KIR-a graph-based model for description of mixed analog/digital systems

Systems can be described in different time models and on various levels of abstraction. We can distinguish between models in discrete-event, discrete and continuous time. Graph-based formal models allow us to use either discrete event/discrete time models or continuous time models. The combined use of all three time models in one system is the main problem when modeling mixed analog/digital systems. In this paper a graph-based model is presented that supports the use of all three time models in different parts of a graph. This allows digital, discrete-time systems to be modeled together with their analog, physical environment