1.\" $OpenBSD: ast.4,v 1.8 2003/06/02 23:30:12 millert Exp $ 2.\" $NetBSD: ast.4,v 1.7 1996/03/16 00:07:07 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.\" from: Id: com.4,v 1.1 1993/08/06 11:19:07 cgd Exp 36.\" 37.Dd March 30, 1994 38.Dt AST 4 39.Os 40.Sh NAME 41.Nm ast 42.Nd multiplexing serial communications interface 43.Sh SYNOPSIS 44.Cd "ast0 at isa? port 0x1a0 irq 5" 45.Cd "ast1 at isa? port 0x2a0 irq 6" 46.Cd "com* at ast? slave ?" 47or 48.Cd "pccom* at ast? slave ?" 49.Sh DESCRIPTION 50The 51.Nm 52driver provides support for boards that multiplex together up to four 53.Tn EIA 54.Tn RS-232C 55.Pf ( Tn CCITT 56.Tn V.28 ) 57communications interfaces. 58Apparently the original master of hardware using this multiplexing protocol 59was AST. 60.Pp 61Each 62.Nm 63device is the master device for up to four 64.Nm com 65or 66.Nm pccom 67devices. 68The kernel configuration specifies these 69.Nm com 70devices as slave devices of the 71.Nm 72device, as shown in the synopsis. 73The slave ID given for each 74.Nm com 75device determines which bit in the interrupt multiplexing register is 76tested to find interrupts for that device. 77The 78.Tn port 79specification for the 80.Nm 81device is used to compute the base addresses for the 82.Nm com 83subdevices and the port for the interrupt multiplexing register. 84.Pp 85On a real AST card, the jumpers are as follows: 86.Bl -tag -width xxxxx 87.It SW1-1 88Turn ON for irq 2. 89Default is OFF. 90.It SW1-2 91Turn ON for irq 3. 92Default is OFF. 93.It SW1-3 94Turn ON for irq 4. 95Default is OFF. 96.It SW2-1 97Turn ON for irq 5. 98This is ON for the first card, OFF otherwise. 99.It SW2-2 100Turn ON for irq 6. 101This is ON for the second card, OFF otherwise. 102.It SW2-3 103Turn ON for irq 7. 104Default is OFF. 105.It SW3-1 106.Dq Compatible mode . 107The 108.Nm ast 109driver needs extended mode, so leave this OFF. 110.It SW3-2 111IO Address. 112In extended mode, this should be OFF for the first card at 1130x1a0-0x1a7 and ON for the second card at 0x2a0-0x2a7. 114.It SW3-3 115Interrupt sharing. 116Default is OFF. 117.It SW3-4 118Reserved, must be OFF. 119.El 120.Sh FILES 121.Bl -tag -width Pa 122.It Pa /dev/tty0? 123.El 124.Sh SEE ALSO 125.Xr com 4 , 126.Xr intro 4 , 127.Xr isa 4 128.Sh HISTORY 129The 130.Nm 131driver was written by Roland McGrath and placed into the public 132domain. 133