When I try to simulate my EDK system that includes a USB core, I get the following error message in ModelSim:
Error: (vsim-3733) Enc_core/xps_usb2_device_v1_00_a/hdl/vhdl/xps_usb2_device.vhd(423): No default binding for component at 'usb_core_i'
Currently, the USB core cannot be behaviorally simulated but can be simulated in a structural format. To do a structural (or netlist) simulation, do the following in XPS with your EDK project loaded:
1 - Select Project > Project Options
2 - Bring the HDL and Simulation tab forward
3 - Under Simulation Models, select Structural
4 - Click the OK button