We consider the problem of mapping communications applications to heterogeneous hardware platforms dynamically based on available hardware. Our approach uses an ontology to specify different communications designs and their implementation in software and hardware. Making use of the ontology and rules, we automatically generate implementations of different communications applications for FPGA hardware, CPU software, or a hybrid design that mixes the two. Designs are specified in terms of “tasks” (or processing elements) and “conduits” (or connectors) for data transfer between tasks. Implementations use a library based approach where tasks are pre-designed for different platforms. Some tasks, such as controllers, are generated at run time and compiled for the appropriate target hardware. This style of specification-based deployment supports the easy migration between target hardware platforms. We present a method that uses ontological definitions for automatic code generation that allows for dynamic deployment of the application to different target hardware. We demonstrate this approach on an application consisting of two tasks: (1) spectrum sensing and (2) transmission. An automatically generated state machine implements the control flow; i.e., it decides what frequency to transmit on depending on the available spectrum. Our results show that this approach generates high quality designs with lower effort from the designer.