Emerging Paradigm

Network-on-Chip is an emerging paradigm for communications within large VLSI systems implemented on a single silicon chip. In a Network-on-Chip system, modules such as processor cores, memories and specialized IP blocks exchange data using a network as a "public transportation" sub-system for the information traffic. A Network-on-Chip is constructed from multiple point-to-point data links interconnected by switches, such that messages can be relayed from any source module to any destination module over several links, by making routing decisions at the switches. A Network-on-Chip is similar to a modern telecommunications network, using digital bit-packet switching over multiplexed links. Although packet-switching is sometimes claimed as necessity for a Network-on-Chip, there are several Network-on-Chip proposals utilizing circuit-switching techniques. This definition based on routers is usually interpreted so that a single shared bus, a single crossbar switch or a point-to-point network are not Network-on-Chip s but practically all other topologies are. This is somewhat confusing since all above mentioned are networks but they are not considered as network-on-chips. Note that some articles erroneously use Network-on-Chip as a synonym for mesh topology although Network-on-Chip paradigm does not dictate the topology. Likewise, the regularity of topology is sometimes considered as a requirement which is, obviously, not the case in research concentrating on "application-specific Network-on-Chip topology synthesis".