Embedded And Reconfigurable Computing System Design Techniques

As a novel computing paradigm, reconfigurable computing has become a hotspotof current computer architecture research. However, in respect of the design-timesupport, it is needed to start the embedded reconfigurable system design fromsystem-level to cope with the increasing design complexity. While in respect of therun-time support, as traditional operating system can not meet the requirements ofnewly emerging reconfigurable computing systems, one of the key problems to besolved is how to make the operating system manage the reconfigurable computingresources, and provide a unified software/hardware programming model forapplication developers.This paper focuses on the problems mentioned above and explores the designtechnology of embedded reconfigurable computing system. It mainly consists of thefollowing four parts of contribution:Firstly, with considering the features of reconfigurable computing, this papercombines the capability of UML with SystemC and presents a model driven designmethodology at system-level. It makes use of UML to describe the embeddedreconfigurable system from the system structure and reconfiguration behavior aspect.Within the scope of Model Driven Architecture, A UML Profile for SystemC is givento implement the transformation from UML model to SystemC executable codeskeleton. The design methodology could derive implementation from specificationdirectly while contribute to rapid system prototyping and initial function verification.Secondly, based on the essential differences between software-tasks andhardware-tasks, this paper presents an operating system framework for reconfigurablecomputing using unified multi-task model. The operating system could managehardware tasks and reconfigurable computing resources through hierarchicalabstraction. A hardware stub task is combined to each hardware task to deal withinter-task communications. This simplifies hardware task design, and makes theoperating system compatible with current software programming models andinter-task communication mechanisms. This operating system framework couldmanage the hardware tasks and reconfigurable computing resources effectively, andprovide a run time support for reconfigurable computing platforms.Thirdly, for data stream driven applications, this paper proposes a Pthreadcompatible Unified Software/Hardware multi-thread programming Model supporting Dynamic Reconfiguration(SHUMDR). Through hardware thread interface design andoperating system kernel extension, we implement an operating system prototype andprovide a light weight unified thread programming library. The experimental resultsindicate that both the overhead time and resource utilization of SHUMDR are at lowlevel, the time for hardware thread creation is largely decreased through configurationbitstream buffer and configuration cache, the inter-thread communication mechanismis simple and effective. SHUMDR could exploit programmable flexibility whileeffectively maintain hardware tasks' performance, and give support for thedevelopment of reconfigurable applications.Finally, for Divisible Load Application(DLA) design on reconfigurablecomputing platforms, this paper gives a performance analysis and forecast throughSHUMDR. Using different way of load allocation according to the characteristics ofthe platform and the DLA, The problem of divisible load scheduling is mainlydiscussed for a reconfigurable computing platform including multiple ReconfigurableProcessing Units(RPUs). It is proved that there exist maximum RPU number andoptimal RPU number when configuration does not completely overlap withcommunication. An optimal solution for the load scheduling and the processing timeis derived for DLA design and implementation.