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4. Status register write / read command

Write status register command can write status register data. The data can be written by this command are 2 bits

BP1 (bit3) and BP0 (bit2) among 8 bits of status register. By BP1 and BP0, write disable block of EEPROM can be set. As for

this command, set CSB LOW, and input ope code of write status register, and input data. Then, by making CSB HIGH,

EEPROM starts writing. Write time requires time of tE/W as same as write. As for CSB rise, start CSB after taking the last

data bit (bit0), and before the next SCK clock starts. At other timing, command is cancelled. Write disable block is determined

by BP1 and BP0, and the block can be selected from 1/4 of memory array, 1/2, and entire memory array. (Refer to the write

disable block setting table.) To the write disabled block, write cannot be made, and only read can be made.

CSB

SCK

High-Z

0

0

0

0

ж

1

ж

0

1

2

4

0

SI

SO

0

3

7

8

5

6

ж

9

10

11

12

13

14

15

ж

ж

BP1 BP0

ж

ж

bit7

bit6

bit5

bit4

bit3

bit2

bit1

bit0

CSB

SCK

High-Z

0

0

0

0

1

WPEN

0

1

2

4

0

SI

SO

0

3

7

8

5

6

*

9

10

11

12

13

14

15

*

*

BP1 BP0

*

*

bit7

bit6

bit5

bit4

bit3

bit2

bit1

bit0

0

Fig.39 Status register write command (BR25H010/020/040-W)

Fig.40 Status register write command (BR25H080/160/320-W)

High-Z

bit7

bit6

bit5

bit4

1

1

BP0

1

BP1

bit3

bit2

bit1

bit0

13

CSB

SCK

SI

1

1

10

6

0

SO

14

1

2

WEN

R/B

11

15

3

7

9

0

5

12

0

0

0

0

ж

4

8

1

High-Z

bit7

bit6

bit5

bit4

0

0

BP0

0

BP1

bit3

bit2

bit1

bit0

13

CSB

SCK

SI

1

1

10

6

0

SO

14

1

2

WEN

R/B

11

15

3

7

9

0

5

12

0

0

0

0

0

4

8

WPEN

Fig.41 Status register read command (BR25H010/020/040-W)

Fig.42 Status register read command (BR25H080/160/320-W)