Integrated Retiming and Placement for Field Programmable Gate Arrays

Retiming is a synchronous circuit transformation that can optimize the delay of a synchronous circuit by moving reg-isters across combinational circuit elements. The combi-national structure remains unchanged and the observable behavior of the circuit is identical to the original. In this paper, we address the problem of applying retiming techniques to circuits implemented in Field Programmable Gate Arrays (FPGAs). FPGAs contain prefabricated and configurable routing elements that allow us to easily im-plement a variety of circuits. However this interconnect contributes greatly to the overall delay in the implemented circuit. If a circuit is retimed prior to the placement and routing phases of the CAD flow, then it has no information about the delays introduced by the configurable intercon