Patent ID: 6625770
Filing Date: 2003-09-23
Classification: G01R,G06F

Abstract:
A method of identifying and displaying relevant ones of a plurality of connected logic cells and waveforms from the relevant logic cells of a circuit described by using a simulation tool, the waveforms including input and output waveforms to and from each relevant logic cell, the simulation tool describing a transition and a transition time point when the transition occurs, said method comprising the steps of:selecting an output waveform and a transition time point of the selected output waveform delivered from a selected logic cell; identifying a predictive input waveform and a transition time of the predictive input waveform to the selected logic cell which causes the transition of the output signal from the selected logic cell at the selected transition time; identifying a predictive logic cell connected to the selected logic cell which supplies the output waveform to the selected logic cell which constitutes the predictive input waveform identified in the preceding step; performing at least one new repetition of the aforesaid three steps to accomplish the selecting and identifying steps under circumstances where the predictive logic cell identified in a previous repetition becomes the selected logic cell for the new repetition and the transition time point of the predictive input waveform to the selected logic cell of the previous repetition becomes the selected transition time of the output waveform of the selected logic cell for the new repetition; obtaining signals from a functional embodiment of the circuit at locations in the functional embodiment of the circuit which correspond to locations of the displayed waveforms; and comparing the displayed waveform to the signals obtained from the corresponding locations in the functional embodiment of the circuit.