A test synthesis technique using redundant register transfers

This paper presents a test synthesis technique for behavioral descriptions. The technique is guided by two testability metrics which quantify the controllability and observability of behavioral variables and structural signals. The method is based on utilizing redundant register transfers in the data path to produce a test behavior with better controllability and observability properties. This approach can avoid unnecessary insertions of test structures in the data path. A test scheme for conditional statements has been developed involving minimal changes in the controller. Our experimental results show improvements in fault coverage at modest hardware overhead.