A behavioral synthesis tool that allows a designer to design an integrated circuit using a generic programming language, such as ANSI C or C++, without the need to include timing information into the source code. In one aspect, the source code is read into the behavioral synthesis tool and the user may dynamically allocate interface resources to the design. In another aspect, the dynamic allocation is accomplished through user input, such as a GUI, a command line, or a file. In another aspect, the behavioral synthesis tool automatically analyzes variables in the source code description and assigns the variables to interface resources. In yet another aspect, the variables and interface resources associated with the variables may be displayed in a hierarchical format in a GUI. In still another aspect, the GUI may allow for expanding and collapsing of different layers in the hierarchy. The GUI may also allow for drag-and-drop operations for modifying the allocation of variables to interface resources.