S-25C010A-H Datasheet, PDF (14/33 Pages) Seiko Instruments Inc – OPERATION SPI SERIAL E2PROM FOR AUTOMOTIVE

105°C OPERATION SPI SERIAL E²PROM FOR AUTOMOTIVE
S-25C010A/020A/040A H Series
Rev.2.3_01_C
3. Write disable (WRDI)
The WRDI instruction is one of ways to reset bit Write Enable Latch (WEL). After selecting the device by the chip select
( CS ), input the instruction code from serial data input (SI).
To reset bit WEL, set the device in the non-select status by CS at the 8th clock of the serial clock. To cancel the WRDI
instruction, input the clock different from a specified value (n = 8 clock) while CS is in “L”.
Bit WEL is reset after the operations shown below.
• The power supply voltage is dropping
• Power-on
• After performing WRDI
• After the completion of Write operation by the WRSR instruction
• After the completion of Write operation by the WRITE instruction
• After setting the WP pin to “L”
CS
WP
High / Low
SCK
SI
1
2
3
4
5
6
7
8
Instruction
X
SO
Remark X = Don’t care.
High-Z
Figure 12 WRDI Operation
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