sc9s12hy64j0vllr Freescale Semiconductor, Inc, sc9s12hy64j0vllr Datasheet - Page 553

• Manufacturer Part Number: sc9s12hy64j0vllr
• Description: S12 Microcontrollers Mcu 16-bit Hcs12 Cisc 32kb Flash 5v Tray
• Manufacturer: Freescale Semiconductor, Inc

15.4.5.11 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
user-supplied keys match those stored in the Flash security bytes of the Flash configuration field (see
Table
containing the backdoor comparison key to avoid code runaway.
Upon clearing CCIF to launch the Verify Backdoor Access Key command, the Memory Controller will
check the FSEC KEYEN bits to verify that this command is enabled. If not enabled, the Memory
Controller sets the ACCERR bit in the FSTAT register and terminates. If the command is enabled, the
Memory Controller compares the key provided in FCCOB to the backdoor comparison key in the Flash
configuration field with Key 0 compared to 0x3_FF00, etc. If the backdoor keys match, security will be
released. If the backdoor keys do not match, security is not released and all future attempts to execute the
Verify Backdoor Access Key command are aborted (set ACCERR) until a reset occurs. The CCIF flag is
set after the Verify Backdoor Access Key operation has completed.
Freescale Semiconductor
1
As found in the memory map for FTMRC64K1.
15-3). The Verify Backdoor Access Key command must not be executed from the Flash block
Register
FSTAT
Table 15-51. Verify Backdoor Access Key Command FCCOB Requirements
Table
CCOBIX[2:0]
MGSTAT1
MGSTAT0
ACCERR
Error Bit
FPVIOL
000
001
010
011
100
Table 15-50. Unsecure Flash Command Error Handling
15-9). The Verify Backdoor Access Key command releases security if
MC9S12HY/HA-Family Reference Manual, Rev. 1.04
Set if CCOBIX[2:0] != 000 at command launch
Set if command not available in current mode (see
Set if any area of the P-Flash or D-Flash memory is protected
Set if any errors have been encountered during the verify operation
Set if any non-correctable errors have been encountered during the verify
operation
1
0x0C
FCCOB Parameters
Key 0
Key 1
Key 2
Key 3
Error Condition
Not required
32 KByte Flash Module (S12FTMRC32K1V1)
Table
15-27)
1
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