Architecture and analysis of a dynamically-scheduled real-time memory controller

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21230%2F16%3A00232410" target="_blank" >RIV/68407700:21230/16:00232410 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1007/s11241-015-9235-y" target="_blank" >http://dx.doi.org/10.1007/s11241-015-9235-y</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s11241-015-9235-y" target="_blank" >10.1007/s11241-015-9235-y</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Architecture and analysis of a dynamically-scheduled real-time memory controller

Popis výsledku v původním jazyce

Memory controller design is challenging as mixed time-criticality embedded systems feature an increasing diversity of real-time (RT) and non-real-time (NRT) applications with variable transaction sizes. To satisfy the requirements of the applications, tight bounds on the worst-case response time (WCRT) of memory transactions must be provided to RT applications, while the lowest possible average response time must be given to the remaining applications. Existing real-time memory controllers cannot efficiently achieve this goal as they either bound the WCRT by sacrificing the average response time, or cannot efficiently support variable transaction sizes. In this article, we propose to use dynamic command scheduling, which is capable of efficiently dealing with transactions with variable sizes. The three main contributions of this article are: (1) a memory controller architecture consisting of a front-end and a back-end, where the former uses a TDM arbiter with a new work-conserving policy and the latter has a dynamic command scheduling algorithm that is independent of the front-end, (2) a formalization of the timings of the memory transactions for the proposed algorithm and architecture, and (3) an analysis of WCRT for transactions to capture the behavior of both the front-end and the back-end. This WCRT analysis supports variable transaction sizes and different degrees of bank parallelism. The critical part of the WCRT is the worst-case execution time (WCET) of a transaction, which is the time spent on command scheduling in the back-end. The WCET is bounded by two techniques applied to both fixed and variable transaction sizes, respectively. We experimentally evaluate the proposed memory controller and compare to an existing semi-static approach. The results demonstrate that dynamic command scheduling significantly outperforms the semi-static approach in the average case, while it performs equally well or better in the worst-case with only a few exceptions.

Název v anglickém jazyce

Architecture and analysis of a dynamically-scheduled real-time memory controller

Popis výsledku anglicky

Memory controller design is challenging as mixed time-criticality embedded systems feature an increasing diversity of real-time (RT) and non-real-time (NRT) applications with variable transaction sizes. To satisfy the requirements of the applications, tight bounds on the worst-case response time (WCRT) of memory transactions must be provided to RT applications, while the lowest possible average response time must be given to the remaining applications. Existing real-time memory controllers cannot efficiently achieve this goal as they either bound the WCRT by sacrificing the average response time, or cannot efficiently support variable transaction sizes. In this article, we propose to use dynamic command scheduling, which is capable of efficiently dealing with transactions with variable sizes. The three main contributions of this article are: (1) a memory controller architecture consisting of a front-end and a back-end, where the former uses a TDM arbiter with a new work-conserving policy and the latter has a dynamic command scheduling algorithm that is independent of the front-end, (2) a formalization of the timings of the memory transactions for the proposed algorithm and architecture, and (3) an analysis of WCRT for transactions to capture the behavior of both the front-end and the back-end. This WCRT analysis supports variable transaction sizes and different degrees of bank parallelism. The critical part of the WCRT is the worst-case execution time (WCET) of a transaction, which is the time spent on command scheduling in the back-end. The WCET is bounded by two techniques applied to both fixed and variable transaction sizes, respectively. We experimentally evaluate the proposed memory controller and compare to an existing semi-static approach. The results demonstrate that dynamic command scheduling significantly outperforms the semi-static approach in the average case, while it performs equally well or better in the worst-case with only a few exceptions.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

JC - Počítačový hardware a software

OECD FORD obor

—

Projekt

<a href="/cs/project/EE2.3.30.0034" target="_blank" >EE2.3.30.0034: Podpora zkvalitnění týmů výzkumu a vývoje a rozvoj intersektorální mobility na ČVUT v Praze</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2016

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Real-Time Systems

ISSN

0922-6443

e-ISSN

—

Svazek periodika

52

Číslo periodika v rámci svazku

5

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

55

Strana od-do

675-729

Kód UT WoS článku

000376604700005

EID výsledku v databázi Scopus

2-s2.0-84937907544