Re: USB 2.0 problems digging me in deeper

From: Stan Mitchell (stanm_at_sourcequest.com)
Date: 02/11/04 

Date: Wed, 11 Feb 2004 09:20:30 -0800

Hi Brad,

I'm not affiliated with Microsoft but maybe I can help you.

First, it sounds like your drivers are installed correctly,
since you see an EHCI entry in device manager.

Each USB host controller has one root hub and multiple ports.

>From your description, your motherboard has 4 host controllers:
1 is EHCI (high speed) and 3 are UHCI(full/low speed).

Each host controller has a root hub and the EHCI has a
"USB 2.0 Root Hub" while the UHCI controllers each have
just a "Root Hub".

The EHCI controller has 6 ports while each of the UHCI
controllers has 2 ports.

To the outside world the EHCI and 3 UHCI controllers are
a single package with 6 ports. If you plug in a high speed
device into any of these ports the EHCI controller will handle
the device. If you plug in a low or full speed device a UHCI
controller will handle the device. Because of this automatic
switching behavior, you can use each of the 6 ports for any
speed device.

Hope that helps,
-Stan Mtichell

"Brad" <anonymous@discussions.microsoft.com> wrote in message
news:33A47117-79B0-48A2-8502-512A7A21DCAF@microsoft.com...
> Well I seem to be talking just to myself, but then computer support has
always been an illusion anyway!
>
> I now have one port that works in hi speed mode. The others just function
at 1.1 speed. The motherboard manual clearly states that all 6 are 2.0.
The chip set is the Intel 82801 DB ICH4.
>
> In device manager, you see "Intel(r) 82801DB/DBM USB 2.0 Enhanced Host
Controller - 24CD" for the first entry.
> Then 3 lines of "Intel(r) 82801DB/DBM USB Universal Host Controller -
24C2" (at ends: 24C2, 24C4, 24C7)
> Then next line "USB 2.0 Root Hub".
> Then 3 lines of "USB Root Hub".
>
> I have spent hours reading other USB problem entries. None seem to
provide anything conclusive. Do I have the right drivers installed? ASUS
says that the XP drivers should be used. And one port does work. So what
the heck is going on???

Relevant Pages

  • Re: USB 2.0 problems digging me in deeper
    ... > since you see an EHCI entry in device manager. ... > Each USB host controller has one root hub and multiple ports. ... If you plug in a low or full speed device a UHCI ...
    (microsoft.public.windowsxp.help_and_support)
  • Re: installing dell resource cd
    ... None of those ports have anything to do with the network. ... However after downloading the 3Com 3C905C drivers and the ... Controller still gets flagged with the yellow question mark. ... I have noticed there are extra extra com ports on this machine. ...
    (alt.sys.pc-clone.dell)
  • Re: PCI USB Card question
    ... a line specifying the appropriate device driver must be ... For example: a six-port controller requires ... each pair of ports. ... I've got a 4 port card here with two UHCI and one EHCI controllers on ...
    (comp.os.os2.setup.storage)
  • Re: PCI USB Card question
    ... According to the OS/2 USB site you need *two* device statements per ... than three OHCI lines produce a "controller not found" type message. ... odd number of USB ports, then increment the number of cards by one, ... would have thought one would run it as either OHCI or EHCI. ...
    (comp.os.os2.setup.storage)
  • [PATCH] Miscellaneous documentation cleanup: 2.6.30-rc3
    ... The Silicon Motion SM501 multimedia companion chip is a multifunction device ... which may provide numerous interfaces including USB host controller USB gadget, ... +asynchronous serial ports, audio functions, and a dual display video interface. ... -Sometimes it happens that a request enters the io scheduler that is contigious ...
    (Linux-Kernel)