ASAHI KASEI
[AK6002A/04A/08A]
Functional Descriptions
WRITE Operations
BYTE WRITE
A write operation requires a word address following the slave address word (R/W=0) and acknowledge. The
word address is comprised of eight bits and provides access to any one of the 256/512/2048 words. Upon
receipt of the word address the AK6002A/04A/08A responds with an acknowledge, and awaits the next eight
bits of data, again, responding with an acknowledge.
The master then terminates the transfer by generating a stop condition, at which time the AK6002A/04A/08A
begins the internal write cycle to the nonvolatile memory. While the internal write cycle is in progress the
AK6002A/04A/08A inputs are disable, and the device will not respond to any requests from the master.
BYTE WRITE
PAGE WRITE
The AK6002A/04A/08A is capable of a sixteen byte page write operation.
It is initiated in the same manner as the byte write operation. But instead of terminating the write cycle after
the first data word is transferred, the master can transmit up to fifteen more words. After the receipt of each
word, the AK6002A/04A/08A will respond with an acknowledge. The master then terminates the transfer by
generating a stop condition, at which time the AK6002A/04A/08A begins the internal write cycle to the
nonvolatile memory.
After the receipt of each word, the four lower order address pointer bits are internally incremented by one. The
higher order four/five/seven bits of the word address remains constant.
AK6002A
When the highest address is reached (XXXX 1111), the address counter rolls over to
address "XXXX 0000" allowing the read cycle to be continued indefinitely.
AK6004A
When the highest address is reached (X XXXX 1111), the address counter rolls over
to address "X XXXX 0000" allowing the read cycle to be continued indefinitely.
AK6008A
When the highest address is reached (XXX XXXX 1111), the address counter rolls
over to address "XXX XXXX 0000" allowing the read cycle to be continued indefinitely.
If the master should transmit more than sixteen words prior to generating the stop condition, the address
counter will "roll over" and the previously written data will be overwritten. When the master transmit eighteen
words prior to the stop condition, seventeenth word will be overwritten to first word, and eighteenth word will
be overwritten to second word.
PAGE WRITE
DAI01E-01
-7-
1999/10
AKM [ ASAHI KASEI MICROSYSTEMS ]
