[En-Nut-Discussion] Software UART anyone?

[Roland Zitzke]

-----Ursprüngliche Nachricht----- 
Von: "Matthias Ringwald" <mringwal at inf.ethz.ch>
An: "Ethernut User Chat (English)" <en-nut-discussion at egnite.de>
Gesendet: Mittwoch, 31. März 2004 14:18
Betreff: [En-Nut-Discussion] Software UART anyone?


> it looks like we will need an additional software driven uart aside the
> 2 hw uarts on the atmega128.
> anybody went into that direction, or could has a working version ?

I would take a look at
http://www.atmel.com/dyn/resources/prod_documents/DOC0952.PDF
or the assembler code produced by
www.fastavr.com
Both versions are simmilar and work with software delays and require all
interrupts to be disabled.

>
> coments on the feasibility are welcomed, as well.
>

This depends on what you need to do. If you just need to send out a couple
of bytes in blocking mode without the need for running interrupts you will
be fine with the above solutions.

However I doubt that you can implement a reliable full-featured software
UART with standard ethernut activities running in parallel.

/Roland