S912XHZ512F1VAG Datasheet, PDF (161/978 Pages) Freescale Semiconductor, Inc – Covers MC9S12XHZ384, MC9S12XHZ256

Chapter 3 512 Kbyte Flash Module (S12XFTX512K4V3)
3.4.2.3 Program Command
The program operation will program a previously erased word in the Flash memory using an embedded
algorithm.
An example flow to execute the program operation is shown in Figure 3-28. The program command write
sequence is as follows:
1. Write an aligned word to a valid address in the Flash array memory to start the command write
sequence for the program command. The data written will be programmed to the address written.
Multiple Flash blocks can be simultaneously programmed by writing to the same relative address
in each Flash block.
2. Write the program command, 0x20, to the FCMD register.
3. Clear the CBEIF flag in the FSTAT register by writing a 1 to CBEIF to launch the program
command.
If a word to be programmed is in a protected area of the Flash block, the PVIOL flag in the FSTAT register
will set and the program command will not launch. Once the program command has successfully launched,
the CCIF flag in the FSTAT register will set after the program operation has completed unless a new
command write sequence has been buffered. By executing a new program command write sequence on
sequential words after the CBEIF flag in the FSTAT register has been set, up to 55% faster programming
time per word can be effectively achieved than by waiting for the CCIF flag to set after each program
operation.
MC9S12XHZ512 Data Sheet, Rev. 1.06
Freescale Semiconductor
161