Re: Linux serial port dropping bytes

On 2008-04-02, Anton Erasmus <nobody@xxxxxxxxxxxxxxxx> wrote:

This turned out to be 5x faster than with the onboard UARTs where one
had to check the FIFO not empty flag every time.
On a 50MHz ARM9 it took about 25us per 16 characters having to do it
the way CBFalconer described it, while it only took about 5us per 16
characters where one could read how many chars were in the Rx FIFO.

There are a lot of micro-controllers out there with horribly
designed UARTs in them. One I've fought with recently is the
in the Samsung S3C4530. Half of the features don't work at
all. Half of the stuff that does work are useless because
whoever specified/designed the UART had never actually done any
serial communications only had a vague understanding of how
things like UARTs and FIFOs are used. For example, it has
FIFOs, but there's no way to flush them. It also has "hardware
flow control", but it doesn't work in a way that can be used
with any other UART on the planet.

--
Grant Edwards grante Yow! ... the MYSTERIANS are
at in here with my CORDUROY
visi.com SOAP DISH!!
.

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