1.\" $OpenBSD: ioasic.4,v 1.2 2017/11/02 15:37:58 jmc Exp $ 2.\" $NetBSD: ioasic.4,v 1.4 2004/05/11 22:42:47 wiz Exp $ 3.\" 4.\" Copyright (c) 1996, 1997 Jonathan Stone. 5.\" All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. All advertising materials mentioning features or use of this software 16.\" must display the following acknowledgement: 17.\" This product includes software developed by Jonathan Stone. 18.\" 4. The name of the author may not be used to endorse or promote products 19.\" derived from this software without specific prior written permission 20.\" 21.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31.\" 32.Dd $Mdocdate: November 2 2017 $ 33.Dt IOASIC 4 alpha 34.Os 35.Sh NAME 36.Nm ioasic 37.Nd 38baseboard IO control ASIC for DEC TURBOchannel systems 39.Sh SYNOPSIS 40.Cd "ioasic0 at tc? slot ? offset ?" 41.Sh DESCRIPTION 42The 43.Nm 44driver provides support for the DEC proprietary IOCTL ASIC found on 45DEC 3000 TURBOchannel machines. 46.Pp 47The 48.Nm 49provides hardware DMA channels and interrupt support for several 50baseboard devices, including one 51.Xr asc 4 52SCSI device with a scatter/gather DMA channel, an mc146818-compatible 53.Nm mcclock , 54an Am7930 audio device 55.Xr bba 4 , 56two 57.Xr zs 4 58dual-port serial devices, and an AMD 7990 LANCE 59.Xr le 4 60Ethernet interface. 61.Pp 62The 63.Nm 64is also used for the audio/ISDN hardware on 65audio-equipped TURBOchannel Alphas, 66where the 67.Nm 68hardware provides a scatter-gather DMA channel between the 16-bit 69device and the 32-bit 70.Nm tc 71DMA address space. 72.Pp 73Support for scatter-gather DMA eliminates the need for additional copying. 74.Sh SEE ALSO 75.Xr asc 4 , 76.Xr bba 4 , 77.Xr intro 4 , 78.Xr le 4 , 79.Xr zs 4 80.Sh HISTORY 81The 82.Nm 83driver 84first appeared in 85.Nx 1.1 , 86derived from DECstation boot-time configuration code in 87.Bx 4.4 . 88