Very simple USB 1.1 PHY. Includes all the goodies: serial/parallel conversion, bit stuffing/unstuff

Very simple USB 1.1 PHY. Includes all the goodies: serial/parallel conversion, bit stuffing/unstuffing, NRZI encoding decoding. Uses a simplified UTMI interface. Currently doesn t do any error checking in the RX section [should probably check for bit unstuffing errors]. Otherwise complete and fully functional. There is currently no test bench available. This core is very simple and is proven in hardware. I see no point of writing a test bench at this time.