W25Q128FVSIG_13 Datasheet, PDF (77/97 Pages) Winbond – 3V 128M-BIT SERIAL FLASH MEMORY WITH DUAL/QUAD SPI & QPI

W25Q128FV
8.2.40 Read Block/Sector Lock (3Dh)
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, SEC, TB,
BP[2:0] 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 read out the lock bit value of a specific block or sector as illustrated in Figure 4d, a Read Block/Sector
Lock command must be issued by driving /CS low, shifting the instruction code “3Dh” into the Data Input
(DI) pin on the rising edge of CLK, followed by a 24-bit address. The Block/Sector Lock bit value will be
shifted out on the DO pin at the falling edge of CLK with most significant bit (MSB) first as shown in Figure
54. If the least significant bit (LSB) is 1, the corresponding block/sector is locked; if LSB=0, the
corresponding block/sector is unlocked, Erase/Program operation can be performed.
Figure 54a. Read Block Lock Instruction (SPI Mode)
Figure 54b. Read Block Lock Instruction (QPI Mode)
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Publication Release Date: October 01, 2012
Revision D