Conversion and interfacing techniques for asynchronous circuits

Asynchronous logic design has gained more and more interest over the last few years. However, as many designers are well aware, there exist various different and mostly diverse asynchronous design methodologies. In order to obtain a highly optimized circuit implementation, it is often necessary to mix different techniques for exploiting their specific benefits. Consequently, the need for efficient conversion and interfacing techniques between these design methodologies arises. In this paper we take a closer look on how such conversion blocks can be built efficiently. We elaborate implementations for signal conversion between three distinct asynchronous design alternatives, discuss their benefits and drawbacks, and provide simulation results. We not only consider cases where both sender and receiver use handshaking protocols for flow control, but also the situation where this kind of lockstep operation is not possible.