Asynchronous Circuits
? Asynchronous Circuits:
???Operation is not synchronized by a clock.
???When an input change occurs, the state of the network can change almost immediately.
???If several storage elements must change state, there is no guarantee they will do so at the same time.
? To simplify this challenging problem we consider only fundamental mode asynchronous circuits:
???The input signals will only change when the circuit is in a stable condition (i.e. no internal signals are changing).
??All of the input signals are considered to be levels, rather than pulses or edges.
??Inputs may not change simultaneously
???Asynchronous circuits may be structured as Mealy and Moore forms, as before, but delays in the feedback path are not clocked and may be different!