usb interfacing

Well all you need to do is look at the datasheets and find out which pins of the USB chip are connected to which pins of the FPGA. Then, again using the datasheet, find out which of the pins should receive ones and zeroes in which order and for how long.

You could do this in software, thus needing a processor and thus using the sopc, but you could do this with some counters and a state machine (I think), but that could be a tad more difficult. Maybe someone has done the work for you and you can find IP (use your favourite internet search engine and search for "isp1362 VHDL" or "isp1362 Verilog" depending on your language of choice).