.\"	$OpenBSD: bussw.4,v 1.6 2008/01/05 21:02:15 jmc Exp $
.\"
.\" Copyright (c) 2003 Paul Weissmann
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.Dd $Mdocdate: January 5 2008 $
.Dt BUSSW 4 mvme88k
.Os
.Sh NAME
.Nm bussw
.Nd BusSwitch local peripheral bus interface
.Sh SYNOPSIS
.Cd "bussw0 at mainbus0 addr 0xfff00000"
.Sh DESCRIPTION
The
.Nm
.Tn BusSwitch
ASIC provides an interface from the MVME197's 64-bit wide system bus
to the
.Tn MC68040
compatible 32-bit wide local bus, to which the system's
I/O devices, e.g. SCSI and Ethernet, are attached.
.Pp
It includes the following features:
.Pp
.Bl -bullet -compact -offset indent
.It
Bus arbitration for the
.Tn MC88110
bus
.It
Seven level interrupt handler
.It
Programmable map decoders
.It
Write post buffers
.It
Two tick timers
.It
Four 32-bit general purpose registers
.El
.Sh SEE ALSO
.Xr intro 4 ,
.Xr pcctwo 4 ,
.Xr syscon 4