME
R/W
CPUSTOP
NOTE: Previous data can be operand data or the STOP opcode, depending on the last
instruction.
ICLK
INT/BREAK
IAB STOP + 2 STOP + 2 SP SP – 1 SP – 2 SP – 3
STOP +1
STOP RECOVERY PERIOD
System Integration Module (SIM)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
76 Freescale Semiconductor
SBSW — SIM Break Stop/Wait
This status bit is useful in applications requiring a return to wait or stop mode after exiting from a break
interrupt. Clear SBSW by writing a logic zero to it. Reset clears SBSW.
1 = Stop mode or wait mode was exited by break interrupt
0 = Stop mode or wait mode was not exited by break interrupt
SBSW can be read within the break state SWI routine. The user can modify the return address on the
stack by subtracting one from it. The following code is an example of this. Writing zero to the SBSW bit
clears it.
5.7.2 Reset Status Register (RSR)
This register contains six flags that show the source of the last reset. Clear the SIM reset status register
by reading it. A power-on reset sets the POR bit and clears all other bits in the register.
POR — Power-On Reset Bit
1 = Last reset caused by POR circuit
0 = Read of RSR
;
;
;
This code works if the H register has been pushed onto the stack in the break
service routine software. This code should be executed at the end of the
break service routine software.
HIBYTE EQU 5
LOBYTE EQU 6
; If not SBSW, do RTI
BRCLR SBSW,BSR, RETURN ;
;
See if wait mode or stop mode was exited
by break.
TST LOBYTE,SP ; If RETURNLO is not zero,
BNE DOLO ; then just decrement low byte.
DEC HIBYTE,SP ; Else deal with high byte, too.
DOLO DEC LOBYTE,SP ; Point to WAIT/STOP opcode.
RETURN PULH
RTI
; Restore H register.
Address: $FE01
Bit 7654321Bit 0
Read: POR PIN COP ILOP ILAD MODRST LVI 0
Write:
POR:10000000
= Unimplemented
Figure 5-21. Reset Status Register (RSR)
SIM Registers
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 77
PIN — External Reset Bit
1 = Last reset caused by external reset pin (RST)
0 = POR or read of RSR
COP — Computer Operating Properly Reset Bit
1 = Last reset caused by COP counter
0 = POR or read of RSR
ILOP — Illegal Opcode Reset Bit
1 = Last reset caused by an illegal opcode
0 = POR or read of RSR
ILAD — Illegal Address Reset Bit (opcode fetches only)
1 = Last reset caused by an opcode fetch from an illegal address
0 = POR or read of RSR
MODRST — Monitor Mode Entry Module Reset bit
1 = Last reset caused by monitor mode entry when vector locations $FFFE and $FFFF are $FF after
POR while IRQ = VDD
0 = POR or read of RSR
LVI — Low Voltage Inhibit Reset bit
1 = Last reset caused by LVI circuit
0 = POR or read of RSR
5.7.3 Break Flag Control Register (BFCR)
The break control register contains a bit that enables software to clear status bits while the MCU is in a
break state.
BCFE — Break Clear Flag Enable Bit
This read/write bit enables software to clear status bits by accessing status registers while the MCU is
in a break state. To clear status bits during the break state, the BCFE bit must be set.
1 = Status bits clearable during break
0 = Status bits not clearable during break
Address: $FE03
Bit 7654321Bit 0
Read:
BCFERRRRRRR
Write:
Reset: 0
R= Reserved
Figure 5-22. Break Flag Control Register (BFCR)
System Integration Module (SIM)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
78 Freescale Semiconductor
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 79
Chapter 6
Oscillator (OSC)
6.1 Introduction
The oscillator module provides the reference clocks for the MCU system and bus. Two oscillators are
running on the device:
Selectable oscillator — for bus clock
Crystal oscillator (XTAL) — built-in oscillator that requires an external crystal or ceramic-resonator.
This option also allows an external clock that can be driven directly into OSC1.
RC oscillator (RC) — built-in oscillator that requires an external resistor-capacitor connection only.
The selected oscillator is used to drive the bus clock, the SIM, and other modules on the MCU. The
oscillator type is selected by programming a bit FLASH memory. The RC and crystal oscillator cannot run
concurrently; one is disabled while the other is selected; because the RC and XTAL circuits share the
same OSC1 pin.
Non-selectable oscillator — for COP
Internal oscillator — built-in RC oscillator that requires no external components.
This internal oscillator is used to drive the computer operating properly (COP) module and the SIM. The
internal oscillator runs continuously after a POR or reset, and is always available.
6.2 Oscillator Selection
The oscillator type is selected by programming a bit in a FLASH memory location; the mask option register
(MOR), at $FFD0.
(See 3.5 Mask Option Register (MOR).)
NOTE
On the ROM device, the oscillator is selected by a ROM-mask layer at
factory.
Address: $FFD0
Bit 7654321Bit 0
Read:
OSCSELRRRRRRR
Write:
Erased:11111111
Reset: Unaffected by reset
Non-volatile FLASH register; write by programming.
R=Reserved
Figure 6-1. Mask Option Register (MOR)
fijwi
Oscillator (OSC)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
80 Freescale Semiconductor
OSCSEL — Oscillator Select Bit
OSCSEL selects the oscillator type for the MCU. The erased or unprogrammed state of this bit is
logic 1, selecting the crystal oscillator option. This bit is unaffected by reset.
1 = Crystal oscillator
0 = RC oscillator
Bits 6–0 — Should be left as logic 1’s.
NOTE
When Crystal oscillator is selected, the OSC2/RCCLK/PTA6/KBI6 pin is
used as OSC2; other functions such as PTA6/KBI6 will not be available.
6.2.1 XTAL Oscillator
The XTAL oscillator circuit is designed for use with an external crystal or ceramic resonator to provide
accurate clock source.
In its typical configuration, the XTAL oscillator is connected in a Pierce oscillator configuration, as shown
in Figure 6-2. This figure shows only the logical representation of the internal components and may not
represent actual circuitry. The oscillator configuration uses five components:
•Crystal, X
1
Fixed capacitor, C1
Tuning capacitor, C2 (can also be a fixed capacitor)
Feedback resistor, RB
Series resistor, RS (optional)
Figure 6-2. XTAL Oscillator External Connections
The series resistor (RS) is included in the diagram to follow strict Pierce oscillator guidelines and may not
be required for all ranges of operation, especially with high frequency crystals. Refer to the crystal
manufacturer’s data for more information.
C1C2
SIMOSCEN
XTALCLK
RB
X1
RS*
*RS can be zero (shorted) when used with higher-frequency crystals.
MCU
From SIM
Refer to manufacturer’s data.
OSC2OSC1
÷ 2
OSCOUT2OSCOUT
To SIMTo SIM
See Chapter 17 for component value requirements.
Internal Oscillator
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 81
6.2.2 RC Oscillator
The RC oscillator circuit is designed for use with external resistor and capacitor to provide a clock source
with tolerance less than 10%.
In its typical configuration, the RC oscillator requires two external components, one R and one C.
Component values should have a tolerance of 1% or less, to obtain a clock source with less than 10%
tolerance. The oscillator configuration uses two components:
•C
EXT
•R
EXT
Figure 6-3. RC Oscillator External Connections
6.3 Internal Oscillator
The internal oscillator clock (ICLK) is a free running 50-kHz clock that requires no external components.
It is used as the reference clock input to the computer operating properly (COP) module and the SIM.
The internal oscillator by default is always available and is free running after POR or reset. It can be
stopped in stop mode by setting the STOP_ICLKDIS bit before executing the STOP instruction.
Figure 6-4 shows the logical representation of components of the internal oscillator circuitry.
Figure 6-4. Internal Oscillator
MCU
REXT CEXT
SIMOSCEN
OSC1
EXT-RC
OSCILLATOR
EN RCCLK ÷ 2
OSCOUT2OSCOUT
To SIMFrom SIM
VDD
PTA6
I/O
0
1PTA6
PTA6EN
RCCLK/PTA6 (OSC2)
To SIM
See Chapter 17 for component value requirements.
