Modeling Pipelined Application with Synchronous Data Flow Graphs

Streaming applications can efficiently exploit multiprocessors architectures by means of pipelined parallelism, but designing this type of applications can be an hard task. Different subproblems have indeed to be solved: partitioning, mapping, scheduling and pipeline stage assignment. For this reason, high level abstraction models are adopted during design flow since they simplify this process by hiding most of the architectural details. Synchronous Data Flow (SDF) graphs, widely adopted to describe streaming applications, naturally model only their partitioning, so they usually have to be integrated with other types of representations. In this paper Pipelined Application Modeling (PAM), a methodology to create a Synchronous Data Flow graph describing all the aspects of a pipelined application, is presented. The methodology starts from the SDF graph describing the partitioning of the application and enriches it with new actors and channels detailing the mapping, the scheduling and the pipeline stage assignment of the considered solution. The obtained SDF graph, describing all the aspects of the solution in a formal and compact way, facilitates the evaluation of different solutions during design space exploration.