Technical Note

10/18

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2010.12 - Rev.B

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●WPB cancel valid area

WPB is normally fixed to “H” or “L” for use, but when WPB is controlled so as to cancel write status register command, pay

attention to the following WPB valid timing.

While write status register command is executed, by setting WPB = “L” in cancel valid area, command can be cancelled.

The area from command ope code to CSB rise at internal automatic write start becomes the cancel valid area. However,

once write is started, by any input write cycle cannot be cancelled. WPB input becomes Don’t Care, and cancellation

becomes invalid.

●HOLDB pin

By HOLDB pin, command communication can be stopped temporarily (HOLD status). The command communications are

carried out when the HOLDB pin is HIGH. To get in HOLD status, at command communication, when SCK=LOW, set the

HOLDB pin LOW. At HOLD status, SCK and SI become Don’t Care, and SO becomes high impedance (High-Z). To release

the HOLD status, set the HOLDB pin HIGH when SCK=LOW. After that, communication can be restarted from the point

before the HOLD status. For example, when HOLD status is made after A5 address input at read, after release of HOLD

status, by starting A4 address input, read can be restarted. When in HOLD status, keep CSB LOW. When it is set

CSB=HIGH in HOLD status, the IC is reset, therefore communication after that cannot be restarted.

Fig.39

WPB valid timing (At inputting WRSR command)

6

7

Ope Code

Data

tE/W

Data write time

SCK

15

16

Valid

(WRSR command is reset by WPB=L)

Invalid