SLOPES: Hardware-software cosynthesis of low-power real-time distributed embedded systems with dynamically reconfigurable FPGAs

In this paper, we present a multiobjective hardware-software cosynthesis system, called SLOPES, for multirate low-power real-time distributed embedded systems consisting of dynamically reconfigurable field-programmable gate arrays (FPGAs), processors, and heterogeneous communication resources. This cosynthesis algorithm simultaneously optimizes system price and average power consumption. First, we present an evolutionary algorithm that automatically determines the quantities and types of system resources, assigns tasks to different potentially reconfigurable processing elements, and assigns communication events to communication resources. Second, we propose a dynamic priority multirate scheduling algorithm to determine the times at which all the tasks and communication events in the system occur. This two-dimensional scheduling algorithm determines task priorities based on real-time constraints and detailed frame-by-frame FPGA reconfiguration overhead information. Experimental results indicate that the proposed method reduces schedule length by an average of 34.3% and reconfiguration energy by an average of 40.4%, compared to a method that does not consider the effect of partial reconfiguration during synthesis. SLOPES yields multiple system architectures that tradeoff system price and average power consumption under real-time constraints.