K60P100M100SF2RM Datasheet, PDF (678/1809 Pages) Freescale Semiconductor, Inc – K60 Sub-Family Reference Manual

Flash Operation in Low-Power Modes
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.
28.4.12.13 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.
Table 28-63. Verify Backdoor Access Key Command FCCOB Requirements
FCCOB Number
0
1-3
4
5
6
7
8
9
A
B
FCCOB Contents [7:0]
0x45 (VFYKEY)
Not Used
Key Byte 0
Key Byte 1
Key Byte 2
Key Byte 3
Key Byte 4
Key Byte 5
Key Byte 6
Key Byte 7
Flash Configuration Field Offset Address
0x0_0000
0x0_0001
0x0_0002
0x0_0003
0x0_0004
0x0_0005
0x0_0006
0x0_0007
After clearing CCIF to launch the Verify Backdoor Access Key command, the FTFL
checks the FSEC[KEYEN] bits to verify that this command is enabled. If not enabled, the
FTFL sets the FSTAT[ACCERR] bit and terminates. If the command is enabled, the
FTFL compares the key provided in FCCOB to the backdoor comparison key in the Flash
Configuration Field. If the backdoor keys match, the FSEC[SEC] field is changed to the
unsecure state and security is 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
immediately aborted and the FSTAT[ACCERR] bit is (again) set to 1 until a reset of the
K60 Sub-Family Reference Manual, Rev. 6, Nov 2011
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