[Sdcc-user] Re: [SOLVED] msc1210 serial putchar|getchar best practise ?

[Philippe L. <phi...@li...>]

Hello,

Le Jeudi 4 Mai 2006 18:00, Jean-Paul a écrit :
> Hello,
>
> Anyway, you are better off with only one serial function.
>
> You might be "freezed" by your putchar routine.

That's effectively happening with the mix between buffered routines and 
register usage.

My previous source file post seems to be a *BAD PRACTISE* example.

>
> Many putchar() routines begin with
> while (!TI)...
>
> TI is set by hardware AFTER a byte has been sent.
> If you don't set TI once after powerup, before calling putchar() the first
> time, you'll wait forever...
>
> You can make it the other way round :
> In putchar():
> clear TI,
> write SBUF
> wait for TI
> return

Good advice ;))
I followed it and it works now like a charm !
I attach a fully working source code example.

So, to get back to best practise, does the following makes sense ?

1. trust ser.h ser_init() routine for serial line initialisation after 
autobaud().

2. KISS (keep it stupid simple) : write your own putchar & getchar with direct 
register use.

Thanks a lot for your help.

>
> Le Jeudi 04 Mai 2006 02:10, Philippe Latu a écrit :
> > Hello list,
> >
> > I'm actually developing labs & docs in french on a MSC1210 board with
>
> SDCC.
>
> > http://www.linux-france.org/~platu/embedded/
> >
> > I have difficulties with serial interface management.
> >
> > I searched through google, sdcc user's guide, .h files, etc.
> >
> > I found 2 different kinds of serial putchar & getchar.
> >
> > . Use of ser_putc and ser_getc provided through ser.h
> > . Use of registers RI, TI, SBUF
> >
> > What is the best practise between these ?
> >
> > I didn't find source files using ser_getc. When I tried it, the serial
>
> line
>
> > became unusable.
> > I attach the example file I'm working on. It's a mixture with ser_putc
>
> and
>
> > RI,SBUF which ... almost works. I still have XON/XOFF problems.
> >
> > Any help would be greatly appreciated ;))
> > --
> > - Philippe Latu
> > (GPG|PGP) KeyId 0x742A6424
> > Public Key http://www.linux-france.org/~platu/key.asc
> > < G N U / Linux >
> > philippe.latu(at)linux-france.org
> > Projet inetdoc.Linux
> > http://www.linux-france.org/prj/inetdoc
> > </>
> > < I U T 'A'  Paul Sabatier >
> > philippe.latu(at)iut-tlse3.fr - 05.62.25.80.28
> > Enseignant/Chargé de mission Systèmes & Réseau
> > </>

-- 
- Philippe Latu
(GPG|PGP) KeyId 0x742A6424
Public Key http://www.linux-france.org/~platu/key.asc
< G N U / Linux >
philippe.latu(at)linux-france.org
Projet inetdoc.Linux 
http://www.linux-france.org/prj/inetdoc
</>
< I U T 'A'  Paul Sabatier >
philippe.latu(at)iut-tlse3.fr - 05.62.25.80.28
Enseignant/Chargé de mission Systèmes & Réseau
</>