Freescale Semiconductor Demonstration Board for Freescale MC9S12XHY256 Microcontroller DEMO9S12XHY256 DEMO9S12XHY256 Manuale Utente

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The Unsecure Flash command will erase the entire P-Flash and D-Flash memory space and, if the erase is
successful, will release security.

Upon clearing CCIF to launch the Unsecure Flash command, the Memory Controller will erase the entire
P-Flash and D-Flash memory space and verify that it is erased. If the Memory Controller verifies that the
entire Flash memory space was properly erased, security will be released. If the erase verify is not
successful, the Unsecure Flash operation sets MGSTAT1 and terminates without changing the security
state. During the execution of this command (CCIF=0) the user must not write to any Flash module
register. The CCIF flag is set after the Unsecure Flash operation has completed.

The Verify Backdoor Access Key command will only execute if it is enabled by the KEYEN bits in the
FSEC register (see

). The Verify Backdoor Access Key command releases security if

user-supplied keys match those stored in the Flash security bytes of the Flash configuration field (see

FSTAT

ACCERR

Set if CCOBIX[2:0] != 001 at command launch

Set if command not available in current mode (see

)

Set if an invalid global address [22:16] is supplied

Set if a misaligned phrase address is supplied (global address [2:0] != 000)

FPVIOL

Set if the selected P-Flash sector is protected

MGSTAT1

Set if any errors have been encountered during the verify operation

MGSTAT0

Set if any non-correctable errors have been encountered during the verify
operation

000

0x0B

Not required

FSTAT

ACCERR

Set if CCOBIX[2:0] != 000 at command launch

Set if command not available in current mode (see

)

FPVIOL

Set if any area of the P-Flash or D-Flash memory is protected

MGSTAT1

Set if any errors have been encountered during the verify operation

MGSTAT0

Set if any non-correctable errors have been encountered during the verify
operation