Formulating Optimal Test Scheduling Problem with Dynamic Voltage and Frequency Scaling

Various techniques for modern high performance designs, such as clock gating and dynamic voltage frequency scaling (DVFS), have been adapted to address power issues. This is a consequence of technology scaling and it is 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 for the desired product quality and to avoid yield loss. Unlike designers who have often benefited from the design for test 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 session less testing methods relative to existing and traditional methods of obtaining test schedules.