Information

After clearing CCIF to launch the Erase All Blocks command, the flash memory module

erases all program flash memory, data flash memory, data flash IFR space, EEPROM

backup memory, and FlexRAM, then verifies that all are erased.

If the flash memory module verifies that all flash memories and the FlexRAM were

properly erased, security is released by setting the FSEC[SEC] field to the unsecure state

and the FCNFG[RAMRDY] bit is set. The Erase All Blocks command aborts if any flash

or FlexRAM region is protected. 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 28-61. 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, data flash memory, or FlexRAM is protected FSTAT[FPVIOL]

Any errors have been encountered during the verify operation FSTAT[MGSTAT0]

28.4.11.12.1 Triggering an Erase All External to the Flash Memory Module

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, data flash memory, data flash IFR

space, EEPROM backup, and FlexRAM regardless of the protection settings. If the post-

erase verify passes, the routine then releases security by setting the FSEC[SEC] field

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.

28.4.11.13 Verify Backdoor Access Key Command

The Verify Backdoor Access Key command only executes if the mode and security

conditions are satisfied (see Flash 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

Flash Operation in Low-Power Modes

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

550 Freescale Semiconductor, Inc.