NXP Semiconductors KE1xF Series, Reference Manual, Page: 400 / 1483

1. The FTFE reads the command code and performs a series of parameter checks and
protection checks, if applicable, which are unique to each command.
If the parameter check fails, the FSTAT[ACCERR] (access error) flag is set.
ACCERR reports invalid instruction codes and out-of bounds addresses. Usually,
access errors suggest that the command was not set-up with valid parameters in the
FCCOB register group.
Program and erase commands also check the address to determine if the operation is
requested to execute on protected areas. If the protection check fails, the
FSTAT[FPVIOL] (protection error) flag is set.
Command processing never proceeds to execution when the parameter or protection
step fails. Instead, command processing is terminated after setting the FSTAT[CCIF]
bit.
2. If the parameter and protection checks pass, the command proceeds to execution.
Run-time errors, such as failure to erase verify, may occur during the execution
phase. Run-time errors are reported in the FSTAT[MGSTAT0] bit. A command may
have access errors, protection errors, and run-time errors, but the run-time errors are
not seen until all access and protection errors have been corrected.
3. Command execution results, if applicable, are reported back to the user via the
FCCOB and FSTAT registers.
4. The FTFE sets the FSTAT[CCIF] bit signifying that the command has completed.
The flow for a generic command write sequence is illustrated in the following figure.
Functional Description
Kinetis KE1xF Sub-Family Reference Manual, Rev. 4, 06/2019
400 NXP Semiconductors