S-25C320A-H Datasheet, PDF (14/31 Pages) Seiko Instruments Inc – OPERATION SPI SERIAL E2PROM FOR AUTOMOTIVE

105°C OPERATION SPI SERIAL E²PROM FOR AUTOMOTIVE
S-25C320A/640A H Series
Rev.2.3_01_H
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
CS
WP
High / Low
SCK
SI
SO
1
2
3
4
5
6
7
8
Instruction
High-Z
Figure 12 WRDI Operation
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