Patent ID: 6795957
Filing Date: 2004-09-21
Classification: G06F

Abstract:
For an integrated circuit (IC) layout describing an IC as having a plurality of vertically stacked layers and as having a plurality of objects, each occupying space within the layers, wherein some of the objects are power wires and vias forming a power distribution network, a method of modifying the layout to add at least one new power wire to the power distribution network and to add new vias connecting the new power wire to existing power wires of the power distribution network, the method comprising steps of:a. providing a global HV tree referencing each layer of the IC and indicating a space on each layer occupied by each of the objects residing on that layer; b. providing a via HV tree referencing each layer of the IC; c. modifying the layout so that it also describes the IC as also including the new power wire residing on one layer of the plurality of layers; d. updating the global HV tree so that it also indicates a space the new power wire occupies on said one layer; and e. querying the global HV tree to establish horizontal dimensions and position of a separate intersection box corresponding to each area of vertical overlap between the new power wire and any one of said power wires of the power distribution network, each intersection box having horizontal dimensions and position similar to its corresponding area of vertical overlap.