Research On Parallel Circuit Simulation Algorithms And Application

Circuit simulation is an indispensable key technology in integrated circuit(IC)design.The parasitic effect caused by the advantaged IC process technology makes circuit simulation play a more and more important role.The rapidly increased number of parasitic devices causes the linear equation solving time in circuit simulation to increase sharply.This leads to longer and longer circuit simulation time,seriously affecting the IC design cycle and product delivery time.Sponsored by the “He-Gao-Ji” national major science & technology project,this paper studies the parallel circuit simulation algorithm aiming at the requirement of high precision IC design.The main work and contributions include:1.A circuit partition method considering load balancing is proposed.This method can solve the problem of load imbalance in matrix parallel operations and improve the performance of parallelization.To improve the quality of circuit partitioning,the circuit structure and matrix solving load are integrated into the circuit hyper-graph model,and the device structure and computation load are treated as reference factor.2.A hybrid LU decomposition and preconditioned matrix free generalized minimal residual(GMRES)method are adopted to solve the circuit equations after a balanced circuit partition.A novel parallel LU decomposition algorithm is proposed to solve the bottom level circuit equations.This adaptive algorithm can significantly reduce the matrix fill-in,which can greatly improve matrix solving efficiency.An algorithm of GMRES method is presented based on circuit topology and property.This preconditioning algorithm can robustly improve the convergence of GMRES method.3.An accurate large-capacity parallel simulator(ALPS)is developed to resolve the linear equation solving bottleneck in large scale analog/mixed-signal circuit simulation based on technologies listed above.ALPS employed an analog engine and digital engine with automatic AD/DA insertion and synchronization which can improve circuit simulation efficiency without accuracy sacrifice.ALPS has been adopted by many top IC entities world widely with proven capability of handing large scale circuit and unprecedented simulation efficiency.