#INCLUDE    <P16F876A.INC>
LIST    P=16F876A
__CONFIG _CP_OFF &_XT_OSC &_PWRTE_ON &_WDT_OFF

ORG 00H
GOTO    INICIO

ORG     04H
GOTO    INTERRUPCION

INICIO
BSF STATUS,5
MOVLW   B'00010001'
MOVWF   TRISB
CLRF    TRISA
CLRF    TRISC
MOVLW   B'1000110'
MOVWF   OPTION_REG
MOVLW   B'10010000'
MOVWF   INTCON

BCF     STATUS,5    ;rp0
CLRF    PORTB
CLRF    PORTA
CLRF    PORTC
CLRF    20H

ACA

BTFSS   20H,0
GOTO    FIN
BSF     PORTB,1
CALL    DEMORA
BCF     PORTB,1
CALL    DEMORA2

FIN
BTFSS   PORTB,4
GOTO    PRENDE
BCF     20H,0

PRENDE
GOTO    ACA

INTERRUPCION
BTFSS   INTCON,2
GOTO    TIMECERO
BSF     20H,1
BCF     INTCON,2
BCF     INTCON,5
RETFIE

TIMECERO
BTFSS   INTCON,1
GOTO    ACA
BSF     20H,0
BCF     INTCON,1
RETFIE

DEMORA
BSF     INTCON,5
MOVLW   D'194'
MOVWF   TMR0
VOLVER
BTFSS   20H,1
GOTO    VOLVER
BCF     20H,1
RETFIE

DEMORA2
BSF INTCON,5
MOVLW   D'131'
MOVWF   TMR0
VOLVER1
BTFSS   20H,1
GOTO    VOLVER1
BCF     20H,1
RETFIE

END