MC68HC908AS32A Datasheet, PDF (29/280 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 2
Memory
2.1 Introduction
The CPU08 can address 64 Kbytes of memory space. The memory map, shown in Figure 2-1, includes:
• 32,256 bytes of FLASH EEPROM
• 1024 bytes of RAM
• 512 bytes of EEPROM with protect option
• 52 bytes of user-defined vectors
• 256 bytes of monitor ROM
2.2 Unimplemented Memory Locations
Accessing an unimplemented location can have unpredictable effects on MCU operation. In 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 MCU operation. In 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
Addresses $0000–$004F, shown in Figure 2-2, contain the I/O data, status, and control registers.
2.5 Additional Status and Control Registers
Selected addresses in the range $FE00–$FF88 contain additional status and control registers as shown
in Figure 2-3. A noted exception is the computer operating properly (COP) control register (COPCTL) at
address $FFFF.
2.6 Vector Addresses and Priority
Addresses in the range $FFDA–$FFFF contain the user-specified vector locations. The vector addresses
are shown in Table 2-1. It is recommended that all vector addresses are defined.
MC68HC908AS32A Data Sheet, Rev. 2.0
Freescale Semiconductor
29