3 uart, eia \- serial communication control
18 The serial line devices serve a one-level directory,
19 giving access to the serial ports.
26 (the control file), and
28 (the read-only status file).
29 Reads of the data file will block until at least one byte is available.
33 It accepts the following commands:
42 is non-zero; else clear it.
53 is non-zero; else clear it.
59 Close input and output queues.
62 Enable/disable the FIFOs.
65 is zero the FIFOs are disabled;
68 is taken as a trigger level for the FIFOs.
69 The trigger levels supported are device dependant,
70 but usually include 1, 4 and 8.
75 causes the maximum-supported trigger level to be set.
83 Set number of bits per byte to
85 Legal values are 5, 6, 7, or 8.
88 Obey modem CTS signal if
94 Make writes non-blocking.
108 Set input and output queue limits to
118 Set number of stop bits to
120 Legal values are 1 or 2.
123 Set the uart clock timer to
128 files contain a textual representation of the status of the line, in the format of the
133 .B /sys/src/9/port/devuart.c
135 .B /sys/src/9/*/uart*.c