Internal Memory Configuration and External Expansion - The HCS12/9S12: An Introduction to Software and Hardware Interfacing - page 715

if (FSTAT & (ACCERR | PVIOL))

return 1; /* error flag is set, command failed */

while(!(FSTAT & CCIF)); /* wait until command completion */

return 0;

}

}

▲

Example 14.8
▼

Write a function that programs a block of words to the flash memory. The number of words
to be programmed, the starting address of the flash memory to be programmed, and the starting
address of data are passed to this function in B, X, and Y, respectively.
Solution: The assembly function that performs the flash programming is as follows:
feProgBlok

tstb ; check word count

bne doFLprog ; word count is valid

rts ; return if word count is zero

doFLprog pshb ; save the word count in stack

fepwait1 brclr FSTAT,CBEIF,fepwait1 ; wait until command buffer is empty

movw 2,y 1 ,2,x 1 ; write data word to flash address

movb #Program,FCMD ; write program command

movb #CBEIF,FSTAT ; launch the command

brclr FSTAT,ACCERR 1 PVIOL,progK ; is there any error?

pulb

ldab #1 ; return error code 1

rts

progOK dec 0,SP ; one word less to be programmed

bne fepwait1 ; more words to be programmed?

pulb

clrb ; return error code 0

rts

The C language version of the function is as follows:
int feProgBlok(char cnt, int *destptr, int *srcptr)
{

if(cnt 55 0)

return 0; /* if word count is 0, do nothing */

while(cnt){

if(FSTAT & CBEIF){ // if command buffer is not empty, do nothing

*destptr 11 5 *srcptr 11 ; // write data word to flash location

FCMD 5 Program; // write program command

FSTAT 5 CBEIF; // launch program command

if(FSTAT & (ACCERR 1 PVIOL))

return 1; // program error?

cnt 2 ;

}

}