1.\" $OpenBSD: addcom.4,v 1.8 2008/05/21 19:05:51 kettenis Exp $ 2.\" 3.\" Copyright (c) 2001 Jason L. Wright (jason@thought.net) 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 18.\" DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, 19.\" INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 20.\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 21.\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 23.\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 24.\" ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 25.\" POSSIBILITY OF SUCH DAMAGE. 26.\" 27.\" 28.Dd $Mdocdate: May 21 2008 $ 29.Dt ADDCOM 4 30.Os 31.Sh NAME 32.Nm addcom 33.Nd multiplexing serial communications interface 34.Sh SYNOPSIS 35.Cd "addcom0 at isa? port 0x108 irq 5" 36.Cd "com* at addcom?" 37.Sh DESCRIPTION 38The 39.Nm 40driver provides support for Addonics FlexPort 8/S (and probably FlexPort 4/S) 41boards that multiplex together up to eight (or four) 42.Tn EIA 43.Tn RS-232C 44.Pf ( Tn CCITT 45.Tn V.28 ) 46communications interfaces. 47.Pp 48Each 49.Nm 50device is the master device for up to eight 51.Nm com 52devices. 53The kernel configuration specifies these 54.Nm com 55devices as slave devices of the 56.Nm 57device, as shown in 58.Sx SYNOPSIS . 59The slave ID given for each 60.Nm com 61device determines which bit in the interrupt multiplexing register is 62tested to find interrupts for that device. 63The 64.Tn port 65specification for the 66.Nm 67device is used to compute the base addresses for the 68.Nm com 69subdevices. 70The port for the interrupt multiplexing register is fixed, 71so it is doubtful that more than one 72.Nm 73can be used in a machine. 74.Sh FILES 75.Bl -tag -width Pa 76.It Pa /dev/tty?? 77.El 78.Sh SEE ALSO 79.Xr com 4 , 80.Xr intro 4 , 81.Xr isa 4 82.Sh HISTORY 83.Ox 84support for 85.Nm 86devices first appeared in 87.Ox 3.0 . 88