James and Iliana Holbrook wrote:
>
> Hola,
>         I'm trying to understand serial communication at the TTL level. My
> understanding is that at a baud rate of say... 4800 bps you have a period
> of 208 microseconds . Correct ?? If I'm correct then a PIC running at 4mhz
> will have executed 208 instructions during the high/low period of the
> signal. Instead of just setting there waiting for the signal to change
> states could you not be doing some other work ?? Is this Ok ?
>         What is the standard for receiving serial data ? Do you get some data
 then
> return to the main loop ?? Or couldn't it be made to check pin state..do
> other work..check pin state...write data to register after period..do other
> work.

Exactly! Use a timer interrupt (TMR0) to jump to your comms routine.

--
Friendly Regards

Tjaart van der Walt
mailto:tjaart@wasp.co.za
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