Many of today's digital circuit designs depend on the tight integration of multiple design modules. These modules, designed by different engineers, interact via an interface, such as a bus or IP core interface. The interface is of utmost importance because it is where the various designers? conceptions come together. If designers do not uniformly interpret the interface specification, modules will not meld together easily or will behave incorrectly when connected. Therefore, the interface protocols must be clearly defined so that the designers can view the expected module behavior consistently. Furthermore, the protocol must be thoroughly debugged a d solid, because so much of the module design depends on it.