A Solution to Overcome some Limitations of SDF Based Models

For computer-aided hardware design, models are usually used to evaluate the designed systems. But there is still a gap between models and their efficient implementations on a real architecture, like FPGAs. For example, some model characteristics may lead to a waste of resources, which can even make a design infeasible. In this paper, we focus on how to overcome some limitations of Static Data Flow based models, especially the version with Access Patterns (SDF-AP). We call the solution the ``stretchable patterns''. It shares some basic principles with SDF-AP model but with other semantics and goals. For example, our model allows to change the characteristics of a source stream that feeds a graph of actors without using extra buffers or even causing an incorrect processing. It greatly simplifies a real implementation when the source is in fact a peripheral that operates at different frequencies. It also spares a lot of logical resources when the target architecture is a FPGA. After the presentation about SDF-AP limitations, this paper summarizes some fundamental notions of our model, and a realistic example is given to point out its advantages over SDF-AP.