Research On Automatic Extraction Technology Of Layout Symmetry And Matching Constraints For Analog Integrated Circuits

With the rapid development of the mixed-singal integrated circuits,the integrated development of digital integrated circuit automation has approached maturity,and more efficient and stable automation auxiliary tools have been developed for digital integrated circuit automation design.However,the progress of analog integrated circuit automation and synthesis technology is moving slowly,and it has become a technical bottleneck for the design of digital-analog hybrid systems.Therefore,the analog integrated circuit automation and synthesis technology has been one of the hot topics in recent years.We firstly analyzed the automated synthesis process and related progress of analog integrated circuits in this thesis,and conducts research on the integrated constraints of analog integrated circuits.Then we poposed a new method to detect symmetry constraints of active devices at the circuit level,and an automatic marking method for symmetry information at the layout level;at the same time,to further realize the circuitlevel matching detection,an optimized design of matching circuit identification method is emploited based on subgraph isomorphism algorithm.The main contributions of this thesis are shown as follows:(1)Aiming at the problem of symmetrical constraint detection of analog integrated circuits,a symmetrical constraint detection method based on vector coding algorithm is proposed.The interconnection relationship of devices on the circuit level is analyzed based on the circuit netlist,and is represented with coded vectors.Combining the optimized representation of the devices and the basic unit modules of analog integrated circuits,the symmetry information of active devices is automatically extracted.The experimental results on the VCD data set and the MAGICAL public data set showed that the method proposed in this thesis obtained the symmetric constraint information of the analog circuits effectively.(2)Based on the rectangular space matching method,the detection of the symmetry information of the integrated circuit layout is realized.By extracting the primitive information in the layout,the rectangles of each layer in the layout were normalized to generate a floorplan of the layout.Then the spatial coordinate relationship of each rectangle was further analyzed to detect the main symmetry axis of the analog integrated circuit layout,and then the symmetry information of the layout was marked.(3)Aiming at the problem of complex circuit matching detection in analog circuits,the feature expression of circuit structure topology is optimized,and matching circirt identification is realized with the subgraph isomorphism algorithm.Matching recognition experiments in circuits of different scales have verified the effectiveness of this method.