S-93C46C Datasheet, PDF (20/39 Pages) Seiko Instruments Inc – 3-WIRE SERIAL E2PROM

3-WIRE SERIAL E²PROM
S-93C46C/56C/66C/76C/86C
Rev.1.1_00
4. Write enable (EWEN) / write disable (EWDS)
The EWEN instruction is an instruction that enables a write operation. The status in which a write operation is enabled
is called the program enable mode.
The EWDS instruction is an instruction that disables a write operation. The status in which a write operation is
disabled is called the program disable mode.
After the CS pin goes to "H", input an instruction in the order of the start bit, EWEN or EWDS instruction, and address
(optional). Each mode becomes valid by inputting "L" to the CS pin after the last address (optional) has been input.
CS
Standby
SK
1
2
3
4
5
6
7
8
9
DI
<1> ⁰
0
11 = EWEN
4xs
00 = EWDS
Figure 17 Write Enable / Disable Timing (S-93C46C)
CS
Standby
SK
1
2
3
4
5
6
7
8
9 10 11
DI
<1> ⁰
0
11 = EWEN
6xs
00 = EWDS
Figure 18 Write Enable / Disable Timing (S-93C56C/66C)
CS
Standby
SK
1
2
3
4
5
6
7
8
9 10 11 12 13
DI
<1> 0
0
11 = EWEN
8xs
00 = EWDS
Figure 19 Write Enable / Disable Timing (S-93C76C/86C)
Remark It is recommended to execute an EWDS instruction for preventing an incorrect write operation if a write
instruction is erroneously recognized when executing instructions other than write instruction, and
immediately after power-on and before power-off.
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