High-speed Switch Design, Signal Integrity Problems

High speed digital circuit design is a complex project. With the system design more complex and the scale of integration increasing, the Signal Integrity problems of high speed circuits often lead the digital circuits based on traditional design method to fail. High speed switch design consists of many components, the density of PCB and the signal rate is very high. Accordingly the Signal Integrity is very important. Without proper disposal of Signal Integrity, the switch will lose packets, even can't work in the course of nature. In this paper, we will introduce the design of one high speed Ethernet switch, SW224, with the background of Community Broadband Network System with Integrated Services.This paper begins with the design of hardware module. Then we will analyze some signal integrity problems encountered during the design, such as the noise of power distribution system, clock jitter, propagation delay and impedance of transmission line. The techniques for solving these problems are summarized in this paper.This paper consists of four chapters. The application background is introduced in the first chapter, which includes the current condition and trends of broadband access technology, an overview of Community Broadband Network System with Integrated Services and some basic concepts of Signal Integrity. In the second chapter the system structure of the high speed switch is given, and the detail designs are presented, which include the designs of switch module, management module, clock module, power module and configuration module. In the third chapter, it is analyzed that the Signal Integrity problems about transmission line, clock module and power module. We also introduce the techniques adopted in the design of SW224, and list the test outcomes of key parameters. The summarization and potential of our system appears in the final chapter.