94 lines
3.1 KiB
Groff
94 lines
3.1 KiB
Groff
.\" $NetBSD: ehci.4,v 1.8 2001/11/21 17:22:56 augustss Exp $
|
|
.\"
|
|
.\" Copyright (c) 2001 The NetBSD Foundation, Inc.
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" This code is derived from software contributed to The NetBSD Foundation
|
|
.\" by Lennart Augustsson.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the NetBSD
|
|
.\" Foundation, Inc. and its contributors.
|
|
.\" 4. Neither the name of The NetBSD Foundation nor the names of its
|
|
.\" contributors may be used to endorse or promote products derived
|
|
.\" from this software without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
|
|
.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
|
|
.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
|
.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
|
|
.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
.\" POSSIBILITY OF SUCH DAMAGE.
|
|
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd November 5, 2001
|
|
.Dt EHCI 4
|
|
.Os
|
|
.Sh NAME
|
|
.Nm ehci
|
|
.Nd USB Enhanced Host Controller driver
|
|
.Sh SYNOPSIS
|
|
.Cd "device ehci"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm
|
|
driver provides support for the
|
|
.Tn USB
|
|
Enhanced Host Controller Interface,
|
|
which is used by
|
|
.Tn USB
|
|
2.0 controllers.
|
|
.Pp
|
|
.Tn EHCI
|
|
controllers are peculiar in that they can only handle the
|
|
.Tn USB
|
|
2.0 protocol.
|
|
This means that they normally have one or more companion controllers
|
|
(i.e.,
|
|
.Xr ohci 4
|
|
or
|
|
.Xr uhci 4 )
|
|
handling USB 1.x devices.
|
|
Consequently each
|
|
.Tn USB
|
|
connector is electrically connected to two
|
|
.Tn USB
|
|
controllers.
|
|
The handling of this is totally automatic,
|
|
but can be noticed since
|
|
.Tn USB
|
|
1.x and
|
|
.Tn USB
|
|
2.0 devices plugged in to the same
|
|
connector appear to connect to different USB busses.
|
|
.Sh SEE ALSO
|
|
.Xr ohci 4 ,
|
|
.Xr uhci 4 ,
|
|
.Xr usb 4
|
|
.Sh HISTORY
|
|
The
|
|
.Nm
|
|
device driver first appeared in
|
|
.Fx 5.1 .
|
|
.Sh BUGS
|
|
The driver is not finished and is quite buggy.
|
|
.Pp
|
|
Currently there is no support for hubs that are connected with high speed upstream
|
|
and low or full speed downstream (i.e., for transaction translators).
|
|
.Pp
|
|
There is also no support for interrupt or isochronous transfers. |