Asynchronous circuit completion detection by current sensing

Since asynchronous circuits lack a clock to synchronize data exchange between elements of a system, they rely on an inter element completion signal to inform a succeeding element that a preceding one has completed its computation. There are several ways to generate a completion signal. This paper will examine the generating of a completion signal from the current consumption of the CMOS circuits. CMOS circuits have the useful property of consuming power only when the gates are switching, and thus easily lend themselves to current sensors. Although current sensing looks like a good mechanism for determining completion, it is slow and consumes significant silicon real estate.