Information

FTFL_FPROTn field descriptions (continued)
Field Description
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.
Each bit in the 32-bit protection register represents 1/32 of the total program flash .
0 Program flash region is protected.
1 Program flash region is not protected
28.34.7 EEPROM Protection Register (FTFL_FEPROT)
The FEPROT register defines which EEPROM regions of the FlexRAM are protected
against program and erase operations. Protected EEPROM regions cannot have their
content changed by writing to it. Unprotected regions can be changed by writing to the
FlexRAM.
Address: FTFL_FEPROT is 4002_0000h base + 16h offset = 4002_0016h
Bit 7 6 5 4 3 2 1 0
Read
EPROT
Write
Reset
x* x* x* x* x* x* x* x*
* Notes:
x = Undefined at reset.•
FTFL_FEPROT field descriptions
Field Description
7–0
EPROT
EEPROM Region Protect
Individual EEPROM regions can be protected from alteration by setting the associated EPROT bit. The
EPROT bits are not used when the FlexNVM Partition Code is set to data flash only. When the FlexNVM
Partition Code is set to data flash and EEPROM or EEPROM only, each EPROT bit covers one-eighth of
the configured EEPROM data (see the EEPROM Data Set Size parameter description).
In NVM Normal mode: The protection can only be increased. This means 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 FEPROT 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 the FEPROT register are writable without restriction. Unprotected
areas can be protected and protected areas can be unprotected.
Restriction: Never write to the FEPROT register while a command is running (CCIF=0).
Memory Map and Registers
K20 Sub-Family Reference Manual, Rev. 2, Feb 2012
514 Freescale Semiconductor, Inc.