Abstract: A computer executable system and method analyzes a circuit design to extract a small set of signals for value collection using an emulator system. The collected signals are for specific purpose checkers such as assertions or interactive testbenches that are hard to emulate. A synthesizable monitor block is generated and added to the emulation environment to collect the signal value changes during emulation. The collected values are then used in localized logic simulation to perform the tasks that the original checkers intent to accomplish. This system leverages fast emulation speed and flexible logic simulation capabilities to perform the intended checker tasks much faster than using logic simulation alone.

Abstract: A computer executable processing component analyzes unknown (X) propagation from uninitialized latches in gate-level simulation and determines if the Xs cause false Xs to be generated due to X-pessimism. For Xs generated due to X-pessimism, simulation results are corrected and fixes are generated. Corrected simulation results match real hardware behavior and greatly reduces engineers' analysis effort on debugging X issues. A computer executable processing component analyzes unknown (X) propagation from sequential cells in gate-level logic simulation and determines if the Xs cause false Xs to be generated due to X-pessimism. For Xs generated due to X-pessimism, simulation results are corrected and fixes are generated. Corrected simulation results match real hardware behavior and greatly reduces engineers' analysis effort on debugging X issues.

Abstract: A computer executable tool analyzes unknowns (Xs) in gate-level simulation and traces their sources to determine if the Xs are generated due to X-pessimism. For Xs generated due to X-pessimism, fixes are generated to correct simulation results. Corrected simulation results match real hardware behavior and greatly reduce the analysis effort of engineers.

Abstract: A retention synthesis application provides a means of analyzing a circuit design, functional test sequences, and the associated power specification to identify registers that do not need retention when a block is powered down. Reducing the number of retention registers reduces power consumption and chip area. The retention synthesis application is based, at least in part, upon symbolic simulation. In symbolic simulation, a symbol is used to represent a value that can be either 0 or 1 and the propagation of symbols is traced through the simulation.

Abstract: This invention provides a system and method for correcting gate-level simulation commences by identifying unknown values (Xs) that are falsely generated during the simulation of a given trace for a design netlist. Then, a sub-circuit of the design netlist is determined for each false X that has inputs of real Xs and an output of a false X. Finally, simulation correction code is generated based on the sub-circuit to eliminate false Xs in simulation of the design netlist. The original design netlist can then be resimulated with the simulation repair code to eliminate false Xs. This allows gate-level simulation to produce correct results.