MC908QL4 FREESCALE [Freescale Semiconductor, Inc], MC908QL4 Datasheet - Page 25

• Manufacturer Part Number: MC908QL4
• Description: M68HC08 Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

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 of the MC68HC908QL4. 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 7 Central Processor Unit (CPU)
for more information on
addressing modes.
MC68HC908QL4 Data Sheet, Rev. 7
Freescale Semiconductor
25