Daniel Gracia Pérez

Learn More
While most research papers on computer architectures include some performance measurements, these performance numbers tend to be distrusted. Up to the point that, after so many research articles on data cache architectures, for instance, few researchers have a clear view of what are the best data cache mechanisms. To illustrate the usefulness of a fair(More)
Simulator development is already a huge burden for many academic and industry research groups; future complex or heterogeneous multi-cores, as well as the multiplicity of performance metrics and required functionality, will make matters worse. We present a new simulation environment, called UNISIM, which is designed to rationalize simulator development by(More)
SystemC is rapidly gaining wide acceptance as a simulation framework for SoC and embedded processors. While its main assets are modularity and the very fact it is becoming a de facto standard, the evolution of the SystemC framework (from version 0.9 to version 2.0.1) suggests the environment is particularly geared toward increasing the framework(More)
In the safety critical domain such as in avionics, existing embedded solutions based on single-core COTS processors are very unlikely to handle the new level of performance requirement of next generation safety-critical applications.
Modern computer microprocessors are composed of hundreds of millions of transistors that interact through intricate protocols. Their performance during program execution may be highly variable and present aperiodic oscillations. In this paper, we apply current nonlinear time series analysis techniques to the performances of modern microprocessors during the(More)
Statistical simulation systems can provide an accurate and efficient way to carry out early design studies for processors. One such system, HLS, has a rapid simulation capability, but our experiments demonstrate that several modeling improvements are possible. The front-end graph structure in HLS is hampered by workload modeling at the instruction level(More)
When integrating mixed critical systems on a multi/many-core, one challenge is to ensure predictability for high criticality tasks and an increased utilization for low criticality tasks. In this paper, we address this problem when several high criticality tasks with different deadlines, periods and offsets are concurrently executed on the system. We propose(More)
Future generations of avionic equipments are expected to embed multi-core processors. Using Components Off-The-Shelf (COTS) processors is considered both by the industrial and academic communities, as well as certification authorities. However, in the safety-critical domain, a common issue with COTS multi-core processors is their lack of predictability,(More)
Commercial-of-the-shelf based multi-core systems present timing anomalies that cannot be ignored by the real-time systems community due to their unpredictable behaviour. These timing anomalies, often caused by applications' uncontrolled accesses to shared resources such as the components in the memory hierarchy or in the I/O subsystem, introduce(More)