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S-25C010A-H Datasheet, PDF (16/33 Pages) Seiko Instruments Inc – OPERATION SPI SERIAL E2PROM FOR AUTOMOTIVE | |||
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105°C OPERATION SPI SERIAL E2PROM FOR AUTOMOTIVE
S-25C010A/020A/040A H Series
Rev.2.3_01_C
5. Write in the status register (WRSR)
The values of status register (BP1, BP0) can be rewritten by inputting the WRSR instruction. But b7, b6, b5, b4, b1, b0
of status register cannot be rewritten. b7 to b4 are always â1â when reading the status register.
Before inputting the WRSR instruction, set bit WEL by the WREN instruction. The operation of WRSR is shown below.
Set the chip select ( CS ) âLâ first. After that, input the instruction code and data from serial data input (SI). To start
WRSR Write (tPR), set the chip select ( CS ) to âHâ after inputting data or before inputting a rising of the next serial
clock. It is possible to confirm the operation status by reading the value of bit WIP during WRSR Write. Bit WIP is â1â
during Write, â0â during any other status. Bit WEL is reset when Write is completed.
With the WRSR instruction, the values of BP1 and BP0; which determine the area size the users can handle as the
Read Only memory; can be changed. When signal WP is âLâ, however, the WRSR instruction is not be performed
(Refer to âï® Protect Operationâ).
Bits BP1 and BP0 keep the value which is the one prior to the WRSR instruction during the WRSR instruction. The
newly updated value is changed when the WRSR instruction has completed.
To cancel the WRSR instruction, input the clock different from a specified value (n = 16 clock) while CS is in âLâ.
CS
WP
High
SCK
SI
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Instruction
Inputs Data in the Status Register
X
b7 b6 b5 b4 b3 b2 b1 b0
SO
Remark X = Donât care.
High-Z
Figure 14 WRSR Operation
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