NXP Semiconductors KE1xF Series, Reference Manual, Page: 377 / 1483

FTFE_FCNFG field descriptions (continued)
Field Description
0 FlexRAM is not available for EEPROM operation
1 FlexRAM is available for EEPROM operations where:
• reads from the FlexRAM return data previously written to the FlexRAM in EEPROM mode and
• writes launch an EEPROM operation to store the written data in the FlexRAM and EEPROM
backup
17.4.4.3 Flash Security Register (FTFE_FSEC)
This read-only register holds all bits associated with the security of the MCU and FTFE
module.
During the reset sequence, the register is loaded with the contents of the flash security
byte in the Flash Configuration Field located in program flash memory. The Flash basis
for the values is signified by X in the reset value.
Address: 4002_0000h base + 2h offset = 4002_0002h
Bit 7 6 5 4 3 2 1 0
Read KEYEN MEEN FSLACC SEC
Write
Reset
x* x* x* x* x* x* x* x*
* Notes:
x = Undefined at reset. •
FTFE_FSEC field descriptions
Field Description
7–6
KEYEN
Backdoor Key Security Enable
These bits enable and disable backdoor key access to the FTFE module.
00 Backdoor key access disabled
01 Backdoor key access disabled (preferred KEYEN state to disable backdoor key access)
10 Backdoor key access enabled
11 Backdoor key access disabled
5–4
MEEN
Mass Erase Enable Bits
Enables and disables mass erase capability of the FTFE module. When the SEC field is set to unsecure,
the MEEN setting does not matter.
00 Mass erase is enabled
01 Mass erase is enabled
10 Mass erase is disabled
11 Mass erase is enabled
Table continues on the next page...
Chapter 17 Flash Memory Module (FTFE)
Kinetis KE1xF Sub-Family Reference Manual, Rev. 4, 06/2019
NXP Semiconductors 377