Silicon Compilers and Expert Systems for VLSI

The present VLSI design crisis was caused by advancements in VLSI technology which allow us to pack almost a million transistors on a single chip. The functional complexity of a chip has increased accordingly. First, this forced a chip designer, usually an experienced circuit designer, to become an expert in logic design, computer architecture, and application software. This requirement for accumulated expertise in one person and increased demand for new designs created a shortage of chip designers. Secondly, the design complexity prolonged the design cycle, which became almost as long as the lifetime of the product. To solve this design Crisis, an advancement in design methodology for VLSI technology is needed. Basically, there are three approaches. knowledse base of an expert system. The knowledge in the knowledge base can be divided basically into three categories: Concepts include basic terms of the problem domain (VLSI design in our case), which can be usually obtained from textbooks. Rules describe particular situations and desirable actions to be performed (design refinements in our case). This knowledge is based on experience, and is obtained from an expert. Strate$ies are procedures that aid in guiding the search through the knowledge base and help resolve conflicts when several equally plausible rules apply. The other two components of an expert system are a workin$ memory that stores current design description, and an inference en$ine that searches the knowledge base for applicable knowledge and makes design refinements on the basis of current design description.