چكيده به لاتين
Data-intensive application imposes heavy traffic on NoC, in which cache miss mostly occurs. When the application encounters cache miss, the evicted L1 cache block is injected to the local routers for traversing the NoC and storing in L2 cache bank. However, this block may be re-referenced due to data locality. This imposes unnecessary traffic in the NoC, which occupies NoC resources. We store the approximate form of the packets in the empty virtual channels of the local routers to avoid packet transmission across the network. Therefore, the next request for this cache block can be replied from the local router. Then, we apply power-efficient voltage-scaling technique in NoC resources as reply from local router have been reduced network congestion, considerably. Nevertheless, voltage reduction trades the latency and system output reliability. As emerging applications accept a specified output error, we modify the architecture of the routers and links to scale the voltage of these resources for approximation parts of the applications. Therefore, the power consumption is significantly improved with no performance degradation. Also, we reduce the transmitted packet size by sending the differences between an adaptive predetermined value on the network and the data to be sent. To avoid hotspot creation, the number of transmitted flits is changed adaptively. To overcome output errors caused by using approximation techniques, a quality control mechanism is employed that compromises the output accuracy with energy consumption and maximize the approximation gain. To reduce the static power consumption, the router would be power gated after determined idle cycles. Powering on the routers incurs some performance penalty due to the wake-up latency of routers and results in more power consumption. In our work, the intermediate routing algorithm is used to increase the power-off time of the routers which reduces the static power consumption. In the case that there was no appropriate intermediate router, downward routing is employed. The power-off routers would be powered on when the congestion has occurred. Also, a threshold congestion value lower than the network congestion is determined to hide the wake-up latency of powered- off routers. In other words, we continue to route the packet by the intermediate routing algorithm to power-off routers on the path become completely awake.
