Abstract: A debugger produces a display based on instructions executed by a circuit simulator or verification tool and on waveform data produced by the simulator or verification tool when executing the instructions. The instructions include a set of statements, each corresponding to a separate circuit signal generated by a circuit and each including a function defining a value of the circuit signal as a function of values of other circuit signals. The simulator evaluates the statements at various simulation times to compute signal values at those simulation times. The waveform data indicates signal values the simulator computes when evaluating the statements. The debugger display includes a set of statement event symbols, each corresponding to a separate evaluation of a statement and each positioned in the display to indicate a simulation time at which the simulator evaluated the statement.

Abstract: A circuit simulator simulates a circuit described by a circuit logic model as having a set of clocked registers interconnected by un-clocked logic to produce waveform data indicating states of each circuit input signal and of each register output signal as functions of clock signal edge timing. The waveform data and the logic model are then processed to produce a temporal schema model characterizing the circuit's logic and behavior. A display based on the temporal schema model depicts circuit behavior using separate symbols to represent successive circuit input signal states and register output signal states at various times during the simulation. The same display also graphically depicts fan-in or fan-out logical relationships by which circuit input signal states and register output signal states influence register input signal states.

Abstract: Described herein is a system for verifying that a circuit described by a hardware description language file has a property of responding to an antecedent event represented by a particular pattern in its input signals by exhibiting a consequent behavior of producing a particular pattern in its output signals during a finite time following the antecedent event. The system includes a conventional circuit simulator for simulating the behavior of the circuit under conditions defined by a user-provided test bench. The simulator produces output waveform data representing the behavior of the circuit input, output and internal signals, including signals representing the circuit's state. When the output waveform data indicates the antecedent event has occurred, the system determines the current state of the circuit from the waveform data.

Abstract: Computer-assisted apparatus/method functionally verifies circuit design through automatic generation of verification rules from reusable functional block or IP core using logic simulator and input stimuli. Rule base captures set of design states or scenarios.

Abstract: Hardware description language (HDL)-centered design system and methodology uses HDL specification effectively as master depository for design intent or knowledge. Through network browser, designers conveniently navigate or explore design graphically. Designers selectively review or save design in entirety or portions. Design capture, analysis, and manipulation are based on HDL specification, either directly through text file editing, or indirectly through use of graphical tools.

Abstract: Prior simulation results and model changes are used to shorten re-simulation time in improved design verification methodology, wherein simulator is re-run on design revision. Accelerated incremental simulation scheme boosts engineer design and verification productivity, and facilitates storage of different design revisions and simulation results.