Table 1134. Lock2_Pgn Register Field Descriptions - STMicroelectronics SPC572L series Reference Manual

RM0400
Field
0–31
Lower 256KByte Block Lock. A value of 1 in a bit of the lock register signifies that the corresponding
block is locked for program and erase.
L_256LCK
The initial value of the lock bits is set via DCF records stored in UTEST Flash block and
copied over during reset. The default value before any DCF record is written is '1', which
indicates a block is locked.
During the Customer Delivery life cycle, the user must program a valid password or a DCF
record that writes this register to unprotect the UTEST for each password group in order to
prevent permanent and irreversible locking of Flash blocks.
Warning:
Once a password group is unlocked, software can set or clear any of the lock bits in the
group, by writing to the registers.
The resulting lock status of a Flash block is determined by the combination of the lock bits of
all password groups. If a block is locked in multiple groups, then all lock bits for the block
need to be cleared before program and erase is possible.. However, unless the life cycle is
older than OEM Production, the Flash blocks are always unlocked regardless of the values
in the password groups.
68.2.1.8 Password Group n - Lock 3 status register (LOCK3_PGn)
Each Password Group has one Lock 3 Status Register. This register shows the current lock
state for the Flash blocks. Each time a password group is unlocked, the PGL bit is cleared
and the Lock registers become writable.
The LOCK bits do not come into effect before the life cycle matures to OEM Production or
older.

Table 1134. LOCK2_PGn register field descriptions

Failure to program valid passwords or DCF records for all
password groups before the life cycle matures to OEM
Production renders the part unusable. However, additional
DCF Records can be written to UTEST to change the initial
value of this register.
DocID027809 Rev 4
Password and Device Security Module (PASS)
Description
2003/2058
2011