Synopsys, Inc.

Gagan Vishal Jain

Johnson Adaikalasamy

Solaiman Rahim

Alexander John Wakefield

Olivier Coudert

Ritesh Mittal

Stanislav Margolin

Parijat Biswas

Alexandru Seibulescu

Raghurama Krishna Srigiriraju

A process is disclosed to identify the minimal set of sequential and combinational signals needed to fully reconstruct the combinational layout after emulation is complete. A minimal subset of sequential and combinational elements is output from the emulator to maximize the emulator speed and limit the utilization of emulator resources, e.g., FPGA resources. An efficient reconstruction of combinational waveforms or SAIF data is performed using a parallel computing grid.

Waveform based reconstruction for emulation

A disclosed system of an emulation environment performs a simulation to construct a waveform of a target signal based on signals traced by an emulator for a time frame including multiple clock cycles. In one embodiment, a simulation is performed in a manner that an input of the logic gate, in a first duration of the time frame at which an output of the logic gate depends on the input, is analyzed to obtain the output, and the input of the logic gate, in a second duration of the time frame at which the output of the logic gate is independent, is omitted. In one aspect, the input of the logic gate is simulated for the first duration based on a periodicity in a waveform of the input in the first duration.

In a method for increasing coverage convergence during verification of a design for an IC, symbolic elements can be generated for the variables and the variable expressions in the hardware code of the design and a test bench. Simulation semantics can be modified and local multi-path analysis can be provided to expand symbolic property collection and symbolic element propagation. Modifying simulation semantics can include transformation of conditional statements, flattening of conditions, avoidance of short circuiting logic, and/or symbolic triggering of events. Symbolic elements are propagated through the design and the test bench during multiple simulation runs to collect symbolic properties. Coverage information from the multiple simulation runs is analyzed to identify coverage points to be targeted. For each identified coverage point, the constraints resulting from the collected symbolic properties are solved to generate directed stimuli for the design. These directed stimuli increase the coverage convergence.

Accelerating coverage convergence and debug using symbolic properties and local multi-path analysis

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Sunnyvale, CA, United States of America

Gagan Vishal Jain