The Study Of CMOL Cell Mapping Based On Satisfiability Modulo Theory

Due to the shrinking feature size of integrated circuits,the current silicon-based microelectronics technology is facing a series of challenges that are difficult to overcome,such as the sharp increase in production costs,the growing quantum effect and so on.In order to continue Moore's law,researchers have proposed a series of new technologies,such as quantum cellular automata,carbon nanotubes,spin devices and so on.Among them,CMOS/nanowire/MOLecular hybrid(CMOL)technology proposed by Likharev et al,which combines nanotechnology with traditional CMOS technology,is considered to be one of the most likely technologies to replace CMOS because of its compatibility with mature CMOS technology and high density of nanowires.Cell mapping automation is an important part of the development of CMOL technology.Firstly,this paper describes the existing methods of CMOL cell mapping,and on this basis,puts forward a new method.The main contents of this paper include the following three aspects:1.Aiming at the problem that the traditional satisfiability-based unit mapping method has too many coding variables and constraints,which leads to a smaller scale of circuits that can be processed,a mapping method based on satisfiability module theory is proposed.The number of variables is greatly reduced by using integer variables,and the number of constraints to be dealt with in each solving process is reduced by step-by-step mapping.The experimental results show that the proposed algorithm can handle larger circuits than the existing satisfiability-based mapping methods.2.Aiming at the slow convergence speed of genetic algorithm and the small-scale problem solved by the satisfiability method,a combination of genetic algorithm and satisfiability method is proposed to make use of their respective advantages.In other words,genetic algorithm is used for global search,and satisfiability modulus theory is used to accelerate the convergence speed of the algorithm when the algorithm searches near the optimal solution.The experimental results show that the proposed method can get the mapping solution faster when dealing with medium-scale circuits,but it has no obvious advantage over genetic algorithm when dealing with large-scale circuits.3.Aiming at the defects of CMOL circuits,the representation of CMOL circuits in satisfiability module theory is studied,and a fault-tolerant mapping method based on satisfiability module theory is proposed.