I would like to add one more thing here. One thing that is very important while designing a development board is the end usage. Are you planning to have the peripheral controllers inside the fpga or will be having separate controller chips on the board? :confused:
For example:
- A board designed for using/designing a USB 2.0 controller inside the FPGA will use a transceiver PHY chip stuffed between the USB connector and FPGA. See:
http://www.slscorp.com/products/development-boards/corecommander.html - While a board designed for using a separate controller with just the interface logic inside the FPGA will use a controller chip stuffed between the USB connector and FPGA. Check DE2 board.