Describing the syntax and semantics of UML statecharts in a heterogeneous modelling environment

In this paper UML statechart diagrams are used as an example of a generic approach to integrating a visual language in a heterogeneous modelling and simulation environment.Asystem represented in a visual language is syntactically defined as an attributed graph, with well-formedness rules specified by a set of firstorder predicates over the abstract syntax of the graph. The language semantics are specified by an Abstract State Machine (ASM) parameterized with syntacticallycorrect attributed graphs. In this paper the key issues in the definition of UML statechart semantics are highlighted.Yan Jin, Robert Esser and Jörn W. Jannec

Trace-based manycore partitioning of stream-processing applications

Application performance on these processor array platforms is highly sensitive to how functionality is physically placed on the device, as this choice crucially determines communication latencies and congestion patterns of the on-chip inter-core communication. The problem of identifying the best, or just a good enough, partitioning and placement does not, in general, admit to an analytic solution, and its combinatorial nature makes solving it by pure experimentation impractical. This paper presents an approach that maps stream programs onto processor arrays using trace analysis as a technique for evaluating candidate solutions and for suggesting alternatives

Partitioning And Optimization Of High Level Stream Applications For Multi Clock Domain Architectures

In this paper we propose a design methodology to partition dataflow applications on a multi clock domain architecture. This work shows how starting from a high level dataflow representation of a dynamic program it is possible to reduce the overall power consumption without impacting the performances. Two different approaches are illustrated, both based on the post-processing and analysis of the causation trace of a dataflow program. Methodology and experimental results are demonstrated in an at-size scenario using an MPEG-4 Simple Profile decoder

Multi-clock domain optimization for reconfigurable architectures in high-level dataflow applications

This paper proposes a new design methodology to partition streaming applications onto a multi clock domain architecture. The objective is to save power by running different parts of the application at the lowest possible clock frequency that will not violate the throughput requirements. The solution involves partitioning the application into an appropriate number of clock domains, and then assigning each of those domains a clock frequency. Two different approaches are illustrated, both based on the post-processing and analysis of the causation trace of a dataflow program. Methodology and initial experimental results are demonstrated in an at-size scenario using an MPEG-4 Simple Profile decoder implemented in a FPGA platform

Actor-oriented control system design: A responsible framework perspective

Complex control systems are heterogeneous, in the sense of discrete computer-based controllers interacting with continuous physical plants, regular data sampling interleaving with irregular communication and user interacting, and multilayer and multimode control laws. This heterogeneity imposes great challenges for control system design in terms of end-to-end control performance modeling and simulation, traceable refinements from algorithms to software/hardware implementation, and component reuse. This paper presents an actor-oriented design methodology that tackles these issues by separating the data-centric computational components (a.k.a. actors) and the control-flow-centric scheduling and activation mechanisms (a.k.a. frameworks). Semantically different frameworks are composed hierarchically to manage. heterogeneous models and achieve actor and framework reuse. We introduce a notion of responsible frameworks to characterize the property that a framework can aggregate individual actor's execution into a well-defined composite execution such that heterogeneous models can be composed. This methodology is implemented in the Ptolemy II software environment. We discuss how some of the most useful models for control system design are implemented as responsible frameworks. As an example, the methodology and the Ptolemy II software environment is applied to the design of a distributed, real-time software implementation of a pendulum inversion,and stabilization system