> Are you sure you don't really want a DCFSNZ instead of DECFSZ here in

OP uses 12F629 where there is no instruction or such pseudo one, but he
solved it elsewhere in his code already, so he will be just fine I think :-)

Tamas



On Wed, May 14, 2008 at 2:42 PM, Mark Scoville <mscoville@unicontrolinc.com>
wrote:

> Hi Matthew...
>
> Are you sure you don't really want a DCFSNZ instead of DECFSZ here in
> set_tx_bit...
>
>        bcf     INTCON, T0IF    ; Clear the interrupt flag
>        decfsz  bit_count, F   <---- **** maybe you intended DCFSNZ??? ****
>         incf    state, F        ; All the bits have been set, advance to
> the
> next state.
>
> Looks like maybe first time through you only send 1 bit, increment the
> state
> to 4, and bail out.
>
> -- Mark
>
>
> > -----Original Message-----
> > From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu]On Behalf
> > Of Matthew Miller
> > Sent: Tuesday, May 13, 2008 9:08 PM
> > To: PIC List
> > Subject: [PIC] Help debugging a software UART routine.
> >
> >
> > Hi everyone,
> >
> > In the past, members of the list have been good at pointing out
> > programming
> > mistakes that I've made and I hope this time is no different. :)
> >
> > I'm trying to learn how to create a software UART which I want to be
> > interrupt driven. I have a transmit routine that uses delay loops
> written
> > and it works fine. My attempt at an interrupt driven transmit doesn't
> work
> > and here is the symptom: no matter what is transmitted, 0xFE is
> > received. The RS-232 parameters are 1200N1.
> >
> > As a guide, the interrupt driven routine is named "trasmit" and
> > the relevant
> > labels in the ISR are uart_3 and uart_4. The delay based routine is
> named
> > "transmit2" and this routine works (Coding this was my fall back after
> > failing to get the "transmit" routine to work.) The main loop sends a
> > sequence of bytes starting with '!'.
> >
> > I would be very grateful with being helped to discover my mistake(s).
> The
> > program source code is attached.
> >
> > BTW: I found out the hard way that setting the OSCCAL value is very
> > important for this kind of application!
> >
> > Thanks!  Matthew
> >
> > --
> > "With reasonable men I will reason; with humane men I will plead; but to
> > tyrants I will give no quarter."  -- William Lloyd
> >
>
>
>
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-- 
Rudonix DoubleSaver
http://www.rudonix.com
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