We are trying to realize a simple processor in silicon by using semiconductor IP cores. And one part is to have a USB port interfaced using UART. I have been looking into some semiconductor IP cores that I can use to interface USB using UART and I've found this project to be useful.
I've studied this project and the codes behind it and understood how UART works. The UART serves just an interface between the processor/FPGA and USB but I was wondering if I plan to interface a USB Flash drive, how would I show that it's working? That the USB UART interface that I borrowed from an IP Core is working and that I can transmit and receive data to the USB Flash drive?
edit: I think my question should be first: What are good examples of things that can be easily interfaced using UART and that can also be easily tested and verified? Also, I should be looking for a controller, I guess.