Tool/software:
Hi,
I used another HUB to verify the test.
As shown in the figure below, when measuring the waveform of USB UP PORT, the D+ waveform will change from H to L, and the function is normal, and can be detect USB Flash drive.
Using TUSB4020BIPHPR HUB to analyze, after inserting DUT, the waveform of USB UP PORT is measured as shown below. The D+ waveform is continuously H, the function is abnormal, and the USB device cannot be recognized.