NXP Semiconductors freescale K51 Series Reference Manual

Addresses: FTFL_FPROT3 is 4002_0000h base + 10h offset = 4002_0010hFTFL_FPROT2 is 4002_0000h base + 11h offset = 4002_0011hFTFL_FPROT1 is 4002_0000h base + 12h offset = 4002_0012hFTFL_FPROT0 is 4002_0000h base + 13h offset = 4002_0013hBit 7 6 5 4 3 2 1 0Read PROTWriteReset x* x* x* x* x* x* x* x** Notes:x = Undefined at reset.•FTFL_FPROTn field descriptionsField Description7–0PROTProgram Flash Region ProtectEach program flash region can be protected from program and erase operations by setting the associatedPROT bit.In NVM Normal mode: The protection can only be increased, meaning that currently unprotectedmemory can be protected, but currently protected memory cannot be unprotected. Since unprotectedregions are marked with a 1 and protected regions use a 0, only writes changing 1s to 0s are accepted.This 1-to-0 transition check is performed on a bit-by-bit basis. Those FPROT bits with 1-to-0 transitionsare accepted while all bits with 0-to-1 transitions are ignored .In NVM Special mode: All bits of FPROT are writable without restriction. Unprotected areas can beprotected and protected areas can be unprotected.Restriction: The user must never write to any FPROT register while a command is running (CCIF=0).Trying to alter data in any protected area in the program flash memory results in a protection violationerror and sets the FSTAT[FPVIOL] bit. A full block erase of a program flash block is not possible if itcontains any protected region.Each bit in the 32-bit protection register represents 1/32 of the total program flash .0 Program flash region is protected.1 Program flash region is not protected28.34.7 EEPROM Protection Register (FTFL_FEPROT)For devices with FlexNVM: The FEPROT register defines which EEPROM regions ofthe FlexRAM are protected against program and erase operations. Protected EEPROMregions cannot have their content changed by writing to it. Unprotected regions can bechanged by writing to the FlexRAM.For devices with program flash only: This register is reserved and not used.Chapter 28 Flash Memory Module (FTFL)K51 Sub-Family Reference Manual, Rev. 6, Nov 2011Freescale Semiconductor, Inc. 627