Rainbow Electronics AT25DQ321 - Manual (Page 29)

29 AT25DQ321 [DATASHEET]
8718D–DFLASH–12/2012
Table 9-2. Valid SPRL and Global Protect/Unprotect Conditions
WP
State
Current
SPRL
Value
New Write Status
Register Byte 1
Data
Protection Operation
New
SPRL
Value Bit
7 6 5 4 3 2 1 0
0 0
0 x 0 0 0 0 x x
0 x 0 0 0 1 x x

0 x 1 1 1 0 x x
0 x 1 1 1 1 x x
1 x 0 0 0 0 x x
1 x 0 0 0 1 x x

1 x 1 1 1 0 x x
1 x 1 1 1 1 x x
Global Unprotect – all Sector Protection Registers reset to 0
No change to current protection
No change to current protection
No change to current protection
Global Protect – all Sector Protection Registers set to 1
Global Unprotect – all Sector Protection Registers reset to 0
No change to current protection
No change to current protection
No change to current protection
Global Protect – all Sector Protection Registers set to 1
0
0
0
0
0
1
1
1
1
1
0 1 x x x x x x x x
No change to the current protection level. All sectors currently protected will remain protected
and all sectors currently unprotected will remain unprotected.
The Sector Protection Registers are hard-locked and cannot be changed when the WP pin is
LOW and the current state of SPRL is 1. Therefore, a Global Protect/Unprotect will not occur.
In addition, the SPRL bit cannot be changed (the WP pin must be HIGH in order to change
SPRL back to a 0).
1 0
0 x 0 0 0 0 x x
0 x 0 0 0 1 x x

0 x 1 1 1 0 x x
0 x 1 1 1 1 x x
1 x 0 0 0 0 x x
1 x 0 0 0 1 x x

1 x 1 1 1 0 x x
1 x 1 1 1 1 x x
Global Unprotect – all Sector Protection Registers reset to 0
No change to current protection
No change to current protection
No change to current protection
Global Protect – all Sector Protection Registers set to 1
Global Unprotect – all Sector Protection Registers reset to 0
No change to current protection
No change to current protection
No change to current protection
Global Protect – all Sector Protection Registers set to 1
0
0
0
0
0
1
1
1
1
1
1 1
0 x 0 0 0 0 x x
0 x 0 0 0 1 x x

0 x 1 1 1 0 x x
0 x 1 1 1 1 x x
1 x 0 0 0 0 x x
1 x 0 0 0 1 x x

1 x 1 1 1 0 x x
1 x 1 1 1 1 x x
No change to the current protection level. All sectors currently protected will remain
protected and all sectors currently unprotected will remain unprotected.
The Sector Protection Registers are soft-locked and cannot be changed when the
current state of SPRL is 1. Therefore, a Global Protect/Unprotect will not occur.
However, the SPRL bit can be changed back to a 0 from a 1 since the WP pin is
HIGH. To perform a Global Protect/Unprotect, the Write Status Register command
must be issued again after the SPRL bit has been changed from a 1 to a 0.
0
0
0
0
0
1
1
1
1
1