FreeBSD (UNIXes?), UARTs, forced parity and "Custom" UART settings
Lev Serebryakov
lev at FreeBSD.org
Fri Nov 19 23:02:00 UTC 2010
Hello, Freebsd-hackers.
When I implemented USB2COM driver, I found that there is NO flags in
termios for forces parity. Here are flags to tunr parity on or off
and make it odd or even, but no mention about forced (alway 1 -- odd
-- or 0 -- even) parity, which is not dependend on data and acts as
one more (inverted sometimes) stop bit.
Virtually every UART has such mode (16x50-compatible UARTS hereis
bit in LCR for it), but no flag in the (POSIX?) API!
Did I miss something? How people communicate with equipment, which
uses (and wants) forced parity? Some equipment uses this bit as
address one...
Another question -- does USB2COM driver need RS-485 mode (which is
supported by hardware), and what is better way to turn it ons --
sysctl or ioctl?
--
// Black Lion AKA Lev Serebryakov <lev at FreeBSD.org>
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