On Feb 3, 2005, at 12:35 PM, Bob Ammerman wrote:
>
>>> Presumably the "problem" is with software uarts that check the full 
>>> stop
>>> bit, and don't have time to "unsynchronize" before the next 
>>> start-bit starts.
>>
>> From my experience most UARTs appear to start looking for a new start 
>> bit
>> about 1/2 way through the stop bit time.
>
> Also, if you can set up to transmit two stop bits then you give the
> receiver more time to be ready for the start bit of each byte.
>
Isn't that where this digression into uart internal operations started?
Someone opined that pauses between characters would help receivers sync
up, and everyone jumped on it as not being needed if the uarts worked
right.  Well, I agree, in principle, but here we are again at "extra
time between characters might help", and I have to agree with that TOO.

I have been contemplating, off and on since I got that good deal on 
eBay,
SW uarts on PICs running off a 32kHz crystal, and how fast they might or
might not be coerced into operating.  Two nop's gets you to just before
the middle of the first bit, three nop's to just after the middle of the
second bit...  Not a lot of time to do everything perfect, and extra 
time
between characters would probably help A LOT...

BillW
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