W25Q256FVBIF-TR Datasheet, PDF (90/108 Pages) Winbond – 3V 256M-BIT SERIAL FLASH MEMORY WITH DUAL/QUAD SPI & QPI

W25Q256FV
8.2.49 Individual Block/Sector Unlock (39h)
The Individual Block/Sector Lock provides an alternative way to protect the memory array from adverse
Erase/Program. In order to use the Individual Block/Sector Locks, the WPS bit in Status Register-3 must
be set to 1. If WPS=0, the write protection will be determined by the combination of CMP, TB, BP[3:0] bits
in the Status Registers. The Individual Block/Sector Lock bits are volatile bits. The default values after
device power up or after a Reset are 1, so the entire memory array is being protected.
To unlock a specific block or sector as illustrated in Figure 4d, an Individual Block/Sector Unlock
command must be issued by driving /CS low, shifting the instruction code “39h” into the Data Input (DI)
pin on the rising edge of CLK, followed by a 24/32-bit address and then driving /CS high.
/CS
CLK
DI
(IO₀)
DO
(IO₁)
Mode 3
0
Mode 0
* ^{= MSB}
123456789
29 30 31
Instruction (39h)
24-Bit Address
23 22
*
High Impedance
210
Mode 3
Mode 0
Figure 53a. Individual Block Unlock Instruction (SPI Mode)
32-Bit Address is required when the device is operating in 4-Byte Address Mode
/CS
CLK
IO₀
Mode 3
Mode 0
01234567
Instruction
39h
A23-16
20 16
A15-8
12 8
A7-0
40
Mode 3
Mode 0
IO₁
21 17 13 9 5 1
IO₂
22 18 14 10 6 2
IO₃
23 19 15 11 7 3
Figure 53b. Individual Block Unlock Instruction (QPI Mode)
32-Bit Address is required when the device is operating in 4-Byte Address Mode
- 89 -