Virtual positive slack in physical synthesis

Abstract

A system and method of performing physical synthesis of a chip design are described. The method includes performing a baseline physical synthesis to determine a timing slack associated with each device, the timing slack indicating a margin by which timing requirements for the associated device are exceeded, determining that a threshold has been exceeded, the determining based on an analysis of a histogram of the timing slack, and executing a stage-by-stage physical synthesis based on determining that the threshold has been exceeded. The executing the stage-by-stage physical synthesis includes running a stage of the stage-by-stage physical synthesis to determine real timing slack, mapping the real timing slack to virtual timing slack, and running a next stage of the stage-by-stage physical synthesis using the virtual timing slack.