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
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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
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Low-power stop and wait modes
MC68HC908AP Family Data Sheet, Rev. 4
Freescale Semiconductor
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FREESCALE [ Freescale ]
