TC1796
System Units (Vol. 1 of 2)
Program Memory Unit
User’s Manual
7-24
V2.0, 2007-07
PMU, V2.0
7.2.5.9
Disable Read Protection Command
The six-cycle Disable Read Protection command temporarily disables an installed Flash
read protection.
The Disable Read 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 to the first and second 32-bit
keyword as defined in the related user configuration block UCB0 (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
Read Protection command is only accepted after the next reset operation.
After the correct execution of this command, the PFLASH and both DFLASH banks are
temporarily unlocked and flag FSR.RPRODIS is set. Read, erase, and write operations
to all unlocked (not separately write-protected) sectors are now possible, until
•
A Resume Protection command is executed, or
•
The next reset operation (hardware or software reset) is executed.
7.2.5.10 Resume Protection Command
With the one-cycle Resume Protection Command, a temporarily unlocked write
protection and/or read protection is terminated and the protection state is resumed. This
command resumes both kinds of temporarily disabled protection, write and read
protection.
Table 7-13
Disable Read 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
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
08
H
Table 7-14
Resume Protection Command
Cycle No.
Address
Data
Cycle 1
A000
5554
H
XXXX XX
5E
H