The Interface Design Of The Innovative USB And Common Serial Communication Bus

Along with the rapid development of the microelectronics technology, computer technology, communication technology and internet technology, the functions of various communication interface chips are getting more and more powerful,meanwhile the interaction among different kinds of interface devices is getting more and more frequent. However, the current interface devices have been limited by the performances which remain to improve, such as the monotonous business, the complex extension, the limited bandwidth, the compatibility of the interfaces, the transmission rate, the economic cost, the synchronicity and transmission efficiency and so on. To improve the performances, if we only commit modifications or completion in the current framework, the effect is not obvious.Compared with the current USB interface technology, a new concept about innovative USB transmission technology is proposed based on the Science and Technology Program for Public Well being named Innovative USB Transmission Technology Research in Family Network. In the other words, the innovative USB interface is aimed at overcoming the shortcomings existing in the data transmission process that include the incompatible interfaces, the restricted rate and frame size, the complex synchronization, and ultimately finishing data transmission between the innovative USB interfaces and the external device interfaces. In combination with common serial communication bus, the innovative USB interfaces first put the data which has different protocols, different transmission rates, different frame formats into the buffer, and then transmit data according to the innovative USB protocol.Since this kind of data transmission doesn't need to extract and package a data source again when data is transmitting, it directly store and transmit the data source which simplifies the circuit, reduces the transmission delay.Moreover, as the medium and large-scale integrated circuits emerge and develop fast at a larger scale, there are more and more logic devices in a single digital-circuit chip. Depending on the adequate user I/O resources, flexible programmable logic,being compatible with a variety of standard levels, the FPGA has unique advantagesover the implementations of the peripheral interfaces. Since common serial communication bus interfaces, such as RS-232, I2 C and SPI and so on, have widespread application in the data transmission process, together with the current and mature USB general bus technology, the interface design is completed by writing my own module with the method of Top to Down that completely free from the shackles of the chip structure in the hardware description language. This interface design that is about innovative USB and common serial communication bus interfaces makes the system of this interfaces have a clearer structure which is easy to transplant, optimize and upgrade.This paper mainly discusses about the specific design of the innovative USB and the simulation and test of the interface, the main contents are as follows.First of all, after making an in-depth study of the current FPGA development technology, the interface communication between USB and the common serial communication bus interfaces, the protocols for data transmission, the interface design of the innovative USB and the common serial communication bus based on the FPGA is proposed and then demonstrated by analyzing the technical features of common communication bus and innovative USB interfaces.As for the system's FPGA specific design, the specific modular design is completed on the Xilinx's integrated development platform, ISE and by using Synopsys' logic synthesis tools, Synplify Pro 9.6.2 with the hardware description language VHDL to finish the programming. According to the every module's function,the designed modules include Physical Layer Digital Interface module or PLDI module for short, FIFO module, innovative USB protocol layer module,human-computer interaction module. Additionally the PLDI module mainly includes three kinds of data receiving model that are the RS-232, the I2 C bus and SPI bus,information packet splitting and data adjustment, bit stuffing, NRZI encoding, CRC verification, parallel-serial conversion. The FIFO module mainly completes the data transmission after the data finishes the bit stuffing and encoding, then according to the system's specific work situation, finds and solves the problem intelligently about the FIFO module's data transmitting or receiving too fast. The functions of the innovative USB protocol layer module are the data validation, NRZI decoding, removing bit stuffing, data receiving and data transmission in the innovative USB protocol. The human-computer interaction module verifies the correctness of the data which is transmitted. Furthermore, this module is composed of controller module and display module. The controller module mainly implements these functions such as the adjustable rate, the adjustable frame length and the control module of the two-wire,four-wire pattern. As for the display module, its main function is to display data from the transport interface to the users. All in all, the PLDI module, innovative USB protocol layer module and human-computer interaction are the most important parts of the whole system's design.Last but not the least, the system simulation and overall test are of great importance. The system's each functional module in the concrete design of the interface is simulated on the professional EDA simulation tool, Model Sim, which achieves the expected function. Finally, the system interfaces can transfer data from the common serial communication bus successfully through the innovative USB interfaces which can fulfill system requirement.In summary, the interface design of the innovative USB and common serial communication bus can be compatible with different communication protocols and succeed in transmitting the data according the innovative USB interface transport protocols. The design makes the equipment not only be compatible with the RS-232,I2 C and SPI serial interface but also own these technology features which include the serial data transmission, optional rate, optional data frame length, optional work pattern, that will strongly promote the development of digital communications.