mc68hc08qa24 Freescale Semiconductor, Inc, mc68hc08qa24 Datasheet - Page 75

• Manufacturer Part Number: mc68hc08qa24
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

MC68HC08QA24
Freescale SemiconductorElectrically Erasable Programmable Read-Only Memory (EEPROM)
Use this step-by-step procedure to program a byte of EEPROM. Refer
to
1. Clear EERAS1 and EERAS0 and set EELAT in the EEPROM
2. Write the desired data to any user EEPROM address.
3. Set the EEPGM bit. (See note c.)
4. Wait for a time, t
5. Clear the EEPGM bit.
6. Wait for the programming voltage time to fall, t
7. Clear EELAT bits. (See note d.)
8. Repeat steps 1 through 7 for more EEPROM programming.
23.6 Control Timing
Notes:
control register (EECR) ($FE1D). Set value of t
a and b.)
a. EERAS1 and EERAS0 must be cleared for programming.
b. Setting the EELAT bit configures the address and data buses
c. The EEPGM bit cannot be set if the EELAT bit is cleared and
d. Any attempt to clear both EEPGM and EELAT bits with a
Otherwise, the mode will be erase mode.
to latch data for programming the array. Only data with a valid
EEPROM address will be latched. If another consecutive valid
EEPROM write occurs, this address and data will override the
previous address and data. Any attempts to read other
EEPROM data will read the latched data. If EELAT is set,
other writes to the EECR will be allowed after a valid
EEPROM write.
a non-EEPROM write has occurred. This is to ensure proper
programming sequence. When EEPGM is set, the on-board
charge pump generates the program voltage and applies it to
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.
single instruction will clear only EEPGM to allow time for
removal of high voltage from the EEPROM array.
Electrically Erasable Programmable Read-Only Memory (EEPROM)
EEPGM
for timing values.
, to program the byte.
EEPGM
EEFPV
.
Technical Data
. (See notes
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