Datasheet

Operating Modes and Resource Mapping
Technical Data MC68HC912D60A — Rev. 3.1
82 Operating Modes and Resource Mapping Freescale Semiconductor
RFSTR1, RFSTR0 — Register Following Stretch
This two bit field determines the amount of clock stretch on accesses
to the 512 byte Register Following Map. It is valid regardless of the
state of the NDRF bit. In Single Chip and Peripheral Modes this bit
has no meaning or effect.
EXSTR1, EXSTR0 — External Access Stretch
This two bit field determines the amount of clock stretch on accesses
to the External Address Space. In Single Chip and Peripheral Modes
this bit has no meaning or effect.
ROMON28, ROMON32 — Enable bits for ROM
These bits are used to enable the Flash EEPROM arrays FEE28 and
FEE32 respectively.
0 = Corresponding Flash EEPROM array disabled from the memory
map.
1 = Corresponding Flash EEPROM array enabled in the memory
map.
Table 5-3. RFSTR Stretch Bit Definition
RFSTR1 RFSTR0
Number of E Clocks
Stretched
00 0
01 1
10 2
11 3
Table 5-4. EXSTR Stretch Bit Definition
EXSTR1 EXSTR0
Number of E Clocks
Stretched
00 0
01 1
10 2
11 3