Freescale Semiconductor MK22FN256VDC12, Reference Manual

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FTFA_FCNFG field descriptions (continued)
Field Description
0 No request or request complete
1 Request to:
1. run the Erase All Blocks command,
2. verify the erased state,
3. program the security byte in the Flash Configuration Field to the unsecure state, and
4. release MCU security by setting the FSEC[SEC] field to the unsecure state.
4
ERSSUSP
Erase Suspend
Allows the user to suspend (interrupt) the Erase Flash Sector command while it is executing.
0 No suspend requested
1 Suspend the current Erase Flash Sector command execution.
3
Reserved
This field is reserved.
This read-only field is reserved and always has the value 0.
2
Reserved
This field is reserved.
This read-only field is reserved and always has the value 0.
1
Reserved
This field is reserved.
This read-only field is reserved and always has the value 0.
0
Reserved
This field is reserved.
This read-only field is reserved and always has the value 0.
29.33.3 Flash Security Register (FTFA_FSEC)
This read-only register holds all bits associated with the security of the MCU and flash
memory 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. •
FTFA_FSEC field descriptions
Field Description
7–6
KEYEN
Backdoor Key Security Enable
Enables or disables backdoor key access to the flash memory module.
Table continues on the next page...
Chapter 29 Flash Memory Module (FTFA)
K22F Sub-Family Reference Manual , Rev. 3, 7/2014
Freescale Semiconductor, Inc. 621