Simple pulse asynchronous state machines

Pulse computation is a hybrid of conventional analog and digital techniques which encodes and processes information in the time domain. In this paper we present a new technique for pulse computation with simple pulse-driven, asynchronous finite state machines. Asynchronous FSMs are robust and timescale-independent, and can be used as building blocks for constructing complex pulse processors. The notion of state within such processors is considerably simpler than in previous (neuromorphic) pulse computation elements. We describe two simple state machines, pulse matchers and pulse differencers, which we have implemented in CMOS 2 μm VLSI. Finally, we discuss some simple image-processing applications to which these devices may be applied