S25FL256SDSMFVE10 View Datasheet(PDF) - Cypress Semiconductor
Part Name
Description
Manufacturer
S25FL256SDSMFVE10
Cypress Semiconductor
S25FL256SDSMFVE10 Datasheet PDF : 144 Pages
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S25FL128S, S25FL256S
8.4.4
PPB Lock Bit (PPBL[0])
The PPB Lock Bit is a volatile bit for protecting all PPB bits. When cleared to 0, it locks all PPBs and when set to 1, it allows the
PPBs to be changed.
The PLBWR command is used to clear the PPB Lock bit to 0. The PPB Lock Bit must be cleared to 0 only after all the PPBs are
configured to the desired settings.
In Persistent Protection mode, the PPB Lock is set to 1 during POR or a hardware reset. When cleared to 0, no software command
sequence can set the PPB Lock bit to 1, only another hardware reset or power-up can set the PPB Lock bit.
In the Password Protection mode, the PPB Lock bit is cleared to 0 during POR or a hardware reset. The PPB Lock bit can only be
set to 1 by the Password Unlock command.
8.4.5
Sector Protection States Summary
Each sector can be in one of the following protection states:
Unlocked — The sector is unprotected and protection can be changed by a simple command. The protection state defaults to
unprotected after a power cycle, software reset, or hardware reset.
Dynamically Locked — A sector is protected and protection can be changed by a simple command. The protection state is not
saved across a power cycle or reset.
Persistently Locked — A sector is protected and protection can only be changed if the PPB Lock Bit is set to 1. The protection
state is non-volatile and saved across a power cycle or reset. Changing the protection state requires programming and or
erase of the PPB bits
Table 8.3 Sector Protection States
PPB Lock
1
1
1
1
0
0
0
0
Protection Bit Values
PPB
1
1
0
0
1
1
0
0
DYB
1
0
1
0
1
0
1
0
Sector State
Unprotected – PPB and DYB are changeable
Protected – PPB and DYB are changeable
Protected – PPB and DYB are changeable
Protected – PPB and DYB are changeable
Unprotected – PPB not changeable, DYB is changeable
Protected – PPB not changeable, DYB is changeable
Protected – PPB not changeable, DYB is changeable
Protected – PPB not changeable, DYB is changeable
8.4.6
Persistent Protection Mode
The Persistent Protection method sets the PPB Lock bit to 1 during POR or Hardware Reset so that the PPB bits are unprotected by
a device hardware reset. Software reset does not affect the PPB Lock bit. The PLBWR command can clear the PPB Lock bit to 0 to
protect the PPB. There is no command to set the PPB Lock bit therefore the PPB Lock bit will remain at 0 until the next power-off or
hardware reset.
Document Number: 001-98283 Rev. *I
Page 61 of 144
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