How to tell if my requested power level has been granted?

[Anonymous]

I understand I set the requested USB power levels in the configuration descriptors.

   

My FX3 has a requirement to turn on some additional hardware once the requested power levels are granted: how do I tell when that has happened?

Are there events/callbacks for that, or can I read certain registers for it?

[Anonymous]

Paul,

   

Yes, the required power should be specified in the configuration descriptors. Generally once FX3 is enumerated it can draw the requested power from the host.

   

You can register a callback in the firmware when you receive a SET_CONF request from the host. In handling that callback you can provide the power to the external hardware.

       

Regards

   

Dhritiman