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TUSB4041I: Keyboard detection issue

Part Number: TUSB4041I

Tool/software:

Dear Brian,

We have responded back on private message to you. Can you please review the information shared and respond back please?

Ambimat Team

  • HI Ambimat team:

       Sorry I  didn't see the message from private message.

       From keyboard waveform, after seeing DM goes high, host  should send Se0 reset, but I didn't see SE0 from waveform.

       Since all other devices works fine, Can you send keyboard to us for debug?

    Best

    Brian

  • Hi Brain

    as per our last discussion we was talking about keyboard detection issue and you asked for the keyboard D+ and D- signal waveforms and I was sent it that time also and now I take current waveforms which is show in below video

    So please suggest me to how we solve this issue for the same
     In this Video Orange indicate DP (D+) signal and Blue indicate DM (D-) signal

  • I Need waveform for DP/DM/Vbus when you plugged keyboard.

    Best

    Brian

  • Hello Brian

    As per your reply we reconnect keyboard as show in below video, we take waveforms DP/DM/VBUS with keyboard and without keyboard.

    So please suggest us to solve this issue

    .

    Here Orange is keyboard DP signal and Blue is keyboard DM signal

  • why DM is 5V at the beginning?  How about other USB device?

    Best

    Brian

  • Hello Brian

    That is not DM in beginning, at beginning is VBUS signal which is 5v, in video first up to 50 sec that is VBUS Signal then after DM signal which is 3.1V

    Best 

    Ambimat Team

  • We resolved our issue

    Thanks

    Ambimat Team