Runtime Online Links Voltage Scaling for Low Energy Networks on Chip

The power dissipated by the links of a network on chip (NoC) accounts for a significant fraction of the overall power budget. Reducing the operating voltage of the network links, results in a square reduction of their power contribution. Unfortunately, the voltage reduction has a negative impact on communication reliability in terms of bit error rate. Starting from the assumption that not all the communications require the same reliability level, we present a technique for dynamically changing the voltage of the links based on the communication reliability requirements. The experiments, carried out under both synthetic and real traffic scenarios, show the effectiveness of the proposed technique which allows to save up of 55% of link energy with a total energy saving of 25% of the entire NoC.