MC68HC908QC16_07 Datasheet, PDF (25/274 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 2
Memory
2.1 Introduction
The central processor unit (CPU08) can address 64 Kbytes of memory space. The memory map is shown
in Figure 2-1.
2.2 Unimplemented Memory Locations
Executing code from an unimplemented location will cause an illegal address reset. In Figure 2-1,
unimplemented locations are shaded.
2.3 Reserved Memory Locations
Accessing a reserved location can have unpredictable effects on MCU operation. In Figure 2-1, reserved
locations are marked with the word reserved or with the letter R.
2.4 Direct Page Registers
Figure 2-2 shows the memory mapped registers. Registers with addresses between $0000 and $00FF
are considered direct page registers and all instructions including those with direct page addressing
modes can access them. Registers between $0100 and $FFFF require non-direct page addressing
modes. See Chapter 6 Central Processor Unit (CPU) for more information on addressing modes.
MC68HC908QC16 • MC68HC908QC8 • MC68HC908QC4 Data Sheet, Rev. 3
Freescale Semiconductor
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