MC68HC08AZ16 Datasheet, PDF (45/527 Pages) Motorola, Inc – HCMOS Microcontroller Unit

EEPROM
the user EEPROM array. When the EEPGM bit is cleared, the
program voltage is removed from the array and the internal
charge pump is turned off.
D. Any attempt to clear both EEPGM and EELAT bits with a
single instruction will only clear EEPGM. This is to allow time
for removal of high voltage from the EEPROM array.
E. While these operations must be performed in the order shown,
other unrelated operations may occur between the steps.
EEPROM erasing
The unprogrammed state is a logic ’1’. Only the valid EEPROM bytes in
the non-protected blocks and EENVR can be erased. When the array is
configured in the redundant mode, erasing the first 256 bytes will also
erase the last 256 bytes.
The following procedure shows how to erase EEPROM:
1. Clear/set EERAS1 and EERAS0 to select byte/block/bulk
erase, and set EELAT in EECR (see Note F.)
2. Write any data to the desired address for byte erase, to any
address in the desired block for block erase, or to any array
address for bulk erase.
3. Set the EEPGM bit. (See Note G.)
4. Wait for a time, t_byte/t_block/t_bulk before erasing the
byte/block/array.
5. Clear EEPGM bit.
6. Wait for the erasing voltage time to fall (t_EEFPV).
7. Clear EELAT bits. (See Note H.)
8. Repeat steps 1 to 7 for more EEPROM byte/block erasing.
The EEBPx bit must be cleared to erase EEPROM data in the
corresponding block. If any EEBPx is set, the corresponding block
cannot be erased and bulk erase mode does not apply.
MC68HC08AZ32
44
EEPROM
4-eeprom
MOTOROLA