The Realization Of USB2.0 Protocol Layer

At present, USB 2.0 has been widely accepted as standard of personal computer and peripheral devices which has been applied into various devices. Comparing to other communication interface, the most advantages of USB interface is its fast speed, feasibility, Plug and Play supporting, and automatic configuration. Since the advent of USB, the application of space constantly expanding has now become one of the computers an indispensable interface. Based on the many advantages of USB, it is foreseeable that with the USB transfer rate improved, real-time transmission of the further enhanced, and its use will become broader. With the development of the times, more flexible, versatile USB interface is the future trend of development.The protocol layer is the core unit of the whole USB devices, which is responsible for processing by the provisions of the agreement USB most of the contents. Through the in-depth research of the protocol layer and development to meet the needs of special chips, science and technology to achieve the transformation of improve the international competitiveness of the information products will be of great significance.This paper studies USB2.0 protocol layer design and implementation. The article first introduced a paper on the purpose and significance, USB on the status quo and development trend, and then outline agreement USB2.0 described some of concept of USB2.0 bus topology, USB signaling, packets, transfer types and device requests were done. USB protocol layer in the architecture of a detailed analysis, according to top-down modular design concept, the design is divided into UTMI interface block, the protocol layer (PL), control/status register, memory interface and Arbiter, function interface, and application of Verilog HDL of the respective module design, use of integrated simulation tools completes the USB2.0 protocol layer realization.