AK6003A Datasheet, PDF (9/17 Pages) Asahi Kasei Microsystems – SOFTWARE WRITE PROTECT I2C BUS 2KBIT EEPROM

ASAHI KASEI
[AK6003A]

Software Write Protect Operation
The AK6003A has a software write protect feature. The software write protect register is
programmed by sending the software write protect command and the write protection is enabled. If
the software write protection is enabled, Write operations onto the lower half of the array($00
$7F)
will not be executed permanently.
Figure5. EEPROM composition
The software write protect operation requires the word address following the slave address word
(R/W=0) and acknowledge. The most significant four bits of the slave address are "0110". Upon
receipt of the word address the AK6003A responds with an acknowledge and awaits for the next
eight bits of data, again, responding with an acknowledge. The word address bits and the next eight
bits of data are don't cares. After the receipt of the slave address set to "0110" and R/W=1, the
AK6003A will not respond with an acknowledge.
The master then terminates the transfer by generating a stop condition, at which time the AK6003A
begins to program the software write protect register. While the programming is in progress the
AK6003A inputs are disable, and the device will not respond to any requests from the master.
Once the software write protect register has been programmed, the write protection can not be
reversed. The software write protection can not be reversed even if the AK6003A is powered down.
Once the software write protect register has been programmed, the software write protect command
is ignored.
SOFTWARE WRITE PROTECT
DAI03E-01
-9-
1999/10