Formal Design of Multi-Function Vehicle Bus Controller

Data of the train communication network(TCN) is becoming more complicated, which results in higher requirements of the data processing unit-the multifunction vehicle bus controller (MVBC) connected within the TCN. Developing an MVBC is challenging because of the integrated hardware-software solutions to support reactions in real time and dynamic environment. Hence, there is an urgent need for a rigorous design framework to facilitate the development of MVBC. In this paper, we propose a design framework TooMVBC to generate executable MVBC code from formal verified computation model. TooMVBC uses formal computation model MVBChart to capture the specification of the MVBC at high level. First, primitive syntax of MVBChart is designed to model MVBC features (e.g. hierarchy structure, data flow of the encoder, the control logic of communication protocol), and semantics of MVBChart is formalized for simulation and verification. Then, semantics-preserving code generation algorithms are designed to generate VHDL code for partitioned hardware implementations and C code for partitioned software implementations from verified MVBChart model. The generated code can be loaded into the proposed flexible MVBC hardware architecture directly. Finally, supporting graphical model editor, simulator, verification translator, partitioning and code generator are implemented and seamlessly integrated into TooMVBC. When we apply TooMVBC to design MVBC with the highest class 5 according to the description of the standard IEC 61375, several critical ambiguousness or bugs in the standard are detected during formal verification of the constructed system model.