Méthodologie de génération de plateforme de prototypage à base de multi-fpga

Multi-FPGA based prototyping is no longer optional for hardware/software integration. We can classify multi-FPGA prototyping platforms in three categories: off-the-shelf, custom and cabling. The cabling platform is semi off-the-shelf and semi custom. Nevertheless, crafting a custom and a cabling platform is today a manual process, which is time-consuming. The performance and the cost of the platform lie on the FPGA expertise and SoC DUT knowledge of the engineers. Compared to OTS platforms, the added value, in terms of performance, of cabling or custom platforms can be heavily impaired by an inefficient board design. Moreover, FPGA I/Os are becoming a scarce resource, worsening the inter-FPGA bandwidth generation after generation. Therefore, it becomes more and more difficult to prototype an SoC/ASIC design at proper performance. The contributions of the manuscript are: (1). An automatic implementation flow for an OTS platform is proposed. (2). An automatic design flow for creating a custom platform is proposed, thus increasing the productivity, enabling the board exploration, and optimizing cost and performance. (3). The cabling platform is proposed where one board is composed of one FPGA and several connectors, with an algorithm to automatically find a solution for the cable distribution. (4). Thanks to the developed automatic tools, the three different multi-FPGA platforms are compared. The custom platform always achieves better performance and lower deployment cost, but still with 3-5 months in time of availability. If the performance or the deployment cost are not rigorous constraints, the cabling platform offers an attractive alternative compared to others.Face à la difficulté de l’intégration matériel/logiciel, le prototypage à base de multi-FPGA devient obligatoire dans la vérification pré-silicium. Les plateformes de prototypage peuvent être classées en trois catégories: OTS, sur mesure et câblées. La plateforme câblée est semi OTS et semi sur mesure. Néanmoins, la création d’une plateforme sur mesure et câblée est un processus manuel et chronophage. La performance et le coût de la plateforme dépend de l'expérience de concepteurs en expertise de FPGA et connaissance du système sur puce. Par rapport à des plateformes OTS, la valeur ajoutée, en terme de performance, des plateformes câblées ou sur mesure peuvent être fortement dégradée par une carte inefficace. En plus, FPGA E/S devient une ressource rare, aggravant la bande passante inter-FPGA. Par conséquent, il devient de plus en plus difficile de prototyper un design à une performance satisfaisante. Les contributions sont: (1). Un flot de implémentation automatique pour une plateforme OTS. (2). Un flot de conception automatique pour créer une plateforme sur mesure, ainsi augmentant la productivité, permettant l’exploration de carte et optimisant le coût et la performance. (3). La plateforme câblée avec un algorithme permettant automatiquement de trouver une solution pour la distribution des câbles. (4). Grâce aux flots automatique, les trois plateformes sont comparées. La plateforme sur mesure toujours réalise plus de performance et moins de coût de déploiement, mais encore avec 3-5 mois en temps de disponibilité. Si la performance ou le coût de déploiement ne sont pas les contraintes strictes, la plateforme câblée est une alternative intéressante par rapport aux autres

Developments and experimental evaluation of partitioning algorithms for adaptive computing systems

Multi-FPGA systems offer the potential to deliver higher performance solutions than traditional computers for some low-level computing tasks. This requires a flexible hardware substrate and an automated mapping system. CHAMPION is an automated mapping system for implementing image processing applications in multi-FPGA systems under development at the University of Tennessee. CHAMPION will map applications in the Khoros Cantata graphical programming environment to hardware. The work described in this dissertation involves the automation of the CHAMPION backend design flow, which includes the partitioning problem, netlist to structural VHDL conversion, synthesis and placement and routing, and host code generation. The primary goal is to investigate the development and evaluation of three different k-way partitioning approaches. In the first and the second approaches, we discuss the development and implementation of two existing algorithms. The first approach is a hierarchical partitioning method based on topological ordering (HP). The second approach is a recursive algorithm based on the Fiduccia and Mattheyses bipartitioning heuristic (RP). We extend these algorithms to handle the multiple constraints imposed by adaptive computing systems. We also introduce a new recursive partitioning method based on topological ordering and levelization (RPL). In addition to handling the partitioning constraints, the new approach efficiently addresses the problem of minimizing the number of FPGAs used and the amount of computation, thereby overcoming some of the weaknesses of the HP and RP algorithms