94 lines
3.3 KiB
Groff
94 lines
3.3 KiB
Groff
.\" $NetBSD: ast.4,v 1.10 2001/09/11 17:39:01 wiz Exp $
|
|
.\"
|
|
.\" Copyright (c) 1990, 1991 The Regents of the University of California.
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" This code is derived from software contributed to Berkeley by
|
|
.\" the Systems Programming Group of the University of Utah Computer
|
|
.\" Science Department.
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the University of
|
|
.\" California, Berkeley and its contributors.
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" from: @(#)dca.4 5.2 (Berkeley) 3/27/91
|
|
.\" from: Id: com.4,v 1.1 1993/08/06 11:19:07 cgd Exp
|
|
.\"
|
|
.Dd March 30, 1994
|
|
.Dt AST 4
|
|
.Os
|
|
.Sh NAME
|
|
.Nm ast
|
|
.Nd
|
|
multiplexing serial communications interface
|
|
.Sh SYNOPSIS
|
|
.Cd "ast0 at isa? port 0x1a0 irq 5"
|
|
.Cd "com2 at ast? slave ?"
|
|
.Cd "com3 at ast? slave ?"
|
|
.Cd "com4 at ast? slave ?"
|
|
.Cd "com5 at ast? slave ?"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm ast
|
|
driver provides support for boards that multiplex together up to four
|
|
.Tn EIA
|
|
.Tn RS-232C
|
|
.Pf ( Tn CCITT
|
|
.Tn V.28 )
|
|
communications interfaces. Apparently the original master of hardware
|
|
using this multiplexing protocol was AST.
|
|
.Pp
|
|
Each
|
|
.Nm
|
|
device is the master device for up to four
|
|
.Nm com
|
|
devices. The kernel configuration specifies these
|
|
.Nm com
|
|
devices as slave devices of the
|
|
.Nm
|
|
device, as shown in the synopsis. The slave ID given for each
|
|
.Nm com
|
|
device determines which bit in the interrupt multiplexing register is
|
|
tested to find interrupts for that device.
|
|
The
|
|
.Tn port
|
|
specification for the
|
|
.Nm
|
|
device is used to compute the base addresses for the
|
|
.Nm com
|
|
subdevices and the port for the interrupt multiplexing register.
|
|
.Sh FILES
|
|
.Bl -tag -width Pa
|
|
.It Pa /dev/tty0?
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr com 4
|
|
.Sh HISTORY
|
|
The
|
|
.Nm
|
|
driver was written by Roland McGrath and placed into the public
|
|
domain.
|