Embedded control system design involves continuous time, discrete event mode switching, and discontinuities in system behavior and requires support for: (i) continuous behavior, (ii) discrete event behavior, and (iii) re-initialization when discrete events occur. The graphical block diagram formalism that supports continuous behavior modeling is extended by logic components that seamlessly integrate. Re-initialization is supported by state reset ports and state output ports of the integrator component. In addition, the dynamic semantics of a formalism is specified by a computational model. For Matlab-Simulink this consists of a number of interface methods that are called at pre-defined points in the model execution. Automatic generation of efficient embedded code allows the use of high-level modeling formalisms for design and analysis.