EHCI(4)                   OpenBSD Programmer's Manual                  EHCI(4)

NAME
     ehci - USB Enhanced Host Controller Interface

SYNOPSIS
     ehci* at cardbus?
     ehci* at pci?
     usb*  at ehci?

DESCRIPTION
     The ehci driver provides support for the USB Enhanced Host Controller In-
     terface, which provides an interface to usb(4) devices.

     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 con-
     trollers (i.e., ohci(4) or uhci(4)) handling USB 1.x devices.  Conse-
     quently 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 buses.

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

OpenBSD 4.7                      June 26, 2008                               1
