A run-time reconfigurable Network-on-Chip for streaming DSP applications
N.K. Kavaldjiev · 2007
With the advance of semiconductor technology, global on-chip wiring is becoming a limiting factor for the overall performance of large System-on-Chip (SoC) designs.In this thesis we propose a global communication architecture that avoids this limitation by structuring and shortening of the global wires.The communication architecture is used in a multiprocessor SoC for streaming DSP applications.The SoC is intended as a platform for wireless multimedia devices, such as PDAs, mobile phones, mobile medical systems, car infotainment systems, etc.To improve the performance of the communication in our SoC we use a Networkon-Chip (NoC) architecture.A NoC provides the chip with a high-performance global communication infrastructure, at the same time structures the global on-chip wires and makes their electrical parameters predictable and controllable.By contrast, the bus solutions and the ad-hoc communications solutions used till now in SoC designs result in long wires with unpredictable electrical parameters and require costly design iterations for improving the communication performance.Our specific NoC uses virtual channel flow control and source routing to provide guaranteed communication services, as well as best effort services.Our NoC is the first on-chip network designed for a run-time reconfigurable system.It offers fast reconfiguration and requires low configuration overhead.Configuring a network path takes less than a millisecond and only costs a few bytes of data overhead.Such time and data overhead is affordable by the run-time reconfigurable SoC for the class of streaming applications we consider.Our NoC is particularly suitable for the specific traffic conditions created by streaming DSP applications.These applications have a simple structure and create simple traffic patterns but need a high data throughput.The main part of the traffic consists of data streams that require guaranteed services.However, our NoC also supports the small part of the traffic with fine granularity and irregular behaviour that requires only best effort services.The implementation area of our network router in 0.13 µm technology can be as small as 0.05 mm 2 depending on the network design parameters.A network channel throughput of several Gbit/s can be achieved, which is enough to satisfy the system applications demands.The specific contributions of this thesis are: At the end of these four years as a PhD student I have to admit that it was not easy.Indeed it was a period in my life when many things have changed, it was the first time for me to live far away from home -an experience that is not always easy to handle.Here I would like to thank to all these people with whom I have worked, from whom I have learned and who have supported me during this long period.I would like to thank my family and especially my mother Maria and my aunts Rosica and Ilka for their constant support and encouragement.Their love makes me feel near home despite the distance and helps me pass the difficult moments.First of all, I would like to express my deepest gratitude and respect to my supervisor Gerard Smit.Supporting me in my everyday work, Gerard is always ready to help me, to give me an advice or just talk with me without any reservation, no matter how busy he is.He has been able to sense the slightest signs of doubts and difficulties in my daily work and always was ready to offer his guidance, but in such delicate way that I never lost the feeling of complete freedom in my work.Although my promoter prof.Pieter Hartel did not work with me on a daily basis I have learned a lot from him.Pieter is highly organised.He always amazes me with his thoroughness and efficiency.Pieter has taught me to be more precise and critical to my work, to question the obvious, and always look for unexpected points of view.He has inexhaustible optimism and enthusiasm.This positive attitude motivates and encourages me to improve.I am much obliged to Pierre Jansen who has also helped me in my daily work.Pierre has always listened to my problems in patience.He is always willing to discuss and share with me his rich experience.I would like to thank Andre Kokkeler who has reviewed the first draft of the thesis.Andre is a thorough reviewer but with a positive attitude that helped me keeping my motivation.I like to thank Jenna Wells who has also reviewed the thesis and provided me with a lot of helpful suggestions for improvement