Low-Cost Dynamic Voltage and Frequency Management based upon Robust Control Techniques under Thermal Constraints

Sylvain Durand, Suzanne Lesecq, Edith Beigne, Christian Fabre, Lionel Vincent, and Diego Puschini.
In Formal Methods for Components and Objects, 10th International Symposium FMCO 2011. State-of-the-Art Survey. Bernhard Beckert, Ferruccio Damiani, Frank de Boer, and Marcello Bonsangue, editors. volume 7542 of LNCS. Springer, 2013.
Mobile computing platforms need ever increasing performance, which implies an increase in the clock frequency applied to the processing elements (PE). As a consequence, the distribution of a single global clock over the whole circuit is tremendously dicult. Globally Asynchronous Locally Synchronous (GALS) designs alleviate the problem of clock distribution by having multiple clocks, each one being distributed on a small area of the chip. Energy consumption is the main limiting factor for mobile platforms as they are powered by batteries. Dynamic Voltage and Frequency Scaling (DVFS) in each Voltage and Frequency Island (VFI) has proven to be highly e ective to reduce the power consumption of the chip while meeting the performance requirements. Environmental parameters (i.e. temperature and supply voltage) changes also strongly a ect the chip performance and its power consumption. Some sensors can be buried in order to estimate via data fusion techniques the supply voltage and the temperature variations. For instance the knowledge of the gap between the temperature and its maximum value can be used to adapt the power management technique. The present paper deals with the design of a voltage and frequency management approach (DVFS) that explicitly takes into account the thermal constraints of the platform.