| Abstract |
Interconnection Networks of digital SoCs are considered an appropriate application for asynchronous design in order to exploit its advantages. This thesis deals with the implementation and study of CHAIN, an asymmetric asynchronous Interconnection Network, custom-designed using one-hot (1-of-n) data encoding. The operation frequency of Interconnection Networks depends directly on their placement and routing. Therefore, the development of models for performance estimation before the implementation is desirable. The targets of this thesis are the analytical study of CHAIN performance and the model development for the performance estimation of asynchronous Interconnection Networks. Following the CHAIN placement and routing with EDA tools, it has been proven that in its basic version (1-of-4 data encoding and one level) was not suitable for high performance data transmission. For that purpose, various alternative implementations have been examined with the same process, in order to correlate the used encoding length with the cycle time. More specifically, the encoding length increase and the implementation of parallel topologies were studied so as to fiand the impact in cycle time. The developped models simulate the real placement and routing of the network, considering that the area of the networks'' components is scalable in relation to the encoding length. The forst model is an analytical model based on logical assumptions about the placement and routing of the network. The second model uses simple placement and routing algorithms in order to approach the real process. Cluster Growth algorithm was selected for placement and Lee''s algorithm was selected for routing. Its estimations of the circuit''s cycle time was performed based on channel density and also wiring delays are taken into account. The third model places randomly the components and follows the previous procedure for cycle time estimation. The last two models are fully automated and have the benefit of small calculation time. In this thesis framework, the models were applied to typical CHAIN topologies, but they can be applied generally in any topology. For the evaluation of the model''s accuracy, we have compared the cycle time estimation for CHAIN topologies with the real placement and routing results. The comparison shows that the forst two models are sufficient accurate for networks with practical encoding lengths. The third model, due to the random placement algorithm, results in less accurate estimations, since it does not approach well the real placement. The second model is the most realistic and approximate with accuracy the placement and routing results. Therefore it could be used in general for the performance estimation of asynchronous interconnection networks before their implementation.
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Αξιολόγηση ασύγχρονων τεχνικών διασύνδεσης για ψηφιακά συστήματα σε Chip
