Chapter 3 Module Mapping Control (MMCV4) Block Description
116
MC9S12C-Family / MC9S12GC-Family
Freescale Semiconductor
Rev 01.24
3.3.2.4
Miscellaneous System Control Register (MISC)
Read: Anytime
Write: As stated in each bit description
NOTE
Writes to this register take one cycle to go into effect.
This register initializes miscellaneous control functions.
Module Base + 0x0013
Starting address location affected by INITRG register setting.
7
6
5
4
3
2
1
0
R
0
0
0
0
EXSTR1
EXSTR0
ROMHM
ROMON
W
Reset: Expanded
or Emulation
0
0
0
0
1
1
0
—
1
Reset: Peripheral
or Single Chip
0
0
0
0
1
1
0
1
Reset: Special Test
0
0
0
0
1
1
0
0
1. The reset state of this bit is determined at the chip integration level.
= Unimplemented or Reserved
Figure 3-6. Miscellaneous System Control Register (MISC)
Table 3-5. INITEE Field Descriptions
Field
Description
3:2
EXSTR[1:0]
External Access Stretch Bits 1 and 0
Write: once in normal and emulation modes and anytime in special modes
This two-bit field determines the amount of clock stretch on accesses to the external address space as shown in
. In single chip and peripheral modes these bits have no meaning or effect.
1
ROMHM
FLASH EEPROM or ROM Only in Second Half of Memory Map
Write: once in normal and emulation modes and anytime in special modes
0 The fixed page(s) of FLASH EEPROM or ROM in the lower half of the memory map can be accessed.
1 Disables direct access to the FLASH EEPROM or ROM in the lower half of the memory map. These physical
locations of the FLASH EEPROM or ROM remain accessible through the program page window.
0
ROMON
ROMON — Enable FLASH EEPROM or ROM
Write: once in normal and emulation modes and anytime in special modes
This bit is used to enable the FLASH EEPROM or ROM memory in the memory map.
0 Disables the FLASH EEPROM or ROM from the memory map.
1 Enables the FLASH EEPROM or ROM in the memory map.
Summary of Contents for MC9S12C Family
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