INTERNAL
EN
SIMOSCEN
STOP_ICLKDIS
CONFIG2
ICLK
From SIM To SIM and COP
OSCILLATOR
Oscillator (OSC)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
82 Freescale Semiconductor
NOTE
The internal oscillator is a free running oscillator and is available after each
POR or reset. It is turned-off in stop mode by setting the STOP_ICLKDIS
bit in CONFIG2 (see 3.4 Configuration Register 2 (CONFIG2)).
6.4 I/O Signals
The following paragraphs describe the oscillator I/O signals.
6.4.1 Crystal Amplifier Input Pin (OSC1)
OSC1 pin is an input to the crystal oscillator amplifier or the input to the RC oscillator circuit.
6.4.2 Crystal Amplifier Output Pin (OSC2/RCCLK/PTA6/KBI6)
For the XTAL oscillator, OSC2 pin is the output of the crystal oscillator inverting amplifier.
For the RC oscillator, OSC2 pin can be configured as a general purpose I/O pin PTA6, or the output of
the RC oscillator, RCCLK.
6.4.3 Oscillator Enable Signal (SIMOSCEN)
The SIMOSCEN signal comes from the system integration module (SIM) and enables/disables the XTAL
oscillator circuit or the RC-oscillator.
6.4.4 XTAL Oscillator Clock (XTALCLK)
XTALCLK is the XTAL oscillator output signal. It runs at the full speed of the crystal (fXCLK) and comes
directly from the crystal oscillator circuit. Figure 6-2 shows only the logical relation of XTALCLK to OSC1
and OSC2 and may not represent the actual circuitry. The duty cycle of XTALCLK is unknown and may
depend on the crystal and other external factors. Also, the frequency and amplitude of XTALCLK can be
unstable at start-up.
6.4.5 RC Oscillator Clock (RCCLK)
RCCLK is the RC oscillator output signal. Its frequency is directly proportional to the time constant of the
external R and C. Figure 6-3 shows only the logical relation of RCCLK to OSC1 and may not represent
the actual circuitry.
6.4.6 Oscillator Out 2 (2OSCOUT)
2OSCOUT is same as the input clock (XTALCLK or RCCLK). This signal is driven to the SIM module.
Oscillator OSC2 pin function
XTAL Inverting OSC1
RC
Controlled by PTA6EN bit in PTAPUE ($000D)
PTA6EN = 0: RCCLK output
PTA6EN = 1: PTA6/KBI6
Low Power Modes
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 83
6.4.7 Oscillator Out (OSCOUT)
The frequency of this signal is equal to half of the 2OSCOUT, this signal is driven to the SIM for generation
of the bus clocks used by the CPU and other modules on the MCU. OSCOUT will be divided again in the
SIM and results in the internal bus frequency being one fourth of the XTALCLK or RCCLK frequency.
6.4.8 Internal Oscillator Clock (ICLK)
ICLK is the internal oscillator output signal (typically 50-kHz), for the COP module and the SIM. Its
frequency depends on the VDD voltage. (See Chapter 17 Electrical Specifications for ICLK parameters.)
6.5 Low Power Modes
The WAIT and STOP instructions put the MCU in low-power consumption standby modes.
6.5.1 Wait Mode
The WAIT instruction has no effect on the oscillator logic. OSCOUT, 2OSCOUT, and ICLK continues to
drive to the SIM module.
6.5.2 Stop Mode
The STOP instruction disables the XTALCLK or the RCCLK output, hence, OSCOUT and 2OSCOUT are
disabled.
The STOP instruction also turns off the ICLK input to the COP module if the STOP_ICLKDIS bit is set in
configuration register 2 (CONFIG2). After reset, the STOP_ICLKDIS bit is clear by default and ICLK is
enabled during stop mode.
6.6 Oscillator During Break Mode
The OSCOUT, 2OSCOUT, and ICLK clocks continue to be driven out when the device enters the break
state.
Oscillator (OSC)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
84 Freescale Semiconductor
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 85
Chapter 7
Monitor ROM (MON)
7.1 Introduction
This section describes the monitor ROM (MON) and the monitor mode entry methods. The monitor ROM
allows complete testing of the MCU through a single-wire interface with a host computer. This mode is
also used for programming and erasing of FLASH memory in the MCU. Monitor mode entry can be
achieved without use of the higher test voltage, VTST, as long as vector addresses $FFFE and $FFFF are
blank, thus reducing the hardware requirements for in-circuit programming.
7.2 Features
Features of the monitor ROM include the following:
Normal user-mode pin functionality
One pin dedicated to serial communication between monitor ROM and host computer
Standard mark/space non-return-to-zero (NRZ) communication with host computer
Execution of code in RAM or FLASH
FLASH memory security feature(1)
FLASH memory programming interface
959 bytes monitor ROM code size
Monitor mode entry without high voltage, VTST, if reset vector is blank ($FFFE and $FFFF contain
$FF)
Standard monitor mode entry if high voltage, VTST, is applied to IRQ
Resident routines for FLASH programming and EEPROM emulation
7.3 Functional Description
The monitor ROM receives and executes commands from a host computer. Figure 7-1 shows a example
circuit used to enter monitor mode and communicate with a host computer via a standard RS-232
interface.
Simple monitor commands can access any memory address. In monitor mode, the MCU can execute
host-computer code in RAM while most MCU pins retain normal operating mode functions. All
communication between the host computer and the MCU is through the PTB0 pin. A level-shifting and
multiplexing interface is required between PTB0 and the host computer. PTB0 is used in a wired-OR
configuration and requires a pull-up resistor.
1. No security feature is absolutely secure. However, Motorola’s strategy is to make reading or copying the FLASH difficult for
unauthorized users.
r;
Monitor ROM (MON)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
86 Freescale Semiconductor
Figure 7-1. Monitor Mode Circuit
NOTES:
1. Monitor mode entry method:
SW1: Position A — High voltage entry (VTST)
Bus clock depends on SW2.
SW1: Position B — Reset vector must be blank ($FFFE = $FFFF = $FF)
Bus clock = OSC1 ÷ 4.
2. Affects high voltage entry to monitor mode only (SW1 at position A):
SW2: Position C — Bus clock = OSC1 ÷ 4
SW2: Position D — Bus clock = OSC1 ÷ 2
5. See Table 17-4 for VTST voltage level requirements.
10M
HC908JL8
RST
IRQ
OSC1
OSC2
VSS
PTB0
20 pF
20 pF
0.1 µF
9.8304MHz
PTB1
VDD
0.1 µF
VDD
PTB2
VDD
10 k
PTB3
VDD
10 k
10 k
SW2
C
D
VDD
(SEE NOTE 2)
A
B
XTAL CIRCUIT
16
15
2
6
VDD
MAX232
V+
V–
VDD
10 k
C1+
C1–
5
4C2+
C2–
+
3
1
1 µF++
+
8
7
DB9
2
3
5
10
9
+
1
234
5
6
74HC125
74HC125
1 k
VTST
VCC
GND
1 µF
1 µF
1 µF
1 µF
8.5 V VDD
10 k
10 k
EXT OSC (50% DUTY)
EXT OSC CONNECTION TO OSC1, WITH OSC2
UNCONNECTED, CAN REPLACE XTAL CIRCUIT.
OSC1
(SEE NOTE 1)
SW1
Functional Description
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 87
7.3.1 Entering Monitor Mode
Table 7-1 shows the pin conditions for entering monitor mode. As specified in the table, monitor mode
may be entered after a POR.
