Operating Modes and On-Chip Memory
Memory Map
MC68HC11E Family
—
Rev. 4
Technical Data
MOTOROLA
Operating Modes and On-Chip Memory
81
Figure 4-8. RAM Standby MODB/V
STBY
Connections
The bootloader program is contained in the internal bootstrap ROM. This
ROM, which appears as internal memory space at locations
$BF00
–
$BFFF, is enabled only if the MCU is reset in special bootstrap
mode.
In expanded modes, the ROM/EPROM/OTPROM (if present) is enabled
out of reset and located at the top of the memory map if the ROMON bit
in the CONFIG register is set. ROM or EPROM is enabled out of reset in
single-chip and bootstrap modes, regardless of the state of ROMON.
For devices with 512 bytes of EEPROM, the EEPROM is located at
$B600
–
$B7FF and has the same read cycle time as the internal ROM.
The 512 bytes of EEPROM cannot be remapped to other locations.
For the MC68HC811E2, EEPROM is located at $F800
–
$FFFF and can
be remapped to any 4-Kbyte boundary. EEPROM mapping control bits
(EE[3:0] in CONFIG) determine the location of the 2048 bytes of
EEPROM and are present only on the MC68HC811E2. Refer to
4.4.3.1 System Configuration Register
for a description of the
MC68HC811E2 CONFIG register.
EEPROM can be programmed or erased by software and an on-chip
charge pump, allowing EEPROM changes using the single V
DD
supply.
4.7 k
MAX
690
V
BATT
+
4.8-V
NiCd
V
DD
V
DD
V
OUT
TO MODB/V
STBY
OF M68HC11