S29GL128S SPANSION [SPANSION], S29GL128S Datasheet - Page 21

• Manufacturer Part Number: S29GL128S
• Manufacturer: SPANSION [SPANSION]

March 16, 2012 S29GL_128S_01GS_00_06
3.4.6
3.4.7
Sector Protection States Summary
Lock Register
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
 Dynamically Locked – A sector is protected and protection can be changed by a simple command. The
 Persistently Locked – A sector is protected and protection can only be changed if the PPB Lock Bit is set to
The Lock Register holds the non-volatile OTP bits for controlling protection of the SSR, and determining the
PPB Lock bit management method (protection mode).
The Secure Silicon Region (SSR) protection bits must be used with caution, as once locked, there is no
procedure available for unlocking the protected portion of the Secure Silicon Region and none of the bits in
the protected Secure Silicon Region memory space can be modified in any way. Once the Secure Silicon
Region area is protected, any further attempts to program in the area will fail with status indicating the area
being programmed is protected. The Region 1 Indicator Bit is located in the Lock Register at bit location 0 and
Region 2 in bit location 6.
As shipped from the factory, all devices default to the Persistent Protection method, with all sectors
unprotected, when power is applied. The device programmer or host system can then choose which sector
protection method to use. Programming either of the following two, one-time programmable, non-volatile bits,
locks the part permanently in that mode:
 Persistent Protection Mode Lock Bit (DQ1)
 Password Protection Mode Lock Bit (DQ2)
protection state defaults to unprotected after a power cycle or hardware reset.
protection state is not saved across a power cycle or hardware reset.
1. The protection state is non-volatile and saved across a power cycle or hardware reset. Changing the
protection state requires programming or erase of the PPB bits.
PPB Lock
15-9
Bit
1
1
1
1
0
0
0
0
8
7
6
5
4
3
2
1
0
Protection Bit Values
Default Value
D a t a
PPB
X
1
1
0
0
1
1
0
0
1
0
1
1
1
1
1
1
0
GL-S MirrorBit
S h e e t
Table 3.1 Sector Protection States
Reserved
Reserved
Reserved
SSR Region 1 (Customer) Lock Bit
Reserved
Reserved
Reserved
Password Protection Mode Lock Bit
Persistent Protection Mode Lock Bit
SSR Region 0 (Factory) Lock Bit
Table 3.2 Lock Register
DYB
1
0
1
0
1
0
1
0
®
Family
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
Name
Sector State
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