MX25L12835F
9-35. Solid Protection Bits
The Solid write Protection bit (SPB) is a nonvolatile bit with the same endurances as the Flash memory. It is
assigned to each sector individually. The SPB is Preprogramming, and its verification prior to erasure are managed
by the device, so system monitoring is not necessary.
When a SPB is set to “1”, the associated sector is protected, preventing any program or erase operation on this
sector. The SPB bits are set individually by SPB program command. However, it cannot be cleared individually.
Issuing the All SPB Erase command will erase all SPB in the same time.
If one of the protected sector need to be unprotected (corresponding SPB set to “0”), a few more steps are required.
First, the SPB lock bit must be cleared by PASSWD unlock command if lock register bit2 is set to "0" or by a power-
on cycle or hardware reset if lock register bit1 is set to "0". The SPBs can then be changed to reflect the desired
settings. Setting the SPB Lock Bit once again locks the SPBs, and the device operates normally again.
To verify the programming state of the SPB for a given sector, issuing a SPB Read Command to the device is
required.
Note:
1. Once SPB Lock Bit is set, its Program or erase command will not be executed and times-out without programming
or erasing the SPB.
SPB Register (SPBR)
Bit
Description
Bit Status
Default
Type
00h= SPB for the sector address unprotected
FFh= SPB for the sector address protected
7 to 0 SPB (Solid protected Bit)
00h
Non-volatile
P/N: PM1795
REV. 1.0, OCT. 23, 2012
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