MPC555
/
MPC556
CDR MoneT FLASH EEPROM
MOTOROLA
USER’S MANUAL
Rev. 15 October 2000
19-19
5. Write to the 64-byte array locations to be programmed. This updates the pro-
gramming page buffer(s) with the information to be programmed. The last write
to a word within the program page buffer will be saved for programming. All ac-
cesses of the array after the first write are to the same block offset address
(ADDR[17:25]) regardless of the address provided. Thus the locations access-
ed after the first programming write are limited to the page locations to be pro-
grammed. Off-page read accesses of the CMF array after the first programming
write are program margin reads. (See section
To select the CMF EEPROM array block(s) to be programmed, the program
page buffers use the CMF EEPROM array configuration and BLOCK[0:7]. Sub-
sequent writes fill in the programming page buffers using the block address to
select the program page buffer and the page word address (ADDR[26:29]) to
select the word in the page buffer.
6. Write EHV = 1 in the CMFCTL register.
NOTE
If a program buffer word has not received a programming write no
programming voltages will be applied to the drain of the correspond-
ing word in the array. Also, at this point writes to the program page
buffers are disabled until SES has been cleared and set.
7. Read the CMFCTL register until HVS = 0.
8. Write EHV = 0.
9. To verify the programming, read the words of the pages that are being pro-
grammed. These are program margin reads. (See
.) If any bit is a 1 after reading all of the locations that are being pro-
grammed, then another pulse needs to be applied to the these locations. If all
the locations verify as programmed go to step 11.
WARNING
After a program pulse, read at least one location with ADDR[26] = 0
and one location with ADDR[26] = 1 on each programmed page. Fail-
ure to do so may result in the loss of information in the CMF
EEPROM array. While this will not physically damage the array a full
erase of all blocks being programmed must be done before the CMF
EEPROM can be used reliably. For more information see
To reduce the time for verification, read two locations in each program page that
is being programmed after reading a non-programmed bit. The first location
must be a location with ADDR[26] = 0, while the second must use ADDR[26] =
1. In addition, after a location has been fully verified (all bits are programmed)
it is not necessary to verify the location again, since no further programming
voltages will be applied to the drain of the corresponding bits. This will reduce
the time required to program the array.
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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