OMAP L138 and a 3G USB Modem

Reino Harmse

Other Parts Discussed in Thread: OMAPL138

Hi,

I am working on a prototyping project using the OMAP L138. We are planning on going into production before the end of 2014 and as such, time is crucial as usual.

I would like to know whether TI has confirmed functionality of any particular 3G USB Modems on the OMAP L138 USB2.0 port? After some research it seems that several customers were able to get things going on the USB 1.1 port, but not the USB 2.0 port.

I would like to avoid this issue from the start.

It is also important to note that we would require interfacing from user space.

Regards,

Reino

over 11 years ago

0 Titusrathinaraj Stalin over 11 years ago

TI__Guru** 116100 points

Hi Reino,

We have not tested in our boards,

But we gave some suggestions to enable USB modem support, also some customers able make it to work, but I'm not sure whether it is from USB1.1 or USB2.0.

Please try to make it and let us update if any issue, surely we will assist you.

Please check it out.

http://e2e.ti.com/support/embedded/linux/f/354/p/324715/1130355.aspx

http://e2e.ti.com/support/dsp/omap_applications_processors/f/42/t/319803.aspx

0 Reino Harmse over 11 years ago in reply to Titusrathinaraj Stalin

Intellectual 330 points

Hi Titus,

Thank you for the quick response and links.

The one link does not cover the actual development progress and the other is interfacing with the 3G modem via UART, which is not really what I want. Surely the UART would be a huge bottle neck.

I am just hoping to get a make and model of a 3G modem that worked on an OMAP L138 (or similar) connected through USB 2.0 with Linux drivers available online and user space support.

Would it not be very beneficial for TI to test 3G support? Perhaps even release a development kit?

Regards,

Reino

0 Titusrathinaraj Stalin over 11 years ago in reply to Reino Harmse

TI__Guru** 116100 points

Hi Reino,

Sorry, I think, we don't have plan for further release for OMAPL138.

0 Titusrathinaraj Stalin over 11 years ago in reply to Titusrathinaraj Stalin

TI__Guru** 116100 points

Hi Reino,

I will try this USB modem support on OMAPL138 LCDK board in my free time and let me update.

0 Reino Harmse over 11 years ago in reply to Titusrathinaraj Stalin

Intellectual 330 points

Hi Titus,

That would be great!

Thank you.

0 -DK- over 11 years ago

TI__Mastermind 27890 points

Hello Reino,

Typically when I see situations in which a particular USB device functions at Full-Speed, but not at High-Speed, the root cause can be traced to signal integrity. In the case of a 3G modem, it is almost certainly so given the fact that the modem is transmitting at frequencies that are fundamentally similar to those used by HS USB which makes it easy for these signal to attach to (and disrupt) the USB.

Care must be taken in the schematic capture and layout processes to ensure that signal quality is maintained even in the presence of aggressor signals such as 3G RF energy. There are several USB layout resources on the web, but I recommend you start with this one: http://www.ti.com/lit/an/spraar7a/spraar7a.pdf.

0 Reino Harmse over 11 years ago in reply to -DK-

Intellectual 330 points

Hi DK,

Thank you for your valuable inputs.

We will pay extra attention to signal integrity in our hardware design.

Regards,

Reino

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OMAP L138 and a 3G USB Modem