R3	SET	0x20		
R4	SET	0x21		
	ORG 0H
	BCF TRISB,0	
OVER	BSF PORTB,0	
	CALL DELAY
	BCF	PORTB,0	
	CALL DELAY
	BRA OVER		
DELAY	MOVLW 0xFF
	MOVWF	R4
D1	MOVLW 0xFF
	MOVWF R3
D2	NOP
	NOP
	DECF	R3,F
	BNZ  D2
	DECF R4,F
	BNZ	D1
	RETURN