IS25LE512MG-RLLA2:PTY datasheet(41/194 Pages) ISSI

41 / 194 page

IS25LE512MG

IS25WE512MG

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

Rev. A6

10/02/2025

7.2.2 ADVANCED SECTOR/BLOCK PROTECTION (ASP)

There are two ways to implement software Advanced Sector/Block Protection on this device: Password Protection

method or Persistent Protection methods. Through these two protection methods, user can disable or enable the

programming or erasing operation to any or all blocks including 32 top 4K sectors or 32 bottom 4K sectors when

block size is 64KB. When block size is uniform 256KB, there will be no 32 4KB parameter blocks.

The Figure 7.1 shows an overview of these methods

Every main flash array block/top sector/bottom sector has a non-volatile (PPB) and a volatile (DYB) protection bit

associated with it. When either bit is 0, the sector is protected from program and erase operations.

The PPB bits are protected from program and erase when the PPB Lock bit is “0”. The PPB bits are erased so that

all main flash array sectors are unprotected when shipped from factory.

There are two methods for managing the state of the PPB Lock bit, Persistent Protection and Password Protection.

The Persistent Protection Mode sets the PPB Lock bit to “1” during power up or Hardware Reset so that the PPB

bits are unprotected. There is a WRPLB command to clear the PPB Lock bit to “0” to protect the PPB bits. There

is no command in the Persistent Protection method to set the PPB Lock bit therefore the PPB Lock bit will remain

at “0” until the next power up or Hardware Reset. The Persistent Protection method allows boot code the option of

changing sector protection by programming or erasing the PPB, then protecting the PPB from further change for

the remainder of normal system operation by clearing the PPB Lock bit. This is sometimes called Boot-code

controlled sector protection.

The Password Protection Mode requires use of a password to control PPB protection. In the Password Protection

Mode, the PPB Lock bit is cleared to “0” during power up or Hardware Reset to protect the PPB bits. A 64-bit

password may be permanently programmed and hidden for the Password Protection Mode. The UNPWD command

can be used to provide a password for comparison with the hidden password. If the password matches the PPB

Lock bit is set to “1” to unprotect the PPB. The WRPLB command can be used to clear the PPB Lock bit to “0”.

After cleaning the PPB Lock bit to “0” with WRPLB command, H/W reset (or Power cycle) is required to use

UNPWD command again to unprotect the PPB.

The selection of the PPB Lock bit management method is made by programming OTP bits in the ASP Register so

as to permanently select the method used.

IS25LE512MG-RLLA2:PTY Datasheet(PDF) 41 Page - Integrated Silicon Solution, Inc