Synopsys, Inc.

Florent Duru

Boris Gommershtadt

Olivier Coudert

Dmitry Korchemny

Leonid Alexander Broukhis

Gabriel Gouvine

Francois Peneloux

A circuit hardware emulation module is configured to identify oscillating subgraphs of an emulated graph, or to identify state-holding subgraphs of an emulated graph. The emulation module identifies one or more loops within an emulated circuit; generates an acyclic emulation of at least a portion of the emulated circuit, wherein the acyclic emulation is characterized by one or more loop breakers; generates a loop detector emulation of a hardware-based loop detector circuit based at least in part on a quantity of loop breakers n characterizing the acyclic emulation, wherein the loop detector emulation comprises at least one of an oscillation detector or a state-holding detector; and executes the loop detector emulation for a plurality of input values for the emulated circuit to generate an output indicating at least one of an oscillation status or a state-holding status of the emulated circuit.

Hardware simulation systems and methods for identifying state-holding loops and oscillating loops

Coverage event counters for hardware verification emulations are implemented as linear feedback shift register-based counters generating encoded counter values indicative of a detected number of coverage events. To decode those counter values, a counter algorithm utilized to generate the encoded counter value may continue to be iterated after counting is complete until reaching a defined pattern, while counting the number of iterations (K) necessary to reach the defined pattern. The resulting counter value having the defined pattern is correlated with a mapping table to identify a numerical value, and an ordinal counter value indicative of the number of coverage events is determined based on the identified numerical value, less K.

Efficient realization of coverage collection in emulation

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Mountain View, CA, United States of America

Florent Duru