Pre-silicon verification of the Alpha 21364 microprocessor error handling system

This paper presents the strategy used to verify the error logic in the Alpha 21364 microprocessor. Traditional pre-silicon strategies of focused testing or unit-level random testing yield limited results in finding complex bugs in the error handling logic of a microprocessor. This paper introduces a technique to simulate error conditions and their recovery in a global environment using random test stimulus closely approximating traffic found in a real system. A significant number of bugs were found using this technique. A majority of these bugs could not be uncovered using a simple random environment, or were counter-intuitive to focused test design.