Logic BIST for large industrial designs: real issues and case studies

This paper discusses practical issues involved in applying logic built-in self-test (BIST) to four large industrial designs. These multi-clock designs, ranging in size from 200K to 800K gates, pose significant challenges to logic BIST methodology, flow, and tools. The paper presents the process of generating a BIST-compliant core along with the logic BIST controller for at-speed testing. Comparative data on fault grades and area overhead between automatic test pattern generation (ATPG) and logic BIST are reported. The experimental results demonstrate that with automation of the proposed solutions, logic BIST can achieve test quality approaching that of ATPG with minimal area overhead and few changes to the design flow.