USB List


J

JohnD

Looking at the entries under Universal Serial Bus controllers in Device
Manager, I have figured out that:
NEC PCI to USB Enhanced Host Controller is my USB2 controller.
The two NEC PCI to USB Open Host Controller entries must refer to the two
unused USB ports.
The two USB Mass Storage Device entries must refer to the two external hard
drives attached to USB ports.

But - what would the three "USB Root Hub" entries mean?

I know you people out there all know the answer, so please share it with me.

Thanks
 
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J

Jose

Looking at the entries under Universal Serial Bus controllers in Device
Manager, I have figured out that:
NEC PCI to USB Enhanced Host Controller is my USB2 controller.
The two NEC PCI to USB Open Host Controller entries must refer to the two
unused USB ports.
The two USB Mass Storage Device entries must refer to the two external hard
drives attached to USB ports.

But - what would the three "USB Root Hub" entries mean?

I know you people out there all know the answer, so please share it with me.

Thanks

Are you having a problem or just curious?

Please provide more information for the most reliable answer:

Click Start, Run and in the box enter:

msinfo32

Click OK, and when the System Summary info appears, click Edit, Select
All, Copy and then paste the information back here.

There will be some personal information (like System Name and User
Name), and whatever appears to be private information to you, just
delete it from the pasted information.

This will minimize back and forth Q&A and eliminate guesswork.
 
R

R. McCarty

USB is internally routed. All sockets/ports are USB 2 capable. USB-1
(1.1) devices route to an associated USB low speed controller & hub.
This is why you'll normally see multiple Controllers and Hubs listed. For
each USB Root Hub there is a parent controller entry.

This is why re-plugging certain USB 1.0 devices into a different socket
causes XP to re-enumerate them. They are being routed to a different
USB 1 Controller/Hub than what originally hosted them.
 
J

JohnD

I'm just curious to know what a USB Root Hub is as opposed, for example, to a
USB Host Controller.
 
R

R. McCarty

The controller is just that ( Logic Circuitry for USB ). The Root Hub is a
secondary device of that where the devices actually connect to.
----PCI Bus---->USB Controller---->Root Hub ------<<Devices
 
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J

Jose

I'm just curious to know what a USB Root Hub is as opposed, for example, to a
USB Host Controller.

Each hub will have at least one controller - usually 4 to 4 (desktop)
or 2 to 2 (laptop).
 
S

smlunatick

I'm just curious to know what a USB Root Hub is as opposed, for example, to a
USB Host Controller.

Your PC has 6 USB ports at the "main box." These ports are paired
together, then every two ports are then "connected" as the USB Root
Hub.
 
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J

Jose

Your PC has 6 USB ports at the "main box."  These ports are paired
together, then every two ports are then "connected" as the USB Root
Hub.

Have you identified the OPs hardware configuration?
 

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