Integrating VSIPL Support in the Dataflow Interchange Format

We have developed the dataflow interchange format (DIF) [2] and the associated DIF package for specifying and working with dataflow models for DSP systems. Our recent progress in the DIF project includes the DIF-based porting approach [2] for porting DSP designs across dataflowbased tools and the DIF-to-C software synthesis framework [3] for automatically generating C implementations from DSP system designs that are programmed in DIF. In this extended abstract, we present a new approach of using VSIPL [4] as an intermediate actor library for porting across different DSP design tools. Applying VSIPL in this manner builds on the increasing popularity of VSIPL as a standard DSP library, and eliminates the need to have actor mapping specifications between every pair of tools that we wish to port across. We also present an important new capability in DIF: DIF-to-VSIPL software synthesis. This capability augments the support of the DIF software synthesis framework and extends the reach of DIF-based interchange to the wide variety of platforms that support VSIPL. The DIF Language and the DIF Package The dataflow interchange format is a language for specifying and working with mixed-grain dataflow models for DSP systems. It provides a unique set of semantic features for specifying graph topologies, hierarchies, and dataflow-related as well as actor-specific information. The DIF package is the associated Java-based software package. It provides object-oriented dataflow representations, algorithm implementations, and infrastructure for porting and software synthesis. Figure 1 illustrates the methodology of using DIF to interface various dataflow models, DSP system designs, DSP libraries, dataflow-based DSP design tools, and their supported embedded processing platforms. The shaded areas in this figure show the new developments that involve the integration of VSIPL support into DIF. VSIPL Integration in the DIF-based Porting The idea behind the DIF-based porting approach is that except for actor information, a DIF specification for a DSP application represents the same semantic information regardless of which, if any, design tool is used to generate it, and furthermore, porting DSP applications can be achieved by properly mapping the tool-dependent actors, while transferring the dataflow semantics unaltered. The left shaded area in Figure 1 presents the porting mechanism that consists of exporting (exporting a design from a tool to DIF), actor mapping (converting attributes of the original actors to attributes associated with corresponding target actors), and importing (importing from DIF to another tool). We have developed the actor interchange format (AIF) [2] for specifying how to map actors across pairs of tools, and we have demonstrated the automation and efficiency provided by our DIF-based porting infrastructure. One limitation of our original porting approach arises however when working with a large number of tools: when many tools are involved in the porting space, we need to specify the mapping information for each pair of tools. This requires effort and additional code that grows quadratically with the number of tools that are involved. The DIF Package Dataflow Models