Causality based generation of directed test cases

Simulation is considered to be the irreplaceable part of design verification. However, the efficiency of this method depends greatly on the test cases used. Random test cases can be generated quickly but have poor coverage. Directed test cases on the other hand require time and manual effort. This paper presents a method for generating directed test cases automatically by making use of signal relationships in the specification. An algorithm is presented that was applied to the GL85 microprocessor, a clone of Intel´s 8085. The results are compared with other methods to see the gain with the proposed method.