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CHAPTER 12 WATCHDOG TIMER
12.6 Program Examples of Watchdog Timer
Program example of watchdog timer is given below:
■ Program Examples of Watchdog Timer
●
Processing specification
• The watchdog timer is cleared each time in the loop of the main program.
• The main program must be executed once within the minimum interval time of the watchdog timer.
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Coding example
WDTC EQU 0000A8H ;Watchdog timer control
register
WTE EQU WDTC:2 ;Watchdog control bit
;
;---------Main program-------------------------------------
CODE CSEG
START: ;Stack pointer (SP), already
;initialized
MOV I:WDTC,#00000011B ;Start up of watchdog timer
;Select interval time 2
21
+2
18
;cycle
LOOP:
CLRB I:WTE ;Clear watchdog timer
ÅE
User processing
ÅE
BRA LOOP
;---------Vector setting------------------------------------------
VECT CSEG ABS=0FFH
ORG 00FFDCH ;Reset vector setting
DSL START
DB 00H ;Setting to single chip mode
VECT ENDS
END START