Various example implementations are directed to circuits and methods for debugging circuit designs. According to an example implementation, waveform data is captured, for a set of signals produced by a circuit design during operation. Data structures are generated for the set of signals and waveform data for the signals is stored in the data structures. Communication channels associated with the set of signals are identified. Waveform data stored in the data structures is analyzed to locate transaction-level events in the set of signal for one or more communication channels. Data indicating locations of the set of transaction-level events is output by the computer system.