Fast and time-accurate cosimulation with OS scheduler modeling

Hardware/Software cosimulation is the key process to shorten the design turn around time. We have proposed a novel technique, called virtual synchronization, for fast and time accurate cosimulation that involves component simulators running concurrently and interacting with each other. In this paper, we further extend the virtual synchronization technique with OS modeling for the case where multiple software tasks are executed under the supervision of a real-time operating system. The OS modeler models the RTOS overheads of context switching and tick interrupt handling as well as preemption behavior. While maintaining the timing accuracy to an acceptable level below a few percents, we could reduce the simulation time drastically compared with existent conservative approaches by removing the need of time synchronization between simulators. It is confirmed with a preliminary experiment on a multimedia example that consists of four real-life tasks.