ref: c6d4cd09a395a24ee993c1edf1031e5b01adddde
dir: /sys/man/3/uart/
.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