1*61595Sbostic.\" Copyright (c) 1980, 1991, 1993 2*61595Sbostic.\" The Regents of the University of California. All rights reserved. 320647Smckusick.\" 447674Scael.\" %sccs.include.redist.man% 520647Smckusick.\" 6*61595Sbostic.\" @(#)dh.4 8.1 (Berkeley) 06/05/93 747674Scael.\" 847674Scael.Dd 947674Scael.Dt DH 4 vax 1047674Scael.Os BSD 4 1147674Scael.Sh NAME 1247674Scael.Nm dh 1347674Scael.Nd 1447674Scael.Tn DH-11 Ns / Tn DM-11 1547674Scaelmultiplexer device interface 1647674Scael.Sh SYNOPSIS 1747674Scael.Cd "device dh0 at uba0 csr 0160020 vector dhrint dhxint" Op Ar flags 1847674Scael.Cd "device dm0 at uba0 csr 0170500 vector dmintr" Op Ar flags 1947674Scael.Sh DESCRIPTION 2047674ScaelA 2147674Scael.Tn DH-11 2247674Scaelprovides 16 serial communication lines; 2347674Scael.Tn DM-11 Ns s 2447674Scaelmay optionally be 2547674Scaelpaired with 2647674Scael.Tn DH-11 Ns s 2747674Scaelto provide modem control for the lines. 2847674Scael.Pp 2947674ScaelAn optional argument 3047674Scael.Ar flags 3147674Scaelmay be supplied with the device specification 3247674Scaelin the 3347674Scael.Xr config 8 3447674Scaelfile indicating 3547674Scaelthat the line corresponding to 3647674Scaelbit number 3747674Scael.Ar i 3847674Scaelis not properly 3947674Scaelconnected, and should be treated as hard-wired with carrier 4047674Scaelalways present. Thus specifying 4147674Scael.Ql flags 0x0004 4247674Scaelfor 4347674Scael.Li dh0 4447674Scaelwould cause line 4547674Scael.Pa ttyh2 4647674Scaelto be treated in this way. 4747674Scael.Pp 4847674ScaelNormal I/O 4947674Scaelcontrol parameters for individual lines are managed by 5047674Scael.Xr ioctl 2 5147674Scaelcalls. 5247674ScaelLine speeds may be initiated via 5347674Scael.Xr getty 8 5447674Scaeland 5547674Scael.Xr stty 1 5647674Scaelor may be communicated by other programs which 5747674Scaelutilize 5847674Scael.Xr ioctl 5947674Scaelsuch as 6047674Scael.Xr ifcongif 8 , 6120647Smckusicksee 6247674Scael.Xr tty 4 . 6347674Scael.Pp 6428259SkarelsThe 6547674Scael.Nm dh 6628259Skarelsdriver monitors the rate of input on each board, 6728259Skarelsand switches between the use of character-at-a-time interrupts 6828259Skarelsand input silos. 6928259SkarelsWhile the silo is enabled during periods of high-speed input, 7028259Skarelsthe driver polls for input 30 times per second. 7147674Scael.Sh FILES 7247674Scael.Bl -tag -width /dev/tty[h-o][0-9a-f]x -compact 7347674Scael.It Pa /dev/tty[h-o][0-9a-f] 7447674Scael.It Pa /dev/ttyd[0-9a-f] 7547674Scael.El 7647674Scael.Sh DIAGNOSTICS 7747674Scael.Bl -diag 7847674Scael.It dh%d: NXM. 7947674ScaelNo response from 8047674Scael.Tn UNIBUS 8147674Scaelon a dma transfer 8247674Scaelwithin a timeout period. This is often followed by a 8347674Scael.Tn UNIBUS 8447674Scaeladapter 8547674Scaelerror. This occurs most frequently when the 8647674Scael.Tn UNIBUS 8747674Scaelis heavily loaded 8847674Scaeland when devices which hog the bus (such as 8947674Scael.Tn RK07 Ns s) are present. 9020647SmckusickIt is not serious. 9147674Scael.Pp 9247674Scael.It dh%d: silo overflow. 9347674ScaelThe character input silo overflowed 9420647Smckusickbefore it could be serviced. This can happen if a hard error occurs 9547674Scaelwhen the 9647674Scael.Tn CPU 9747674Scaelis running with elevated priority, as the system will 9828259Skarelsthen print a message on the console with interrupts disabled. 9920647SmckusickIt is not serious. 10047674Scael.El 10147674Scael.Sh SEE ALSO 10247674Scael.Xr tty 4 10347674Scael.Sh HISTORY 10447674ScaelA 10547674Scael.Nm 10647674Scaeldriver appeared in 10747674Scael.At v6 . 108