LIST P=16F628, R=DEC
#include "P16F628.INC"
__config  _INTRC_OSC_NOCLKOUT & _LVP_OFF & _WDT_OFF & _PWRTE_ON & _BODEN_ON 
	CBLOCK 0x20
	Loop1,Loop2
	ENDC
	ORG	0x000  
	CLRF	PORTA
	CLRF	PORTB
	BSF	STATUS,RP0
	MOVLW	B'11111111'     
	MOVWF	TRISA
	CLRF	TRISB
	BCF	STATUS,RP0
	MOVLW	7 
	MOVWF	CMCON 

PIROS	BSF	PORTB,4
	BCF	PORTB,1
	BTFSS	PORTA,2
	GOTO 	PIROS
	CALL	TIME
	BSF	PORTB,1
	CALL	TIME
	BCF	PORTB,4
	BCF	PORTB,1
ZOLD	BSF	PORTB,2
	BTFSS	PORTA,2
	GOTO	ZOLD
	CALL 	TIME
	BSF	PORTB,1
	BCF	PORTB,2
	CALL 	TIME
	GOTO 	PIROS	

TIME	MOVLW	200
        MOVWF	Loop1 
Outer	MOVLW	200 
	MOVWF	Loop2 
Inner	NOP 
	NOP 
	DECFSZ	Loop2,F 
	GOTO	Inner
	DECFSZ	Loop1,F 
        GOTO	Outer 
	RETURN 

	END