Modern, high performance microprocessors are extremely complex machines which require substantial validation effort to ensure functional correctness prior to tapeout. Generating the corner cases to test these designs is a mostly manual process, where completion is hard to judge. Experience shows that the errors that are caught late in the design, many post-silicon, are interactions between different components in very improbable corner case situations. In this paper we present a technique that targets such error-causing interactions by automatically generating test vectors that will cause the processor to exercise all transitions of the control logic in simulation. We use techniques from formal verification to derive transition tours of a fully enumerated state graph of the control logic of the processor. Our system works from a Verilog description of the original machine and is currently being used to validate an embedded dual-issue processor in the node controller of the Stanford FLA...

iv Acknowledgments vi Table of Contents vii List of Tables x List of Figures xi Chapter 1.

Abstract- The next generation UltraSPARC-I CPU represents a significant step forward in processor performance at the cost of increased design complexity. Added complexity increases the risks in achieving functionally correct first silicon. Existing design verification techniques were supplemented by applying emulation to obtain an early look at functionality. Discussed are the goals, methods and results of the UltraSPARC-I emulation. I.