MultiCS: Circuit switched NoC with multiple sub-networks and sub-channels

Abstract

We propose a multi-channel and multi-network circuit switched NoC (MultiCS) with a probe searching setup method to explore different channel partitioning and configuration policies. Our design has a variable number of channels which can be configured either as sub-channels (spatial division multiplexing channels) or sub-networks. Packets can be delivered on an established connection with one or multiple channels. An adaptive channel allocation scheme, which determines a connection width according to the dynamic use of channels, can greatly reduce the delay, compared to a deterministic allocation scheme. However, the latter can offer exact connection width as requested. The benefits and burden of using different number of channels and configurations are studied by analysis and experiments. Our experimental results show that sub-network configurations are superior to sub-channel configurations in delay and throughput, when working at the highest clock frequency of each configuration. Under reasonable channel partitioning, sub-networks with narrow channels can generally achieve higher throughput than the network using single wide channels.