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Ecole polytechnique de Bruxelles
Ben Rodriguez
tel 02 650 67 93,
Campus du Solbosch
CP165/56, avenue F.D. Roosevelt 50, 1050 Bruxelles

unités de recherche

Parallel Architectures for real-Time Systems [Parallel Architectures for Real-Time Systems] (PARTS)
Qualité et sécurité des systèmes informatiques [Quality and security of information systems] (QualSec)


Ordonnancement temps réel et contraint par l'énergie [Power-Aware real-time scheduling]
Ordonnancement temps réel et contraint par l'énergie [Energy consumption and battery lifetime are nowadays major constraints in the design of mobile embedded systems. Amongst all hardware and software techniques aimed at reducing energy consumption, supply voltage reduction, and hence reduction of CPU speed, is particularly effective. This is because CPU requires a large amount of energy (e.g., 30W at maximal frequency for an Intel P4 Mobile 1.8GHz[1]) and the energy consumption of the processor is usually at least quadratic in the speed of the processor (see [1] for more details). The aim is thus to minimize the processor frequency as much as possible while satisfying the performance constraints of the system. Many power-constrained embedded systems are built upon multiprocessor platforms because of high-computational requirements and because multiprocessing often significantly simplifies the design. As pointed out in [2] and [3], another advantage is that multiprocessor systems are theoritically more energy efficient than equally powerful uniprocessor platforms because raising the frequency of a single processor results in a multiplicative increase of the consumption while adding processors leads to an additive increase. We address the problem of determining one or several processor speeds which involve significant power savings while system is running. The determined speeds must satisfy all the temporal constraints of the system. In the second part of our research, we investigate the various models of battery and include their behavior into the scheduling algorithms in order to take into account a more realist supply voltage delivery.]

Services matériels pour des systèmes multi processeur temps réel [Hardware services for MPSoC with real-time operating systems]
Services matériels pour des systèmes multi processeur temps réel [In recent years we have witnessed a paradigm shift in computer systems. Increasing the frequency has given way to multi-core architectures exploiting the parallelism. In the field of embedded systems, such a vision is seen in the form of Multi-Processor System-on-Chip - MPSoC. The advantages of such a platform in comparison with a uni-processor one are multiples in several domains like power consumption, scalability and reusability. In the same time, a lot of existing systems need Real Time Operating Systems not only to guarantee a given treatment capacity but also to guarantee a deadline for multiple tasks. To break with the sub-optimality of the actual philosophy consisting to see the design of software and hardware as two worlds apart, the aim of this thesis is, through a co-design methodology, to design a configurable MPSoC environment with services tailored directly for high level real-time scheduling algorithms.]

disciplines et mots clés déclarés

Sciences de l'ingénieur

co-design multi-processor system-on-chip ordonnancement temps réel