High Speed Serial

[Summertown]

Hipy!
I have been looking at interest at the threads on highn speed serial....
I am running a 28x
Summerising what has been written;
Conventional wisdom says that at a 4meg clock 2400 is the highest recommended by Reved. Correct?
If you use the peek/poke method yo can run at 9600. Correct?
If you are running a 28x at 16meg the 2400 will become 9600. Is this stable? or do you need to resort to peek/poke bit banging?
Thanks in advance.
Gonzo
at 16megs,

 

[hippy]

At 16MHz 2400 baud will become 9600 baud, or it can be achieved by peeking and poking the on chip AUSART. I'd recommend using standard SERIN/SEROUT over using the AUSART unless there's a very good reason to use it.

The 28X can also use 9600 baud by specifying 4800 baud and running at 8MHz.

The issue of recommended maximum baud rate is a complex matter. For transmission there should be no problems; any errors in timing should percentage-wise be the same regardless of clock speed. Likewise for reception, but that has the added issue that in a SERIN reading multiple bytes and particularly #numbers the PICAXE needs time to process, store the data, and be ready for the next byte. It's hard to quantify in absolute terms for all possible cases so I am sure that's the basis of the 'catch-all' recommendation.

 

[MPep]

Also, of course, at 16MHz 4800 (in program) becomes 19200 baud. I am using 19200 reliably, no problems encountered.