Design And Realization Of Circuit Simulation System Based On SPICE

With the improvement of computer performance and the development of numerical algorithms, technology of computer aided design and analysis of circuit has more and more applications. Technology of circuit simulation plays an important role in the field of electronics. For example, it could substitute cumbersome manual analysis, reduce labor intensity, enhance the design and analysis ability, and avoid errors in the approximation used in analytical methods. Moreover, circuit simulation system could be used in analyzing basic circuit properties, and visualizing simulation results by wave charts or texts. System also could be used in making statistics on the parameters of circuit components, simulation analysis, optimized simulated design.SPICE, developed by UC Berkeley, is the most common circuit level simulation program. SPICE could be used in nonlinear DC analysis, nonlinear transient analysis and linear AC analysis of the circuit. The components of the analyzed circuit could include resistors, capacitors, inductors, mutual inductance, independent voltage sources, independent current source, a variety of linear controlled sources, transmission lines and active semiconductor devices.Based on the former research and SPICE, this paper will propose a novel algorithm which improves circuit design and simulation efficiency by using SPICE, FDTD, and network distributed parallel technology. The main work of the paper is as follows:Firstly, this paper introduces the current status and the prospects of the circuit simulation system, as well as the involved theoretical knowledge, such as circuit simulation methods, SPICE, finite-difference time-domain methods and so on.Secondly, a simulation method of the circuit consisting of frequency-dependent interconnects is proposed in this paper based on SPICE. The main idea is that based on multi-port equivalent circuit model, separate interconnects from other circuit components such that the simulation of each interconnect is independent, in which multi-core computers and distributed computer network could be used. During each time step, simulation result of interconnects will be exchanged with other simulation results. This method greatly improves the simulation efficiency of circuit with interconnects.Finally, a circuit simulation system is designed and implemented based on the aforementioned methods. The system provides two ways to describe circuit: editing circuit net list and drawing circuit graph model and both way could be displayed in one screen. System also can compile the circuit net list using lexical parser based on a third-party program Flex++&Bison++ and output the right results by waveform.