LIST P=16F628A
 #INCLUDE "P16F628A.INC"
 __CONFIG _XT_OSC&_CP_OFF&_WDT_OFF&_LVP_OFF

	CBLOCK 0X20
	T1
	ENDC
	
	ORG 0
	
START
	BANKSEL	TRISA
	MOVLW	B'00001100'
	MOVWF	TRISA
	MOVLW	B'00000000'
	MOVWF	TRISB
	
VILLOGO
	MOVLW	B'00000000'
	MOVWF	PORTB
	CALL	DELAY
	MOVLW 	B'11111111'
	MOVWF	PORTB
	CALL	DELAY
	GOTO 	VILLOGO

DELAY
	MOVLW 	d'100'
	MOVWF	T1
DEL
	NOP
	NOP
	NOP
	NOP
	NOP
	NOP
	NOP
	DECFSZ		T1,f
	GOTO		DEL
	RETURN
	END