On Improving Diagnostic Test Generation for Scan Chain Failures

In this paper, we present test generation procedures to improve scan chain failure diagnosis. The proposed test generation procedures improve diagnostic resolution by using multi-cycle scan test patterns. A diagnostic test generation flow to speed up diagnosis is proposed to address the issue of long run times of test generation and large number of test patterns for the cases where the range of suspected cells is large. Experimental results on several industrial designs show the effectiveness of the proposed procedures in improving diagnostic resolution, reducing run times of test generation and also reducing the number of test patterns.