Datasheet

Chapter 4 Memory
MC9S08JM16 Series Data Sheet, Rev. 2
Freescale Semiconductor 49
Aborting a command in this way sets the FACCERR access error flag which must be cleared before
starting a new command.
A strictly monitored procedure must be obeyed or the command will not be accepted. This minimizes the
possibility of any unintended changes to the flash memory contents. The command complete flag (FCCF)
indicates when a command is complete. The command sequence must be completed by clearing FCBEF
to launch the command. Figure 4-2 is a flowchart for executing all of the commands except for burst
programming. The FCDIV register must be initialized before using any flash commands. This must be
done once following a reset.
Figure 4-2. Flash Program and Erase Flowchart
4.5.4 Burst Program Execution
The burst program command is used to program sequential bytes of data in less time than would be
required using the standard program command. This is possible because the high voltage to the flash array
does not need to be disabled between program operations. Ordinarily, when a program or erase command
START
WRITE TO FLASH
TO BUFFER ADDRESS AND DATA
WRITE COMMAND TO FCMD
NO
YES
FPVIOL OR
WRITE 1 TO FCBEF
TO LAUNCH COMMAND
AND CLEAR FCBEF
2
1
0
FCCF?
ERROR EXIT
DONE
0
FACCERR?
CLEAR ERROR
FACCERR?
WRITE TO FCDIV
1
1
FLASH PROGRAM AND
ERASE FLOW
1
Required only once after reset.
2
Wait at least four bus cycles before checking FCBEF or FCCF.