Communication at 9600 baud will be established provided one of the following sets of conditions is met:
1. If IRQ = VTST:
Clock on OSC1 is 4.9125MHz
–PTB3 = low
2. If IRQ = VTST:
Clock on OSC1 is 9.8304MHz
PTB3 = high
3. If $FFFE and $FFFF are blank (contain $FF):
Clock on OSC1 is 9.8304MHz
–IRQ
= VDD
If VTST is applied to IRQ and PTB3 is low upon monitor mode entry (Table 7-1 condition set 1), the bus
frequency is a divide-by-two of the clock input to OSC1. If PTB3 is high with VTST applied to IRQ upon
monitor mode entry (Table 7-1 condition set 2), the bus frequency is a divide-by-four of the clock input to
OSC1. Holding the PTB3 pin low when entering monitor mode causes a bypass of a divide-by-two stage
at the oscillator only if VTST is applied to IRQ. In this event, the OSCOUT frequency is equal to the
2OSCOUT frequency, and OSC1 input directly generates internal bus clocks. In this case, the OSC1
signal must have a 50% duty cycle at maximum bus frequency.
Entering monitor mode with VTST on IRQ, the COP is disabled as long as VTST is applied to either IRQ or
RST. (See Chapter 5 System Integration Module (SIM) for more information on modes of operation.)
If entering monitor mode without high voltage on IRQ and reset vector being blank ($FFFE and $FFFF)
(Table 7-1 condition set 3, where applied voltage is VDD), then all port B pin requirements and conditions,
Table 7-1. Monitor Mode Entry Requirements and Options
IRQ
$FFFE
and
$FFFF
PTB3
PTB2
PTB1
PTB0
OSC1 Clock(1)
1. RC oscillator cannot be used for monitor mode; must use either external oscillator or XTAL oscillator circuit.
Bus Frequency Comments
VTST(2)
2. See Table 17-4 for VTST voltage level requirements.
X 0011 4.9152MHz 2.4576MHz High voltage entry to monitor
mode.
9600 baud communication on
PTB0. COP disabled.
VTST(1) X 1011 9.8304MHz 2.4576MHz
VDD
BLANK
(contain
$FF)
X X X 1 9.8304MHz 2.4576MHz
Blank reset vector
(low-voltage) entry to monitor
mode.
9600 baud communication on
PTB0. COP disabled.
VDD
NOT
BLANK XXXX X OSC1 ÷ 4 Enters User mode.
Monitor ROM (MON)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
88 Freescale Semiconductor
including the PTB3 frequency divisor selection, are not in effect. This is to reduce circuit requirements
when performing in-circuit programming.
Entering monitor mode with the reset vector being blank, the COP is always disabled regardless of the
state of IRQ or the RST.
Figure 7-2. shows a simplified diagram of the monitor mode entry when the reset vector is blank and IRQ
= VDD. An OSC1 frequency of 9.8304MHz is required for a baud rate of 9600.
Figure 7-2. Low-Voltage Monitor Mode Entry Flowchart
Enter monitor mode with the pin configuration shown above by pulling RST low and then high. The rising
edge of RST latches monitor mode. Once monitor mode is latched, the values on the specified pins can
change.
Once out of reset, the MCU waits for the host to send eight security bytes. (See 7.4 Security.) After the
security bytes, the MCU sends a break signal (10 consecutive logic zeros) to the host, indicating that it is
ready to receive a command. The break signal also provides a timing reference to allow the host to
determine the necessary baud rate.
In monitor mode, the MCU uses different vectors for reset, SWI, and break interrupt. The alternate vectors
are in the $FE page instead of the $FF page and allow code execution from the internal monitor firmware
instead of user code.
Table 7-2 is a summary of the vector differences between user mode and monitor mode.
IS VECTOR
BLANK?
POR
TRIGGERED?
NORMAL USER
MODE
MONITOR MODE
EXECUTE
MONITOR
CODE
NO
NO
YES
YES
POR RESET
Functional Description
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 89
When the host computer has completed downloading code into the MCU RAM, the host then sends a
RUN command, which executes an RTI, which sends control to the address on the stack pointer.
7.3.2 Baud Rate
The communication baud rate is dependant on oscillator frequency. The state of PTB3 also affects baud
rate if entry to monitor mode is by IRQ =V
TST. When PTB3 is high, the divide by ratio is 1024. If the PTB3
pin is at logic zero upon entry into monitor mode, the divide by ratio is 512.
7.3.3 Data Format
Communication with the monitor ROM is in standard non-return-to-zero (NRZ) mark/space data format.
(See Figure 7-3 and Figure 7-4.)
Figure 7-3. Monitor Data Format
Figure 7-4. Sample Monitor Waveforms
Table 7-2. Monitor Mode Vector Differences
Modes
Functions
COP
Reset
Vector
High
Reset
Vector
Low
Break
Vector
High
Break
Vector
Low
SWI
Vector
High
SWI
Vector
Low
User Enabled $FFFE $FFFF $FFFC $FFFD $FFFC $FFFD
Monitor Disabled(1) $FEFE $FEFF $FEFC $FEFD $FEFC $FEFD
Notes:
1. If the high voltage (VTST) is removed from the IRQ pin or the RST pin, the SIM asserts
its COP enable output. The COP is a mask option enabled or disabled by the COPD bit
in the configuration register.
Table 7-3. Monitor Baud Rate Selection
Monitor Mode
Entry By:
OSC1 Clock
Frequency PTB3 Baud Rate
IRQ = VTST
4.9152 MHz 0 9600 bps
9.8304 MHz 1 9600 bps
4.9152 MHz 1 4800 bps
Blank reset vector,
IRQ = VDD
9.8304 MHz X 9600 bps
4.9152 MHz X 4800 bps
BIT 5
START
BIT BIT 0 BIT 1
NEXT
STOP
BIT
START
BIT
BIT 2 BIT 3 BIT 4 BIT 6 BIT 7
BIT 5
START
BIT BIT 0 BIT 1
NEXT
STOP
BIT
START
BIT
BIT 2 BIT 3 BIT 4 BIT 6 BIT 7
START
BIT BIT 0 BIT 1 NEXT
STOP
BIT START
BIT
BIT 2
$A5
BREAK BIT 3 BIT 4 BIT 5 BIT 6 BIT 7
ߢ W
Monitor ROM (MON)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
90 Freescale Semiconductor
The data transmit and receive rate can be anywhere from 4800 baud to 28.8k-baud. Transmit and receive
baud rates must be identical.
7.3.4 Echoing
As shown in Figure 7-5, the monitor ROM immediately echoes each received byte back to the PTB0 pin
for error checking.
Figure 7-5. Read Transaction
Any result of a command appears after the echo of the last byte of the command.
7.3.5 Break Signal
A start bit followed by nine low bits is a break signal. (See Figure 7-6.) When the monitor receives a break
signal, it drives the PTB0 pin high for the duration of two bits before echoing the break signal.
Figure 7-6. Break Transaction
7.3.6 Commands
The monitor ROM uses the following commands:
READ (read memory)
WRITE (write memory)
IREAD (indexed read)
IWRITE (indexed write)
READSP (read stack pointer)
RUN (run user program)
ADDR. HIGHREADREAD ADDR. HIGH ADDR. LOW ADDR. LOW DATA
ECHO
SENT TO
MONITOR
RESULT
01234567 01234567
MISSING STOP BIT
TWO-STOP-BIT DELAY BEFORE ZERO ECHO
Functional Description
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 91
Table 7-4. READ (Read Memory) Command
Description Read byte from memory
Operand Specifies 2-byte address in high byte:low byte order
Data Returned Returns contents of specified address
Opcode $4A
Command Sequence
Table 7-5. WRITE (Write Memory) Command
Description Write byte to memory
Operand Specifies 2-byte address in high byte:low byte order; low byte followed by data byte
Data Returned None
Opcode $49
Command Sequence
ADDR. HIGHREADREAD ADDR. HIGH ADDR. LOW ADDR. LOW DATA
ECHO
SENT TO
MONITOR
RESULT
ADDR. HIGHWRITEWRITE ADDR. HIGH ADDR. LOW ADDR. LOW DATA
ECHO
SENT TO
MONITOR
DATA
Monitor ROM (MON)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
92 Freescale Semiconductor
NOTE
A sequence of IREAD or IWRITE commands can sequentially access a
block of memory over the full 64-Kbyte memory map.
