27.3.1 Flash Configuration Field DescriptionThe program flash memory contains a 16-byte flash configuration field that stores defaultprotection settings (loaded on reset) and security information that allows the MCU torestrict access to the flash memory module.Flash Configuration Field ByteAddressSize (Bytes) Field Description0x0_0400 - 0x0_0407 8 Backdoor Comparison Key. Refer toVerify Backdoor Access Key Commandand Unsecuring the Chip UsingBackdoor Key Access.0x0_0408 - 0x0_040B 4 Program flash protection bytes. Refer tothe description of the Program FlashProtection Registers (FPROT0-3).0x0_040F 1 Reserved0x0_040E 1 Reserved0x0_040D 1 Flash nonvolatile option byte. Refer tothe description of the Flash OptionRegister (FOPT).0x0_040C 1 Flash security byte. Refer to thedescription of the Flash SecurityRegister (FSEC).27.3.2 Program Flash IFR MapThe program flash IFR is nonvolatile information memory that can be read freely, but theuser has no erase and limited program capabilities (see the Read Once, Program Once,and Read Resource commands in Read Once Command, Program Once Command andRead Resource Command). The contents of the program flash IFR are summarized in thefollowing table and further described in the subsequent paragraphs.The program flash IFR is located within the program flash 0 memory block.Address Range Size (Bytes) Field Description0x00 – 0xBF 192 Reserved0xC0 – 0xFF 64 Program Once Field27.3.2.1 Program Once FieldThe Program Once Field in the program flash IFR provides 64 bytes of user data storageseparate from the program flash main array. The user can program the Program OnceField one time only as there is no program flash IFR erase mechanism available to theChapter 27 Flash Memory Module (FTFA)KL04 Sub-Family Reference Manual, Rev. 3.1, November 2012Freescale Semiconductor, Inc. 383
