136 lines
2.0 KiB
Plaintext
136 lines
2.0 KiB
Plaintext
|
.TH UART 3
|
||
|
|
.SH NAME
|
||
|
|
uart, eia \- serial communication control
|
||
|
|
.SH SYNOPSIS
|
||
|
|
.nf
|
||
|
|
.B bind -a #t /dev
|
||
|
|
|
||
|
|
.B /dev/eia0
|
||
|
|
.B /dev/eia0ctl
|
||
|
|
.B /dev/eia0status
|
||
|
|
.B /dev/eia1
|
||
|
|
.B /dev/eia1ctl
|
||
|
|
.B /dev/eia1status
|
||
|
|
\&...
|
||
|
|
.fi
|
||
|
|
.SH DESCRIPTION
|
||
|
|
.PP
|
||
|
|
The serial line devices serve a one-level directory,
|
||
|
|
giving access to the serial ports.
|
||
|
|
Device
|
||
|
|
.I n
|
||
|
|
is accessed through
|
||
|
|
.BI eia n
|
||
|
|
(the data file),
|
||
|
|
.BI eia n ctl
|
||
|
|
(the control file), and
|
||
|
|
.BI eia n status
|
||
|
|
(the read-only status file).
|
||
|
|
Reads of the data file will block until at least one byte is available.
|
||
|
|
The
|
||
|
|
control file
|
||
|
|
configures the port.
|
||
|
|
It accepts the following commands:
|
||
|
|
.TP
|
||
|
|
.BI b n
|
||
|
|
Set the baud rate to
|
||
|
|
.IR n .
|
||
|
|
.TP
|
||
|
|
.BI c n
|
||
|
|
Set hangup on DCD if
|
||
|
|
.I n
|
||
|
|
is non-zero; else clear it.
|
||
|
|
.TP
|
||
|
|
.BI d n
|
||
|
|
Set DTR if
|
||
|
|
.I n
|
||
|
|
is non-zero;
|
||
|
|
else clear it.
|
||
|
|
.TP
|
||
|
|
.BI e n
|
||
|
|
Set hangup on DSR if
|
||
|
|
.I n
|
||
|
|
is non-zero; else clear it.
|
||
|
|
.TP
|
||
|
|
.B f
|
||
|
|
Flush output queue.
|
||
|
|
.TP
|
||
|
|
.B h
|
||
|
|
Close input and output queues.
|
||
|
|
.TP
|
||
|
|
.BI i n
|
||
|
|
Enable/disable the FIFOs.
|
||
|
|
If
|
||
|
|
.I n
|
||
|
|
is zero the FIFOs are disabled;
|
||
|
|
otherwise
|
||
|
|
.I n
|
||
|
|
is taken as a trigger level for the FIFOs.
|
||
|
|
The trigger levels supported are device dependant,
|
||
|
|
but usually include 1, 4 and 8.
|
||
|
|
An unrecognised,
|
||
|
|
but non-zero,
|
||
|
|
value of
|
||
|
|
.I n
|
||
|
|
causes the maximum-supported trigger level to be set.
|
||
|
|
.TP
|
||
|
|
.BI k n
|
||
|
|
Send a break lasting
|
||
|
|
.I n
|
||
|
|
milliseconds.
|
||
|
|
.TP
|
||
|
|
.BI l n
|
||
|
|
Set number of bits per byte to
|
||
|
|
.IR n .
|
||
|
|
Legal values are 5, 6, 7, or 8.
|
||
|
|
.TP
|
||
|
|
.BI m n
|
||
|
|
Obey modem CTS signal if
|
||
|
|
.I n
|
||
|
|
is non-zero;
|
||
|
|
else clear it.
|
||
|
|
.TP
|
||
|
|
.B n
|
||
|
|
Make writes non-blocking.
|
||
|
|
.TP
|
||
|
|
.BI p c
|
||
|
|
Set parity to odd if
|
||
|
|
.I c
|
||
|
|
is
|
||
|
|
.BR o ,
|
||
|
|
to even if
|
||
|
|
.I c
|
||
|
|
is
|
||
|
|
.BR e ;
|
||
|
|
else set no parity.
|
||
|
|
.TP
|
||
|
|
.BI q n
|
||
|
|
Set input and output queue limits to
|
||
|
|
.IR n .
|
||
|
|
.TP
|
||
|
|
.BI r n
|
||
|
|
Set RTS if
|
||
|
|
.I n
|
||
|
|
is non-zero;
|
||
|
|
else clear it.
|
||
|
|
.TP
|
||
|
|
.BI s n
|
||
|
|
Set number of stop bits to
|
||
|
|
.IR n .
|
||
|
|
Legal values are 1 or 2.
|
||
|
|
.TP
|
||
|
|
.BI w n
|
||
|
|
Set the uart clock timer to
|
||
|
|
n times 100us.
|
||
|
|
.IP
|
||
|
|
.PP
|
||
|
|
The status
|
||
|
|
files contain a textual representation of the status of the line, in the format of the
|
||
|
|
commands used on the
|
||
|
|
control
|
||
|
|
file.
|
||
|
|
.SH SOURCE
|
||
|
|
.B /sys/src/9/port/devuart.c
|
||
|
|
.br
|
||
|
|
.B /sys/src/9/*/uart*.c
|