;***********************************************************
; 2022.02.21 V002
; PIC12F675 WDT function
; Internal OSC is used and clock is 4Mhz
;***********************************************************
        LIST    P=12F675
        INCLUDE P12F675.INC
        __CONFIG _INTRC_OSC_NOCLKOUT & _WDT_OFF & _MCLRE_ON

TIM1    EQU     H'20'
TIM2    EQU     H'21'
TIM3    EQU     H'22'

        ORG     0
        GOTO    START
START

        BCF     STATUS,RP0        ;set bank0
        MOVLW   B'00000001'       ;GP[0]:high
        MOVWF   GPIO
        MOVLW   B'00000111'       ;コンパレーターは使用しない
        MOVWF   CMCON

        BSF     STATUS,RP0        ;set bank1
        MOVLW   B'00111100'       ;GP[0:1]:output
        MOVWF   TRISIO
        MOVLW   B'00000000'       ;set GP[0:5] to digital
        MOVWF   ANSEL
                
        BCF     STATUS,RP0        ;set bank0
MAIN
        CALL    WAIT              ;wait 20sec
        BCF     GPIO,0            ;set GP[0] low
        CALL    WAIT_1MS          ;wait 1msec
        BSF     GPIO,0            ;set GP[0] high

        GOTO    MAIN
        
;*************************************
;  WAIT 30sec
;*************************************
WAIT
        MOVLW   D'30'
        MOVWF   TIM1
WAIT_1
        MOVLW   D'250'
        MOVWF   TIM2
WAIT_2
        MOVLW   D'250'
        MOVWF   TIM3
WAIT_3
        NOP
        NOP
        NOP
        NOP
        NOP
        NOP
        NOP
        BSF     GPIO,1
        NOP
        NOP
        NOP
        NOP
        NOP
        NOP
        NOP
        NOP
        BCF     GPIO,1
        DECFSZ  TIM3,F
        GOTO    WAIT_3
        DECFSZ  TIM2,F
        GOTO    WAIT_2
        DECFSZ  TIM1,F
        GOTO    WAIT_1
        RETURN

;*************************************
;  WAIT 3msec
;*************************************
WAIT_1MS
        MOVLW   D'3'
        MOVWF   TIM1
WAIT_1MS_1
        MOVLW   D'10'
        MOVWF   TIM2
WAIT_1MS_2
        MOVLW   D'34'
        MOVWF   TIM3
WAIT_1MS_3
        DECFSZ  TIM3,F
        GOTO    WAIT_1MS_3
        DECFSZ  TIM2,F
        GOTO    WAIT_1MS_2
        DECFSZ  TIM1,F
        GOTO    WAIT_1MS_1
        RETURN


        END