Jump to content

Welcome to Geeks to Go - Register now for FREE

Geeks To Go is a helpful hub, where thousands of volunteer geeks quickly serve friendly answers and support. Check out the forums and get free advice from the experts. Register now to gain access to all of our features, it's FREE and only takes one minute. Once registered and logged in, you will be able to create topics, post replies to existing threads, give reputation to your fellow members, get your own private messenger, post status updates, manage your profile and so much more.

Create Account How it Works

question on USB controllers

  • Please log in to reply




  • Member
  • PipPip
  • 72 posts
I have 6 USB connectors on my computer - 2 on the front panel and 4 on the back.

I am trying to understand how they show up on Device Manager and Norton Checkit Diagnoistics.

On Device Manager it shows.
  • 3 entries for: Intelฎ 82801EB USB Universal Hub Controller
    one as 24D2, one as 24D4 and one as 24D7
  • 1 entry for: Standard Enhanced PCI to USB Host Controller
  • 4 entries for USB Root Hub
on Checkit It Diagnostics it shows:
  • 3 entries in the form of:
    82801EB Universal Host Controller xxxx (one entry is 24D2, another is 24D4, another is 24D7)
    under each controller is an entry for Root HUB
    under each Root Hub is 2 entries - one for port1 and one for port2
  • 1 entry for Standard Enhanced PCI to USB Host controller
    unders this controller is an entry for Root Hub
    under this Root Hub are entries for 8 ports: 1-8
Looking at the entries show by Checkit Diagnostics I can determine which controller and port belongs to which connector by moving a usb device to different connectors and seeing where the device shows up in checkit diagnostics.
The 2 connectors on the front are for controller 24D7
The top 2 connectors on the back are for controller 24D4
The bottom 2 connectors on the back are for controller 24D2.

That covers the 6 USB conenctors I have on the computer

So, what is the entry for Standard Enhanced PCI to USB hos controller for - checkit diagnostics shows 8 ports there - what are they? -

I believe I read that the Enchanced controller was for USB2 suppor t- but I do now know why ther are 8 ports there and I never see any device show up there.

Can anyone explain how this works?

Thanks, Fay


Edited by fay47, 01 September 2005 - 03:46 PM.

  • 0




    Trusted Tech

  • Retired Staff
  • 944 posts
Topic: USB Controllers
Date: 1st Sept-2005

Here is some of my USB knowledge/experience – that may help ??

USB – Universal Serial Bus – is not perfectly universal – It is a lot easier to use than the old COM Ports – but does not always work – and sometimes give strange results - & sometimes you have to fiddle with IRQ & DMA. And Video & Sound conflicts can still occur & requires – GEEKING –

There are 3 versions of USB – (1) – USB 1.0 – (2) – USB 1.1 – (3) – USB 2.0 – Which can coexist on one bus –
But the lowest speed will degrade/limit the higher speeds & affect data transfers –

Although USB has standards that make it universal – The USB Specification did not define the HCI – Host Controller Interface – Unfortunately, the HCI is the USB controller – and is often referred to as the USB CHIPSET –

The HCI can be – (1)-embedded in the motherboard chipset – (2)-a separate motherboard chip – or (3)- an add-on peripheral PCI card –

And -

There are 3 Types of HCI – Host Controller Interface – Which is where the conflicts/confusion of USB is caused-

(1) – OHCI – Open Host Controller Interface – This is USB 1-X interface that has the managing USB functions being driven by Hardware – Usually used by non INTEL chipsets – And is included in WIN 98SE/Me & WIN2000/XP
(2) – UHCI – Universal Host Controller Interface – This is also a USB 1-X interface that uses Software to manage USB functions – Usually used by INTEL chipsets – Also included in WIN 98SE/Me & in WIN 2000/XP – Now we see the origin of INTEL USB Hardware not being compatible with the OCHI USB –
(3) – EHCI – Enhanced Host Controller Interface – This is the only USB 2.0 interface used for USB 2.0 devices/peripherals – which makes life a little easier on the USB – this is included only in WIN 2000 & WIN 2000 XP – Microsoft is not going to release any drivers for WIN 9X – Hence the fly in the ointment by MS again – When upgrading from WIN 9X to WIN 2000 – not all old USB hardware that had work will continue to work – And other compatibility USB issues/conflicts might arise with different hardware configurations and peripherals connected via USB –

Now this takes us back to our motherboard USB Controller support – chipsets or USB Chip and what OS we are using & what OS was updated from – PLUS what Service Pack OS is updated to & what MS Updates are downloaded – what current drivers are installed & of Course you have the infamous BIOS UPDATES to add to the Equation – Bill Gates – You gatta love him –

One way around this problem Could be: - Purchase a – GOOD – USB 2.0 PCI EXPANSION CARD that has the EHCI – Enhanced Host Controller Interface – if you are using an older motherboard and want to use newer hardware – or use a cheaper USB 1.1 PCI EXPANSION CARD that has OHCI – Open Host Controller Interface that is HARDWARE MANAGED for older hardware ????? – Just a thought for US Old Diehards that like Old Stuff


Normally I would need to know what motherboard & chipsets are used – but your POST showed that you have 82801EB UHCI – An INTEL – Host Controller Interface which supports 8 USB 2.0 root hub ports. The diagnostic program can only detect what chipset controller you have – not how many ports that you have wired-
So if you have the motherboard documentation – you may have 1 additional motherboard USB connector that you possibly could add 2 more USB Ports that would take up a PCI – Expansion Slot.

If you need more info about your PC:

Download Free Home Edition of EVEREST



Or Download Free Belarc Advisor


Edited by Jack123, 01 September 2005 - 05:14 PM.

  • 0




  • Topic Starter
  • Member
  • PipPip
  • 72 posts
Thanks for your reply.

I still do not understand why when I move the USB floppy to different USB connectors it always shows up under one of the 82801EB Universal Host Controller ports, nothing every shows up under the Standard Enhanced PCI to USB Host controller ports.

Thank you for the information you supplied.

  • 0

Similar Topics

0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users

As Featured On:

Microsoft Yahoo BBC MSN PC Magazine Washington Post HP