Probabilistic State-Based RT-Analysis of SDFGs on MPSoCs with Shared Memory Communication

Ralf Stemmer1,a, Henning Schlender1,b, Maher Fakih2,d, Kim Grüttner2,e and Wolfgang Nebel1,c
1University of Oldenburg
aralf.stemmer@uol.de
bhenning.schlender@uol.de
cwolfgang.nebel@uol.de
2OFFIS e.V.
dmaher.fakih@offis.de
ekim.gruettner@offis.de

ABSTRACT


This paper extends a state-based timing analysis for Synchronous Dataflow Applications on an MPSoC with shared memory. The existing approach transforms a mapped and timing annotated SDF graph into a timed automata representation for the analysis of timing properties. One major drawback of the existing timing annotation approach is the usage of best- and worst-case execution time intervals, resulting in an overestimation of the actual timing behavior. This paper proposes to replace the timing bound annotation with a probability density function. For the overall timing analysis we use a stochastic timed automata model.

We demonstrate and evaluate our approach on a Sobel filter, which is used in many image and video processing algorithms. As a reference, we compare our stochastic execution time model against a fixed best-/worst-case execution time model and against the measured execution time on an FPGA prototype.

The results are promising and clearly indicate that our probabilistic approach provides tighter timing analysis results in comparison to the best-/worst-case execution analysis model.



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