Interface-Based Design of Real-Time Systems

Today most embedded systems consist of a collection of computation and communication components that are supplied by different vendors and assembled by a system manufacturer. Such a component-based design methodology is followed in several domains such as automotive, avionics, and consumer electronics. The system manufacturer responsible for component assembly has to take design decisions (related to the choice of components and how they are to be connected, e.g. using a bus or a network-on-chip) and perform system analysis. Such important analysis is usually related to verifying that buffers in components never overflow or underflow, end-to-end delays or worst-case traversal times (WCTTs) of data through a component network fall within given deadlines, and others. Typically performance analysis methods are used for the analysis of a component-based real-time system design a posteriori. This means that a realtime system is designed and dimensioned in a first step, and only after completion of this first step, the performance analysis is applied to the system design in a second step. The analysis result will then give an answer to the binary question whether the system design that was developed in the first step meets all real-time requirements, or not. A designer must then go back to the first step, change the design, and iterate on the two steps until an appropriate system design is found.