Probe points and markers for critical paths and integrated circuits

Abstract

A method for automated placement of markers or probe points adjacent to critical timing paths in an integrated circuit design. The markers aid in identifying critical path interconnect lines for purposes of failure analysis or design verification. In a method according to the invention, timing information related to various signal paths in an integrated path is analyzed to isolated critical timing paths. Once a signal path is determined to be a critical timing path, layout data for the critical path is extracted from a layout database. An unused area(s) is then located adjacent to the critical path. Marker information is next inserted into the unused area(s) of the layout database. The act of inserting marker information is performed by a specialized software tool capable of modifying a layout database. Alternatively, existing automated floorplanning or layout tools, or other electronic design automation (EDA) tools, whether proprietary or industry standard, are modified to insert the marker information. The marker information causes markers to be fabricated at strategic points along the critical path in the unused areas without violating design rules. Hence, upon visual inspection of the integrated circuit, a failure analyst can readily locate the markers and identify critical paths.