An area-efficient topology for VLSI implementation of Viterbi decoders and other shuffle-exchange type structures

This paper proposes two-dimensional directed graphs (or digraphs for short) as a promising alternative to the popular 2D mesh topology for networks-onchip (NoCs). Mesh is the most popular topology for the NoCs, mainly due to its suitability for on-chip implementation and low cost. However, the fact that a digraph offers a lower diameter than its equivalent linear array of equal cost motivated us to evaluate digraphs as the underlying topology of NoCs. This paper introduces a family of NoC topologies based on three well-known digraphs, namely de Bruijn, shuffleexchange, and Kautz. We study topological properties of the proposed topologies. We show that the proposed digraph-based topologies have several attractive features including constant node degree, low diameter and cost, and low zero load latency which result in superior performance over the mesh. We introduce a deadlock-free routing algorithm for the proposed NoC topologies and compare NoCs employing the proposed topologies and the mesh topology in terms of power consumption and 2 R. Sabbaghi-Nadooshan et al.performance. Simulation results also reveal that the proposed NoC topologies offer higher performance and consume lower power than the mesh NoC.

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“…The latter can be solved by a number of efficient VLSI layouts proposed for digraphs (i.e. the layout proposed in [14]). …”

Section: Summary Of Resultsmentioning

confidence: 99%

“…It is a popular interconnection topology for multiprocessors and multicomputers due to its scalability and distributed self-routing capability [13]. Several researchers have studied the topological properties [12] and efficient VLSI layout [14] of the shuffle-exchange network.…”

Section: The Shuffle-exchange Networkmentioning

confidence: 99%

The 2D digraph-based NoCs: attractive alternatives to the 2D mesh NoCs

2010

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“…Several researchers have studied the topological properties, routing algorithms, efficient VLSI layout and other aspects of the shuffle-exchange networks [2,7,13,14,17,18,20].…”

Section: Introductionmentioning

confidence: 99%

The 2D SEM: A novel high-performance and low-power mesh-based topology for networks-on-chip

Sabbaghi‐Nadooshan

Modarressi

Sarbazi-Azad

2010

International Journal of Parallel, Emergent and Distributed Sys

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In this paper, a 2D shuffle-exchange based mesh topology, or 2D shuffle-exchange mesh (SEM) for short, is presented for network-on-chips. The proposed 2D topology applies the conventional well-known shuffle-exchange structure in each row and each column of the network. Compared to an equal sized mesh which is the most common topology in on-chip networks, the proposed shuffle-exchange based mesh network has smaller diameter but for an equal cost. Finally for better performance cross-shuffle is proposed. Simulation results show that the 2D SEM and 2D cross-shuffle effectively reduce the power consumption and improve performance metrics of the on-chip networks compared to the conventional mesh topology.

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“…This can lead to some variations in the delay and power of the network links and may also have link placement difficulty. The latter can be solved by a number of efficient VLSI layouts proposed for shuffle-exchange networks (Steinberg & Rodeh, 1981;Sparso et al, 1991). Moreover, since the operating frequency of a NoC is often determined by the router critical path, the long wires may not degrade the NoC speed.…”

Section: The Structurementioning

confidence: 99%

“…This topology is one of the most popular interconnection architectures for multiprocessors and multicomputers due to its scalability and distributed self routing capability (Kim & Veidenbaum, 1995). Several researchers have studied the topological properties (Park & Agrawal, 1995;Pifarre et al, 1994) and efficient VLSI layout (Steinberg & Rodeh, 1981;Sparso et al, 1991) of the shuffle-exchange networks. In a shuffle-exchange network, each node is identified by a unique n-bit binary address, hence the network size (number of nodes), N, equals 2 n .…”

Section: The Structurementioning

confidence: 99%