TUSB8020B: compliance test issue

Jeff YANG

Part Number: TUSB8020B

Hi,

I used mt8930 platform and CPU provide test pattern via hub TUSB8020B, but can measure the test pattern waveform from both 2 ports.

We've used USB disk on port 2, and check port 2 path is work. But the path seems disconnect after we send compliance test command.

Both USB2.0 and USB3.0 are fail.

Below is schematic for you reference,

over 3 years ago

0 JMMN over 3 years ago

TI__Guru 60870 points

Hi Jeff,

Please see these FAQs:

https://e2e.ti.com/support/interface-group/interface/f/interface-forum/1080227/faq-tusb8041-how-do-i-test-usb-3-0-usb-3-1-usb-3-2-electrical-compliance-on-usb-hubs

https://e2e.ti.com/support/interface-group/interface/f/interface-forum/1031982/faq-tusb8041-tusb8041-how-do-i-force-a-usb-hub-to-send-usb-2-0-high-speed-test-packets-for-eye-diagram-testing

Regards,

JMMN

0 JMMN over 3 years ago in reply to JMMN

TI__Guru 60870 points

Please note that USB_VBUS is a detection input to the hub and should only be high when an active host is connected to the upstream port.

Regards,

JMMN

0 Jeff YANG over 3 years ago in reply to JMMN

Mastermind 8200 points

Hi JMMN,

My customer reply their host MT8390 (MTK) not windos base, so their question is how to using MT8390 set pro_test to hub.

MT8390 can output test pattern to Hub(8082B) by itself, but the pattern can't pass through hub.

If Hub(8082B) can let upstream test pattern change to downstream output think can fix this issue.

Is there have any way to dedicate an downstream port keep turn? if can let downstream port keep turn I think test pattern will be pass through via Hub(8082B) and normal output.

Thanks!

Jeff

0 JMMN over 3 years ago in reply to Jeff YANG

TI__Guru 60870 points

Hi Jeff,

The only way to force the hub to stay enabled and pass through a USB test packet would require specific commands to be sent by the host (SET FORCE ENABLE). Are another other USB compliance commands supported by the host?

Regards,

JMMN

0 Jeff YANG over 3 years ago in reply to JMMN

Mastermind 8200 points

Hi JMMN,

They can use ADB command to set any register of TUSB8020B.

Does it any register can force let downstream port force turn on to finished compliance test. thanks!

Jeff

0 JMMN over 3 years ago in reply to Jeff YANG

TI__Guru 60870 points

Hi Jeff,

The TUSB8020B registers only set the configuration of the hub. There is no ability to force enable ports or test modes using registers.

Regards,

JMMN

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TUSB8020B: compliance test issue