NXP Semiconductors freescale K51 Series Reference Manual

FTFL_FSEC field descriptions (continued)Field DescriptionThese bits define the security state of the MCU. In the secure state, the MCU limits access to FTFLmodule resources. The limitations are defined per device and are detailed in the Chip Configurationdetails. If the FTFL module is unsecured using backdoor key access, the SEC bits are forced to 10b.00 MCU security status is secure01 MCU security status is secure10 MCU security status is unsecure (The standard shipping condition of the FTFL is unsecure.)11 MCU security status is secure28.34.4 Flash Option Register (FTFL_FOPT)The flash option register allows the MCU to customize its operations by examining thestate of these read-only bits, which are loaded from NVM at reset. The function of thebits is defined in the device's Chip Configuration details.All bits in the register are read-only .During the reset sequence, the register is loaded from the flash nonvolatile option byte inthe Flash Configuration Field located in program flash memory. The flash basis for thevalues is signified by X in the reset value.Address: FTFL_FOPT is 4002_0000h base + 3h offset = 4002_0003hBit 7 6 5 4 3 2 1 0Read OPTWriteReset x* x* x* x* x* x* x* x** Notes:x = Undefined at reset.•FTFL_FOPT field descriptionsField Description7–0OPTNonvolatile OptionThese bits are loaded from flash to this register at reset. Refer to the device's Chip Configuration detailsfor the definition and use of these bits.Memory Map and RegistersK51 Sub-Family Reference Manual, Rev. 6, Nov 2011624 Freescale Semiconductor, Inc.