What is Clock Gating?
Clock gating is one of the power-saving methods used on several synchronous circuits with the Pentium four processors. To save power, clock gating consider to adding additional logic to a circuit to prune the clock tree, therefore disabling portions of the circuitry here flip flops do not change state.
Though asynchronous circuits by description do not have a "clock", the word "perfect clock gating" is utilised to describe how different clock gating techniques are simply approximations of the data dependent behavior demonstrated by asynchronous circuitry, and which as the granularity onto that you gate the clock of a synchronous circuit approaches zero, hence the power consumption of that circuit approaches which of an asynchronous circuit.