IC test using the energy consumption ratio

Dynamic-current based test techniques can potentially address the drawbacks of traditional and I_ddq test methodologies. The quality of dynamic current based test is degraded by process variations in IC manufacture. The energy consumption ratio (ECR) is a new metric that improves the effectiveness of dynamic current test by reducing the impact of process variations by an order of magnitude. We address several issues of significant practical importance to an ECR-based test methodology. We use the ECR to test a low-voltage submicron IC with a microprocessor core. The ECR more than doubles the effectiveness of the dynamic current test already used to test the IC. The fault coverage of the ECR is greater than that offered by any other test, including I_ddq. We develop a logic-level fault simulation tool for the ECR and techniques to set the threshold for an ECR-based test process. Our results demonstrate that the ECR offers the potential to be a high-quality low-cost test methodology. To the best of our knowledge, this is the first dynamic-current based test technique to be validated with manufactured ICs