Datasheet

6/16
BR25L010-W, BR25L020-W, BR25L040-W, BR25L080-W, BR25L160-W, BR25L320-W, BR25L640-W
Technical Note
R/B
Write cycle status (READY / BUSY) status confirmation bit
-
bit
Memory
location
Function
WPEN EEPROM
BP1
BP0
EEPROM
WEN Register
WP pin enable / disable designation bit
EEPROM write disable block designation bit
Write and write status register write enable / disable status confirmation bit
Register
Contents
WEN = 0 = prohibited
WEN = 1 = permitted
WPEN = 0 = invalid
WPEN = 1 = valid
-
-
R/B
=
0
=
READY
R/B
=
1
=
BUSY
Features
Status registers
Write disable block setting
BR25L010-W
BR25L020-W 1
WPEN
BR25L040-W
BR25L080-W
BR25L160-W
BR25L320-W
BR25L640-W
Product number bit 7
1
0
bit 6
1
0
bit 5
1
0
bit 4
BP1
BP1
bit 3
BP0
BP0
bit 2
WEN
WEN
bit 1
R/B
-
R/B
-
bit 0
BP0
None
60h-7Fh
40h-7Fh
00h-7Fh
BR25L010-W
None
C0h-FFh
80h-FFh
00h-FFh
BR25L020-W
None
180h-1FFh
100h-1FFh
000h-1FFh
BR25L040-W
None
300h-3FFh
200h-3FFh
000h-3FFh
BR25L080-W
None
600h-7FFh
400h-7FFh
000h-7FFh
BR25L160-W
None
C00h-FFFh
800h-FFFh
000h-FFFh
BR25L320-W
None
1800h-1FFFh
1000h-1FFFh
0000h-1FFFh
BR25L640-W
Write disable block
0
1
0
1
BP1
0
0
1
1
BR25L010-W
BR25L020-W
Prohibition
possible
Prohibition
possible but
WPEN bit "1"
BR25L040-W
BR25L080-W
BR25L160-W
BR25L320-W
BR25L640-W
Product number WRSR
Prohibition
possible
Prohibition
impossible
WRITE
Status registers
This IC has status registers. The status registers are of 8 bits and express the following parameters.
BP0 and BP1 can be set by write status register command. These 2 bits are memorized into the EEPROM, therefore are
valid even when power source is turned off.
Rewrite characteristics and data hold time are same as characteristics of the EEPROM.
WEN can be set by write enable command and write disable command. WEN becomes write disable status when power
source is turned off. R/B is for write confirmation, therefore cannot be set externally.
The value of status register can be read by read status command.
This enables / disables the functions
of WP pin.
This designates the write disable area
of EEPROM. Write designation areas
of product numbers are shown below.
WP pin
By setting WP = LOW, write command is prohibited. As for BR25L080, 160, 320, 640-W, only when WPEN bit is set "1",
the WP pin functions become valid. And the write command to be disabled at this moment is WRSR. As for BR25L010,
020, 040-W, both WRITE and WRSR commands are prohibited.
However, when write cycle is in execution, no interruption can be made.
HOLD pin
By HOLD pin, data transfer can be interrupted. When SCK = "1", by making HOLD from "1" into "0", data transfer to
EEPROM is interrupted. When SCK = "0", by making HOLD from "0" into "1", data transfer is restarted.
2010.07 - Rev. B
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