AK9844A Datasheet, PDF (4/17 Pages) Asahi Kasei Microsystems – 4Kbit EEPROM with 4ch 8bit D/A Converter

ASAHI KASEI
[AK9844A]
„ Data Protection
To protect against accidental data disturb, the AK9844A has programming enable state and
programming disable state. In programming disable state, the programming operation is not
executed.
When VCC is applied to the AK9844A, the AK9844A is powered up in the programming disable
mode. The programming instruction should be preceded by the WREN instruction. Once the
WREN instruction is executed, the programming state remains enabled until the WRDS instruction
is executed or VCC is removed from the device. Execution of the READ instruction is independent
of both WREN and WRDS instructions.
The AK9844A also can prohibit to program into the DAC register block by the control of the
PROTECT pin. When the PROTECT pin is "L", the programming into the DAC register block is not
executed.
PROTECT pin
Programming State
Memory Block
DAC Register Block
PROTECT="H"
Enable
Disable
○
×
○
×
○: Programming into the block is executed.
×: Programming into the block is not executed.
PROTECT="L"
Enable
Disable
○
×
×
×
Table 1. Relation between the programming operation and the PROTECT pin
DAD05E-00
-4-
2005/03