Table 7-6. IREAD (Indexed Read) Command
Description Read next 2 bytes in memory from last address accessed
Operand Specifies 2-byte address in high byte:low byte order
Data Returned Returns contents of next two addresses
Opcode $1A
Command Sequence
Table 7-7. IWRITE (Indexed Write) Command
Description Write to last address accessed + 1
Operand Specifies single data byte
Data Returned None
Opcode $19
Command Sequence
DATAIREADIREAD DATA
ECHO
SENT TO
MONITOR
RESULT
DATAIWRITEIWRITE DATA
ECHO
SENT TO
MONITOR
Security
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 93
7.4 Security
A security feature discourages unauthorized reading of FLASH locations while in monitor mode. The host
can bypass the security feature at monitor mode entry by sending eight security bytes that match the
bytes at locations $FFF6–$FFFD. Locations $FFF6–$FFFD contain user-defined data.
NOTE
Do not leave locations $FFF6–$FFFD blank. For security reasons, program
locations $FFF6–$FFFD even if they are not used for vectors.
During monitor mode entry, the MCU waits after the power-on reset for the host to send the eight security
bytes on pin PTB0. If the received bytes match those at locations $FFF6–$FFFD, the host bypasses the
security feature and can read all FLASH locations and execute code from FLASH. Security remains
bypassed until a power-on reset occurs. If the reset was not a power-on reset, security remains bypassed
and security code entry is not required. (See Figure 7-7.)
Table 7-8. READSP (Read Stack Pointer) Command
Description Reads stack pointer
Operand None
Data Returned Returns stack pointer in high byte:low byte order
Opcode $0C
Command Sequence
Table 7-9. RUN (Run User Program) Command
Description Executes RTI instruction
Operand None
Data Returned None
Opcode $28
Command Sequence
SP HIGHREADSPREADSP SP LOW
ECHO
SENT TO
MONITOR
RESULT
RUNRUN
ECHO
SENT TO
MONITOR
Monitor ROM (MON)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
94 Freescale Semiconductor
Figure 7-7. Monitor Mode Entry Timing
Upon power-on reset, if the received bytes of the security code do not match the data at locations
$FFF6–$FFFD, the host fails to bypass the security feature. The MCU remains in monitor mode, but
reading a FLASH location returns an invalid value and trying to execute code from FLASH causes an
illegal address reset. After receiving the eight security bytes from the host, the MCU transmits a break
character, signifying that it is ready to receive a command.
NOTE
The MCU does not transmit a break character until after the host sends the
eight security bytes.
To determine whether the security code entered is correct, check to see if bit 6 of RAM address $60 is
set. If it is, then the correct security code has been entered and FLASH can be accessed.
If the security sequence fails, the device should be reset by a power-on reset and brought up in monitor
mode to attempt another entry. After failing the security sequence, the FLASH module can also be mass
erased by executing an erase routine that was downloaded into internal RAM. The mass erase operation
clears the security code locations so that all eight security bytes become $FF (blank).
7.5 ROM-Resident Routines
Eight routines stored in the monitor ROM area (thus ROM-resident) are provided for FLASH memory
manipulation. Six of the eight routines are intended to simplify FLASH program, erase, and load
operations. The other two routines are intended to simplify the use of the FLASH memory as EEPROM.
Table 7-10 shows a summary of the ROM-resident routines.
BYTE 1
BYTE 1 ECHO
BYTE 2
BYTE 2 ECHO
BYTE 8
BYTE 8 ECHO
COMMAND
COMMAND ECHO
PTB0
RST
VDD
4096 + 32 ICLK CYCLES
24 BUS CYCLES
141 12 1
BREAK
NOTES:
2 = Data return delay, 2 bit times
4 = Wait 1 bit time before sending next byte.
4
FROM HOST
FROM MCU
1 = Echo delay, 2 bit times
ROM-Resident Routines
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 95
The routines are designed to be called as stand-alone subroutines in the user program or monitor mode.
The parameters that are passed to a routine are in the form of a contiguous data block, stored in RAM.
The index register (H:X) is loaded with the address of the first byte of the data block (acting as a pointer),
and the subroutine is called (JSR). Using the start address as a pointer, multiple data blocks can be used,
any area of RAM be used. A data block has the control and data bytes in a defined order, as shown in
Figure 7-8.
During the software execution, it does not consume any dedicated RAM location, the run-time heap will
extend the system stack, all other RAM location will not be affected.
Figure 7-8. Data Block Format for ROM-Resident Routines
Table 7-10. Summary of ROM-Resident Routines
Routine Name Routine Description Call Address Stack Used(1)
(bytes)
PRGRNGE Program a range of locations $FC06 15
ERARNGE Erase a page or the entire array $FCBE 9
LDRNGE Loads data from a range of locations $FF30 9
MON_PRGRNGE Program a range of locations in monitor
mode $FF28 17
MON_ERARNGE Erase a page or the entire array in monitor
mode $FF2C 11
MON_LDRNGE Loads data from a range of locations in
monitor mode $FF24 11
EE_WRITE Emulated EEPROM write. Data size ranges
from 2 to 15 bytes at a time. $FD3F 24
EE_READ Emulated EEPROM read. Data size ranges
from 2 to 15 bytes at a time. $FDD0 16
1. The listed stack size excludes the 2 bytes used by the calling instruction, JSR.
DATA SIZE (DATASIZE)
START ADDRESS HIGH (ADDRH)
START ADDRESS LOW (ADDRL)
DATA 0
DATA 1
BUS SPEED (BUS_SPD)
FILE_PTR
DATA N
DATA
ARRAY
$XXXX
DATA
BLOCK
ADDRESS AS POINTER
RAM
Monitor ROM (MON)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
96 Freescale Semiconductor
The control and data bytes are described below.
Bus speed — This one byte indicates the operating bus speed of the MCU. The value of this byte
should be equal to 4 times the bus speed, and should not be set to less than 4 (i.e. minimum bus
speed is 1MHz).
Data size — This one byte indicates the number of bytes in the data array that are to be
manipulated. The maximum data array size is 128. Routines EE_WRITE and EE_READ are
restricted to manipulate a data array between 2 to 15 bytes. Whereas routines ERARNGE and
MON_ERARNGE do not manipulate a data array, thus, this data size byte has no meaning.
Start address — These two bytes, high byte followed by low byte, indicate the start address of the
FLASH memory to be manipulated.
Data array — This data array contains data that are to be manipulated. Data in this array are
programmed to FLASH memory by the programming routines: PRGRNGE, MON_PRGRNGE,
EE_WRITE. For the read routines: LDRNGE, MON_LDRNGE, and EE_READ, data is read from
FLASH and stored in this array.
7.5.1 PRGRNGE
PRGRNGE is used to program a range of FLASH locations with data loaded into the data array.
The start location of the FLASH to be programmed is specified by the address ADDRH:ADDRL and the
number of bytes from this location is specified by DATASIZE. The maximum number of bytes that can be
programmed in one routine call is 128 bytes (max. DATASIZE is 128).
ADDRH:ADDRL do not need to be at a page boundary, the routine handles any boundary misalignment
during programming. A check to see that all bytes in the specified range are erased is not performed by
this routine prior programming. Nor does this routine do a verification after programming, so there is no
return confirmation that programming was successful. User must assure that the range specified is first
erased.
The coding example below is to program 32 bytes of data starting at FLASH location $EF00, with a bus
speed of 4.9152 MHz. The coding assumes the data block is already loaded in RAM, with the address
pointer, FILE_PTR, pointing to the first byte of the data block.
Table 7-11. PRGRNGE Routine
Routine Name PRGRNGE
Routine Description Program a range of locations
Calling Address $FC06
Stack Used 15 bytes
Data Block Format Bus speed (BUS_SPD)
Data size (DATASIZE)
Start address high (ADDRH)
Start address (ADDRL)
Data 1 (DATA1)
:
Data N (DATAN)
ROM-Resident Routines
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 97
ORG RAM
:
FILE_PTR:
BUS_SPD DS.B 1; Indicates 4x bus frequency
DATASIZE DS.B 1; Data size to be programmed
START_ADDR DS.W 1; FLASH start address
DATAARRAY DS.B 32; Reserved data array
PRGRNGE EQU $FC06
FLASH_START EQU $EF00
ORG FLASH
INITIALISATION:
MOV #20, BUS_SPD
MOV #32, DATASIZE
LDHX #FLASH_START
STHX START_ADDR
RTS
MAIN:
BSR INITIALISATION
:
:
LDHX #FILE_PTR
JSR PRGRNGE
7.5.2 ERARNGE
ERARNGE is used to erase a range of locations in FLASH.
