EHCI(4) 						   BSD Kernel Interfaces Manual 						   EHCI(4)

NAME

     ehci -- USB Enhanced Host Controller driver

SYNOPSIS

     ehci* at cardbus? function ?
     ehci* at pci? dev ? function ?
     usb*  at 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

     cardbus(4), ohci(4), pci(4), uhci(4), usb(4)

HISTORY

     The ehci driver appeared in NetBSD 1.6.

BUGS

     The support for hubs that are connected with high speed upstream and low or full speed downstream (i.e., for transaction translators) is lim-
     ited.

BSD
								   Aug 10, 2008 							       BSD