SST25VF040B-20-4C-QAE Microchip Technology, SST25VF040B-20-4C-QAE Datasheet - Page 6

• 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 Protection
Write Protect Pin (WP#)
Figure 4: Hold Condition Waveform
SST25VF040B provides software Write protection. The Write Protect pin (WP#) enables or disables
the lock-down function of the status register. The Block-Protection bits (BP3, BP2, BP1, BP0, and BPL)
in the status register provide Write protection to the memory array and the status register. See Table 4
for the Block-Protection description.
The Write Protect (WP#) pin enables the lock-down function of the BPL bit (bit 7) in the status register.
When WP# is driven low, the execution of the Write-Status-Register (WRSR) instruction is determined
by the value of the BPL bit (see Table 2). When WP# is high, the lock-down function of the BPL bit is
disabled.
Table 2: Conditions to execute Write-Status-Register (WRSR) Instruction
HOLD#
SCK
WP#
H
L
L
Active
BPL
X
1
0
6
Hold
Execute WRSR Instruction
Not Allowed
Allowed
Allowed
4 Mbit SPI Serial Flash
Active
Hold
SST25VF040B
S71295-06-000
Active
1295 HoldCond.0
Data Sheet
T2.0 1295
02/11