AK6440BL Datasheet, PDF (2/13 Pages) Asahi Kasei Microsystems – 4096bit Serial CMOS EEPROM

ASAHI KASEI
[AK6440B]
General Description
The AK6440B is a 4096bit, serial, read/write, non-volatile memory device fabricated using
an advanced CMOS EEPROM technology. The AK6440B has 4096bits of memory
organized into 256 registers of 16 bits each. The AK6440B can operate full function under
wide operating voltage range from 1.8V to 5.5V. The charge up circuit is integrated for high
voltage generation that is used for write operation.
The AK6440B can connect to the serial communication port of popular one chip
microcomputer directly (3 line negative clock synchronous interface). At write operation,
AK6440B takes in the write data from data input pin (DI) to a register synchronously with
rising edge of input pulse of serial clock pin (SK). And at read operation, AK6440B takes
out the read data from a register to data output pin (DO) synchronously with falling edge of
SK.
The AK6440B has 4 instructions such as READ, WRITE, WREN (write enable) and WRDS
(write disable). Each instruction is organized by op-code block (8bits), address block (8bits)
and data (8bits×2). When input level of SK pin is high level and input level of chip select
(CS) pin is changed from high level to low level, AK6440B can receive the instructions.
Special features of the AK6440B include : automatic write time-out with auto-ERASE,
Ready/Busy status signal output and ultra-low standby power mode when deselected
(CS=high).
・ Software and Hardware controlled write protection
The AK6440B has 2 (hardware and software) write protection functions.
After power on or after execution of WRDS (write disable) instruction, execution of WRITE
instruction will be disabled. This write protection condition continues until WREN
instruction is executed or VCC is removed from the part.
Execution of READ instruction is independent of both WREN and WRDS instructions.
Reset pin should be low level when WRITE instruction is executed. When the Reset pin is
high level, the WRITE instruction is not executed.
・ Ready/Busy status signal
The DO pin indicates the Busy status. When input level of SK pin is low level and input
level of CS pin is changed from high level to low level, the AK6440B is in the status output
mode and the DO pin indicates the Ready/Busy status. The Ready/Busy status outputs on
DO pin until CS pin is changed from low level to high level, or first bit ("1") of op-code of
next instruction is given to the part. Except when the device is in the status output mode or
outputs data, the DO pin is in the high impedance state.
 Type of Products
Model
AK6440BH
AK6440BL
Memory Size
4Kbits
Temp.Range
VCC
-40C ~ +85C 1.8V ~ 5.5V
-40C ~ +85C 1.8V ~ 5.5V
Package
8pin Plastic MSOP
8 pin Plastic SON
DAS03E-01
-2-
2012/09