NXP Semiconductors Kinetis KE1xZ256, Reference Manual

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FTFE_FSEC field descriptions (continued)
Field Description
10 Factory access denied
11 Factory access granted
SEC Flash Security
These bits define the security state of the MCU. In the secure state, the MCU limits access to FTFE
module resources. The limitations are defined per device and are detailed in the Chip Configuration
details. If the FTFE module is unsecured using backdoor key access, the SEC bits are forced to 10b.
00 MCU security status is secure
01 MCU security status is secure
10 MCU security status is unsecure (The standard shipping condition of the FTFE is unsecure.)
11 MCU security status is secure
16.4.4.4 Flash Option Register (FTFE_FOPT)
The flash option register allows the MCU to customize its operations by examining the
state of these read-only bits, which are loaded from NVM at reset. The function of the
bits 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 in
the Flash Configuration Field located in program flash memory. The flash basis for the
values is signified by X in the reset value.
Address: 4002_0000h base + 3h offset = 4002_0003h
Bit 7 6 5 4 3 2 1 0
Read OPT
Write
Reset
x* x* x* x* x* x* x* x*
* Notes:
x = Undefined at reset. •
FTFE_FOPT field descriptions
Field Description
OPT Nonvolatile Option
These bits are loaded from flash to this register at reset. Refer to the device's Chip Configuration details
for the definition and use of these bits.
Memory map and registers
Kinetis KE1xZ256 Sub-Family Reference Manual, Rev. 3, 07/2018
300 NXP Semiconductors