Transformations for the synthesis and optimization of asynchronous distributed control

Asynchronous design has been the focus of renewed interest. However, a key bottleneck is the lack of high-quality CAD tools for the synthesis of large-scale systems which also allow design-space exploration. This paper proposes a new synthesis method to address this issue, based on transformations. The method starts with a scheduled and resource-bounded Control-Data Flow Graph (CDFG). Global transformations are first applied to the entire CDFG, unoptimized controllers are then extracted, and, finally, local transforms are applied to the individual controllers. The result is a highly-optimized set of interacting distributed controllers. The new transforms include aggressive timing- and area-oriented optimizations, several of which have not been previously supported by existing asynchronous CAD tools. As a case study the method is applied to the well-known differential equation solver synthesis benchmark. Results comparable to a highly-optimized manual design by Yun et al. (1997) can be obtained by applying the new automated transformations. Such an implementation cannot be obtained using existing asynchronous CAD tools.