Generating synthetic benchmark circuits for evaluating CAD tools

For the development and evaluation of computer-aided design tools for partitioning, floorplanning, placement, and routing of digital circuits, a huge amount of benchmark circuits with suitable characteristic parameters is required. Observing the lack of industrial benchmark circuits available for use in evaluation tools, one could consider to actually generate synthetic circuits. In this paper, we extend a graph-based benchmark generation method to include functional information. The use of a user-specified component library, together with the restriction that no combinational loops are introduced, now broadens the scope to timing-driven and logic optimizer applications. Experiments show that the resemblance between the characteristic Rent curve and the net degree distribution of real versus synthetic benchmark circuits is hardly influenced by the suggested extensions and that the resulting circuits are more realistic than before. An indirect validation verifies that existing partitioning programs have comparable behavior for both real and synthetic circuits. The problems of accounting for timing-aware characteristics in synthetic benchmarks are addressed in detail and suggestions for extensions are included.