Datasheet

Table Of Contents
MC68HC908GR60A • MC68HC908GR48A • MC68HC908GR32A Data Sheet, Rev. 5
Freescale Semiconductor 29
Chapter 2
Memory
2.1 Introduction
The CPU08 can address 64 Kbytes of memory space. The memory map, shown in Figure 2-1, includes:
62,078 bytes of user FLASH memory
2048 bytes of random-access memory (RAM)
52 bytes of user-defined vectors
2.2 Unimplemented Memory Locations
Accessing an unimplemented location can cause an illegal address reset. In the memory map
(Figure 2-1) and in register figures in this document, unimplemented locations are shaded.
2.3 Reserved Memory Locations
Accessing a reserved location can have unpredictable effects on microcontroller (MCU) operation. In the
Figure 2-1 and in register figures in this document, reserved locations are marked with the word Reserved
or with the letter R.
2.4 Input/Output (I/O) Section
Most of the control, status, and data registers are in the zero page area of $0000–$003F, or at
$0440–$0461. Additional I/O registers have these addresses:
$FE00; SIM break status register, BSR
$FE01; SIM reset status register, SRSR
$FE02; reserved
$FE03; SIM break flag control register, BFCR
$FE04; interrupt status register 1, INT1
$FE05; interrupt status register 2, INT2
$FE06; interrupt status register 3, INT3
$FE07; interrupt status register 4, INT4
$FE08; FLASH-2 control register, FL2CR
$FE09; break address register high, BRKH
$FE0A; break address register low, BRKL
$FE0B; break status and control register, BRKSCR
$FE0C; LVI status register, LVISR
$FE0D; FLASH-2 test control register, FLTCR2
$FE0E; FLASH-1 test control register, FLTCR1
$FF80; FLASH-1 block protect register, FL1BPR
$FF81; FLASH-2 block protect register, FL2BPR
$FF88; FLASH-1 control register, FL1CR
Data registers are shown in Figure 2-2. Table 2-1 is a list of vector locations.