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.Dd November 5, 2001 38.Dt EHCI 4 39.Os 40.Sh NAME 41.Nm ehci 42.Nd USB Enhanced Host Controller driver 43.Sh SYNOPSIS 44.Cd "ehci* at cardbus? dev ? function ?" 45.Cd "ehci* at pci? dev ? function ?" 46.Cd "usb* at ehci?" 47.Sh DESCRIPTION 48The 49.Nm 50driver provides support for the USB Enhanced Host Controller Interface, 51which is used by USB 2.0 controllers. 52.Pp 53EHCI controllers are peculiar in that they can only handle the USB 2.0 54protocol. This means that they normally have one or more companion controllers 55(i.e., 56.Xr ohci 4 57or 58.Xr uhci 4 ) 59handling USB 1.x devices. Consequently each USB connector is electrically 60connected to two USB controllers. The handling of this is totally automatic, 61but can be noticed since USB 1.x and USB 2.0 devices plugged in to the same 62connector appear to connect to different USB busses. 63.Sh SEE ALSO 64.Xr cardbus 4 , 65.Xr ohci 4 , 66.Xr pci 4 , 67.Xr uhci 4 , 68.Xr usb 4 69.Sh HISTORY 70The 71.Nm 72driver 73appeared in 74.Nx 1.6 . 75.Sh BUGS 76The driver is not finished and is quite buggy. 77.Pp 78There is no support (yet) for hubs that are connected with high speed upstream 79and low or full speed downstream (i.e., for transaction translators). 80.Pp 81There is no support (yet) for interrupt or isochronous transfers. 82