Information

FTFL_FDPROT field descriptions (continued)

Field Description

Reset: During the reset sequence, the FDPROT register is loaded with the contents of the data flash

protection byte in the Flash Configuration Field located in program flash memory. The flash basis for the

reset values is signified by X in the register diagram. To change the data flash protection that will be

loaded during the reset sequence, unprotect the sector of program flash that contains the Flash

Configuration Field. Then, erase and reprogram the data flash protection byte.

Trying to alter data with the program and erase commands in any protected area in the data flash memory

results in a protection violation error and sets the FSTAT[FPVIOL] bit. A full block erase of the data flash

memory (see the Erase Flash Block command description) is not possible if the data flash memory

contains any protected region or if the FlexNVM block has been partitioned for EEPROM.

0 Data Flash region is protected

1 Data Flash region is not protected

28.4 Functional Description

The following sections describe functional details of the flash memory module.

28.4.1 Flash Protection

Individual regions within the flash memory can be protected from program and erase

operations. Protection is controlled by the following registers:

• FPROTn — Four registers that protect 32 regions of the program flash memory as

shown in the following figure

Program flash size / 32

FPROT3[PROT0]

0x0_0000

FPROT3[PROT1]

FPROT3[PROT2]

FPROT3[PROT3]

FPROT0[PROT29]

FPROT0[PROT31]

FPROT0[PROT30]

Program flash

Last program flash address

Figure 28-26. Program flash protection

Functional Description

K20 Sub-Family Reference Manual, Rev. 2, Feb 2012

518 Freescale Semiconductor, Inc.