19 Aug
2012
19 Aug
'12
9:09 a.m.
On Sun, 19 Aug 2012 01:16:38 -0400
Dave McGuire <mcguire at neurotica.com> wrote:
I *think* there is a USB async serial I/O profile,
but nobody (that I
know of) has implemented it, and there has to be a reason for that.
You talk about
USB CDC, Communications Device Class. This device class
features several interfaces that e.g. mimic Ethernet or async serial
connections. I am really surprised why it doesn't get widespread use
like USB mass storage. Either it has some major design flaw. Or it is
"too open". I.e. vendors like FTDI or Profilic are not able to "lock
in" customers by folowing a generalized device class. Maybe it is just
lazzyness of developers. They prefere to use a ready made chip that
implements all the USB stuff then to implement a CDC device in there
own firmware. Have a look at this application notes:
http://www.atmel.com/images/doc4322.pdf
http://www.atmel.com/images/doc7619.pdf
and the official class definitions:
http://www.usb.org/developers/devclass_docs/CDC1.2_WMC1.1_012011.zip
--
\end{Jochen}
\ref{http://www.unixag-kl.fh-kl.de/~jkunz/}