1. How function controller transfers are identified to be either targeting Buffer Memory or USB Core registers?
2. How does function controller exactly know which address of SRAM it should read/write in USB??
first please explain why you posted in the "RF, Microwave, Antennas and Optics" section.
To your question:
Again a very unelaborated question. I assume nobody can help you when you don´t explain what you are talking about.
Give a link to internet pages. What datasheets and specifications do you refer to?
Draw a sketch about your idea.