Hi miguel

The mistake is :

WF AUTOMACAO wrote:

> Dear old friends, help me!
>
>           ; Inicio
>           list p=16F84
>           radix     dec
>           include <P16F84.INC>
>           ; Variables
> contador   equ d'12'
>           org     0x000
>           movlw   0x1F
>           tris    PORTA
>           movlw   0x00
>           tris    PORTB
>
>           movlw 0
>           movwf contador
>
> loop
>           incf contador,f
>

instead :

>
>           movlw contador

has to be:

            movf    contador,w

>
>           movwf PORTB
>
>           goto loop
>
>           END
>
> Why don't my PORTB pulse? (The level is constant in all BITS of PORTB... ;(  )
>
> Can you see what i'm doing wrong?
>
> Thanks!
>
> Miguel

Valter