Patent ID: 7310786

Claim:
A method for modifying an integrated circuit (IC) layout based on a cell library containing a plurality of cells, wherein each cell corresponds to a separate electronic device that can be incorporated into the IC and describes a layout for its corresponding electronic device as comprising a set of device objects, each device object being formed of a single type of IC material, and each cell indicating a shape and position of each device object within the layout of its corresponding electronic device, wherein the IC layout describes positions and orientations of a plurality of cell instances, each cell instance being a layout for a corresponding electronic device and being derived from a layout described a corresponding one of the cells' wherein the IC layout also describes shapes, positions and orientations of a plurality of path objects forming nets for interconnecting electronic devices corresponding to the cell instances, each path object being formed of a single type of IC material, wherein device objects and path objects within the IC layout have edges, and wherein distances between edges of path and device objects are subject to constraints imposed by a set of design rules, the method comprising the steps of: a. providing a separate set of device rules corresponding to each cell, each set of device rules indicating how modifications to the layout described by the corresponding cell can be made without affecting a behavior of the electronic device corresponding to the cell, and b. altering the IC layout in accordance with the design rules by repositioning cell instances and path objects within the IC layout, by modifying path objects, and by modifying the internal layout of at least one cell instance of the plurality of cell instances in accordance with the device rules corresponding to the cell from which the at least one cell instance was derived.