AN2156 Freescale Semiconductor / Motorola, AN2156 Datasheet - Page 31

• Manufacturer Part Number: AN2156
• Description: Programming and Erasing FLASH and EEPROM Memories on the MC68HC908AS60A/AZ60A
• Manufacturer: Freescale Semiconductor / Motorola

AUTO Mode EEPROM Erase Operation
AN2156
MOTOROLA
The EEPROM can be erased on a byte, block (128 bytes), or bulk array
(512 bytes) basis. If the block protection register shows the desired
erase region to be protected, erasing will fail. Therefore, first ensure that
the block protection feature is disabled for the relevant addresses.
On this EEPROM memory, another erase operation mode is provided. It
is called AUTO mode. When AUTO mode is selected, the erase cycle is
terminated by the internal timer, which polls the EEPGM bit in the
EExCR register. Therefore, fixed delay times are not required in the
AUTO mode.
The flowchart for the AUTO mode EEPROM erase operation is included
as
2. Write any data to an EEPROM location. For byte erase, this
3. Set the EEPGM bit.
4. Wait for a time, t
5. Clear the EEPGM bit.
6. Wait for a time, t
7. Clear the EELAT bit.
8. Repeat steps 1 to 7 for more EEPROM byte/block/bulk erasing.
1. Clear/set EERAS1 and EERAS0 to select byte/block/bulk erase,
2. Write any data to an EEPROM location. For byte erase, this
3. Set the EEPGM bit.
4. Poll the EEPGM bit until it is cleared by the internal timer.
5. Clear the EELAT bit.
6. Repeat steps 1 to 5 for more EEPROM byte/block/bulk erasing.
Freescale Semiconductor, Inc.
Figure
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should be the address to erase. For block or bulk erase, this is any
address within the block or array to erase.
byte/block/whole array.
and set EELAT and AUTO in the EExCR.
should be the address to erase. For block or bulk erase, this is any
address within the block or array to erase.
13.
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EEBYTE
EEFPV
, for the erasing voltage to fall.
/t
EEBLOCK
AUTO Mode EEPROM Erase Operation
/t
EEBULK
, to erase a
Application Note
31