Hybrid computing systems consisting of multiple platform types (e.g., general purpose processors, FPGAs etc.) are increasingly being used to achieve higher performance and lower costs than can be obtained with homogeneous systems (e.g., processor clusters). Different platforms have different languages and simulators associated with them. Auto-Pipe has been developed as a toolset to reduce the complexity inherent in deploying an application to a diverse resource set. In Auto-Pipe, applications are expressed using the data flow coordination language X, which describes the application in terms of interactions between functional blocks.

As part of the Auto-Pipe system, X-Sim has been developed as a federated distributed simulator that can be used to conveniently and efficiently simulate applications. After a short introduction to Auto-Pipe and the X Language, this paper considers issues involved with total system simulation of an application mapped to a hybrid resource set. The paper then demonstrates the use of X-Sim with a realtime signal processing application employed in the VERITAS gamma-ray astronomy project.