1.\" $NetBSD: dh.4,v 1.9 2002/08/20 15:54:08 wiz Exp $ 2.\" 3.\" Copyright (c) 1980, 1991, 1993 4.\" The Regents of the University of California. 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.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. 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: @(#)dh.4 8.1 (Berkeley) 6/5/93 35.\" 36.Dd June 5, 1993 37.Dt DH 4 vax 38.Os 39.Sh NAME 40.Nm dh 41.Nd 42.Tn DH-11 Ns / Tn DM-11 43serial multiplexer device interface 44.Sh SYNOPSIS 45.Cd "dh0 at uba0 csr 0160020 vector dhrint dhxint" Op Ar flags 46.Cd "dm0 at uba0 csr 0170500 vector dmintr" Op Ar flags 47.Sh DESCRIPTION 48NOTE: This driver has not been ported from 49.Bx 4.4 50yet. 51.Pp 52A 53.Tn DH-11 54provides 16 serial communication lines; 55.Tn DM-11 Ns s 56may optionally be 57paired with 58.Tn DH-11 Ns s 59to provide modem control for the lines. 60.Pp 61An optional argument 62.Ar flags 63may be supplied with the device specification 64in the 65.Xr config 8 66file indicating 67that the line corresponding to 68bit number 69.Ar i 70is not properly 71connected, and should be treated as hard-wired with carrier 72always present. Thus specifying 73.Ql flags 0x0004 74for 75.Li dh0 76would cause line 77.Pa ttyh2 78to be treated in this way. 79.Pp 80Normal I/O 81control parameters for individual lines are managed by 82.Xr ioctl 2 83calls. 84Line speeds may be initiated via 85.Xr getty 8 86and 87.Xr stty 1 88or may be communicated by other programs which 89utilize 90.Xr ioctl 2 91such as 92.Xr ifconfig 8 , 93see 94.Xr tty 4 . 95.Pp 96The 97.Nm dh 98driver monitors the rate of input on each board, 99and switches between the use of character-at-a-time interrupts 100and input silos. 101While the silo is enabled during periods of high-speed input, 102the driver polls for input 30 times per second. 103.Sh FILES 104.Bl -tag -width /dev/tty[h-o][0-9a-f]x -compact 105.It Pa /dev/tty[h-o][0-9a-f] 106.It Pa /dev/ttyd[0-9a-f] 107.El 108.Sh DIAGNOSTICS 109.Bl -diag 110.It dh%d: NXM. 111No response from 112.Tn UNIBUS 113on a dma transfer 114within a timeout period. This is often followed by a 115.Tn UNIBUS 116adapter 117error. This occurs most frequently when the 118.Tn UNIBUS 119is heavily loaded 120and when devices which hog the bus (such as 121.Tn RK07 Ns s ) 122are present. 123It is not serious. 124.Pp 125.It dh%d: silo overflow. 126The character input silo overflowed 127before it could be serviced. This can happen if a hard error occurs 128when the 129.Tn CPU 130is running with elevated priority, as the system will 131then print a message on the console with interrupts disabled. 132It is not serious. 133.El 134.Sh SEE ALSO 135.Xr tty 4 136.Sh HISTORY 137A 138.Nm 139driver appeared in 140.At v6 . 141