FreeBSD 7.0 manual page repository

FreeBSD is a free computer operating system based on BSD UNIX originally. Many IT companies, like DeployIS is using it to provide an up-to-date, stable operating system.

ehci - USB Enhanced Host Controller driver



      ehci - USB Enhanced Host Controller driver


      device ehci


      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 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 busses.
      ohci(4), uhci(4), usb(4)


      The ehci device driver first appeared in FreeBSD 5.1.


      The driver is not finished and is quite buggy.
      There is currently no support for isochronous transfers.


Based on BSD UNIX
FreeBSD is an advanced operating system for x86 compatible (including Pentium and Athlon), amd64 compatible (including Opteron, Athlon64, and EM64T), UltraSPARC, IA-64, PC-98 and ARM architectures. It is derived from BSD, the version of UNIX developed at the University of California, Berkeley. It is developed and maintained by a large team of individuals. Additional platforms are in various stages of development.