MC68HC05P18 Datasheet, PDF (74/144 Pages) Freescale Semiconductor, Inc – Advance Information

EEPROM
Freescale Semiconductor, Inc.
8.4 Programming/Erasing Procedures
NOTE:
To program a byte of EEPROM, set LATCH = CPEN = 1,
set ER1 = ER0 = 0, write data to the desired address, and then set
EEPGM for a time, t_EPGM.
Any bit should be erased before it is programmed. However, if
write/erase cycling is a concern, the following procedure will minimize
the cycling of each bit in each EEPROM byte.
If PB • EB = 0, then program the new data over the existing data without
erasing it first. If PB • EB ≠ 0, then erase the byte before programming
where PB = byte data to be programmed and
EB = existing EEPROM byte data.
To erase a byte of EEPROM, set LATCH = 1, CPEN = 1, ER1 = 0, and
ER0 = 1, write to the address to be erased and set EEPGM for a time,
t_EBYT.
To erase a block of EEPROM, set LATCH = 1, CPEN = 1, ER1 = 1, and
ER0 = 0, write to any address in the block, and set EEPGM for a time,
t_EBLOCK.
For a bulk erase, set LATCH = 1, CPEN = 1, ER1 = 1, and ER0 = 1, write
to any address in the array, and set EEPGM for a time, t_EBULK.
To terminate the programming or erase sequence, clear EEPGM, delay
for a time t_FPV to allow the program voltage to fall, and then clear LATCH
and CPEN to free up the buses. Following each erase or programming
sequence, clear all programming control bits.
NOTE:
Erased/programmed state of the programming EEPROM (128 bytes)
and the user EEPROM (8064 bytes) is opposite. An erased EEPROM
memory location is a logic 0 for user EEPROM, while it is a logic 1 for
programming EEPROM.
Advance Information
74
MC68HC(8)05P18 — Rev. 2.0
EEPROM
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