Abstract: Operation of an integrated circuit is simulated. The simulation includes tracking propagation of taint from source data (such as sensitive information or faults) by using taint indicators. The source data is marked as “tainted” by setting a value of a corresponding taint indicator to a taint value. Propagation of the source data along signal paths in the integrated circuit is simulated. The signal paths contain elements through which the source data is propagated. Propagation of the taint from the source data is simulated by calculating values of taint indicators corresponding to signals along the signal paths. These taint indicators indicate whether the taint of the source data has propagated to the corresponding signals. The values of these taint indicators are calculated based on the elements in the signal paths and on the input signals and/or output signals for these elements.

Abstract: A method of capturing signals during hardware verification of a circuit design utilizes at least one field-programmable gate array (FPGA) and includes selecting, at run time and using one or more pre-compiled macros, a group of signals to be captured during verification of the circuit design and storing values of the group of signals in at least first and second random access memories disposed in the at least one FPGA. The first and second random access memories may be addressable spaces of the same random access memory.

Abstract: A method of capturing signals during hardware verification of a circuit design utilizes at least one field-programmable gate array (FPGA) and includes selecting, at run time and using one or more pre-compiled macros, a group of signals to be captured during verification of the circuit design and storing values of the group of signals in at least first and second random access memories disposed in the at least one FPGA. The first and second random access memories may be addressable spaces of the same random access memory.

Abstract: A method of capturing signals during hardware verification of a circuit design utilizes at least one field-programmable gate array (FPGA) and includes selecting, at run time and using one or more pre-compiled macros, a group of signals to be captured during verification of the circuit design and storing values of the group of signals in at least first and second random access memories disposed in the at least one FPGA. The first and second random access memories may be addressable spaces of the same random access memory.

Abstract: Methods and apparatuses are described for reducing or eliminating X-pessimism in gate-level simulation and/or formal verification. A system can identify a set of reconvergent inputs of a combinational block in a gate-level design. Next, the system can determine whether or not the combinational block is expected to exhibit X-pessimism during gate-level simulation. If the combinational block is expected to exhibit X-pessimism during gate-level simulation, the system can modify the gate-level design to reduce X-pessimism during gate-level simulation. In some embodiments, the system can build a model for the gate-level design by using unique free input variables to represent sources of indeterminate values. The system can then use the model to perform formal verification.

Abstract: One embodiment of the present invention provides a system that simulates behavioral constructs of a register transfer level design using indeterminate values. The system may receive hardware description language code which includes a construct that behaves differently depending on the value of an expression, e.g., the construct may execute different portions of code based on the value of a control expression, or it may store data in different storage locations based on the value of an index expression, etc. In response to determining that the expression's value is indeterminate, the system can execute two or more alternatives that are controlled by the expression, and then merge the results in some prescribed way. An embodiment of the present invention can enable a user to reduce the discrepancy between the results generated by a register transfer level simulation and the results generated by the associated gate level simulation.

Abstract: Methods and apparatuses are described for reducing or eliminating X-pessimism in gate-level simulation and/or formal verification. A system can identify a set of reconvergent inputs of a combinational block in a gate-level design. Next, the system can determine whether or not the combinational block is expected to exhibit X-pessimism during gate-level simulation. If the combinational block is expected to exhibit X-pessimism during gate-level simulation, the system can modify the gate-level design to reduce X-pessimism during gate-level simulation. In some embodiments, the system can build a model for the gate-level design by using unique free input variables to represent sources of indeterminate values. The system can then use the model to perform formal verification.

Abstract: One embodiment of the present invention provides a system that simulates behavioral constructs of a register transfer level design using indeterminate values. The system may receive hardware description language code which includes a construct that behaves differently depending on the value of an expression, e.g., the construct may execute different portions of code based on the value of a control expression, or it may store data in different storage locations based on the value of an index expression, etc. In response to determining that the expression's value is indeterminate, the system can execute two or more alternatives that are controlled by the expression, and then merge the results in some prescribed way. An embodiment of the present invention can enable a user to reduce the discrepancy between the results generated by a register transfer level simulation and the results generated by the associated gate level simulation.

Abstract: One embodiment of the present invention provides a system that simulates behavioral constructs of a register transfer level design using indeterminate values. The system may receive hardware description language code which includes a construct that behaves differently depending on the value of an expression, e.g., the construct may execute different portions of code based on the value of a control expression, or it may store data in different storage locations based on the value of an index expression, etc. In response to determining that the expression's value is indeterminate, the system can execute two or more alternatives that are controlled by the expression, and then merge the results in some prescribed way. An embodiment of the present invention can enable a user to reduce the discrepancy between the results generated by a register transfer level simulation and the results generated by the associated gate level simulation.

Abstract: One embodiment of the present invention provides a system that simulates behavioral constructs of a register transfer level design using indeterminate values. The system may receive hardware description language code which includes a construct that behaves differently depending on the value of an expression, e.g., the construct may execute different portions of code based on the value of a control expression, or it may store data in different storage locations based on the value of an index expression, etc. In response to determining that the expression's value is indeterminate, the system can execute two or more alternatives that are controlled by the expression, and then merge the results in some prescribed way. An embodiment of the present invention can enable a user to reduce the discrepancy between the results generated by a register transfer level simulation and the results generated by the associated gate level simulation.