Real time operating system modeling in a system level design environment

Modeling complex embedded systems requires design tools that are able to represent a variety of heterogenous components at several level of abstraction. These components often include hardware and software blocks, which play very different roles with respect to cost, performance and flexibility of the design. Early evaluation of possible design choices and trade-offs is therefore of paramount importance for an efficient implementation. One kind of component that is often neglected in the first stages of the design cycle is the operating system. However, since it sits between the software and the hardware domains, its effects on the final implementation are relevant. This paper presents a technique to model a general POSIX compliant real time operating system within the Metropolis framework. Possible models are presented and discussed with respect to their efficiency, taking into consideration the scheduling policy, the multitasking environment, interrupts and communication primitives