NIOS-II and USB

Sorry forgot it wasn't you're board but off the shelf.

I'd start by searching for that chip to see how it works. Then the next step is to find the signals going to it from the controller IC to the FPGA. Once you know how the controller works then you probably won't need an example.

If they give you drivers (NIOS II I assume), then make sure you have the correct system downloaded to your board. Again, if you can figure out how to use the controller and how it's connected to the FPGA you can develope your own method to talk to it.