There are two sizes of erase ranges: a page or the entire array. The ERARNGE will erase the page (64
consecutive bytes) in FLASH specified by the address ADDRH:ADDRL. This address can be any address
within the page. Calling ERARNGE with ADDRH:ADDRL equal to $FFFF will erase the entire FLASH
array (mass erase). Therefore, care must be taken when calling this routine to prevent an accidental mass
erase. To avoid undesirable routine return addresses after a mass erase, the ERARNGE routine should
not be called from code executed from FLASH memory. Load the code into an area of RAM before calling
the ERARNGE routine.
The ERARNGE routine do not use a data array. The DATASIZE byte is a dummy byte that is also not
used.
Table 7-12. ERARNGE Routine
Routine Name ERARNGE
Routine Description Erase a page or the entire array
Calling Address $FCBE
Stack Used 9 bytes
Data Block Format Bus speed (BUS_SPD)
Data size (DATASIZE)
Starting address (ADDRH)
Starting address (ADDRL)
Monitor ROM (MON)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
98 Freescale Semiconductor
The coding example below is to perform a page erase, from $EF00–$EF3F. The Initialization subroutine
is the same as the coding example for PRGRNGE (see 7.5.1 PRGRNGE).
ERARNGE EQU $FCBE
MAIN:
BSR INITIALISATION
:
:
LDHX #FILE_PTR
JSR ERARNGE
:
7.5.3 LDRNGE
LDRNGE is used to load the data array in RAM with data from a range of FLASH locations.
The start location of FLASH from where data is retrieved is specified by the address ADDRH:ADDRL and
the number of bytes from this location is specified by DATASIZE. The maximum number of bytes that can
be retrieved in one routine call is 128 bytes. The data retrieved from FLASH is loaded into the data array
in RAM. Previous data in the data array will be overwritten. User can use this routine to retrieve data from
FLASH that was previously programmed.
The coding example below is to retrieve 32 bytes of data starting from $EF00 in FLASH. The Initialization
subroutine is the same as the coding example for PRGRNGE (see 7.5.1 PRGRNGE).
LDRNGE EQU $FF30
MAIN:
BSR INITIALIZATION
:
:
LDHX #FILE_PTR
JSR LDRNGE
:
Table 7-13. LDRNGE Routine
Routine Name LDRNGE
Routine Description Loads data from a range of locations
Calling Address $FF30
Stack Used 9 bytes
Data Block Format Bus speed (BUS_SPD)
Data size (DATASIZE)
Starting address (ADDRH)
Starting address (ADDRL)
Data 1
:
Data N
ROM-Resident Routines
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 99
7.5.4 MON_PRGRNGE
In monitor mode, MON_PRGRNGE is used to program a range of FLASH locations with data loaded into
the data array.
The MON_PRGRNGE routine is designed to be used in monitor mode. It performs the same function as
the PRGRNGE routine (see 7.5.1 PRGRNGE), except that MON_PRGRNGE returns to the main program
via an SWI instruction. After a MON_PRGRNGE call, the SWI instruction will return the control back to
the monitor code.
7.5.5 MON_ERARNGE
In monitor mode, ERARNGE is used to erase a range of locations in FLASH.
The MON_ERARNGE routine is designed to be used in monitor mode. It performs the same function as
the ERARNGE routine (see 7.5.2 ERARNGE), except that MON_ERARNGE returns to the main program
via an SWI instruction. After a MON_ERARNGE call, the SWI instruction will return the control back to the
monitor code.
Table 7-14. MON_PRGRNGE Routine
Routine Name MON_PRGRNGE
Routine Description Program a range of locations, in monitor mode
Calling Address $FC28
Stack Used 17 bytes
Data Block Format Bus speed
Data size
Starting address (high byte)
Starting address (low byte)
Data 1
:
Data N
Table 7-15. MON_ERARNGE Routine
Routine Name MON_ERARNGE
Routine Description Erase a page or the entire array, in monitor mode
Calling Address $FF2C
Stack Used 11 bytes
Data Block Format Bus speed
Data size
Starting address (high byte)
Starting address (low byte)
Monitor ROM (MON)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
100 Freescale Semiconductor
7.5.6 MON_LDRNGE
In monitor mode, LDRNGE is used to load the data array in RAM with data from a range of FLASH
locations.
The MON_LDRNGE routine is designed to be used in monitor mode. It performs the same function as the
LDRNGE routine (see 7.5.3 LDRNGE), except that MON_LDRNGE returns to the main program via an
SWI instruction. After a MON_LDRNGE call, the SWI instruction will return the control back to the monitor
code.
7.5.7 EE_WRITE
EE_WRITE is used to write a set of data from the data array to FLASH.
The start location of the FLASH to be programmed is specified by the address ADDRH:ADDRL and the
number of bytes in the data array is specified by DATASIZE. The minimum number of bytes that can be
Table 7-16. ICP_LDRNGE Routine
Routine Name MON_LDRNGE
Routine Description Loads data from a range of locations, in monitor mode
Calling Address $FF24
Stack Used 11 bytes
Data Block Format Bus speed
Data size
Starting address (high byte)
Starting address (low byte)
Data 1
:
Data N
Table 7-17. EE_WRITE Routine
Routine Name EE_WRITE
Routine Description Emulated EEPROM write. Data size ranges from 2 to 15 bytes at
a time.
Calling Address $FD3F
Stack Used 24 bytes
Data Block Format Bus speed (BUS_SPD)
Data size (DATASIZE)(1)
Starting address (ADDRH)(2)
Starting address (ADDRL)(1)
Data 1
:
Data N
1. The minimum data size is 2 bytes. The maximum data size is 15 bytes.
2. The start address must be a page boundary start address: $xx00, $xx40, $xx80, or $00C0.
f”””””1
ROM-Resident Routines
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 101
programmed in one routine call is 2 bytes, the maximum is 15 bytes. ADDRH:ADDRL must always be the
start of boundary address (the page start address: $XX00, $XX40, $XX80, or $00C0) and DATASIZE
must be the same size when accessing the same page.
In some applications, the user may want to repeatedly store and read a set of data from an area of
non-volatile memory. This is easily possible when using an EEPROM array. As the write and erase
operations can be executed on a byte basis. For FLASH memory, the minimum erase size is the page —
64 bytes per page for MC68HC908JL8. If the data array size is less than the page size, writing and erasing
to the same page cannot fully utilize the page. Unused locations in the page will be wasted. The
EE_WRITE routine is designed to emulate the properties similar to the EEPROM. Allowing a more
efficient use of the FLASH page for data storage.
When the user dedicates a page of FLASH for data storage, and the size of the data array defined, each
call of the EE_WRTIE routine will automatically transfer the data in the data array (in RAM) to the next
blank block of locations in the FLASH page. Once a page is filled up, the EE_WRITE routine automatically
erases the page, and starts to reuse the page again. In the 64-byte page, an 4-byte control block is used
by the routine to monitor the utilization of the page. In effect, only 60 bytes are used for data storage. (see
Figure 7-9). The page control operations are transparent to the user.
Figure 7-9. EE_WRITE FLASH Memory Usage
When using this routine to store a 3-byte data array, the FLASH page can be programmed 20 times before
the an erase is required. In effect, the write/erase endurance is increased by 20 times. When a 15-byte
data array is used, the write/erase endurance is increased by 5 times. Due to the FLASH page size
limitation, the data array is limited from 2 bytes to 15 bytes.
The coding example below uses the $EF00–$EE3F page for data storage. The data array size is 15 bytes,
and the bus speed is 4.9152 MHz. The coding assumes the data block is already loaded in RAM, with the
address pointer, FILE_PTR, pointing to the first byte of the data block.
