LIST	P=16F84A		
	#INCLUDE	"P16F84A.inc"

	__CONFIG _XT_OSC&_CP_OFF&_WDT_OFF

	ORG	0

	BANKSEL	TRISA
	MOVLW	b'00011111'
	MOVWF	TRISA
	MOVLW	b'00000000'
	MOVWF	TRISB
	BANKSEL	PORTB
	CLRF	PORTB

GOMB
	BTFSS	PORTA,0
	GOTO	GOMB
	CALL	VAR
	BTFSC	PORTA,0
	GOTO	GOMB
	CALL	VAR
	MOVLW	B'10000000'
	XORWF	PORTB,F
	GOTO	GOMB

VAR
	MOVLW	D'100'
	MOVWF	V1
V1
	MOVLW	D'100'
	MOVWF	V2
V2
	NOP
	NOP
	DECFSZ	V2,F
	GOTO	V2
	DECFSZ	V1,F
	GOTO	V1
	RETURN
END