Nonlinear and asymmetric thermal-aware DVFS control

Embedded devices using highly integrated circuits must cope with conflicting constraints. They have become more sensitive to variabilities with technology scaling while requiring computational efficiency under even more limited energy storage. Power management techniques, mainly based on Dynamic Voltage and Frequency Scaling (DVFS) algorithms, are hence of great interest. Also, temperature increase/decrease is directly related to the power consumption and platform characteristics highly depend on the temperature. As a result, temperature must be controlled, at least limited. In the present paper, the nonlinearity between power and temperature is analyzed and a thermal-aware DVFS control technique is discussed. The proposed strategy implements a chopped scheme on top of a robust DVFS approach in order to limit the temperature increase. The nonlinearity notably leads to an asymmetry in the temperature behavior, which makes the final attained temperature is higher than in the linear case.