Concurrent hybrid switching for massively parallel systems-on-chip: The CYBER architecture

Massively Parallel Systems-on-chip represent the new frontier of integrated computing systems for general purpose computing. The integration of a huge number of cores poses several issues such as the efficiency and flexibility of the interconnection network in order to serve in the best way the different traffic patterns that can arise. In this paper we present the CYBER architecture, an advanced Network-on-Chip (NoC) for concurrent hybrid switching with prioritized best effort Quality of Service. Compared to similar architectures, CYBER allows the simultaneous exploitation of packet switching and circuit switching, providing two different priorities to packets in order to be able to transmit urgent messages (e.g. signalling) while long-lasting transactions and huge packets congestion are present. In terms of the typical NoC metrics, evaluated on synthetic traffic representative of several application categories, their standard trend is degraded while serving both circuit and packet switching simultaneously but the architecture preserves a predictable behaviour. A CMOS 90nm implementation reveals a maximum operating frequency of about 1GHz.