On Wed, Mar 07, 2001 at 02:34:26PM -0500, [EMAIL PROTECTED] wrote:
> I found that a native UART has a latency of 1-2ms for a single byte.
> That latency increases with packet size. When run over the 8U232AM
> the 1 byte latency is about 16-17ms and remains about 15ms longer than
> the native UART for larger packet sizes. Is this latency somehow
> tunable?
USB to serial devices will always be much slower (have much greater
latency) than UARTs. This is due to the fact that you add at least 1
USB transaction to the whole time. And since you are doing a loopback
you have the following sequence to go through:
- data across USB to UART in device
- data out of UART
- data back into UART
- data back across USB to host
Some USB to serial devices handle latencies better than others. But of
course they cost more :)
I'll let Bill Ryder answer the odd data characters, as he's the main
author and maintainer of the driver, and I don't have one of these
devices.
thanks,
greg k-h
--
greg@(kroah|wirex).com
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