NXP Semiconductors K32 L2A Series, Reference Manual, Page: 655 / 1379

module reverts back to the flash security byte in the Flash Configuration Field. The
Verify Backdoor Access Key command sequence has no effect on the program and erase
protections defined in the program flash protection registers.
If the backdoor keys successfully match, the unsecured chip has full control of the
contents of the Flash Configuration Field. The chip may erase the sector containing the
Flash Configuration Field and reprogram the flash security byte to the unsecure state and
change the backdoor keys to any desired value.
24.4.13 Reset Sequence
On each system reset the flash memory module executes a sequence which establishes
initial values for the flash block configuration parameters, FPROT, FOPT, FSEC,
FXACC, FSACC, and FACNFG registers.
FSTAT[CCIF] is cleared throughout the reset sequence. The flash memory module holds
off CPU access during the reset sequence. Flash reads are possible when the hold is
removed. Completion of the reset sequence is marked by setting CCIF which enables
flash user commands.
If a reset occurs while any flash command is in progress, that command is immediately
aborted. The state of the word being programmed or the sector/block being erased is not
guaranteed. Commands and operations do not automatically resume after exiting reset.
Chapter 24 Flash Memory Module (FTFA)
K32 L2A Reference Manual, Rev. 2, 01/2020
NXP Semiconductors 655