Datasheet

MC68HC908GP20 — Rev 2.1 Advance Information
Freescale Semiconductor 43
Advance Information — MC68HC908GP20
Section 2. Memory Map
2.1 Contents
2.2 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
2.3 Unimplemented Memory Locations . . . . . . . . . . . . . . . . . . . . . .43
2.4 Reserved Memory Locations . . . . . . . . . . . . . . . . . . . . . . . . . .44
2.5 Input/Output (I/O) Section. . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
2.2 Introduction
The CPU08 can address 64 Kbytes of memory space. The memory
map, shown in Figure 2-1, includes:
• 20 Kbytes of FLASH memory, 19,968 bytes of user space
• 512 bytes of random-access memory (RAM)
• 36 bytes of user-defined vectors
• 307 bytes of monitor ROM
2.3 Unimplemented Memory Locations
Accessing an unimplemented location can cause an illegal address
reset if illegal address resets are enabled. In the memory map
(Figure 2-1) and in register figures in this document, unimplemented
locations are shaded.