LIST P=16F877
#INCLUDE "P16F877.INC"
__CONFIG X_OSC&_CP_OFF&_WDT_OFF&_LVP_OFF
	CBLOCK 0X20
	T1
	T2
	T3
	ENDC
	
	ORG
	
START
	BCF STATUS,RP1
	BSF STATUS,RP0
	MOVLW	0X06
	MOVWF	ADCON1
	MOVLW	B'00011111'
	MOVWF	TRISA
	MOVLW	B'00000000'
	MOVWF	TRISD
	BCF STATUS,RP0
	MOVLW	B'00000000'
	MOWWF	PORTD
		
MAIN
	MOVLW	B'00000000'
	BTFSS	PORTA,0
	CALL	LED
	MOVLW	B'00000000'
	BTFSS	PORTA,1
	CALL	LED1
	MOVLW	B'00000000'
	BTFSS	PORTA,2
	CALL	LED2
	GOTO	MAIN
	
LED
	BSF	PORTD,7
	BTFSC	PORTA,0
	CALL	LED_KI
	RETURN
	
LED1
	BSF	PORTD,6
	BTFSC	PORTA,1
	CALL	LED1_KI
	RETURN
	
LED2
	BSF	PORTD,5
	BTFSC	PORTA,2
	CALL	LED2_KI
	RETURN
	
LED_KI
	BCF	PORTD,7
	RETURN
	
LED1_KI
	BCF	PORTD,6
	RETURN
	
LED2_KI
	BCF	PORTD,5
	RETURN
	
	END