Well I4ve found FSR and INDF, but that can solve half my problem... with
this I can select porta, portb or portc easily, but what about bits, how can
I choose between them?

    Petra: I should use any port, and any bit... my idea is to make a
subrutine to read a bit using sofware filter...

    Regards,

    Gonzalo

----- Mensaje original -----
De: "Olin Lathrop" <olin_piclist@EMBEDINC.COM>
Para: <PICLIST@MITVMA.MIT.EDU>
Enviado: Jueves 4 de Enero de 2001 2:31 PM
Asunto: Re: [PIC]: Not use the address but what is inside that address


| >     What I want to do exactly is to have to variables, one with the port
I
| > want to use (let4s call it "port") and another one with the bit I want
to
| > read (let4s call it "bit") then use the instruccion btfss.
| >
| >     Something like this:
| >
| >     porta --> port
| >     3 -->    bit
| >
| >     btfss    port, bit
| >
| >     What should mean btfss porta, 3
| >
| >     Is it possible?
|
| If "bit" and "port" are assembler variables, then yes.  No matter how you
| may try to disguise it, the register and bit referenced by a BTFSS
| instruction are hard coded into the instruction, and therefore must be
known
| at assembly time.
|
| If you need to dynamically select a register at runtime, use an FSR.
There
| are more options for dynamically selecting a bit, most of which require
bit
| shifting or mask selecting.
|
|
| *****************************************************************
| Olin Lathrop, embedded systems consultant in Devens Massachusetts
| (978) 772-3129, olin@embedinc.com, http://www.embedinc.com
|
| --
| http://www.piclist.com hint: The PICList is archived three different
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|
|
|

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