Serial com weirdness

Started by holopoint.rm July 27, 2003
Hey all.
I have a PIC18F452 doing serial comm with my PC via one of it's UARTs.
I wrote a simple test program that outputs a char every second,
and echos serial input. I open up a terminal, chars are coming
in every second, key strokes are echoed, all is well.
Until I try to send a bunch of chars quickly, like pressing
keys very fast. The first 5-8 chars get through (are echoed) and
the rest are ignored, they simple do not arrive at the PIC,
nor does any other key pressed after that. It's like I chocked
the UART and killed it. Only a reset fixes the problem.
Any ideas why this is happening ?



> It's like I chocked
> the UART and killed it. Only a reset fixes the problem.
> Any ideas why this is happening ?

- are you sure the problem in't on the PC side?
- when sending fast, do you wait for the UART buffer to be empty?

Wouter van Ooijen

-- -------
Van Ooijen Technische Informatica: www.voti.nl
consultancy, development, PICmicro products



--- In , "Wouter van Ooijen" <wouter@v...>
wrote:
> > It's like I chocked
> > the UART and killed it. Only a reset fixes the problem.
> > Any ideas why this is happening ?
>
> - are you sure the problem in't on the PC side?
> - when sending fast, do you wait for the UART buffer to be empty?
>
> Wouter van Ooijen
>
Aha !
Good point, no, no waiting on the PC side.
Tommorow's headlines,
"buffer overflow kills UART"

Thanks.