109 lines
3.7 KiB
Groff
109 lines
3.7 KiB
Groff
.\"
|
|
.\" Copyright (c) 1996 Jonathan Stone.
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" 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 Jonathan Stone.
|
|
.\" 3. The name of the author may not be used to endorse or promote products
|
|
.\" derived from this software without specific prior written permission
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
|
|
.\"
|
|
.\" $NetBSD: scc.4,v 1.4 1998/03/20 13:31:58 fair Exp $
|
|
.\"
|
|
.Dd August 6, 1996
|
|
.Dt SCC 4 pmax
|
|
.Os NetBSD 1.2
|
|
.Sh NAME
|
|
.Nm scc
|
|
.Nd
|
|
Zilog 8530 Serial Communications Controller interface
|
|
.Sh SYNOPSIS
|
|
.Cd "scc0 at ioasic?"
|
|
.Cd "scc1 at ioasic?"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm
|
|
driver provies support for the Zilog 8530 Serial Communcations
|
|
Controller (SCC) via the IOCTL ASIC on DECstation 5000 models
|
|
in the /100, /20, and /240 series.
|
|
Each SCC device has two serial ports.
|
|
The model 20 provides one SCC device.
|
|
Other models provide two, but one port of each device is dedicated
|
|
to mouse and keyboard input, respectively.
|
|
.Pp
|
|
Input and output for each line may set to one of following baud rates:
|
|
50, 75, 110, 134.5, 150, 300, 600, 1200, 1800, 2400, 4800, 9600,
|
|
19200, 38400, or 57600.
|
|
Speeds up to 230400 are supported by the chip and the motherboard,
|
|
but speeds higher than 57600 do not work reliably without an external
|
|
clock signal.
|
|
.Sh FILES
|
|
.Bl -tag -width Pa
|
|
.It Pa /dev/ttya
|
|
.It Pa /dev/ttyb
|
|
.It Pa /dev/ttyc
|
|
.It Pa /dev/ttyd
|
|
.El
|
|
.Pp
|
|
The mapping from units to serial-hardware outlets is idiosyncratic.
|
|
The even ports are wired serial connectors and the odd-numbered ports
|
|
are reserved for mouse and keyboard.
|
|
On machines with one port like
|
|
.Tn "Personal DECstations" ,
|
|
the single device is
|
|
.Pa ttya .
|
|
On the
|
|
.Tn "5000/1xx"
|
|
and
|
|
.Tn "5000/2xx" ,
|
|
the first serial port (default serial console) is
|
|
.Pa ttyc
|
|
and the second port is
|
|
.Pa ttya .
|
|
.Sh HISTORY
|
|
The
|
|
.Nm
|
|
driver first appeared in
|
|
.Bx 4.4 .
|
|
.Sh BUGS
|
|
The IOCTL ASIC provides internal DMA channels that can be programmed
|
|
to transfer up to 4096 bytes of data into, or out, of an SCC without
|
|
further software intervention.
|
|
This feature of the IOCTL ASIC is not yet supported.
|
|
.Pp
|
|
The mapping from device-special files (major and minor number) to chip
|
|
and port is arguably backwards.
|
|
.Tn Ultrix
|
|
tries to hide the hardware mapping, but
|
|
.Nx
|
|
does not.
|
|
Users wanting to use
|
|
.Tn "Ultrix"
|
|
compatible tty names
|
|
.Pa /dev/tty0
|
|
and
|
|
.Pa /dev/tty1
|
|
for the
|
|
.Nm
|
|
comm-port lines should make links or device-special files which match
|
|
their hardware setup.
|