Introducing the superGT network-on-chip: SuperGT QoS: more than just GT

Predictability of multi-processor systems-on-chip communication is critical and needs to be addressed by providing the right mix of soft and hard real-time guarantees. To this end, state-of-the-art packet-switched networks-on-chip (NoC) provide different levels of quality-of-service (QoS) such as best effort (BE) and guaranteed throughput (GT). Unfortunately, GT resources have to be reserved for the worst-case, resulting in over-allocated resources. We introduce the SuperGT NoC, a packet-switched NoC that, besides BE and GT, supports a new SuperGT QoS. A SuperGT connection combines guaranteed and non guaranteed traffic while maintaining in-order packet delivery. Time-slots are allocated to provide guarantees and extra BE resources are claimed by injecting data during free slots. Simulation results demonstrate the advantages of SuperGT over GT. Synthesis results of the SuperGT virtual channel manager show that the SuperGT router is an inexpensive enhancement to state-of-the-art packet-switched NoCs.