Converting graphical DSP programs into memory constrained software prototypes

Since software prototypes of DSP applications are most efficient when their code and data space requirements can be accommodated entirely within the on-chip memory of the target processor it is crucial to employ efficient memory-minimizing compilation techniques in a DSP software prototyping system. In this paper, we introduce two techniques for the combined minimization of code and data when compiling graphical programs that are based on the synchronous dataflow (SDF) model. The first method is a customization to acyclic graphs of a bottom-up technique, called Pairwise Grouping of Adjacent Nodes (PGAN), that was proposed earlier for general SDF graphs. We show that our customization significantly reduces the complexity of the general PGAN algorithm and performs optimally for a certain class of applications. The second approach is a top-down technique, called Recursive Partitioning by Minimum Cuts (RPMC), that is based on a generalized minimum cut operation. From an extensive experimental study, we conclude that RPMC and our customization of PGAN are complementary, and both should be incorporated into SDF-based prototyping environments in which the minimization of memory requirements is important.