The 'factory' margin is a bigger deviation from the norm, a more stringent read criteriathat should only be attempted immediately (or very soon) after completion of an erase orprogram command, early in the cycling life. 'Factory' margin levels can be used to checkthat flash memory contents have adequate margin for long-term data retention at thenormal level setting. If unexpected results are encountered when checking flash memorycontents at 'factory' margin levels, the flash memory contents should be erased andreprogrammed.CAUTIONFactory margin levels must only be used during verify of theinitial factory programming.45.4.10 Flash Command DescriptionThis section describes all flash commands that can be launched by a command writesequence.The flash memory module sets the FSTAT[ACCERR] bit and aborts the commandexecution if any of the following illegal conditions occur:• There is an unrecognized command code in the FCCOB FCMD field.• There is an error in a FCCOB field for the specific commands. Refer to the errorhandling table provided for each command.Ensure that FSTAT[ACCERR] and FSTAT[FPVIOL] are cleared prior to starting thecommand write sequence. As described in Launch the Command by Clearing CCIF, anew command cannot be launched while these error flags are set.Do not attempt to read a flash block while the flash memory module is running acommand (FSTAT[CCIF] = 0) on that same block. The flash memory module may returninvalid data to the MCU with the collision error flag (FSTAT[RDCOLERR]) set.CAUTIONFlash data must be in the erased state before beingprogrammed. Cumulative programming of bits (adding morezeros) is not allowed.Chapter 45 Flash Memory Module (FTFA)KL27 Sub-Family Reference Manual , Rev. 5, 01/2016Freescale Semiconductor, Inc. 911
