CACBR: Congestion Aware Cluster Buffer base routing algorithm with minimal cost on NOC

Abstract

Congestion aware routing algorithm enhanced the Network on Chip (NoC) performance and power consumption. The main assignment to reach this goal is to select the most proper congestion parameters along with the accuracy of collecting the congestion data. Congestion detection can be perceived while monitoring the network resources (for example monitoring the free buffers of nodes) or predicting the network traffic injection rate. The network monitoring has communication overheads as the number of nodes extend, and predicting the traffic injection rate has communication overhead along with processing overhead. In a congestion aware routing algorithm, after determining possible paths, the selection function chooses a path among the suggested ones, using the congestion detection function. In this paper, congestion detection investigates the free resources of the next cluster (neighbor). This method is distinguished in two phases. In the first phase, candidate paths will be selected by a minimal adaptive algorithm, and in the next phase, the cluster’s congestion information will be sent to the selected node in order to select the best path among the suggested paths. There has been no extra signal added to the network to transfer the congestion information. In order to ensure deadlock freedom of the routing algorithm, turn restriction and virtual channels are used. Experimental results can clearly prove the improvements of average delay and network performance, whereas the average delay is reduced by 13% and 2.5% based on the traffic patterns used, and network performance gained 9% and 57% direct improvement on the algorithm output.