S-25A010A Datasheet, PDF (17/35 Pages) Seiko Instruments Inc – Write protect function during the low power supply voltage

Rev.5.2_01
FOR AUTOMOTIVE 125°C OPERATION SPI SERIAL E²PROM
S-25A010A/020A/040A
4. Read the status register (RDSR)
Reading data in the status register is possible by the RDSR instruction. During the write operation, it is possible to
confirm the progress by checking bit WIP.
Set the chip select ( CS ) "L" first. After that, input the instruction code from serial data input (SI). The status of bit in
the status register is output from serial data output (SO). Sequential read is available for the status register. To stop
the read cycle, set CS to "H".
It is possible to read the status register always. The bits in it are valid and can be read by RDSR even in the write
cycle.
The 2 bits WEL and WIP are updated during the write cycle. The updated nonvolatile bits BP1 and BP0 can be
acquired by performing a new RDSR instruction after verifying the completion of the write cycle.
b7, b6, b5, and b4 are "1" when they are read by the RDSR instruction.
CS
WP
High / Low
SCK
SI
SO
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Instruction
X
High-Z
Outputs Data in the Status Register
b7 b6 b5 b4 b3 b2 b1 b0 b7
Remark X = Don't care.
Figure 14 RDSR Operation
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