Transition test bring-up and diagnosis on UltraSPARCTM processors

We describe methods to use PLL-based transition test in support of chip bring-up. We used it to diagnose slow paths for performance improvement. During bring-up, often the issues of setup, design, scan patterns, and silicon slow paths are mixed together, making diagnosis more difficult. We discuss techniques used to understand and resolve these issues, and show examples of the benefit of transition test over functional and system test.