Patent ID: 7475297
Filing Date: 2009-01-06
Classification: G06F

Abstract:
1. A method for determining a setup skew, comprising: determining a nearest common ancestor (NCA) in a clock distribution network, which NCA is an ancestor node for a plurality of descendant nodes including a destination node and a source node; determining minimum and maximum NCA clock delays for the NCA; determining a minimum clock delay for the destination node and subtracting the minimum NCA clock delay to determine a destination node minimum delta clock delay; determining a maximum clock delay for the source node and subtracting the maximum NCA clock delay to determine a source node maximum delta clock delay; subtracting the source node maximum delta clock delay from the destination node minimum delta clock delay to determine the setup skew between the source and destination nodes; wherein determining the NCA comprises determining a list of ancestors each having a set of descendant nodes, wherein each set includes both the source and the destination node.