ex0301.asm

PIC单片机指令集

	LIST	P=16F877, R=DEC
	INCLUDE	<P16F877.INC>
;
	CBLOCK	H'20'		; USEFUL FOR RAM DECLARATION
	ENDC
;
	ORG	0
	NOP	
	BANKSEL TRISD
	MOVLW 	0
	MOVWF 	TRISD
	BANKSEL	PORTD
AGAIN:
	MOVLW	B'11111110'	
	MOVWF	PORTD		; LIGHT UP D1
	CALL	D100mS		; DELAY 0.1 SEC
	MOVLW	B'11111101'	
	MOVWF 	PORTD		; LIGHT UP D2
	CALL	D100mS		; DELAY 0.1 SEC
	MOVLW	B'11111011'	
	MOVWF	PORTD		; LIGHT UP D3
	CALL	D100mS		; DELAY 0.1 SEC
	MOVLW	B'11110111'	
	MOVWF	PORTD		; LIGHT UP D4
	CALL	D100mS		; DELAY 0.1 SEC
	GOTO 	AGAIN		; REPEAT
;
	CBLOCK
	R0_D100mS, R1_D100mS, R2_D100mS
	ENDC
D100mS:
	MOVLW	10
	MOVWF	R0_D100mS
D100mS1:
	MOVLW	50
	MOVWF	R1_D100mS
D100mS2:
	MOVLW	200
	MOVWF	R2_D100mS
D100mS3:
	DECFSZ	R2_D100mS
	GOTO	D100mS3	
	DECFSZ	R1_D100mS
	GOTO 	D100mS2
	DECFSZ	R0_D100mS
	GOTO	D100mS1
	RETURN
;
	END