Exploration within the Network-on-Chip Paradigm

The NoC is a specific flavour of interconnection networks. Interconnection networks have been studied for more than two decades and a solid foundation of design techniques is available. We will give a short introduction to the terminology, principles, theory of interconnection networks that are relevant for this thesis. Furthermore, we describe specific characteristics of NoCs in comparison with networks in general. We also present some NoC solutions and present the techniques they employ. In this chapter we describe the basic principles of a NoC and present some examples of NoC architectures. The NoC is a specific flavour of interconnection networks. According to the definition given by Dally and Towles [39], an interconnection network is a defined as: “A programmable system that transports data between terminals.” A terminal refers to a general block that generates data for or consumes data from other terminals. This definition of an interconnection network occurs at many scales. For example, networks to interconnect on-chip local memories, registers and arithmetic units in a single processor, networks to interconnect processors and memories on pcb and racks, and finally local-area and wide-area networks that connect systems in a building or across the globe. The NoC interconnects the various components of a single vlsi architecture. These components can be small arithmetic units, but most of the NoC studies focus on the interconnection of processing cores and large on-chip memories. The NoC transports data that is communicated between those components and we refer to the combination of the NoC with the components as a System-on-Chip (SoC) architecture. Figure 2.1 depicts an example of a SoC architecture to illustrate the major components for the global on-chip communication. Throughout this thesis we will