AK6440BL Datasheet, PDF (6/13 Pages) Asahi Kasei Microsystems – 4096bit Serial CMOS EEPROM

ASAHI KASEI
[AK6440B]
Read
The read instruction is the only instruction which outputs serial data on the DO pin. When
the 17th falling edge of SK is received, the DO pin will come out of high impedance state
and shift out the data from D15 first in descending order which is located at the address
specified in the instruction.
The data in the next address can be read sequentially by continuing to provide clock. The
address automatically cycles to the next higher address after the 16bit data shifted out.
When the highest address is reached ($FF), the address counter rolls over to address $00
allowing the read cycle to be continued indefinitely.
CS
SK
1 2 3 4 5 6 7 8 9 10
15 16 17 18
32 33 34
48
DI
1 0 1 0 1 0 0 0 A7 A6
A1 A0
Hi-Z
DO
D15 D14
D0 D15 D14
D0
address [A7 ~ A0] address[A7 ~ A0]+1
READ
WREN / WRDS ( Write Enable and Write Disable )
When VCC is applied to the part, it powers up in the programming disable (WRDS) state.
Programming must be preceded by a programming enable (WREN) instruction.
Programming remains enabled until a programming disable (WRDS) instruction is executed
or VCC is removed from the part. The programming disable instruction is provided to
protect against accidental data disturb. Execution of a read instruction is not affected by
both WREN and WRDS instructions.
CS
SK
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
DI
1 01000
XXXXXXXX
WREN=11
WRDS=00
Hi-Z
DO
※ SK pulses exceeding 17 are ignored.
WREN / WRDS
DAS03E-01
-6-
2012/09