1.\" $NetBSD: ehci.4,v 1.8 2001/11/21 17:22:56 augustss Exp $ 2.\" 3.\" Copyright (c) 2001 The NetBSD Foundation, Inc. 4.\" All rights reserved. 5.\" 6.\" This code is derived from software contributed to The NetBSD Foundation 7.\" by Lennart Augustsson. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 3. All advertising materials mentioning features or use of this software 18.\" must display the following acknowledgement: 19.\" This product includes software developed by the NetBSD 20.\" Foundation, Inc. and its contributors. 21.\" 4. Neither the name of The NetBSD Foundation nor the names of its 22.\" contributors may be used to endorse or promote products derived 23.\" from this software without specific prior written permission. 24.\" 25.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 26.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 27.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 28.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 29.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 30.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 31.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 32.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 33.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 34.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 35.\" POSSIBILITY OF SUCH DAMAGE. 36.\" 37.\" $FreeBSD$ 38.\" 39.Dd March 20, 2005 40.Dt EHCI 4 41.Os 42.Sh NAME 43.Nm ehci 44.Nd USB Enhanced Host Controller driver 45.Sh SYNOPSIS 46.Cd "device ehci" 47.Sh DESCRIPTION 48The 49.Nm 50driver provides support for the 51.Tn USB 52Enhanced Host Controller Interface, 53which is used by 54.Tn USB 552.0 controllers. 56.Pp 57.Tn EHCI 58controllers are peculiar in that they can only handle the 59.Tn USB 602.0 protocol. 61This means that they normally have one or more companion controllers 62(i.e., 63.Xr ohci 4 64or 65.Xr uhci 4 ) 66handling USB 1.x devices. 67Consequently each 68.Tn USB 69connector is electrically connected to two 70.Tn USB 71controllers. 72The handling of this is totally automatic, 73but can be noticed since 74.Tn USB 751.x and 76.Tn USB 772.0 devices plugged in to the same 78connector appear to connect to different USB busses. 79.Sh SEE ALSO 80.Xr ohci 4 , 81.Xr uhci 4 , 82.Xr usb 4 83.Sh HISTORY 84The 85.Nm 86device driver first appeared in 87.Fx 5.1 . 88.Sh BUGS 89The driver is not finished and is quite buggy. 90.Pp 91There is currently no support for isochronous transfers. 92