Inducing Thermal-Awareness in Multicore Systems Using Networks-on-Chip

Technology scaling imposes an ever increasing temperature stress on digital circuit design due to transistor density, especially on highly integrated systems, such as Multi- Processor Systems-on-Chip (MPSoCs). Therefore, temperature-aware design is mandatory and should be performed at the early design stages of MPSoCs to avoid iterations and delays in the deployment of final consumer products. In this paper we present a novel hardware infrastructure to provide thermal control of MPSoC architectures, which is based on exploiting the NoC interconnects of the baseline system as an active component to communicate and coordinate between temperature sensors scattered around the chip, in order to globally monitor the actual temperature of of the system. Then, a thermal management unit and clock frequency controllers are included as part of the active NoC-based thermal control infrastructure to adjust the frequency and voltage of the processing elements according to the temperature requirements of each MPSoC design at runtime. We show experimental results of the application of the proposed active NoC-based thermal management infrastructure to implement effective global temperature control policies for a real-life 4-core MPSoC, running real-life video processing benchmarks, emulated on an FPGA-based thermal emulation framework. Furthermore, due to the better thermal balancing of our proposed active NoC-based thermal control, the MPSoC performance improves almost 40% and achieves 45% energy savings with respect to local DVFS thermal control approaches.