EHCI(4) BSD Kernel Interfaces Manual EHCI(4)
NAME
ehci -- USB Enhanced Host Controller driver
SYNOPSIS
device ehci
DESCRIPTION
The ehci driver provides support for the USB Enhanced Host Controller Interface, which is used by USB 2.0 controllers.
EHCI controllers are peculiar in that they can only handle the USB 2.0 protocol. This means that they normally have one or more companion
controllers (i.e., ohci(4) or uhci(4)) handling USB 1.x devices. Consequently each USB connector is electrically connected to two USB con-
trollers. The handling of this is totally automatic, but can be noticed since USB 1.x and USB 2.0 devices plugged in to the same connector
appear to connect to different USB busses.
SEE ALSO
ohci(4), uhci(4), usb(4)
HISTORY
The ehci device driver first appeared in FreeBSD 5.1.
BUGS
The driver is not finished and is quite buggy.
There is currently no support for isochronous transfers.
BSD March 20, 2005 BSD
