Datasheet

©2011 Silicon Storage Technology, Inc. DS25071A 12/11
18
32 Mbit SPI Serial Flash
SST25VF032B
Data Sheet
A
Microchip Technology Company
Write-Enable (WREN)
The Write-Enable (WREN) instruction sets the Write-Enable-Latch bit in the Status Register to ‘1’
allowing Write operations to occur. The WREN instruction must be executed prior to any Write (Pro-
gram/Erase) operation. The WREN instruction may also be used to allow execution of the Write-Sta-
tus-Register (WRSR) instruction; however, the Write-Enable-Latch bit in the Status Register will be
cleared upon the rising edge CE# of the WRSR instruction. CE# must be driven high before the WREN
instruction is executed.
Figure 17: Write Enable (WREN) Sequence
Write-Disable (WRDI)
The Write-Disable (WRDI) instruction resets the Write-Enable-Latch bit and AAI bit to ‘0,’ therefore,
preventing any new Write operations. The WRDI instruction will not terminate any programming opera-
tion in progress. Any program operation in progress may continue up to T
BP
after executing the WRDI
instruction. CE# must be driven high before the WRDI instruction is executed.
Figure 18: Write Disable (WRDI) Sequence
CE#
SO
SI
SCK
01234567
06
HIGH IMPEDANCE
MODE 0
MODE 3
1327 F18.0
MSB
CE#
SO
SI
SCK
01234567
04
HIGH IMPEDANCE
MODE 0
MODE 3
1327 F19.0
MSB