| 1. |
- Lu, Zhonghai, et al.
(författare)
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Flow Regulation for On-Chip Communication
- 2009
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Ingår i: DATE. - 9781424437818 ; , s. 578-581
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Konferensbidrag (refereegranskat)abstract
- We propose (sigma, rho)-based flow regulation as a design instrument for System-on-Chip (SoC) architects to control quality-of-service and achieve cost-effective communication, where sigma bounds the traffic burstiness and rho the traffic rate. This regulation changes the burstiness and timing of traffic flows, and can be used to decrease delay and reduce buffer requirements in the SoC infrastructure. In this paper, we define and analyze the regulation spectrum, which bounds the upper and lower limits of regulation. Experiments on a Network-on-Chip (NoC) with guaranteed service demonstrate the benefits of regulation We conclude that flow regulation may exert significant positive impact on communication performance and buffer requirements.
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| 2. |
- Lu, Zhonghai, et al.
(författare)
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NNSE: Nostrum Network-on-Chip Simulation Environment
- 2005
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Ingår i: Proceedings of Swedish System-on-Chip Conference, Stockholm, Sweden, April 2005..
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A main challenge for Network-on-Chip (NoC) design isto select a network architecture that suits a particular application.NNSE enables to analyze the performance impactof NoC configuration parameters. It allows one to(1) configure a network with respect to topology, flow controland routing algorithm etc.; (2) configure various regularand application specific traffic patterns; (3) evaluatethe network with the traffic patterns in terms of latency and throughput.
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| 3. |
- Millberg, Mikael, et al.
(författare)
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A study of NoC Exit Strategies
- 2007
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Ingår i: NOCS 2007. - 9780769527734 ; , s. 217-217
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Konferensbidrag (refereegranskat)abstract
- The throughput of a network is limited due to several interacting components. Analysing simulation results made it clear that the component that was worth attacking was the exit bandwidth between the network and the connected resources. The obvious approach is to increase this bandwidth; the benefit is a higher throughput of the network and a significant lowering of the buffer requirements at the entry points of the network this because worst case scenarios now happens at a higher injection rate. The result we present shows significant differences in throughput as well as in average and worst case latency.
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| 4. |
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| 5. |
- Millberg, Mikael, et al.
(författare)
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Increasing NoC performance and utilisation using a Dual Packet Exit strategy
- 2007
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Ingår i: DSD 2007. - LOS ALAMITOS : IEEE COMPUTER SOC. - 9780769529783 ; , s. 511-518
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Konferensbidrag (refereegranskat)abstract
- When designing a network the use of buffers is inevitable. Buffers are used at the entry point, inside and at the exits of the network. The usage of these buffers significantly changes the performance of the system. as a whole. In order to enhance the buffer utilisation the concept of letting more than one packet exit the network at every switch each clock cycle is introduced - Dual Packet Exit (DPE). The approach is tried on a 4x4 and a 6x6 mesh. We demonstrate the buffers used in combination with different routing strategies for best effort performance. The result we present shows a 50% reduction in terms of worst case latency and a 30% reduction in terms of average latency as well as an increased throughput both from a system and network perspective. We define the term Operational Efficiency as a measure of the network efficiency and show that it increases by roughly 20 % with the DPE technique.
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| 6. |
- Millberg, Mikael, et al.
(författare)
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Priority Based Forced Requeue to Reduce Worst-Case Latencies for Bursty Traffic
- 2009
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Ingår i: DATE. - : IEEE. - 9781424437818 ; , s. 1070-1075
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Konferensbidrag (refereegranskat)abstract
- In this paper we introduce Priority Based Forced Requeue to decrease worst-case latencies in NoCs offering best effort services. Forced Requeue is to prematurely lift out low priority packets from the network and requeue them outside using priority queues. The first benefit of this approach, applicable to any NoC offering best effort services, is that packets that have not yet entered the network now compete with packets inside the network and hence tighter bounds on admission times can be given. The second benefit - which is more specific to deflective routing as in the Nostrum NoC - is that packet "reshuffling" dramatically reduces the latency inside the network for bursty traffic due to a lowered risk of collisions at the exit of the network. This paper studies the Forced Requeuing on a mesh with varying burst sizes and traffic scenarios. The experimental results show a 50% reduction in worst-case latency from a system perspective thanks to a reshaped latency distribution whilst keeping the average latency the same.
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| 7. |
- Wolf, Pieter van der, et al.
(författare)
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Definition of Device Level Interface with QoS : Draft Specification
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The extensions to standard IP communication interfaces proposed in SPRINT WP3document D3.1 are defined. Flow identification signals are added to the DLI signal level interface so transactionscan indicate the services they require. These services are specified as Contracts thatdefine the flow characteristics required for correct operation. These characteristics arethe main input to an analysis method to validate that a SoC design achieves its performance targets. DLI-Guard units are defined that enforce Contracts by regulating an IP module’s identified flows. Monitoring of flow characteristics, such as latency, is also optionally provided. A configuration API for DLI-Guards is outlined together with example code toillustrate its use. This specification is successfully applied to AMBA AXI, the prime example DLI
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