How Parameterizable Run-time FPGA Reconfiguration can Benefit Adaptive Embedded Systems

Adaptive embedded systems are currently investigated as an answer to more stringent requirements on low power, in combination with significant performance. It is clear that runtime adaptation can offer benefits to embedded systems over static implementations as the architecture itself can be tuned to the problem at hand. Such architecture specialisation should be done fast enough so that the overhead of adapting the system does not overshadow the benefits obtained by the adaptivity. In this paper, we propose a methodology for FPGA design that allows such a fast reconfiguration for dynamic datafolding applications. Dynamic Data Folding (DDF) is a technique to dynamically specialize an FPGA configuration according to the values of a set of parameters. The general idea of DDF is that each time the parameter values change, the device is reconfigured with a configuration that is specialized for the new parameter values. Since specialized configurations are smaller and faster than their generic counterpart, the hope is that their corresponding system implementation will be more cost efficient. In this paper, we show that DDF can be implemented on current commercial FPGAs by using the parameterizable run-time reconfiguration methodology. This methodology comprises a tool flow that automatically transforms DDF applications to a runtime adaptive implementation. Experimental results with this tool flow show that we can reap the benefits (smaller area and faster clocks) without too much reconfiguration overhead.