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TC1796
System Units (Vol. 1 of 2)
Program Memory Unit
User’s Manual
7-23
V2.0, 2007-07
PMU, V2.0
7.2.5.8
Disable Write Protection Command
The six-cycle Disable Write Protection command temporarily disables the write
protection of all protected PFLASH sectors as defined for user 0 (indicated in register
PROCON0) or user 1 (indicated in register PROCON1).
The Disable Write Protection command is not accepted for UCB2 because UCB2 is a
OTP write-protected UCB.
The Disable Write Protection command is a protected command sequence, meaning
that two passwords (data in cycle 4 and 5) must be issued within the command. The first
and second 32-bit passwords are internally compared with the first and second 32-bit
keyword as defined in the related UCB0 or UCB1 (see
). If one or both
passwords are not identical to their related keywords, the sectors remain protected and
the protection error flag FSR.PROER is set. In this case, a new Disable Write Protection
command is only accepted after the next reset operation.
After the correct execution of the Disable Write Protection command, all protected
sectors as defined for UCB0 or UCB1 are unlocked (if no read protection is additionally
installed and active) and flag FSR.WPRODIS0 or FSR.WPRODIS1 is set. Erase and
write operations to temporarily unlocked sectors are now possible, until
•
A Resume Protection command is executed, or
•
The next reset operation (hardware or software reset) is executed.
Table 7-12
Disable Write Protection Command
Cycle No.
Address
Data
Cycle 1
A000
5554
H
XXXX XX
AA
H
Cycle 2
A000
AAA8
H
XXXX XX
55
H
Cycle 3
A000
553C
H
XXXX XX
00
H
(user 0, UCB0) or
XXXX XX
01
H
(user 1, UCB1)
Cycle 4
A000
AAA8
H
First 32-bit password
Cycle 5
A000
AAA8
H
Second 32-bit password
Cycle 6
A000
5558
H
XXXX XX
05
H