A Simple And Complete USB Interface Package For Test Bench Development

摘要

A simple and complete USB interface package has been developed simultaneously at the hardware, firmware and software levels. It targets the development of boards and test benches, permitting easy access from a computer through a simple USB cable. The goal is to propose a 《plug and play》 system comprising the hardware interface on the board, the decoding block to be integrated within a FPGA on the user side and the graphical software interface on the computer. The hardware is based upon the FT245B circuit from the FTDI Company. The latter offers a USB 2.0 full-speed interface running up to 12Mbits/s. Its block diagram is displayed on figure 1. As one can notice, the user interface is very simple, limited to an 8-bit data bus and 4 control lines. It can also control access to an USB configuration EEPROM.