1.\" $OpenBSD: com.4,v 1.11 2003/06/02 23:30:12 millert Exp $ 2.\" $NetBSD: com.4,v 1.5 1996/03/16 00:07:08 thorpej Exp $ 3.\" 4.\" Copyright (c) 1990, 1991 The Regents of the University of California. 5.\" All rights reserved. 6.\" 7.\" This code is derived from software contributed to Berkeley by 8.\" the Systems Programming Group of the University of Utah Computer 9.\" Science Department. 10.\" Redistribution and use in source and binary forms, with or without 11.\" modification, are permitted provided that the following conditions 12.\" are met: 13.\" 1. Redistributions of source code must retain the above copyright 14.\" notice, this list of conditions and the following disclaimer. 15.\" 2. Redistributions in binary form must reproduce the above copyright 16.\" notice, this list of conditions and the following disclaimer in the 17.\" documentation and/or other materials provided with the distribution. 18.\" 3. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" from: @(#)dca.4 5.2 (Berkeley) 3/27/91 35.\" 36.Dd July 12, 1998 37.Dt COM 4 38.Os 39.Sh NAME 40.Nm com , 41.Nm pccom 42.Nd serial communications interface 43.Sh SYNOPSIS 44.Cd "# i386 - pccom or com attachments" 45.Cd "pccom0 at isa? port 0x3f8 irq 4" 46.Cd "pccom1 at isa? port 0x2f8 irq 3" 47.Cd "pccom2 at isa? port 0x3e8 irq 5" 48.Cd "pccom3 at isa? port 0x2e8 irq 9" 49.Cd "pccom* at isapnp?" 50.Cd "pccom* at pcmcia? function ?" 51.Cd "pccom* at puc? port ?" 52.Pp 53.Cd "pccom* at addcom? slave ?" 54.Cd "pccom* at ast? slave ?" 55.Cd "pccom* at boca? slave ?" 56.Cd "pccom* at hsq? slave ?" 57.Cd "pccom* at rtfps? slave ?" 58.Pp 59.Cd "# alpha" 60.Cd "com0 at isa? port 0x3f8 irq 4" 61.Cd "com1 at isa? port 0x2f8 irq 3" 62.Pp 63.Cd "# sparc64" 64.Cd "com* at asio?" 65.Cd "com* at ebus?" 66.Pp 67.Cd "# hppa" 68.Cd "com0 at gsc? offset 0x5000 irq 5" 69.Cd "com0 at gsc? offset 0x23000 irq 5" 70.Cd "com1 at gsc? offset 0x22000 irq 6" 71.Cd "com2 at gsc? offset ? irq 13" 72.Sh DESCRIPTION 73The 74.Nm com 75and 76.Nm pccom 77drivers provide support for NS8250-, NS16450-, NS16550-, ST16650-, and 78TI16750-based 79.Tn EIA 80.Tn RS-232C 81.Pf ( Tn CCITT 82.Tn V.28 ) 83communications interfaces. 84The 85.Nm pccom 86driver (i386-only) also supports the XR16850 UART. 87.Pp 88The NS8250 and NS16450 have single 89character buffers, the NS16550 has a 16 character buffer, while 90the ST16650 has a 32 character buffer, and the TI16750 has a 64 character 91buffer. 92The XR16850 has a 128 character buffer. 93.Pp 94The 95.Nm com 96and 97.Nm pccom 98drivers are mutually exclusive; both may not be present in the same system at 99the same time. 100Attempting to compile such a system will fail. 101.Pp 102Input and output for each line may be set to one of following baud rates; 10350, 75, 110, 134.5, 150, 300, 600, 1200, 1800, 2400, 4800, 9600, 10419200, 38400, 57600, or 115200, or any other baud rate which is a factor 105of 115200. 106.Sh FILES 107.Bl -tag -width Pa -compact 108.It Pa /dev/tty00 109.It Pa /dev/tty01 110.It Pa /dev/cua00 111.It Pa /dev/cua01 112.El 113.Sh DIAGNOSTICS 114.Bl -diag 115.It com%d: %d silo overflows 116The input 117.Dq silo 118has overflowed and incoming data has been lost. 119.It com%d: weird interrupt: iir=%x 120The device has generated an unexpected interrupt 121with the code listed. 122.El 123.Sh SEE ALSO 124.Xr addcom 4 , 125.Xr asio 4 , 126.Xr ast 4 , 127.Xr boca 4 , 128.Xr ebus 4 , 129.Xr gsc 4 , 130.Xr hsq 4 , 131.Xr intro 4 , 132.Xr isa 4 , 133.Xr isapnp 4 , 134.Xr pcmcia 4 , 135.Xr puc 4 , 136.Xr rtfps 4 , 137.Xr tty 4 138.Sh HISTORY 139The 140.Nm 141driver was originally derived from the 142.Nm HP9000/300 143.Nm dca 144driver and is 145.Ud 146.Sh BUGS 147Data loss is possible on busy systems with unbuffered UARTs at high speed. 148.Pp 149The name of this driver and the constants which define the locations 150of the various serial ports are holdovers from 151.Nm DOS . 152