VCD-on-demand system and method

An electronic design automation system for verifying a user design, comprising:

• a computing system including a central processing unit and memory for modeling the user design in software to establish a software model of the user design;
• an internal bus system coupled to the computing system;
• reconfigurable hardware logic coupled to the internal bus system for modeling at least a portion of the user design in hardware to establish a hardware model of the user design;
• control logic coupled to the internal bus system for controlling delivery of data between the reconfigurable hardware logic and the computing system;
• and
• value change dump (VCD) on-demand logic for recording primary inputs provided to the hardware model from the software model in a simulation history during a simulation session range of a first simulation run, selecting a simulation target range within the simulation session range, evaluating the hardware model using the primary inputs recorded in the simulation history to record state information generated by the hardware model in a VCD file during the simulation target range of a second simulation run, and regenerating logic elements of the software model using the state information recorded in the VCD file to debug the user design.

A value change dump (VCD) on-demand system for debugging a design having a hardware model and a software model, comprising:

• means for recording primary inputs provided to the hardware model from the software model in a simulation history during a simulation session range of a first simulation run;
• means for selecting a simulation target range, within the simulation session range;
• and
• means for evaluating the hardware model using the primary inputs recorded in the simulation history to record state information generated by the hardware model in a value change dump (VCD) file during the simulation target range of a second simulation run;
• and
• means for regenerating logic elements in the software model using the state information recorded in the VCD file to debug the design.