NonDeterministic Behavior Analysis for Embedded Software Based on Probabilistic Model Checking The realtime interaction between embedded software and its external environment is conducted through the interrupt mechanism. Since the interrupt request is random and responds according to priority, the execution of embedded software is nonsequential, which leads to the nondeterministic software behaviors. If these nondeterministic behaviors can be quantitatively preanalyzed during the software design phase, the reliability of embedded software can be improved effectively. In this paper, we first provide an embedded software behavior model based on extended deterministic and stochastic Petri nets (EDSPN). Through EDSPN, the interrupt behavior of embedded software can be effectively modeled. Then we put forward a probabilistic model checking method of Continuous Stochastic Logic (CSL) for EDSPN to analyze embedded software behavior. For alleviating the state explosion problem, the above method uses the bounded model checking (BMC) technique. We present the model checking methods and the probability metric calculation methods for CSL operators under bounded semantics. Finally, by analyzing the EDSPN model of embedded software with multiple interrupts, we compare the analytical capabilities of BMC method and nonBMC method. The experiment shows that when the state space of EDSPN is large and is hard to calculate, the bounded checking algorithm can be used to approximate the software behavior. The conclusions obtained are helpful to understand the properties to be verified.

Implementation of state transition models in IEC 61499 and its use for recognition and selection of sequences of events and objects Efficient application of modelbased software design methodologies in industrial automation requires methods and tools for automatic code generation. Formal models can be especially useful to avoid ambiguity, to verify and evaluate performance, which ultimately will improve the quality and reliability of the project and lead to lower design costs. This paper proposes methods for implementing statetransition formal models, such as finite state and pushdown automata, as well as extended Petri nets (Anets) by means of IEC 61499 function blocks. These implementation approaches can be used in the design of industrial cyberphysical systems for monitoring, diagnostics, conformance checking, detection and selection of specified sequences of events and parameterized objects from an input stream. One of the proposed applications is illustrated using an example of an assembly process with LEGO blocks.