Optimal Test Scheduling Formulation under Power Constraints with Dynamic Voltage and Frequency Scaling

As a consequence of technology scaling and increasing power consumption of modern high performance designs, various techniques, such as clock gating and Dynamic Voltage and Frequency Scaling (DVFS), have been adapted to address power issues. These techniques are important and desirable to address reliability needs as well as economic issues. From a testing point of view, introduction of power constraints during testing is needed to achieve the desired product quality and to avoid yield loss. Unlike designers who have benefited from the Design-forTest hardware introduced for testing, test engineers have rarely taken advantage of the extra hardware introduced to meet design needs. In this paper, we make use of the DVFS technology and its associated hardware to improve test economics. We formulate the power constrained testing problem as an optimization problem that makes use of DVFS technology. We show that we can obtain superior test schedules for both session-based and sessionless testing methods relative to existing and traditional methods of obtaining test schedules.