Hi All,
My first project with the PIC16F87X doesn't work. I am simply trying to do a
conversion A/D in the PORTA0 and show it  in PORTB with leds.Also a led
blinking in the PORTC6 using TMRO overflow. I'm using a 4MHZ cristal.

See my Codes below.

#DEFINE LED     PORTC6

        list p=16f873

        include "p16f873.inc"


         __CONFIG _CP_OFF & _WDT_OFF & _BODEN_OFF & _PWRTE_OFF & _XT_OSC &
_WRT_ENABLE_OFF

;----------------------------------------------------
; Start at the reset vector
        org 0x000


Start:
        clrf PORTA
        clrf PORTB
        clrf PORTC
        bsf STATUS,RP0
        movlw B'00000111'     ;TMR0 prescaler, 1:256
        movwf OPTION_REG
        movlw b'00000001'     ;PA0=IN
        movwf TRISA
        movlw b'00000000'
        movwf TRISB                 ;PB=OUT
        movlw b'00000000'       ;PC=OUT
        movwf TRISC
        movlw b'00001110'     ;VREF+ VDD E VREF- VSS, PORTA0  A/D IN
        movwf ADCON1
        bcf STATUS,RP0      ;Fosc/8, A/D ON
        movlw b'01000001'
        movwf ADCON0



MAIN:
        clrf TMR0
        btfss INTCON,T0IF     ;Wait for Timer0 to timeout
        goto $-1
        bcf INTCON,T0IF
        btfss LED
        goto LED_ON
        bcf LED
        goto SET_AD

LED_ON:
        bsf LED

SET_AD:
        bsf ADCON0,GO     ;Start A/D conversion

Wait:
        btfss PIR1,ADIF     ;Wait for conversion to complete
        goto $-1

        movf ADRESH,W     ;Write A/D result to PORTB
        movwf PORTB
        goto MAIN

I would appreciate it if someone could make a suggestion.

Thanks in advanced.
Anbar.