Abstract: 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.

Abstract: 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.

Abstract: 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.