A dynamic and distributed TDM slot-scheduling protocol for QoS-oriented Networks-on-Chip

Abstract

We propose a run-time distributed and dynamic scheduling protocol for Quality-of-Service oriented Networks-on-Chip implementing Time Division Multiplexing of the channels. Our protocol automatically allocates the channel time-slots according to the specific routing algorithm implemented by the routers and the communication requirements of the applications currently executing. We present a theoretical analysis to model the protocol performance based on the traffic characteristics and to optimize the configuration of the NoC architecture which we propose to implement the protocol. This architecture relies on two independent and parallel networks: the first network transfers QoS-demanding data while the second is used to control the first and for best-effort traffic. System-level simulations demonstrate the effectiveness of this approach by showing that the runtime-generated reservation requests for QoS-demanding data are accepted by the NoC with very low blocking probability and that once a reservation has been established the requested latency and throughput guarantees are consistently met.