EHCI(4) BSD Kernel Interfaces Manual EHCI(4)
ehci -- USB Enhanced Host Controller Interface
ehci* at cardbus?
ehci* at pci?
usb* at ehci?
The ehci driver provides support for the USB Enhanced Host Controller
Interface, 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)) or an internal rate-matching hub to
handle USB 1.x devices.
If at least one companion controller is present, each USB connector is
electrically connected to two USB controllers. 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
cardbus(4), ohci(4), pci(4), uhci(4), usb(4)
BSD March 30, 2017 BSD