1.\" $NetBSD: ehci.4,v 1.16 2008/08/10 13:39:58 jmcneill Exp $ 2.\" 3.\" Copyright (c) 2001, 2004, 2005, 2008 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.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 19.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 20.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 21.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 22.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28.\" POSSIBILITY OF SUCH DAMAGE. 29.\" 30.Dd Aug 10, 2008 31.Dt EHCI 4 32.Os 33.Sh NAME 34.Nm ehci 35.Nd USB Enhanced Host Controller driver 36.Sh SYNOPSIS 37.Cd "ehci* at cardbus? function ?" 38.Cd "ehci* at pci? dev ? function ?" 39.Cd "usb* at ehci?" 40.Sh DESCRIPTION 41The 42.Nm 43driver provides support for the USB Enhanced Host Controller Interface, 44which is used by USB 2.0 controllers. 45.Pp 46EHCI controllers are peculiar in that they can only handle the USB 2.0 47protocol. 48This means that they normally have one or more companion controllers 49(i.e., 50.Xr ohci 4 51or 52.Xr uhci 4 ) 53handling USB 1.x devices. 54Consequently each USB connector is electrically connected to two 55USB controllers. 56The handling of this is totally automatic, but can be noticed since 57USB 1.x and USB 2.0 devices plugged in to the same connector appear 58to connect to different USB busses. 59.Sh SEE ALSO 60.Xr cardbus 4 , 61.Xr ohci 4 , 62.Xr pci 4 , 63.Xr uhci 4 , 64.Xr usb 4 65.Sh HISTORY 66The 67.Nm 68driver appeared in 69.Nx 1.6 . 70.Sh BUGS 71The support for hubs that are connected with high speed upstream 72and low or full speed downstream (i.e., for transaction translators) 73is limited. 74