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TUSB8043A: Can the hub device descriptor to set to bus powered instead of self-powered

DHaas59
Prodigy 180 points

Part Number: TUSB8043A

The end device is a compound USB device (hub + 1 or more embedded devices).  I would like to set the hub descriptor to indicate the required power.  I'm assuming this would be done on the HS hub and not the SS hub.

Is this possible?

  • +1
    TI__Guru**** 158325 points

    Hello:

             per USB specification device descriptors must report the device configuration (bus-powered vs. self-powered) and max VBus power consumption.

    In the case of the TUSB8043A, this data is fixed reporting the device as a self-powered USB Hub with 0mA bMaxPower.

    Functionally you can configure the TUSB8043A as bus-powered, and it will have no issues; however it will not pass USB compliance tests since the descriptors will always report a self-powered configuration..

    Regards

    Brian