list        p=16F887, r=dec, w=1
        include     <P16F887.INC>
        __config    _CONFIG1,_LVP_OFF & _FCMEN_OFF & _IESO_OFF & _BOR_OFF & _PWRTE_ON & _WDT_OFF & _INTOSCIO
        __config    _CONFIG2,_WRT_HALF & _BOR21V

#define     LED0        PORTD,0

        cblock      0x20
                COUNT1
                COUNT2
        endc

        org     0x000       ;reset vector
        goto        START

START       clrf        PORTA       ;init ports
        clrf        PORTB
        clrf        PORTC
        clrf        PORTD
        clrf        PORTE
        banksel     ANSEL       ;bank 3
        movlw       b'00000000' ;all ports digital I/O
        movwf       ANSEL
        movwf       ANSELH
        banksel     TRISA       ;bank 1
        movlw       b'00000000' ;all ports output
        movwf       TRISA
        movwf       TRISB
        movwf       TRISC
        movwf       TRISD
        movwf       TRISE
        banksel     0x00        ;bank 0

        movlw       b'00000001'
        xorwf       PORTD,F
        call        DELAY
        goto        $-2

DELAY       movlw       0xFF
        movwf       COUNT1
        movwf       COUNT2
        decfsz      COUNT1,F
        goto        $-1
        decfsz      COUNT2,F
        goto        $-3
        return

        end