As companies move towards many-core chips, an efficient onchip communication fabric to connect these cores assumes critical importance. To address limitations to wire delay scalability and increasing bandwidth demands, state-of-the-art on-chip networks use a modular packet-switched design with routers at every hop which allow sharing of network channels over multiple packet flows. This, however, leads to packets going through a complex router pipeline at every hop, resulting in the overall communication energy/delay being dominated by the router overhead, as opposed to just wire energy/delay. In this work, we propose token flow control (TFC), a flow control mechanism in which nodes in the network send out tokens in their local neighborhood to communicate information about their available resources. These tokens are then used in both routing and flow control: to choose less congested paths in the network and to bypass the router pipeline along those paths. These bypass paths are f...
Amit Kumar 0002, Li-Shiuan Peh, Niraj K. Jha