MC68HC908AT32 Datasheet, PDF (111/378 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 10
Configuration Register (CONFIG-2)
10.1 Introduction
This section describes the configuration register (CONFIG-2). This register contains bits that configure
these options:
• Configures the MC68HC908AT32 to either the MC68HC08AZ32 emulator or the MC68HC08AS20
emulator
• Enables the memory extenion for the MC68HC08AS20 emulator
• Disables the CAN module
NOTE
The MEMEXT bit comes up enabled. If you are planning or emulating an
MC68HC08AS20, be aware that this extra memory is not available.
10.2 Functional Description
The configuration register is a write-once register. Out of reset, the configuration register will read the
default. Once the register is written, further writes will have no effect until a reset occurs.
Address: $FE09
Bit 7
6
5
4
3
2
1
Bit 0
Read:
0
0
0
MSCAND
0
0
MEMEXT AZ32
Write:
Reset: 0
0
0
1
0
0
1
0
Figure 10-1. Configuration Register (CONFIG-2)
MSCAND — MSCAN Disable Bit
MSCAND disables the MSCAN module. See Chapter 23 MSCAN Controller.
1 = MSCAN module disabled
0 = MSCAN Module enabled
MEMEXT — Memory Extention Enable Bit
MEMEXT enables the extra memory locations in the RAM and the FLASH modules. See Chapter 2
Memory Map.
1 = Extra RAM and FLASH enabled
0 = Extra RAM and FLASH disabled
NOTE
This function comes up enabled. Be careful when emulating the
MC68HC08AS20 since this is not an option on the MC68HC08AS20.
MC68HC908AT32 Data Sheet, Rev. 3.1
Freescale Semiconductor
111