Communication Services for Networks on Chip

Networks are emerging as a possible solution for future on-chip interconnects. In this chapter, we show how networks on chip (NoC) are similar to and differ from both off-chip networks (e.g., computer networks) and current on-chip interconnects (e.g., buses). We re-examine their communication services in the context of NoCs. To enable a clean separation between the NoC and IP blocks, we provide services that abstract from network implementations. We define a request-response transaction model similar to bus protocols, to make our approach backward compatible. To exploit the full power of NoCs, we also provide connection-oriented communication with differentiated services. Examples are bandwidth guarantees, transaction orderings, and end-to-end flow control.