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* Fix several mandoc typos. Describe ioasic DMA channels as mapping

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from 16-bit device addresses to 32-bit TC DMA space.
* Sync with reality (pmax config now attaches ioasic at tc, not
  vice-versa, for compatibility with the Alpha.)
This commit is contained in:
jonathan 1997-10-31 02:26:09 +00:00
parent 4589c896eb
commit 51bd1dfec7
1 changed files with 25 additions and 20 deletions

45
share/man/man4/man4.pmax/ioasic.4

@ -1,5 +1,5 @@
.\"
.\" Copyright (c) 1996 Jonathan Stone.
.\" Copyright (c) 1996, 1997 Jonathan Stone.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
@ -27,7 +27,7 @@
.\" (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: ioasic.4,v 1.3 1997/10/13 11:23:50 lukem Exp $
.\" $NetBSD: ioasic.4,v 1.4 1997/10/31 02:26:09 jonathan Exp $
.\"
.Dd August 6, 1996
.Dt IOASIC 4 pmax
@ -35,40 +35,44 @@
.Sh NAME
.Nm ioasic
.Nd
turbochannel SCSI adaptor
baseboard IO control ASIC for DEC TurboChannel systems
.Sh SYNOPSIS
.Cd "ioasic? at mainbus"
.Cd "ioasic0 at tc?"
.Sh DESCRIPTION
The
.Nm
driver provides support for the DEC proprietary IOCTL asic found on
Decstation 5000 series machines (excluding the 5000/200), and on
Turbochannel-based Alphas. On these machines (including the
5000/200), all baseboard devices should be configured as children
of the
.Nm ioasic .
all DEC Turbochannel machines with MIPS (decstation 5000 series,
excuding the 5000/200) and Alpha (3000-series) processors. On these
machines (including the 5000/200), all baseboard devices should be
configured as children of the
.Nm "" .
The
.nm
.Nm
provides hardware DMA channels and interrupt support for
several baseboard devices, including one
.Nm asc
scsi device with a scatter/gather DMA channel, up to two
scsi device with a scatter/gather DMA channel, an mc146818-compatible
.Nm mcclock,
one or two
.Nm scc
devices, a
.Nm tc
turbochannel expansion bus with two, three, or six slots.
two-port serial devices, and a am9770 LANCE
.Nm le
Ethternet interface.
.Pp
The
.Nm
is also used for theose
floppy-disc drive and audio/ISDN hardware
on the Personal Decstation and Alpha.
on the Personal Decstation and audio-equppied TC Alphas, where the
.Nm
hardware is used to interface to
hardware provides a
a
scatter-gather DMA channel.
scatter-gather DMA channel betweent he 16-bit deviec and the 32-bit
.Nm tc
DMA address space.
.Pp
Support for scatter-gather DMA eliminates the need for copying.
Support for scatter-gather DMA eliminates the need for additional copying.
A baseboard
.Nm asc
SCSI adaptor attached to an
@ -78,7 +82,7 @@ will give slightly better performance than its
counterpart.
.Sh SEE ALSO
.Xr intro 4 ,
.Xr clock 4 ,
.Xr mcclock 4 ,
.Xr asc 4 ,
.Xr le 4 ,
.Xr scc 4 ,
@ -89,7 +93,8 @@ The
driver
first appeared in
.Nx 1.1 ,
derived from the
derived from DECstation boot-time configuration code in
.Bx 4.4 .
.Sh BUGS
The Decstation 5000/200 does not actually have an
.Nm ioasic