Program flash protection register
Program flash protection bits
FPROT0
PROT[31:24]
FPROT1
PROT[23:16]
FPROT2
PROT[15:8]
FPROT3
PROT[7:0]
During the reset sequence, the FPROT registers are loaded with the contents of the
program flash protection bytes in the Flash Configuration Field as indicated in the
following table.
Program flash protection register
Flash Configuration Field offset address
FPROT0
0x000B
FPROT1
0x000A
FPROT2
0x0009
FPROT3
0x0008
To change the program flash protection that is loaded during the reset sequence,
unprotect the sector of program flash memory that contains the Flash Configuration
Field. Then, reprogram the program flash protection byte.
Address: 4002_0000h base + 10h (1d × i), where i=0d to 3d
Bit
7
6
5
4
3
2
1
0
Read
Write
Reset
* Notes:
x = Undefined at reset.
•
FTFA_FPROTn field descriptions
Field
Description
PROT
Program Flash Region Protect
Each program flash region can be protected from program and erase operations by setting the associated
PROT bit.
In NVM Normal mode: The protection can only be increased, meaning that currently unprotected memory
can be protected, but currently protected memory cannot be unprotected. Since unprotected regions are
marked with a 1 and protected regions use a 0, only writes changing 1s to 0s are accepted. This 1-to-0
transition check is performed on a bit-by-bit basis. Those FPROT bits with 1-to-0 transitions are accepted
while all bits with 0-to-1 transitions are ignored.
In NVM Special mode: All bits of FPROT are writable without restriction. Unprotected areas can be
protected and protected areas can be unprotected.
Restriction: The user must never write to any FPROT register while a command is running (CCIF=0).
Trying to alter data in any protected area in the program flash memory results in a protection violation
error and sets the FSTAT[FPVIOL] bit. A full block erase of a program flash block is not possible if it
contains any protected region.
Memory Map and Registers
KL02 Sub-Family Reference Manual, Rev. 2.1, July 2013
314
Freescale Semiconductor, Inc.