PAGE BOUNDARY
CONTROL: 8 BYTES
DATA ARRAY
DATA ARRAY
DATA ARRAY
$XX00, $XX40, $XX80, OR $XXC0
PAGE BOUNDARY
ONE PAGE = 64 BYTES
FLASH
Monitor ROM (MON)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
102 Freescale Semiconductor
ORG RAM
:
FILE_PTR:
BUS_SPD DS.B 1; Indicates 4x bus frequency
DATASIZE DS.B 1; Data size to be programmed
START_ADDR DS.W 1; FLASH starting address
DATAARRAY DS.B 15; Reserved data array
EE_WRITE EQU $FD3F
FLASH_START EQU $EF00
ORG FLASH
INITIALISATION:
MOV #20, BUS_SPD
MOV #15, DATASIZE
LDHX #FLASH_START
STHX START_ADDR
RTS
MAIN:
BSR INITIALISATION
:
:
LHDX #FILE_PTR
JSR EE_WRITE
NOTE
The EE_WRITE routine is unable to check for incorrect data blocks, such
as the FLASH page boundary address and data size. It is the responsibility
of the user to ensure the starting address indicated in the data block is at
the FLASH page boundary and the data size is 2 to 15. If the FLASH page
is already programmed with a data array with a different size, the
EE_WRITE call will be ignored.
ROM-Resident Routines
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Freescale Semiconductor 103
7.5.8 EE_READ
EE_READ is used to load the data array in RAM with a set of data from FLASH.
The EE_READ routine reads data stored by the EE_WRITE routine. An EE_READ call will retrieve the
last data written to a FLASH page and loaded into the data array in RAM. Same as EE_WRITE, the data
size indicated by DATASIZE is 2 to 15, and the start address ADDRH:ADDRL must the FLASH page
boundary address.
The coding example below uses the data stored by the EE_WRITE coding example (see 7.5.7
EE_WRITE). It loads the 15-byte data set stored in the $EF00–$EE7F page to the data array in RAM. The
initialization subroutine is the same as the coding example for EE_WRITE (see 7.5.7 EE_WRITE).
EE_READ EQU $FDD0
MAIN:
BSR INITIALIZATION
:
:
LDHX FILE_PTR
JSR EE_READ
:
NOTE
The EE_READ routine is unable to check for incorrect data blocks, such as
the FLASH page boundary address and data size. It is the responsibility of
the user to ensure the starting address indicated in the data block is at the
FLASH page boundary and the data size is 2 to 15. If the FLASH page is
programmed with a data array with a different size, the EE_READ call will
be ignored.
Table 7-18. EE_READ Routine
Routine Name EE_READ
Routine Description Emulated EEPROM read. Data size ranges from 2 to 15 bytes at
a time.
Calling Address $FDD0
Stack Used 16 bytes
Data Block Format Bus speed (BUS_SPD)
Data size (DATASIZE)
Starting address (ADDRH)(1)
Starting address (ADDRL)(1)
Data 1
:
Data N
1. The start address must be a page boundary start address: $xx00, $xx40, $xx80, or $00C0.
Monitor ROM (MON)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
104 Freescale Semiconductor
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 105
Chapter 8
Timer Interface Module (TIM)
8.1 Introduction
This section describes the timer interface (TIM) module. The TIM is a two-channel timer that provides a
timing reference with Input capture, output compare, and pulse-width-modulation functions. Figure 8-1 is
a block diagram of the TIM.
This particular MCU has two timer interface modules which are denoted as TIM1 and TIM2.
8.2 Features
Features of the TIM include:
Two input capture/output compare channels:
Rising-edge, falling-edge, or any-edge input capture trigger
Set, clear, or toggle output compare action
Buffered and unbuffered pulse-width-modulation (PWM) signal generation
Programmable TIM clock input
7-frequency internal bus clock prescaler selection
External clock input on timer 2 (bus frequency ÷2 maximum)
Free-running or modulo up-count operation
Toggle any channel pin on overflow
TIM counter stop and reset bits
8.3 Pin Name Conventions
The text that follows describes both timers, TIM1 and TIM2. The TIM input/output (I/O) pin names are
T[1,2]CH0 (timer channel 0) and T[1,2]CH1 (timer channel 1), where “1” is used to indicate TIM1 and “2”
is used to indicate TIM2. The two TIMs share four I/O pins with four I/O port pins. The external clock input
for TIM2 is shared with the an ADC channel pin. The full names of the TIM I/O pins are listed in Table 8-1.
The generic pin names appear in the text that follows.
NOTE
References to either timer 1 or timer 2 may be made in the following text by
omitting the timer number. For example, TCH0 may refer generically to
T1CH0 and T2CH0, and TCH1 may refer to T1CH1 and T2CH1.
Table 8-1. Pin Name Conventions
TIM Generic Pin Names: T[1,2]CH0 T[1,2]CH1 T2CLK
Full TIM
Pin Names:
TIM1 PTD4/T1CH0 PTD5/T1CH1
TIM2 PTE0/T2CH0 PTE1/T2CH1 ADC12/T2CLK
Timer Interface Module (TIM)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
106 Freescale Semiconductor
8.4 Functional Description
Figure 8-1 shows the structure of the TIM. The central component of the TIM is the 16-bit TIM counter
that can operate as a free-running counter or a modulo up-counter. The TIM counter provides the timing
reference for the input capture and output compare functions. The TIM counter modulo registers,
TMODH:TMODL, control the modulo value of the TIM counter. Software can read the TIM counter value
at any time without affecting the counting sequence.
The two TIM channels (per timer) are programmable independently as input capture or output compare
channels.
Figure 8-1. TIM Block Diagram
Figure 8-2 summarizes the timer registers.
NOTE
References to either timer 1 or timer 2 may be made in the following text by
omitting the timer number. For example, TSC may generically refer to both
T1SC and T2SC.
PRESCALER
PRESCALER SELECT
INTERNAL
16-BIT COMPARATOR
PS2 PS1 PS0
16-BIT COMPARATOR
16-BIT LATCH
TCH0H:TCH0L
TOF
TOIE
16-BIT COMPARATOR
16-BIT LATCH
TCH1H:TCH1L
CHANNEL 0
CHANNEL 1
TMODH:TMODL
TRST
TSTOP
TOV0
CH0IE
CH0F
TOV1
CH1IE
CH1MAX
CH1F
CH0MAX
MS0B
16-BIT COUNTER
INTERNAL BUS
BUS CLOCK
T[1,2]CH0
INTERRUPT
LOGIC
PORT
LOGIC
INTERRUPT
LOGIC
INTERRUPT
LOGIC
PORT
LOGIC
T2CLK
CH01IE
ELS0B ELS0A
MS0A
ELS0B ELS0A
MS0A
T[1,2]CH1
(FOR TIM2 ONLY)
Functional Description
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 107
Addr.Register Name Bit 7654321Bit 0
$0020
TIM1 Status and Control
Register
(T1SC)
Read: TOF TOIE TSTOP 00
PS2 PS1 PS0
Write: 0 TRST
Reset:00100000
$0021
TIM1 Counter Register
High
(T1CNTH)
Read: Bit 15 14 13 12 11 10 9 Bit 8
Write:
Reset:00000000
$0022
TIM1 Counter Register
Low
(T1CNTL)
Read:Bit 7654321Bit 0
Write:
Reset:00000000
$0023
TIM Counter Modulo
Register High
(TMODH)
Read: Bit 15 14 13 12 11 10 9 Bit 8
Write:
Reset:11111111
$0024
TIM1 Counter Modulo
Register Low
(T1MODL)
Read: Bit 7654321Bit 0
Write:
Reset:11111111
$0025
TIM1 Channel 0 Status
and Control Register
(T1SC0)
Read: CH0F CH0IE MS0B MS0A ELS0B ELS0A TOV0 CH0MAX
Write: 0
Reset:00000000
$0026
TIM1 Channel 0
Register High
(T1CH0H)
Read: Bit 15 14 13 12 11 10 9 Bit 8
Write:
Reset: Indeterminate after reset
$0027
TIM1 Channel 0
Register Low
(T1CH0L)
Read: Bit 7654321Bit 0
Write:
Reset: Indeterminate after reset
$0028
TIM1 Channel 1 Status
and Control Register
(T1SC1)
Read: CH1F CH1IE 0MS1A ELS1B ELS1A TOV1 CH1MAX
Write: 0
Reset:00000000
$0029
TIM1 Channel 1
Register High
(T1CH1H)
Read: Bit 15 14 13 12 11 10 9 Bit 8
Write:
Reset: Indeterminate after reset
$002A
TIM1 Channel 1
Register Low
(T1CH1L)
Read: Bit 7654321Bit 0
Write:
Reset: Indeterminate after reset
$0030
TIM2 Status and Control
Register
(T2SC)
Read: TOF TOIE TSTOP 00
PS2 PS1 PS0
Write: 0 TRST
Reset:00100000
$0031
TIM2 Counter Register
High
(T2CNTH)
Read: Bit 15 14 13 12 11 10 9 Bit 8
Write:
Reset:00000000
$0032
TIM2 Counter Register
Low
(T2CNTL)
Read:Bit 7654321Bit 0
Write:
Reset:00000000
$0033
TIM2 Counter Modulo
Register High
(T2MODH)
Read: Bit 15 14 13 12 11 10 9 Bit 8
Write:
Reset:11111111
= Unimplemented
Figure 8-2. TIM I/O Register Summary (Sheet 1 of 2)
Timer Interface Module (TIM)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
108 Freescale Semiconductor
8.4.1 TIM Counter Prescaler
The TIM1 clock source can be one of the seven prescaler outputs; TIM2 clock source can be one of the
seven prescaler outputs or the TIM2 clock pin, T2CLK. The prescaler generates seven clock rates from
the internal bus clock. The prescaler select bits, PS[2:0], in the TIM status and control register select the
TIM clock source.
