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.\" Copyright (c) 1997 Roman Hodek
.\"
.\" setSCCserial and this man page are free software. You can redistribute
.\" it and/or modify it under the terms of the GNU General Public License as
.\" published by the Free Software Foundation: either version 2 or
.\" (at your option) any later version.
.\"
.TH SETSCCSERIAL 8 "December 8 1997" "Linux" "MAINTENANCE COMMANDS"
.SH NAME
setSCCserial \- configure input clocks of a SCC
.SH SYNOPSIS
.B setSCCserial
[
.B \-v
]
.I device
[
.B rtxc=
.I freq
]
[
.B trxc=
.I freq
]
[
.B pclk=
.I freq
]
[
.B subst
.I baud1
=
.I baud2
]
.PP
.B setSCCserial
[
.B \-v
]
.I device
.B default
.SH DESCRIPTION
.B setSCCserial
is used to inform your kernel that your SCC chip has non-standard
clock inputs. (Only possible if you modified your hardware.) It
recalculates the speed tables accordingly and installs them into the
SCC driver in the kernel.
.PP
Settings are done for the channel which is related to \fIdevice\fR.
That can (currently) be /dev/ttyS1 (channel B, Modem2), /dev/ttyS3
(channel A, Serial2), or /dev/ttyS4 (channel A, LAN).
.SH OPTIONS
.TP
.IP "\fB\-v"
Verbose operation: show how baud rates will be generated, i.e. which
clock input they use and which divisor. If \fB-v\fR is given twice,
also the calculation of which clock source to use is shown.
.IP "\fBrtxc=\fIfreq\fR"
Set clock frequency connected to the RTxC pin of the channel. The
frequency is in Hz, kHz or MHz can be denoted by appending a 'k' or 'M'.
.IP "\fBtrxc=\fIfreq\fR"
Set clock frequency connected to the TRxC pin of the channel. The
frequency is in Hz, kHz or MHz can be denoted by appending a 'k' or 'M'.
.IP "\fBpclk=\fIfreq\fR"
Set clock frequency connected to the PCLK pin of the SCC. The
frequency is in Hz, kHz or MHz can be denoted by appending a 'k' or 'M'.
Note that there is only one PCLK pin (the SCC's master clock), so that
setting affects both channels!
.IP "\fBsubst \fIbaud1\fR=\fIbaud2\fR"
Calculate baud tables so that \fIbaud2\fR is used in place of
\fIbaud1\fR. Most often this is used to use 76.8kbps instead of
57.6kbps and 153.6kbps instead of 115.2kbps on a TT, since the usual
rates aren't possible with the available clock sources.
.IP "\fBdefault\fR"
Reset input clocks and speed tables to kernel defaults (depends on
machine type).
.RE
.SH NOTES
There is a more verbose description of
.B setSCCserial
in /usr/doc/setsccserial/README.gz.
.SH BUGS
In a TT, the frequency of RTxCB is programmable, because it is
connected to a MFP timer. Neither the kernel nor
.B setSCCserial
yet support changing this frequency. It is hardwired to 307.2 kHz (the
same value as used by TOS).
.SH AUTHOR
Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
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