16-33
PROGRAMMING THE NONVOLATILE MEMORY
The calling routine must pass two parameters to this routine — the data to be programmed (in
DATA_TEMP) and the address (in ADDR_TEMP).
Figure 16-15. Run-time Programming Code Example
PROGRAM:
PUSHA ;clear PSW, WSR, INT_MASK, INT_MASK1
LD WSR,#7BH ;select 32-byte window with EPA0_CON
LD COUNT,#5 ;set up for 5 programming cycles
ANDB INT_PEND,#CLEAR_EPA0 ;clear EPA0 pending bit
LDB INT_MASK,#ENABLE_EPA0 ;enable EPA0 interrupt
LDB EPA0_CON,#EPA0_TIMER ;set up EPA0 as software timer
LOOP:
LD TEMP0,TIMER1 ;load TIMER1 value into TEMP0
ADD EPA0_TIME,TEMP0,#PGM_PULSE
;load EPA0_TIME with TIMER1 + PGM_PULSE
EI ;enable unmasked interrupt(EPA0)
ST DATA_TEMP,[ADDR_TEMP] ;store passed data at passed address
IDLPD #1 ;enter idle mode
DJNZ COUNT,LOOP ;decrement COUNT and loop if not 0
;to complete 5 programming cycles
POPA ;restore PSW, WSR, and INT_MASKs
RET
EPA0_ISR:
RET
