[FAQ] AM6412: Passing USB compliance test patterns trhough a USB 2.0 hub

SeanHC Lin

Intellectual 390 points

Part Number: AM6412

Hi TI,

I can generate USB compliance test patterns on AM64 SoC by the following command

# devmem2 0x0f410480 w 0xA0
# devmem2 0x0f410080 w 0x4
# devmem2 0x0f410484 w 0x40000000

However, the test pattern stops transferring before the GL852GT USB 2.0 HUB.

I want to measure the signal at the USB connector behind the USB 2.0 HUB.

They seem to be discarded by USB HUB.

Could I tell the USB 2.0 HUB to forward the signal to port 1 by specifying the destination (downstream port) for the test patterns?

How do I get USB compliance test patterns to pass through the USB 2.0 hub to USB connector 1?

Thanks,

Sean

over 2 years ago

0 Bin Liu over 2 years ago

TI__Guru**** 153651 points

Hi Sean,

The USB HUB won't forward the test packets from the USB host controller to any HUB downstream port. This is not how USB protocol works.

Instead, the USB host can send SetPortFeature(PORT_TEST) SETUP packet to the HUB to trigger the HUB generating the test packets to a specific HUB downstream port. Please see the USB 2.0 Specifications Section 11.24.2.7.1.9 PORT_TEST for details.

0 Taylor Lin over 2 years ago in reply to Bin Liu

Prodigy 150 points

Hi Bin

Search E2C,

https://e2e.ti.com/support/interface-group/interface/f/interface-forum/1097877/tusb4041i-usb-2-0-hub-ehost-pre-compliance-testing/4071549?tisearch=e2e-sitesearch&keymatch=USB%2525252520HUB%2525252520test%2525252520modes#4071549.

Maybe we could try it, if you have other suggestions, please let us know, thanks.

https://github.com/MicrochipTech/USB-Hub-Linux-Examples/tree/master/General%20USB%20Examples/USB%20High%20Speed%20Electrical%20Test

BR,

Taylor

0 Bin Liu over 2 years ago in reply to Taylor Lin

TI__Guru**** 153651 points

Hi Taylor,

AM64x (and other Sitara processors) don't have a builtin usb hub module, so we don't perform this type of hub test, I am unable to recommend any tool for such test. But I am glad you found a tool, seems you are on the right track.

0 SeanHC Lin over 2 years ago in reply to Taylor Lin

Intellectual 390 points

Hi Tylor and Bin,

The tool is suited for me.
It can trigger the HUB to generate the test packets.

Thanks,

Sean

0 Bin Liu over 2 years ago in reply to SeanHC Lin

TI__Guru**** 153651 points

Hi Sean,

Glad it works. Thanks for the update.

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[FAQ] AM6412: Passing USB compliance test patterns trhough a USB 2.0 hub