MX25L12835F
9-32. Advanced Sector Protection
There are two ways to implement software Advanced Sector Protection on this device: Password method or Solid
method. Through these two protection methods, user can disable or enable the programming or erasing operation
to any individual sector or all sectors.
There is a non-volatile (SPB) and volatile (DPB) protection bit related to the single sector in main flash array. Each
of the sectors is protected from programming or erasing operation when the bit is set.
The figure below helps describing an overview of these methods. The device is default to the Solid mode when
shipped from factory. The detail algorithm of advance sector protection is shown as follows:
Figure 58. Advanced Sector Protection Overview
Start
Bit 1=0
Bit 2=0
Set
Lock Register ?
Solid Protection Mode
Password Protection Mode
Set 64 bit Password
SPBL = 0
SPB Lock bit locked
All SPB can not be changeable
SPB Lock Bit ?
SPBL = 1
SPB Lock bit Unlocked
SPB is changeable
SPB Access Register
(SPBR)
Dynamic Protect Bit Register
(DPBR)
Sector Array
SPBR=1 Write Protect
DPBR=1 sector protect
SPBR=0 Write Unprotect
DPBR=0 sector unprotect
DPBR 0
DPBR 1
SA 0
SA 1
SPBR 0
SPBR 1
DPBR 2
SA 2
SPBR 2
:
:
:
:
:
:
DPBR N-1
DPBR N
SA N-1
SA N
SPBR N-1
SPBR N
P/N: PM1795
REV. 1.0, OCT. 23, 2012
65
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