SST25VF040B-20-4C-QAE Microchip Technology, SST25VF040B-20-4C-QAE Datasheet - Page 18

• Manufacturer Part Number: SST25VF040B-20-4C-QAE
• Description: Flash 512K X 8 14 us
• Manufacturer: Microchip Technology

Specifications of SST25VF040B-20-4C-QAE

• Product Category: Flash
• Rohs: yes
• Memory Size: 4 Mbit
• Interface Type: SPI
• Access Time: 20 ns
• Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• Package / Case: WSON-8

A Microchip Technology Company
©2011 Silicon Storage Technology, Inc.
Write-Enable (WREN)
Write-Disable (WRDI)
The Write-Enable (WREN) instruction sets the Write-Enable-Latch bit in the Status Register to 1 allow-
ing Write operations to occur. The WREN instruction must be executed prior to any Write (Program/
Erase) operation. The WREN instruction may also be used to allow execution of the Write-Status-Reg-
ister (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 instruc-
tion is executed.
Figure 17:Write Enable (WREN) Sequence
The Write-Disable (WRDI) instruction resets the Write-Enable-Latch bit and AAI bit to 0 disabling any
new Write operations from occurring. The WRDI instruction will not terminate any programming opera-
tion in progress. Any program operation in progress may continue up to T
instruction. CE# must be driven high before the WRDI instruction is executed.
Figure 18:Write Disable (WRDI) Sequence
SCK
CE#
SCK
CE#
SO
SO
SI
SI
MODE 3
MODE 0
MODE 3
MODE 0
18
HIGH IMPEDANCE
HIGH IMPEDANCE
MSB
0 1 2 3 4 5 6 7
MSB
0 1 2 3 4 5 6 7
04
06
1295 WREN.0
1295 WRDI.0
4 Mbit SPI Serial Flash
BP
after executing the WRDI
SST25VF040B
S71295-06-000
Data Sheet
02/11