> Van: Dennis Plunkett <dennis@RDD.NECA.NEC.COM.AU>
> Aan: PICLIST@MITVMA.MIT.EDU
> Onderwerp: Re: I/O Problem with 16F84
> Datum: donderdag 4 juni 1998 4:17

[Cut]

> I gather that you are using an F84, if this is so, then you must select
the
> correct register bank in the STATUS register (RP0) in order to write to
the
> port direction control register (TRISA and TRISB), do this and all should
be

Not when you use the (outdated) TRIS _command_.

Re-write the code using the TRIS commando's like this (like dennis tried to
say) :

bsf STATUS,RP0
movlw 0x1f
movwf TRISA
movlw 0x00    ;\ or use : CLRF TRISB
movwf TRISB  ;/
bcf STATUS,RP0

> fine. I also note that the value written to the port a register is 0x3f,
> should be 0xff

Port A has only 5 I/O bits (on a 16x84) , so the value is OK.

> Have fun
>
> Dennis
>