s-93c46b Seiko Instruments Inc., s-93c46b Datasheet - Page 19

• Manufacturer Part Number: s-93c46b
• Description: Cmos Serial E2prom
• Manufacturer: Seiko Instruments Inc.

Rev.4.3
5. Write enable (EWEN) and 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 CS goes high, input an instruction in the order of the start bit, EWEN or EWDS instruction, and
address (optional). Each mode becomes valid by inputting a low level to CS after the last address
(optional) has been input.
(1) Recommendation for write operation disable instruction
_00
CS
SK
DI
It is recommended to implement a design that prevents an incorrect write operation when a write
instruction is erroneously recognized by executing the write operation disable instruction when
executing instructions other than write instruction, and immediately after power-on and before
power off.
CS
SK
DI
Figure 19 Write Enable/Disable Timing (S-93C56B, S-93C66B)
<1>
1
Figure 18 Write Enable/Disable Timing (S-93C46B)
<1>
0
2
1
0
0
3
2
11 = EWEN
00 = EWDS
0
Seiko Instruments Inc.
4
3
11 = EWEN
00 = EWDS
5
4
6
5
7
6
6Xs
8
7
4Xs
9
8
10
9
CMOS SERIAL E
11
S-93C46B/56B/66B
Standby
Standby
2
PROM
19