USB tranciever + controller in FPGA

I'm trying to put together a small board design that I can use to verify the functionality of a microcontroller that has a USB controller/tranceiver built into it. On the board I would like to have only the controller and a single FPGA (say Xilinx Virtex-4), with the FPGA hooked to every I/O of the controller I'm trying to test, including the USB signals. From what I can tell the FPGA supports LVDS with specs that seem to be in line with the USB differential signalling requirements. My question is, has anyone connected an FPGA like this directly to a USB client/host chip, without using a tranciever on the board?

Thanks

Eric