LIST P=16F84A
    #include "p16f84a.inc"
    __CONFIG _PWRTE_ON & _WDT_OFF & _FOSC_EXTRC & _CP_OFF
    
#DEFINE LEDA    PORTA,1
NO1 EQU	0Ch
NO2 EQU	0Dh
NO3 EQU	0Eh
    
    BSF	    STATUS,RP0
    MOVLW   B'00000000'
    MOVWF   TRISA
    MOVLW   B'00000000'
    MOVWF   TRISB
    BCF	    STATUS,RP0
 
    CLRF	PORTA
    CLRF	NO1
    CLRF	NO2
    CLRF	NO3
   
    
START	BSF	LEDA
	MOVLW	10
	MOVWF	NO3
		
TIME1	INCFSZ	NO1,1
	GOTO	TIME1
	INCFSZ	NO2,1
	GOTO	TIME1
	DECFSZ	NO3,1
	GOTO	TIME1
	
	BCF	LEDA
	
    end