Commit | Line | Data |
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9903e566 CL |
1 | .\" Copyright (c) 1980, 1991 Regents of the University of California. |
2 | .\" All rights reserved. | |
90a856fd | 3 | .\" |
9903e566 | 4 | .\" %sccs.include.redist.man% |
90a856fd | 5 | .\" |
9903e566 CL |
6 | .\" @(#)dh.4 6.3 (Berkeley) %G% |
7 | .\" | |
8 | .Dd | |
9 | .Dt DH 4 vax | |
10 | .Os BSD 4 | |
11 | .Sh NAME | |
12 | .Nm dh | |
13 | .Nd | |
14 | .Tn DH-11 Ns / Tn DM-11 | |
15 | multiplexer device interface | |
16 | .Sh SYNOPSIS | |
17 | .Cd "device dh0 at uba0 csr 0160020 vector dhrint dhxint" Op Ar flags | |
18 | .Cd "device dm0 at uba0 csr 0170500 vector dmintr" Op Ar flags | |
19 | .Sh DESCRIPTION | |
20 | A | |
21 | .Tn DH-11 | |
22 | provides 16 serial communication lines; | |
23 | .Tn DM-11 Ns s | |
24 | may optionally be | |
25 | paired with | |
26 | .Tn DH-11 Ns s | |
27 | to provide modem control for the lines. | |
28 | .Pp | |
29 | An optional argument | |
30 | .Ar flags | |
31 | may be supplied with the device specification | |
32 | in the | |
33 | .Xr config 8 | |
34 | file indicating | |
35 | that the line corresponding to | |
36 | bit number | |
37 | .Ar i | |
38 | is not properly | |
39 | connected, and should be treated as hard-wired with carrier | |
40 | always present. Thus specifying | |
41 | .Ql flags 0x0004 | |
42 | for | |
43 | .Li dh0 | |
44 | would cause line | |
45 | .Pa ttyh2 | |
46 | to be treated in this way. | |
47 | .Pp | |
48 | Normal I/O | |
49 | control parameters for individual lines are managed by | |
50 | .Xr ioctl 2 | |
51 | calls. | |
52 | Line speeds may be initiated via | |
53 | .Xr getty 8 | |
54 | and | |
55 | .Xr stty 1 | |
56 | or may be communicated by other programs which | |
57 | utilize | |
58 | .Xr ioctl | |
59 | such as | |
60 | .Xr ifcongif 8 , | |
90a856fd | 61 | see |
9903e566 CL |
62 | .Xr tty 4 . |
63 | .Pp | |
fa15f16d | 64 | The |
9903e566 | 65 | .Nm dh |
fa15f16d MK |
66 | driver monitors the rate of input on each board, |
67 | and switches between the use of character-at-a-time interrupts | |
68 | and input silos. | |
69 | While the silo is enabled during periods of high-speed input, | |
70 | the driver polls for input 30 times per second. | |
9903e566 CL |
71 | .Sh FILES |
72 | .Bl -tag -width /dev/tty[h-o][0-9a-f]x -compact | |
73 | .It Pa /dev/tty[h-o][0-9a-f] | |
74 | .It Pa /dev/ttyd[0-9a-f] | |
75 | .El | |
76 | .Sh DIAGNOSTICS | |
77 | .Bl -diag | |
78 | .It dh%d: NXM. | |
79 | No response from | |
80 | .Tn UNIBUS | |
81 | on a dma transfer | |
82 | within a timeout period. This is often followed by a | |
83 | .Tn UNIBUS | |
84 | adapter | |
85 | error. This occurs most frequently when the | |
86 | .Tn UNIBUS | |
87 | is heavily loaded | |
88 | and when devices which hog the bus (such as | |
89 | .Tn RK07 Ns s) are present. | |
90a856fd | 90 | It is not serious. |
9903e566 CL |
91 | .Pp |
92 | .It dh%d: silo overflow. | |
93 | The character input silo overflowed | |
90a856fd | 94 | before it could be serviced. This can happen if a hard error occurs |
9903e566 CL |
95 | when the |
96 | .Tn CPU | |
97 | is running with elevated priority, as the system will | |
fa15f16d | 98 | then print a message on the console with interrupts disabled. |
90a856fd | 99 | It is not serious. |
9903e566 CL |
100 | .El |
101 | .Sh SEE ALSO | |
102 | .Xr tty 4 | |
103 | .Sh HISTORY | |
104 | A | |
105 | .Nm | |
106 | driver appeared in | |
107 | .At v6 . |