The Universal Serial Bus may be new to some users and developers. This application note tries to describe the major architecture differences that need to be considered by both software and hardware designers when changing from a traditional RS232 based solution to one that uses the FT232R, FT2232C (UART mode) or FT232BM USB to serial interface devices. Much of the information in this application note also applies to the FT245R, FT2232C (FIFO mode) and FT245BM USB to parallel FIFO interface devices.