Datasheet

Chapter 24 128 KByte Flash Module (S12XFTM128K2V1)
MC9S12XE-Family Reference Manual Rev. 1.25
Freescale Semiconductor 875
24.4.2.10 Unsecure Flash Command
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.
24.4.2.11 Verify Backdoor Access Key Command
The Verify Backdoor Access Key command will only execute if it is enabled by the KEYEN bits in the
FSEC register (see Table 24-11). 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 Table 24-
3). The Verify Backdoor Access Key command must not be executed from the Flash block containing the
backdoor comparison key to avoid code runaway.
Table 24-51. Unsecure Flash Command FCCOB Requirements
CCOBIX[2:0] FCCOB Parameters
000 0x0B Not required
Table 24-52. Unsecure Flash Command Error Handling
Register Error Bit Error Condition
FSTAT
ACCERR
Set if CCOBIX[2:0] != 000 at command launch
Set if command not available in current mode (see Table 24-30)
FPVIOL Set if any area of the P-Flash memory is protected
MGSTAT1 Set if any errors have been encountered during the verify operation
(1)
1. As found in the memory map for FTM256K2.
MGSTAT0
Set if any non-correctable errors have been encountered during the verify
operation
1
FERSTAT EPVIOLIF Set if any area of the buffer RAM EEE partition is protected
Table 24-53. Verify Backdoor Access Key Command FCCOB Requirements
CCOBIX[2:0] FCCOB Parameters
000 0x0C Not required
001 Key 0
010 Key 1