com.4 revision 1.12
$OpenBSD: com.4,v 1.12 2003/11/08 16:55:35 miod Exp $
$NetBSD: com.4,v 1.5 1996/03/16 00:07:08 thorpej 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
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from: @(#)dca.4 5.2 (Berkeley) 3/27/91

.Dd July 12, 1998 .Dt COM 4 .Os .Sh NAME .Nm com , .Nm pccom .Nd serial communications interface .Sh SYNOPSIS .Cd "# i386 - pccom or com attachments" .Cd "pccom0 at isa? port 0x3f8 irq 4" .Cd "pccom1 at isa? port 0x2f8 irq 3" .Cd "pccom2 at isa? port 0x3e8 irq 5" .Cd "pccom3 at isa? port 0x2e8 irq 9" .Cd "pccom* at isapnp?" .Cd "pccom* at pcmcia? function ?" .Cd "pccom* at puc? port ?"

p .Cd "pccom* at addcom? slave ?" .Cd "pccom* at ast? slave ?" .Cd "pccom* at boca? slave ?" .Cd "pccom* at hsq? slave ?" .Cd "pccom* at rtfps? slave ?"

p .Cd "# alpha" .Cd "com0 at isa? port 0x3f8 irq 4" .Cd "com1 at isa? port 0x2f8 irq 3"

p .Cd "# hppa" .Cd "com0 at gsc? offset 0x5000 irq 5" .Cd "com0 at gsc? offset 0x23000 irq 5" .Cd "com1 at gsc? offset 0x22000 irq 6" .Cd "com2 at gsc? offset ? irq 13"

p .Cd "# pegasos" .Cd "com0 at isa? port 0x2f8 irq 3"

p .Cd "# sparc64" .Cd "com* at asio?" .Cd "com* at ebus?" .Sh DESCRIPTION The .Nm com and .Nm pccom drivers provide support for NS8250-, NS16450-, NS16550-, ST16650-, and TI16750-based .Tn EIA .Tn RS-232C

f ( Tn CCITT .Tn V.28 ) communications interfaces. The .Nm pccom driver (i386-only) also supports the XR16850 UART.

p The NS8250 and NS16450 have single character buffers, the NS16550 has a 16 character buffer, while the ST16650 has a 32 character buffer, and the TI16750 has a 64 character buffer. The XR16850 has a 128 character buffer.

p The .Nm com and .Nm pccom drivers are mutually exclusive; both may not be present in the same system at the same time. Attempting to compile such a system will fail.

p Input and output for each line may be set to one of following baud rates; 50, 75, 110, 134.5, 150, 300, 600, 1200, 1800, 2400, 4800, 9600, 19200, 38400, 57600, or 115200, or any other baud rate which is a factor of 115200. .Sh FILES l -tag -width Pa -compact t Pa /dev/tty00 t Pa /dev/tty01 t Pa /dev/cua00 t Pa /dev/cua01 .El .Sh DIAGNOSTICS l -diag t com%d: %d silo overflows The input .Dq silo has overflowed and incoming data has been lost. t com%d: weird interrupt: iir=%x The device has generated an unexpected interrupt with the code listed. .El .Sh SEE ALSO .Xr addcom 4 , .Xr asio 4 , .Xr ast 4 , .Xr boca 4 , .Xr ebus 4 , .Xr gsc 4 , .Xr hsq 4 , .Xr intro 4 , .Xr isa 4 , .Xr isapnp 4 , .Xr pcmcia 4 , .Xr puc 4 , .Xr rtfps 4 , .Xr tty 4 .Sh HISTORY The .Nm driver was originally derived from the .Nm HP9000/300 .Nm dca driver and is d .Sh BUGS Data loss is possible on busy systems with unbuffered UARTs at high speed.

p The name of this driver and the constants which define the locations of the various serial ports are holdovers from .Nm DOS .