Synopsys, Inc.

Yogesh Pandey

Eduard Rudolf Cerny

Saptarshi Ghosh

Manish Jain

Diganchal Chakraborty

Sivaprasad Acharya

Vijay Anand Sankar

A method of verifying a circuit design, includes, in part, identifying a first groups of signals associated with the circuit, selecting a signal sampling window depth, performing a first verification of the circuit using a first test bench adapted to cause transitions in the first group of signals, storing values of the signals in the first group during each of the cycles defined by the sapling window depth to generate a first functional coverage, performing a second verification of the circuit design using a second test bench to generate a second functional coverage, comparing the second functional coverage to the first functional coverage, and automatically generating one or more cover property statements if the second functional coverage is less than the first functional coverage. The one or more cover property statements cause the second functional coverage to become equal to or greater than the first functional coverage.

Automatic definition and extraction of functional coverage metric for emulation-based verification

Groups of signals in an electronic design for which interesting assertions, such as assert, assume and cover properties, can be generated are identified. A sliding temporal window of fixed depth is used to sample unique present and past value combinations of signals in the signals groups generated by one or more simulations or emulations. The values of signals in the signal groups are organized into truth tables. Minimal functional relations are extracted from the truth tables, using techniques similar to those for synthesis of partial finite memory machines from traces, and used to generate assertions. The assertions are filtered using a cost function and pertinence heuristics, and a formal verification tool used to prune unreachable properties and generate traces for reachable cover properties. Syntactically correct assert, assume and cover property statements for the generated properties are instantiated and packaged into a file suitable for further simulation or emulation or formal verification.

Assertion extraction from design and its signal traces

A computer is programmed to prepare a computer program for simulating operation of an integrated circuit (IC) chip, in order to test scan circuitry therein. The computer is programmed to trace a path through combinational logic in a design of the IC chip, starting from an output port of a first scan cell and ending in an input port of a second scan cell. If the first and second scan cells receive a common scan enable signal, then the computer generates at least a portion of the computer program, i.e. software to perform simulation of propagating a signal through the path conditionally, for example when the common scan enable signal is inactive and alternatively to skip performing simulation when the common scan enable signal is active. The computer stores the portion of the computer program in memory, for use with other such portions of the computer program.

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Bengaluru, India

Yogesh Pandey