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TUSB4041I: How to recognize the speed of USB devices

Kuramochi Tadahiko
Guru 28715 points
Part Number: TUSB4041I

Hi,

I would like to know how to recognize the speed(full/high/low) of USB devices on the TUSB4041I.

Is it general way as observing D± pin voltage during enumeration?

Best Regards,

Kuramochi

  • 0
    TI__Guru**** 178256 points
    Kuramochi-san

    For LS USB device, D- will driven high, and D+ will driven low when device is inserted into the hub.

    For FS/HS USB device, D+ will driven high, and D- will driven low when device is inserted into the hub. Further, if the device is HS capable, then device will drive chirp k onto D+/D- bus, and if hub is HS capable, it will respond with KJKJKJ. If hub is not HS capable, it will not respond with KJKJKJ, and then the USB stays in FS mode.

    Thanks
    David