IS25LP032 datasheet(72/90 Pages) ISSI

72 / 90 page

IS25LP032/064/128

Integrated Silicon Solution, Inc.- www.issi.com

Rev. D

10/03/2014

8.38 SECTOR LOCK/UNLOCK FUNCTIONS

SECTOR UNLOCK OPERATION (SECUNLOCK, 26h)

The Sector Unlock command allows the user to select a specific sector to allow program and erase operations.

This instruction is effective when the blocks are designated as write-protected through the BP0, BP1, BP2, and

BP3 bits in the Status register. Only one sector can be enabled at any time. To enable a different sector, a

previously enabled sector must be disabled by executing a Sector Lock command. The instruction code is

followed by a 24-bit address specifying the target sector, but A0 through A11 are not decoded. The remaining

sectors within the same block remain as read-only.

In the Sector Unlock procedure, [A11:A0]

must be “0” for the unlock procedure to execute properly. The chip will

regard anything else as an illegal command.

Figure 8.56 Sector Unlock Sequence

Instruction = 26h

CE #

SCK

3-byte Address

High Impedance

Mode 3

Mode 0

20 16 12

21 17 13

IO0

IO1

22 18 14

23 19 15

8 4 0

9 5 1

10 6 2

11 7 3

IO2

IO3

Notes:

1. If the number of clock cycles do not match 8 cycles (command) + 24 clocks (address), the command will be

ignored.

2. WREN (06h) must be executed before sector unlock instructions.

IS25LP032 Datasheet(PDF) 72 Page - Integrated Silicon Solution, Inc