mc9s12xs128 Freescale Semiconductor, Inc, mc9s12xs128 Datasheet - Page 606

• Manufacturer Part Number: mc9s12xs128
• Description: Hcs12 Microcontrollers 16-bit Automotive Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

128 KByte Flash Module (S12XFTMR128K1V1)
erased the MCU will be unsecured. All BDM commands will be enabled and the Flash security byte may
be programmed to the unsecure state by the following method:
19.5.3
The availability of Flash module commands depends on the MCU operating mode and security state as
shown in
19.6
On each system reset the Flash module executes a reset sequence which establishes initial values for the
Flash Block Configuration Parameters, the FPROT and DFPROT protection registers, and the FOPT and
FSEC registers. The Flash module reverts to built-in default values that leave the module in a fully
protected and secured state if errors are encountered during execution of the reset sequence. If a double bit
fault is detected during the reset sequence, both MGSTAT bits in the FSTAT register will be set.
CCIF remains clear throughout the reset sequence. The Flash module holds off all CPU access for the
initial portion of the reset sequence. While Flash reads are possible when the hold is removed, writes to
the FCCOBIX, FCCOBHI, and FCCOBLO registers are ignored to prevent command activity while the
Memory Controller remains busy. Completion of the reset sequence is marked by setting CCIF high which
enables writes to the FCCOBIX, FCCOBHI, and FCCOBLO registers to launch any available Flash
command.
If a reset occurs while any Flash command is in progress, that command will be immediately aborted. The
state of the word being programmed or the sector/block being erased is not guaranteed.
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Send BDM commands to execute a ‘Program P-Flash’ command sequence to program the Flash
security byte to the unsecured state and reset the MCU.
Table
Initialization
Mode and Security Effects on Flash Command Availability
19-28.
S12XS Family Reference Manual, Rev. 1.10
Freescale Semiconductor