8.4.2 Input Capture
With the input capture function, the TIM can capture the time at which an external event occurs. When an
active edge occurs on the pin of an input capture channel, the TIM latches the contents of the TIM counter
into the TIM channel registers, TCHxH:TCHxL. The polarity of the active edge is programmable. Input
captures can generate TIM CPU interrupt requests.
8.4.3 Output Compare
With the output compare function, the TIM can generate a periodic pulse with a programmable polarity,
duration, and frequency. When the counter reaches the value in the registers of an output compare
channel, the TIM can set, clear, or toggle the channel pin. Output compares can generate TIM CPU
interrupt requests.
$0034
TIM2 Counter Modulo
Register Low
(T2MODL)
Read: Bit 7654321Bit 0
Write:
Reset:11111111
$0035
TIM2 Channel 0 Status
and Control Register
(T2SC0)
Read: CH0F CH0IE MS0B MS0A ELS0B ELS0A TOV0 CH0MAX
Write: 0
Reset:00000000
$0036
TIM2 Channel 0
Register High
(T2CH0H)
Read: Bit 15 14 13 12 11 10 9 Bit 8
Write:
Reset: Indeterminate after reset
$0037
TIM2 Channel 0
Register Low
(T2CH0L)
Read: Bit 7654321Bit 0
Write:
Reset: Indeterminate after reset
$0038
TIM2 Channel 1 Status
and Control Register
(T2SC1)
Read: CH1F CH1IE 0MS1A ELS1B ELS1A TOV1 CH1MAX
Write: 0
Reset:00000000
$0039
TIM2 Channel 1
Register High
(T2CH1H)
Read: Bit 15 14 13 12 11 10 9 Bit 8
Write:
Reset: Indeterminate after reset
$003A
TIM2 Channel 1
Register Low
(T2CH1L)
Read: Bit 7654321Bit 0
Write:
Reset: Indeterminate after reset
Addr.Register Name Bit 7654321Bit 0
= Unimplemented
Figure 8-2. TIM I/O Register Summary (Sheet 2 of 2)
Functional Description
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 109
8.4.3.1 Unbuffered Output Compare
Any output compare channel can generate unbuffered output compare pulses as described in 8.4.3
Output Compare. The pulses are unbuffered because changing the output compare value requires writing
the new value over the old value currently in the TIM channel registers.
An unsynchronized write to the TIM channel registers to change an output compare value could cause
incorrect operation for up to two counter overflow periods. For example, writing a new value before the
counter reaches the old value but after the counter reaches the new value prevents any compare during
that counter overflow period. Also, using a TIM overflow interrupt routine to write a new, smaller output
compare value may cause the compare to be missed. The TIM may pass the new value before it is written.
Use the following methods to synchronize unbuffered changes in the output compare value on channel x:
When changing to a smaller value, enable channel x output compare interrupts and write the new
value in the output compare interrupt routine. The output compare interrupt occurs at the end of
the current output compare pulse. The interrupt routine has until the end of the counter overflow
period to write the new value.
When changing to a larger output compare value, enable TIM overflow interrupts and write the new
value in the TIM overflow interrupt routine. The TIM overflow interrupt occurs at the end of the
current counter overflow period. Writing a larger value in an output compare interrupt routine (at
the end of the current pulse) could cause two output compares to occur in the same counter
overflow period.
8.4.3.2 Buffered Output Compare
Channels 0 and 1 can be linked to form a buffered output compare channel whose output appears on the
TCH0 pin. The TIM channel registers of the linked pair alternately control the output.
Setting the MS0B bit in TIM channel 0 status and control register (TSC0) links channel 0 and channel 1.
The output compare value in the TIM channel 0 registers initially controls the output on the TCH0 pin.
Writing to the TIM channel 1 registers enables the TIM channel 1 registers to synchronously control the
output after the TIM overflows. At each subsequent overflow, the TIM channel registers (0 or 1) that
control the output are the ones written to last. TSC0 controls and monitors the buffered output compare
function, and TIM channel 1 status and control register (TSC1) is unused. While the MS0B bit is set, the
channel 1 pin, TCH1, is available as a general-purpose I/O pin.
NOTE
In buffered output compare operation, do not write new output compare
values to the currently active channel registers. User software should track
the currently active channel to prevent writing a new value to the active
channel. Writing to the active channel registers is the same as generating
unbuffered output compares.
8.4.4 Pulse Width Modulation (PWM)
By using the toggle-on-overflow feature with an output compare channel, the TIM can generate a PWM
signal. The value in the TIM counter modulo registers determines the period of the PWM signal. The
channel pin toggles when the counter reaches the value in the TIM counter modulo registers. The time
between overflows is the period of the PWM signal.
As Figure 8-3 shows, the output compare value in the TIM channel registers determines the pulse width
of the PWM signal. The time between overflow and output compare is the pulse width. Program the TIM
Timer Interface Module (TIM)
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110 Freescale Semiconductor
to clear the channel pin on output compare if the state of the PWM pulse is logic 1. Program the TIM to
set the pin if the state of the PWM pulse is logic 0.
The value in the TIM counter modulo registers and the selected prescaler output determines the
frequency of the PWM output. The frequency of an 8-bit PWM signal is variable in 256 increments. Writing
$00FF (255) to the TIM counter modulo registers produces a PWM period of 256 times the internal bus
clock period if the prescaler select value is $000. See 8.9.1 TIM Status and Control Register.
Figure 8-3. PWM Period and Pulse Width
The value in the TIM channel registers determines the pulse width of the PWM output. The pulse width of
an 8-bit PWM signal is variable in 256 increments. Writing $0080 (128) to the TIM channel registers
produces a duty cycle of 128/256 or 50%.
8.4.4.1 Unbuffered PWM Signal Generation
Any output compare channel can generate unbuffered PWM pulses as described in 8.4.4 Pulse Width
Modulation (PWM). The pulses are unbuffered because changing the pulse width requires writing the new
pulse width value over the old value currently in the TIM channel registers.
