FTFA_FSEC field descriptions (continued)
Field
Description
00
Backdoor key access disabled
01
Backdoor key access disabled (preferred KEYEN state to disable backdoor key access)
10
Backdoor key access enabled
11
Backdoor key access disabled
5–4
MEEN
Mass Erase Enable Bits
Enables and disables mass erase capability of the flash memory module. The state of this field is relevant
only when SEC is set to secure outside of NVM Normal Mode. When SEC is set to unsecure, the MEEN
setting does not matter.
00
Mass erase is enabled
01
Mass erase is enabled
10
Mass erase is disabled
11
Mass erase is enabled
3–2
FSLACC
Freescale Failure Analysis Access Code
Enables or disables access to the flash memory contents during returned part failure analysis at
Freescale. When SEC is secure and FSLACC is denied, access to the program flash contents is denied
and any failure analysis performed by Freescale factory test must begin with a full erase to unsecure the
part.
When access is granted (SEC is unsecure, or SEC is secure and FSLACC is granted), Freescale factory
testing has visibility of the current flash contents. The state of the FSLACC bits is only relevant when SEC
is set to secure. When SEC is set to unsecure, the FSLACC setting does not matter.
00
Freescale factory access granted
01
Freescale factory access denied
10
Freescale factory access denied
11
Freescale factory access granted
1–0
SEC
Flash Security
Defines the security state of the MCU. In the secure state, the MCU limits access to flash memory module
resources. The limitations are defined per device and are detailed in the Chip Configuration details. If the
flash memory module is unsecured using backdoor key access, SEC is 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 flash memory module is
unsecure.)
11
MCU security status is secure.
29.33.4 Flash Option Register (FTFA_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 .
Memory Map and Registers
K22F Sub-Family Reference Manual , Rev. 3, 7/2014
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Freescale Semiconductor, Inc.