Performance Analysis of Weakly-Consistent Scenario-Aware Dataflow Graphs

The timed dataflow model of computation is a useful performance analysis tool for Electronic System Level Design automation and embedded software synthesis. Its determinism gives it strong analysability properties. It is expressive enough to cover a large class of applications and platforms. The trend however, in both embedded applications and their platforms is to become more dynamic, reaching the limits of what the model can express and analyse with tight performance guarantees. Scenario-aware dataflow (SADF) allows more dynamism to be expressed, introducing a controlled amount of non-determinism into the model to represent different scenarios of behaviour. We investigate so-called weakly consistent graphs in which the scenario changes are not tightly coupled with periods of repetitive behaviour of the static dataflow behaviour in scenarios as in previous methods. We define the semantics of such graphs in terms of (max, +)-algebra and we introduce a method to analyse throughput using a generalisation of (max, +)-automata. An extended version of this paper can be found in [15].