W29GL256SH9T-TR Datasheet, PDF (37/88 Pages) Winbond – 256M-BIT 3.0-VOLT PARALLEL FLASH MEMORY WITH PAGE MODE

W29GL256S
The selection of the Individual Protection mode is set at the factory by programming OTP bit in the
Lock Register.
When shipped from Winbond, all the sector IPB bits are erased so that all main memory array sectors
are unprotected.
8.11.2 IPB Lock
This one per device volatile Individual Protection Bit Lock is a bit that will protect all IPB bits. When
programmed to 0, it locks all sector IPBs and if the bit is 1, it allows the all sector IPBs to be changed.
Only after the sector IPBs are configured to the desired state should the IPB Lock bit be programmed
to 0. Note the IPB Lock command can only program the bit to 0.
To erase the IPB Lock bit, only a Power Up Reset or a hardware reset will restore the value to 1 to
allow sector IPB bits to be changed. There is no software command operation that can clear the IPB
Lock to a 1.
8.11.3 Individual Protection Bits (IPB)
The non-volatile Individual Protection Bits (IPB) is located in a separate non-volatile flash array. There
is one IPB bit assigned to each sector. When an IPB is 0 their corresponding sectors is protected
from program and erase operations. The IPB can be programmed individually, but are erased as a
group. Important to note, the Write State Controller takes care of the preprogramming and verification
prior to erasure.
When programming an IPB bit the typical word programming time is required. To monitor the
operation status of an IPB bit programming or erase, DQ6 Toggle Bit I of the Data Polling Status will
toggle until the operation is complete. Note; typical sector erase time is required to erasing all the
IPBs.
Program or erase command will not execute and will time-out, if the IPB Lock is equal 0, without
programming or erasing the IPB.
The IPB Status Read command can be used to check the protection state of an IPB for a given
sector, but you must first enter the IPB MMO mode. See Instruction Definition Tables.
8.11.4 Dynamic Protection Bits (DPB)
The volatile Dynamic Protection Bits are exclusive for each sector and can be individually changed.
Only sectors that have their IPBs clear to 1 (unprotected) can the DPBs control. By issuing the DPB
Set or Clear command sequences, the DPB are clear to 1 or set to 0, thus placing each sector in the
Publication Release Date: Jul 02, 2014
Revision C
37