Dataflow Graph Partitioning for Area-Efficient High-Level Synthesis with Systems Perspective

Abstract

Area efficiency in datapath synthesis is a widely accepted goal of high-level synthesis. Applications represented by their dataflow graphs are synthesized using resource sharing principles to reduce the area. However, existing resource sharing algorithms focus on absolute area reduction and maximal resource sharing. This kind of a design approach leads to constraints on how often, in terms of number of clock cycles, a new set of input data can be fed to an application. It also leads to very large multiplexers in case of very big dataflow graphs with hundreds of nodes. An adaptive dataflow graph partitioning algorithm is proposed that partitions a graph taking into account a user-defined constraint on how often a new set of input data (generally referred to as data initiation interval) is available. At the same time, a resource sharing algorithm is applied to such partitions in order to reduce area. Multiple design points are generated for a given dataflow graph with different area and time measures to enable a designer to make decisions. We demonstrate our graph partitioning algorithm using synthetically generated large dataflow graphs and on some benchmark applications.