DEBUGGING USING TAGGED FLIP-FLOPS

Approaches for testing a module of a circuit design include tagging flip-flops in a netlist of the module with respective path names of the flip-flops from a hardware description language specification of the module. In simulating with the netlist, event data are captured to a first file. A process determines whether or not event data in the first file matches event data in a second file of event data. In response to a difference determined between the first file and the second file, an earliest occurrence of an event in the first file having an associated signal value of a first signal that does not match an associated signal value of a corresponding event in the second file is determined. The one of the plurality of flip-flops that output the first signal is determined, and the respective path name of the one flip-flop is output.