Information

All Blocks operation. The security byte and all other contents of the flash configuration
field (see Flash Configuration Field Description) are erased by the Erase All Blocks
command. If the erase-verify fails, the FSTAT[MGSTAT0] bit is set. The CCIF flag is
set after the Erase All Blocks operation completes.
Table 28-55. Erase All Blocks Command Error Handling
Error Condition Error Bit
Command not available in current mode/security FSTAT[ACCERR]
Any region of the program flash memory is protected FSTAT[FPVIOL]
Any errors have been encountered during the verify operation FSTAT[MGSTAT0]
28.4.10.12.1 Triggering an Erase All External to the FTFL
The functionality of the Erase All Blocks command is also available in an uncommanded
fashion outside of the flash memory. Refer to the device's Chip Configuration details for
information on this functionality.
Before invoking the external erase all function, the FSTAT[ACCERR and PVIOL] flags
must be cleared and the FCCOB0 register must not contain 0x44. When invoked, the
erase-all function erases all program flash memory, program flash 1 IFR space regardless
of the protection settings or if the swap system has been initialized. If the post-erase
verify passes, the routine then releases security by setting the FSEC[SEC] field register to
the unsecure state and the FCNFG[RAMRDY] bit sets. The security byte in the Flash
Configuration Field is also programmed to the unsecure state. The status of the erase-all
request is reflected in the FCNFG[ERSAREQ] bit. The FCNFG[ERSAREQ] bit is
cleared once the operation completes and the normal FSTAT error reporting is available
as described in Erase All Blocks Command.
28.4.10.13 Verify Backdoor Access Key Command
The Verify Backdoor Access Key command only executes if the mode and security
conditions are satisfied (see FTFL Commands by Mode). Execution of the Verify
Backdoor Access Key command is further qualified by the FSEC[KEYEN] bits. The
Verify Backdoor Access Key command releases security if user-supplied keys in the
FCCOB match those stored in the Backdoor Comparison Key bytes of the Flash
Configuration Field (see Flash Configuration Field Description). The column labelled
Flash Configuration Field offset address shows the location of the matching byte in the
Flash Configuration Field.
Chapter 28 Flash Memory Module (FTFL)
K20 Sub-Family Reference Manual, Rev. 6, Nov 2011
Freescale Semiconductor, Inc. 641