Portland State University. Department of Electrical and Computer Engineering
Date of Award
Master of Science (M.S.) in Electrical and Computer Engineering
Electrical and Computer Engineering
1 online resource (xi, 93 p.) : ill. (some col.)
Networks on a chip, Computer algorithms, Routing (Computer network management)
Traditionally, on-chip network communication was achieved with shared medium networks where devices shared the transmission medium with only one device driving the network at a time. To avoid performance losses, it required a fast bus arbitration logic. However, a single shared bus has serious limitations with the heterogeneous and multi-core communication requirements of today's chip designs. Point-to-point or direct networks solved some of the scalability issues, but the use of routers and of rather complex algorithms to connect nodes during each cycle caused new bottlenecks. As technology scales, the on-chip physical interconnect presents an increasingly limiting factor for performance and energy consumption. Network-on-chip, an emerging interconnect paradigm, provide solutions to these interconnect and communication challenges. Motivated by future bottom-up self-assembled fabrication techniques, which are believed to produce largely unstructured interconnect fabrics in a very inexpensive way, the goal of this thesis is to explore the design trade-offs of such irregular, heterogeneous, and unreliable networks. The important measures we care about for our complex on-chip network models are the information transfer, congestion avoidance, throughput, and latency. We use two control parameters and a network model inspired by Watts and Strogatz's small-world network model to generate a large class of different networks. We then evaluate their cost and performance and introduce a function which allows us to systematically explore the trade-offs between cost and performance depending on the designer's requirement. We further evaluate these networks under different traffic conditions and introduce an adaptive and topology-agnostic ant routing algorithm that does not require any global control and avoids network congestion.
Parashar, Neha, "Design Space Analysis and a Novel Routing Agorithm for Unstructured Networks-on-Chip" (2010). Dissertations and Theses. Paper 89.