mc68hc705v12 Freescale Semiconductor, Inc, mc68hc705v12 Datasheet - Page 129

• Manufacturer Part Number: mc68hc705v12
• Description: M68hc05-based Mcu Hc05 Freescale Semiconductor
• Manufacturer: Freescale Semiconductor, Inc

12.9 EEPROM Programming/Erasing Procedure
MC68HC705V12
—
Rev. 3.0
To program a byte of EEPROM:
In general, all bits should be erased before being programmed.
However, if write/erase cycling is a concern, a procedure can be
followed to minimize the cycling of each bit in each EEPROM byte. The
erased state is 1; therefore, if any bits within the byte need to be changed
from a 0 to a 1, the byte must be erased before programming. The
decision whether to erase a byte before programming is summarized in
Table
To erase a byte of EEPROM:
To erase a block of EEPROM:
1. Set EELAT = CPEN = 1.
2. Set ER1 = ER0 = 0.
3. Write data to the desired address.
4. Set EEPGM for a time, t
1. Set EELAT = 1, CPEN = 1, ER1 = 0, and ER0 = 1.
2. Write to the address to be erased.
3. Set EEPGM for a time, t
1. Set EELAT = 1, CPEN = 1, ER1 = 1, and ER0 = 0.
2. Write to any address in the block.
3. Set EEPGM for a time, t
Freescale Semiconductor, Inc.
To Be Programed
For More Information On This Product,
EEPROM Data
12-3.
Table 12-3. EEPROM Write/Erase Cycle Reduction
0
0
1
1
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EPROM and EEPROM
Before Programming
EEPGM
EBYT
EBLOCK
EEPROM Data
EEPROM Programming/Erasing Procedure
.
0
1
0
1
.
.
EPROM and EEPROM
Advance Information
Programming?
Erase Before
Yes
No
No
No