CORDS: hardware-software co-synthesis of reconfigurable real-time distributed embedded systems

Field programmable gate arrays (FPGAs) are commonly used in embedded systems. Although it is possible to reconfigure some FPGAs while an embedded system is operational, this feature is seldom exploited. Recent improvements in the flexibility and reconfiguration speed of FPGAs have made it practical to reconfigure them dynamically, reducing the amount of hardware required in an embedded system. We have developed a system, called CORDS, which synthesizes multi-rate, real-time, periodic distributed embedded systems containing dynamically reconfigurable FPGAs. Executing different tasks on the same FPGA requires that potentially time-consuming reconfiguration be carried out between tasks. CORDS uses a novel preemptive, dynamic priority, multi-rate scheduling algorithm to deal with this problem. To the best of our knowledge, dynamically reconfigured FPGAs have not previously been used in hardware-software co-synthesis of embedded systems. Experimental results indicate that using dynamically reconfigured FPGAs in distributed real-time embedded systems has the potential to reduce their price and allow the synthesis of architectures which meet system specifications that would otherwise be infeasible.