Local (V,T) estimation in integrated circuits using a set of statistical tests

Mobile platforms need ever-increasing computational performances under stringent energy consumption limitation mainly due to the battery lifespan. An optimal operating point is obtained thanks to a compromise between performance and power consumption. For distributed architectures (e.g. MultiProcessor System on Chip), the supply voltage and the operating frequency of each processing element are dynamically tuned to reach efficient performance/power consumption trade-offs. To increase the performance of each “actuator”, the physical state (e.g. the current supply voltage and temperature) of the integrated circuit must be monitored to locally adapt the control parameters. During this keynote, we will present a new estimation method based on statistical tests to estimate the supply voltage and the temperature of a local area in an integrated circuit. Standard ring oscillators buried in the chip provide the raw measurements that are fused to estimate the IC physical state. The results presented here have been developed in cooperation between the CEA-LETI (Mrs E. Beigné, Mr. L. Vincent, Dr. S. Lesecq), Grenoble, France and the LIRMM, Montpellier, France (Dr. Ph. Maurines).