Run-Time Reconfiguration for Automatic Hardware/Software Partitioning

Parameterisable configurations allow very fast run-time reconfiguration in FPGAs. The main advantage of this new concept is the automated tool flow that converts a hardware design into a more resource-efficient run-time reconfigurable design without a large design effort. In this paper, we show that the automated tool flow for run-time reconfiguration can be used to easily optimize a full hardware implementation for area by converting it automatically to a hardware/software implementation. This tool flow can partition the design in a very short time and, at the same time, result in significant area gains. The usage of run time reconfiguration allows us to extend the hardware/software boundary so more functionality can be moved to software. We will explain the core principles behind the run-time reconfiguration technique using the AES encoder as an example. For the AES encoder the manual hardware/software partitioning is clear. This manual partitioning will serve as a comparison to the automated partitioning that uses parameterisable configurations. Several possible AES encoder implementations are compared. Our automatically partitioned AES design shows a 20.6% area gain compared to an unoptimized hardware implementation and a 5.3% gain compared to a manually optimized 3rd party hardware implementation. In addition, we discuss the results of our technique on other applications, where the hardware/software partitioning is less clear. Among these, a TripleDES implementation shows a 29.3% area gain using our technique. Based on our AES encoder results, we derive some guidelines for optimizing the impact of parameterisable configurations in general designs.