Program slicing for hierarchical test generation

Sequential Automatic Test Pattern Generation (ATPG) is extremely computation intensive and produces good results only on relatively small designs. This paper develops an elegant theoretical basis, based on program slicing, for hierarchical ATPG which targets one module at a time and abstracts the rest of the design. The technique for obtaining a "constraint slice" for each embedded Module Under Test (MUT) within a design is described in detail. The technique has been incorporated in an automated tool for designs described in Verilog, and results on large benchmark circuits show the significant benefits of the approach.