Performance evaluation of on-chip sensor network (SENoC) in MPSoC

As technology scaling, more processing units (PUs) are integrated in multiprocessor system-on-chip (MPSoC) to achieve higher performance. Due to the higher variations resulted from reducing feature sizes and the needs of lower power consumption, on-chip monitoring of environmental information, such as thermal, voltage, and frequency, is becoming increasingly important. To address this need, sensors are integrated into network-on-chip (NoC) to perform system monitoring. However, sensors which transfer their data through NOC will compete with PUs for the limited bandwidth resources, thus communication between PUs will be delayed. To evaluate the sensors´ overhead on the regular data traffic, we implement a VC based NoC. The sensor data are transferred through NoC together with the regular data. We study the average delay of regular data and sensor data, respectively. We compare the experimental results with that of a NOC without sensors. The results show that the overhead of sensors is negligible, with a max delay overhead of 0.80% when the traffic is not that heavy.