MKL04Z32VFK4 Datasheet, PDF (414/658 Pages) Freescale Semiconductor, Inc – KL04 Sub-Family Reference Manual

Functional Description
Table 27-49. Verify Backdoor Access Key Command Error Handling (continued)
Error Condition
Backdoor key access has not been enabled (see the description of the FSEC register)
This command is launched and the backdoor key has mismatched since the last power down
reset
Error Bit
FSTAT[ACCERR]
FSTAT[ACCERR]
27.4.11 Security
The flash memory module provides security information to the MCU based on contents
of the FSEC security register. The MCU then limits access to flash memory resources as
defined in the device's Chip Configuration details. During reset, the flash memory
module initializes the FSEC register using data read from the security byte of the Flash
Configuration Field (see Flash Configuration Field Description).
The following fields are available in the FSEC register. The settings are described in the
Flash Security Register (FTFA_FSEC) details.
Table 27-50. FSEC register fields
FSEC field
KEYEN
MEEN
FSLACC
SEC
Description
Backdoor Key Access
Mass Erase Capability
Freescale Factory Access
MCU security
27.4.11.1 Flash Memory Access by Mode and Security
The following table summarizes how access to the flash memory module is affected by
security and operating mode.
Table 27-51. Flash Memory Access Summary
Operating Mode
NVM Normal
NVM Special
Unsecure
Full command set
Chip Security State
Secure
Full command set
Only the Erase All Blocks and Read 1s All
Blocks commands.
KL04 Sub-Family Reference Manual, Rev. 3.1, November 2012
414
Freescale Semiconductor, Inc.