It is not very clearly indicated in the data sheet.†

As I recall high-speed controller (EHCI) only supports ULPI interface to PHY and the full-speed controller (OHCI) only supports serial PHY interface.†

Since these interfaces share pins it is challenging to support both simultaneously unless one can find a PHY that shares exactly the same pins for the same signals. And of course to do this you'd have to spin your own board and possibly add support for the OMAP OHCI controller as well.

(See OP35xx TRM -- High-Speed USB Host Controller Architecture)

Gumstix points this out here:†
"Gumstix "Host" = USB High speed (480Mbit/s ONLY). You will need a hub to connect to most USB -> Serial adapters"

†- Juha

On Wed, Dec 19, 2012 at 12:18 PM, Eric Crossley <> wrote:

I know we are using the Host port but I donít see anything in the documentation that says it is 2.0 only.

We will switch to a 2.0 hub.


Eric Crossley

From: Juha Kuikka [via Gumstix] [mailto:[hidden email]]
Sent: Wednesday, December 19, 2012 1:46 PM

To: Crossley, J. Eric
Subject: Re: Embedded USB hub

How would you know which USB port you are using? Check your schematic against†click here.

View this message in context: RE: Embedded USB hub
Sent from the Gumstix mailing list archive at

LogMeIn Rescue: Anywhere, Anytime Remote support for IT. Free Trial
Remotely access PCs and mobile devices and provide instant support
Improve your efficiency, and focus on delivering more value-add services
Discover what IT Professionals Know. Rescue delivers
gumstix-users mailing list

Duck tape is like the force, it has a light side and a dark side and it holds the universe together.