Clock period minimization with wave pipelining

Abstract

A method using a linear program for adjusting clock delays in individual flip-flops to minimize the clock period through the use of wave pipelining is discussed. Edge-triggered flip-flops are used as the circuit memory elements, and controlled delays are introduced in the time of clock signal arrivals at these elements. Constraints that relate the logic path delays from pairs of input flip-flops are derived. These constraints, in addition to known constraints relating input and output flip-flops, prevent destructive logic signal propagation interference. It is shown that in circuits without feedback the clock period reduction is limited by the shortest paths in the logic and the required signal separation between signals of distinct cycles. Application of this technique to logic with feedback is discussed. >