This paper describes an object-oriented model and a re-use-oriented methodology for the codesign of embedded computing systems. Our approach has been founded on a hierarchy of classes which describes all possible specifications of systems of a certain domain, the behavior of hard- and software-components, and the target-architectures.The content of this knowledge base (re-usable, formalized descriptions) is determined by the analysis of known systems. We present solutions for a specification methodology, the modeling of heterogeneous systems by task graphs, and the mapping process from specified requirements down to hard- or software components in a target architecture. The approach is illustrated by functions of the domain of robot controls.