Automating the VLSI design process using expert systems and silicon compilation

This paper describes the automatic design of custom integrated circuits from higher level specifications. The paper covers four topic areas: the problem domain and solution approach, higher level synthesis, module to layout automation systems, typically called silicon compiliers, and expert systems which control the design process. In the first three sections, several features of the VLSI problem domain which complicate automation are listed. The VLSI design process is diagrammed and the individual steps described. The term "silicon compilation" is defined to cover the entire process, and definitions for various subcategories of silicon compilers are given. The next Section describes both algorithmic and knowledge-based techniques Which perform higher level synthesis, including area estimation and module binding concurrent with synthesis. Research at Bell Labs, USC, CMU, and in Canada is described, along with other projects. The fifth section discusses the three categories of silicon compilers: commercially available systems, experimental compilers being developed by industry, and artificial intelligence approaches from university research. A survey of several systems is provided. The last section focuses on two systems developed at CMU and USC which plan or control design activities, Ulysses and DPE. Both systems allow the integration of various design automation tools and determine the proper tool invocation to automatically create a design. ADAM takes an autonomous approach, while ULYSSES follows user-defined scripts.