High-level linear projection circuit design optimization framework for FPGAs under over-clocking

Frequently, the high-level algorithm parameter selection and its mapping into hardware are considered to be independent processes, often leading to suboptimal solutions. When DSP applications with real-time constraints are targeted, it is often desirable the resulting hardware system to be clocked at as high frequency as possible. Even though the trend in modern devices is to provide a fabric that can support higher frequencies, its variability makes the design tools to be pessimistic about maximum clock frequency estimates. The proposed framework optimizes and mitigates the probabilistic behaviour of digital circuits, by trying to expose the impact of variability of the fabric into high-level algorithmic specifications. FPGAs are well positioned to tackle this problem because they can be reconfigured, allowing an off-line characterization of the specific device before implementing the complete optimized circuit on the same device. Circuits generated by the proposed framework outperform typical implementations, by minimizing area, errors, and maximizing its operating clock frequency. An example of a linear projection circuit, over-clocked by 232%, shows savings up to 39% in hardware resources for the same target PSNR over traditional implementation.