Controlling event spacing in self-timed rings

Prior research in event spacing has identified two effects which contribute to the phenomenon of bursting events in self-timed systems, namely the Charlie and the Drafting effects. In this paper we attempt to further the understanding of these effects by presenting an analysis of their magnitude for a range of asynchronous handshaking controller implementations. The main contribution of this work is to demonstrate that event spacing irregularities are not an inherent property of self-timed circuits, but can be controlled by careful circuit design. We demonstrate that bursting effects are indeed dependent on the specific implementation of the handshaking circuits used in an asynchronous system, by showing that the magnitude of the Charlie and Drafting effects is implementation-dependent. We also explain how both of these effects can be mitigated by altering the electrical characteristics of the circuit implementation.