  This paper considers the use of routerless networks-on-chip as an alternative
on-chip interconnect for multiprocessor systems requiring hard real-time
guarantees for inter-processor communication. It presents a novel analytical
framework that can provide latency upper bounds to real-time packet flows sent
over routerless networks-on-chip, and it uses that framework to evaluate the
ability of such networks to provide real-time guarantees. Extensive comparative
analysis is provided, considering different architectures for routerless
networks and a state-of-the-art wormhole network based on priority-preemptive
routers as a baseline.
