A Sensitivity Analysis of Two Worst-Case Delay Computation Methods for SpaceWire Networks

Ferrandiz, Thomas; Frances, Fabrice; Fraboul, Christian

doi:10.1109/ecrts.2012.35

Cited by 17 publications

(13 citation statements)

References 7 publications

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“…In a very recent work by Ferrandiz et al [2012], the authors compare their newly proposed NC method against their previous RC method considering different parameters. In our approach we combine the best of both methodologies, namely an ability to exploit the simplicity and intuition behind RC methods without losing the input traffic characterization provided by NC methods.…”

Section: Related Workmentioning

confidence: 98%

“…The model and assumptions to support this methodology have, as a common denominator, the assumption that flows inject packets at the maximum rate to saturate the network. The initial assumption of these approaches is that all the intermediate buffers in the switches between the source and the destination are filled to their capacity [Ferrandiz et al 2012]. The method thus ensures capturing the worst-case scenario.…”

Section: Related Workmentioning

confidence: 99%

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NoC contention analysis using a branch-and-prune algorithm

Dasari

Nikolic

Nélis

et al. 2014

ACM Trans. Embed. Comput. Syst.

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Many-core" systems based on a Network-on-Chip (NoC) architecture offer various opportunities in terms of performance and computing capabilities, but at the same time they pose many challenges for the deployment of real-time systems, which must fulfill specific timing requirements at runtime. It is therefore essential to identify, at design time, the parameters that have an impact on the execution time of the tasks deployed on these systems and the upper bounds on the other key parameters. The focus of this work is to determine an upper bound on the traversal time of a packet when it is transmitted over the NoC infrastructure. Towards this aim, we first identify and explore some limitations in the existing recursive-calculus-based approaches to compute the Worst-Case Traversal Time (WCTT) of a packet. Then, we extend the existing model by integrating the characteristics of the tasks that generate the packets. For this extended model, we propose an algorithm called "Branch and Prune" (BP). Our proposed method provides tighter and safe estimates than the existing recursive-calculus-based approaches. Finally, we introduce a more general approach, namely "Branch, Prune and Collapse" (BPC) which offers a configurable parameter that provides a flexible trade-off between the computational complexity and the tightness of the computed estimate. The recursive-calculus methods and BP present two special cases of BPC when a trade-off parameter is 1 or ∞, respectively. Through simulations, we analyze this trade-off, reason about the implications of certain choices, and also provide some case studies to observe the impact of task parameters on the WCTT estimates. ACM Reference Format:Dakshina Dasari, Borislav Nikolić, Vincent Nélis, and Stefan M. Petters. 2014. NoC contention analysis using a branch-and-prune algorithm.

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Section: Related Workmentioning

confidence: 98%

Section: Related Workmentioning

confidence: 99%

NoC contention analysis using a branch-and-prune algorithm

Dasari

Nikolic

Nélis

et al. 2014

ACM Trans. Embed. Comput. Syst.

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“…However, the bounds provided in [19] required assuming packet injection is limited. In later works [11], [29] this limitation is removed.…”

Section: Wctt In Wnocsmentioning

confidence: 99%

“…al [8] achieve tighter WCTT bounds -than those derived with [11], [29] -based on the following two observations: (1) flows injection rate is inherently limited by the speed at which the processor pipeline can process request-generating instructions (e.g load or stores); and (2) packets of a given flow do not always contend with the flow under analysis due to the existing release time of their request of a flow/core. Regarding observation (1) we have shown that while limiting the injection effectively reduces WCTT values the actual contention that packets in the NoC suffer remains unaltered, hence producing no effect on WCD.…”

Section: Wctt In Wnocsmentioning

confidence: 99%

Modeling High-Performance Wormhole NoCs for Critical Real-Time Embedded Systems

Panic

Hernández

Quiñones

et al. 2016

2016 IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS)

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Abstract-Manycore chips are a promising computing platform to cope with the increasing performance needs of critical realtime embedded systems (CRTES). However, manycores adoption by CRTES industry requires understanding task's timing behavior when their requests use manycore's network-on-chip (NoC) to access hardware shared resources. This paper analyzes the contention in wormhole-based NoC (wNoC) designs -widely implemented in the high-performance domain -for which we introduce a new metric: worst-contention delay (WCD) that captures wNoC impact on worst-case execution time (WCET) in a tighter manner than the existing metric, worst-case traversal time (WCTT). Moreover, we provide an analytical model of the WCD that requests can suffer in a wNoC and we validate it against wNoC designs resembling those in the Tilera-Gx36 and the Intel-SCC 48-core processors. Building on top of our WCD analytical model, we analyze the impact on WCD that different design parameters such as the number of virtual channels, and we make a set of recommendations on what wNoC setups to use in the context of CRTES.

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“…In SpaceWire, the transmission of command/control messages needs to verify that messages can be delivered before their deadline. In [6], the computation of an upper bound of the worst case ETE delay of each message is proposed. Two methods have been studied: one based on Network Calculus and one based on a recursive flow analysis.…”

Section: Introductionmentioning

confidence: 99%

Modeling a spacewire architecture using timed automata to compute worst-case end-to-end delays

Fraboul

2013

2013 IEEE 18th Conference on Emerging Technologies &Amp; Factory Automation (ETFA)

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Spacewire is a real-time communication network for use onboard satellites. It has been designed to transmit both payload and control/command data. To guarantee that communications respect the real-time constraints, designers use tools to compute the worst-case end-to-end delays. Among these tools, recursive flow analysis and Network Calculus approaches have been studied. This paper proposes to use the model-checking approach based on timed automata. A case study based on an industrial one is shown. Our approach is compared with recursive flow analysis and Network Calculus.

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A Sensitivity Analysis of Two Worst-Case Delay Computation Methods for SpaceWire Networks

Cited by 17 publications

References 7 publications

NoC contention analysis using a branch-and-prune algorithm

NoC contention analysis using a branch-and-prune algorithm

Modeling High-Performance Wormhole NoCs for Critical Real-Time Embedded Systems

Modeling a spacewire architecture using timed automata to compute worst-case end-to-end delays

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