An unsynchronized write to the TIM channel registers to change a pulse width value could cause incorrect
operation for up to two PWM periods. For example, writing a new value before the counter reaches the
old value but after the counter reaches the new value prevents any compare during that PWM period.
Also, using a TIM overflow interrupt routine to write a new, smaller pulse width value may cause the
compare to be missed. The TIM may pass the new value before it is written.
Use the following methods to synchronize unbuffered changes in the PWM pulse width on channel x:
When changing to a shorter pulse width, enable channel x output compare interrupts and write the
new value in the output compare interrupt routine. The output compare interrupt occurs at the end
of the current pulse. The interrupt routine has until the end of the PWM period to write the new
value.
When changing to a longer pulse width, enable TIM overflow interrupts and write the new value in
the TIM overflow interrupt routine. The TIM overflow interrupt occurs at the end of the current PWM
period. Writing a larger value in an output compare interrupt routine (at the end of the current pulse)
could cause two output compares to occur in the same PWM period.
TCHx
PERIOD
PULSE
WIDTH
OVERFLOW OVERFLOW OVERFLOW
OUTPUT
COMPARE OUTPUT
COMPARE
OUTPUT
COMPARE
Functional Description
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 111
NOTE
In PWM signal generation, do not program the PWM channel to toggle on
output compare. Toggling on output compare prevents reliable 0% duty
cycle generation and removes the ability of the channel to self-correct in the
event of software error or noise. Toggling on output compare also can
cause incorrect PWM signal generation when changing the PWM pulse
width to a new, much larger value.
8.4.4.2 Buffered PWM Signal Generation
Channels 0 and 1 can be linked to form a buffered PWM channel whose output appears on the TCH0 pin.
The TIM channel registers of the linked pair alternately control the pulse width of the output.
Setting the MS0B bit in TIM channel 0 status and control register (TSC0) links channel 0 and channel 1.
The TIM channel 0 registers initially control the pulse width on the TCH0 pin. Writing to the TIM channel
1 registers enables the TIM channel 1 registers to synchronously control the pulse width at the beginning
of the next PWM period. At each subsequent overflow, the TIM channel registers (0 or 1) that control the
pulse width are the ones written to last. TSC0 controls and monitors the buffered PWM function, and TIM
channel 1 status and control register (TSC1) is unused. While the MS0B bit is set, the channel 1 pin,
TCH1, is available as a general-purpose I/O pin.
NOTE
In buffered PWM signal generation, do not write new pulse width values to
the currently active channel registers. User software should track the
currently active channel to prevent writing a new value to the active
channel. Writing to the active channel registers is the same as generating
unbuffered PWM signals.
8.4.4.3 PWM Initialization
To ensure correct operation when generating unbuffered or buffered PWM signals, use the following
initialization procedure:
1. In the TIM status and control register (TSC):
a. Stop the TIM counter by setting the TIM stop bit, TSTOP.
b. Reset the TIM counter and prescaler by setting the TIM reset bit, TRST.
2. In the TIM counter modulo registers (TMODH:TMODL), write the value for the required PWM
period.
3. In the TIM channel x registers (TCHxH:TCHxL), write the value for the required pulse width.
4. In TIM channel x status and control register (TSCx):
a. Write 0:1 (for unbuffered output compare or PWM signals) or 1:0 (for buffered output compare
or PWM signals) to the mode select bits, MSxB:MSxA. (See Table 8-3.)
b. Write 1 to the toggle-on-overflow bit, TOVx.
c. Write 1:0 (to clear output on compare) or 1:1 (to set output on compare) to the edge/level
select bits, ELSxB:ELSxA. The output action on compare must force the output to the
complement of the pulse width level. (See Table 8-3.)
NOTE
In PWM signal generation, do not program the PWM channel to toggle on
output compare. Toggling on output compare prevents reliable 0% duty
Timer Interface Module (TIM)
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
112 Freescale Semiconductor
cycle generation and removes the ability of the channel to self-correct in the
event of software error or noise. Toggling on output compare can also
cause incorrect PWM signal generation when changing the PWM pulse
width to a new, much larger value.
5. In the TIM status control register (TSC), clear the TIM stop bit, TSTOP.
Setting MS0B links channels 0 and 1 and configures them for buffered PWM operation. The TIM channel
0 registers (TCH0H:TCH0L) initially control the buffered PWM output. TIM status control register 0
(TSCR0) controls and monitors the PWM signal from the linked channels.
Clearing the toggle-on-overflow bit, TOVx, inhibits output toggles on TIM overflows. Subsequent output
compares try to force the output to a state it is already in and have no effect. The result is a 0% duty cycle
output.
Setting the channel x maximum duty cycle bit (CHxMAX) and setting the TOVx bit generates a 100% duty
cycle output. (See 8.9.4 TIM Channel Status and Control Registers.)
8.5 Interrupts
The following TIM sources can generate interrupt requests:
TIM overflow flag (TOF) — The TOF bit is set when the TIM counter reaches the modulo value
programmed in the TIM counter modulo registers. The TIM overflow interrupt enable bit, TOIE,
enables TIM overflow CPU interrupt requests. TOF and TOIE are in the TIM status and control
register.
TIM channel flags (CH1F:CH0F) — The CHxF bit is set when an input capture or output compare
occurs on channel x. Channel x TIM CPU interrupt requests are controlled by the channel x
interrupt enable bit, CHxIE. Channel x TIM CPU interrupt requests are enabled when CHxIE = 1.
CHxF and CHxIE are in the TIM channel x status and control register.
8.6 Low-Power Modes
The WAIT and STOP instructions put the MCU in low power- consumption standby modes.
8.6.1 Wait Mode
The TIM remains active after the execution of a WAIT instruction. In wait mode, the TIM registers are not
accessible by the CPU. Any enabled CPU interrupt request from the TIM can bring the MCU out of wait
mode.
If TIM functions are not required during wait mode, reduce power consumption by stopping the TIM before
executing the WAIT instruction.
8.6.2 Stop Mode
The TIM is inactive after the execution of a STOP instruction. The STOP instruction does not affect
register conditions or the state of the TIM counter. TIM operation resumes when the MCU exits stop mode
after an external interrupt.
TIM During Break Interrupts
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor 113
8.7 TIM During Break Interrupts
A break interrupt stops the TIM counter.
The system integration module (SIM) controls whether status bits in other modules can be cleared during
the break state. The BCFE bit in the break flag control register (BFCR) enables software to clear status
bits during the break state. (See 5.7.3 Break Flag Control Register (BFCR).)
To allow software to clear status bits during a break interrupt, write a logic 1 to the BCFE bit. If a status
bit is cleared during the break state, it remains cleared when the MCU exits the break state.
To protect status bits during the break state, write a logic 0 to the BCFE bit. With BCFE at logic 0 (its
default state), software can read and write I/O registers during the break state without affecting status bits.
Some status bits have a 2-step read/write clearing procedure. If software does the first step on such a bit
before the break, the bit cannot change during the break state as long as BCFE is at logic 0. After the
break, doing the second step clears the status bit.
8.8 I/O Signals
Port D shares two of its pins with TIM1 and port E shares two of its pins with TIM2. The ADC12/T2CLK
pin is an external clock input to TIM2. The four TIM channel I/O pins are T1CH0, T1CH1, T2CH0, and
T2CH1.
8.8.1 TIM Clock Pin (ADC12/T2CLK)
ADC12/T2CLK is an external clock input that can be the clock source for the TIM2 counter instead of the
prescaled internal bus clock. Select the ADC12/T2CLK input by writing logic 1’s to the three prescaler
select bits, PS[2:0]. (See 8.9.1 TIM Status and Control Register.) The minimum T2CLK pulse width,
T2CLKLMIN or T2CLKHMIN, is:
The maximum T2CLK frequency is:
bus frequency ÷ 2
ADC12/T2CLK is available as a ADC input channel pin when not used as the TIM2 clock input.
8.8.2 TIM Channel I/O Pins (PTD4/T1CH0, PTD5/T1CH1, PTE0/T2CH0, PTE1/T2CH1)
Each channel I/O pin is programmable independently as an input capture pin or an output compare pin.