Patent ID: 8607186

Claim:
A computer-implemented method for verifying equivalence between a merged mode for a circuit and a plurality of individual modes for the circuit, the method comprising: identifying, by a computer, a source set of timing nodes and a sink set of timing nodes in a set of netlists, the sink set comprising a reconvergent node on at least two timing paths from a start point to an end point, and the source set comprising a timing node on one of the timing paths, the timing node connected to the reconvergent node by an edge, wherein a merged mode and a plurality of individual modes are defined for the netlists, the merged mode and the individual modes comprising timing constraints for netlists in the set of netlists; identifying, by the computer, timing relationships for each individual mode and the merged mode, each timing relationship comprising a first timing node, a second timing node, and one or more timing constraints for a timing path from the first timing node to the second timing node; determining, by the computer, an aggregate set of timing relationships encountered by traversing from the source set of timing nodes to the sink set of timing nodes for each individual mode and the merged mode; comparing, by the computer, timing relationships in the aggregate set from the merged mode with timing relationships in aggregate sets from each of the individual modes to identify a mismatch between the merged mode and the plurality of individual modes, the comparing comprising: identifying a timing relationship present in the aggregate set from the merged mode such that the timing relationship is absent in all of the aggregate sets from the individual modes; responsive to identifying a mismatch between timing relationships in the aggregate set from the merged mode and timing relationships in aggregate sets from the individual modes, determining that the merged mode is not equivalent to the plurality of individual modes; and sending information indicating the merged mode is not equivalent to the plurality of individual modes.