S-93C46A Datasheet, PDF (13/53 Pages) Seiko Instruments Inc – CMOS SERIAL E2PROM

CMOS SERIAL E²PROM
S-93C46A/56A/66A
3. Write enable (EWEN) and Write disable (EWDS)
The EWEN instruction puts the S-93C46A/56A/66A into write enable mode, which accepts WRITE, ERASE, WRAL,
and ERAL instructions. The EWDS instruction puts the S-93C46A/56A/66A into write disable mode, which refuses WRITE,
ERASE, WRAL, and ERAL instructions.
The S-93C46A/56A/66A powers on in write disable mode, which protects data against unexpected, erroneous write
operations caused by noise and/or CPU malfunctions. It should be kept in write disable mode except when performing write
operations.
CS
STANDBY
SK
123456789
DI
10
0
11=EWEN
4Xs
00=EWDS
Figure 19 EWEN/EWDS Timing (S-93C46A)
CS
STANDBY
SK
1 2 3 4 5 6 7 8 9 10 11
DI
10
0
11=EWEN
6Xs
00=EWDS
Figure 20 EWEN/EWDS Timing (S-93C56A)
CS
STANDBY
SK
1 2 3 4 5 6 7 8 9 10 11
DI
10
0
11=EWEN
6Xs
00=EWDS
Figure 21 EWEN/EWDS Timing (S-93C66A)
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Seiko Instruments Inc.