AM4372: Connection via a Full-Speed USB hub

Hi Sasaki,

Sh.Sasaki said:

Incidentally, he also tried another USB hub, but it failed to connect with the same problem.

I assume you mean an intermediate hub is used between the PC and the AM437x EVM? If so, what happens when the EVM is connected directly to the PC?

Did the customer try a USB hub that supports high speed?

Sh.Sasaki said:

My customer's SW : USB_DevBulk_evmAM437x_armExampleProject  or  USB_DevMsc_evmAM437x_armExampleProject  (pdk_am335x_1_0_16)

Do you mean pdk_am437x_1_0_16?

I see this in the PRSDK docs: software-dl.ti.com/.../index_device_drv.html, USB generic bulk device class

The USB bulk demo application configures the USB endpoints as high speed endpoints

I don't know if the example supports falling back to full-speed. I'll reach out to internal experts to see if this is supported.

I gather the customer has inspected the USB traffic using a USB logic analyzer. Is this correct? What exactly happens during enumeration?

Regards,
Frank

Hi Frank-san,

Thank you for your reply.

Frank Livingston said:

I assume you mean an intermediate hub is used between the PC and the AM437x EVM?

Yes. That's right.

Frank Livingston said:

If so, what happens when the EVM is connected directly to the PC?

When the EVM is connected directly to the PC, the communication is working properly.

Frank Livingston said:

I'll reach out to internal experts to see if this is supported.

Thank you for your help. Please let me know if you get any information.

Frank Livingston said:

Do you mean pdk_am437x_1_0_16?

This is a typo, and pdk_am437x_1_0_16 is correct.

Frank Livingston said:

I gather the customer has inspected the USB traffic using a USB logic analyzer. Is this correct? What exactly happens during enumeration?

My customer is using a USB logic analyzer, and enumeration is done correctly.

Best regards,
Sasaki

Hi Frank-san,

Thank you for your reply.

Frank Livingston said:

I consulted with internal experts and found that the TI PRSDK drivers don't support full speed.

I understand.

Best regards,
Sasaki