Abstract: Methods and systems for performing timing analysis during the design of a circuit are described. In one embodiment, a simulation system can generate an effective resistance value (or an impedance value based on the effective resistance value) for an instance and use the effective resistance value in a simulation to determine a minimum timing delay for the instance when only the instance switches during such simulations.

Abstract: Systems and methods are provided for simulating an integrated circuit system. A file representative of an integrated circuit layout is received, the integrated circuit layout including a plurality of cells and characteristics of power supply and ground paths to each cell. A vulnerable cell of the integrated circuit layout based on a vulnerability characteristic of the vulnerable cell. A power analysis of a portion of the integrated circuit layout is performed to determine a plurality of power and ground levels within a timing window for each of a plurality of cells including the vulnerable cell. A timing analysis of the vulnerable cell is performed, where the timing analysis receives a single power level and single ground level for the vulnerable cell and determines a slack level for the vulnerable cell. An at risk path is identified based on the vulnerable cell slack level, and a dynamic power/ground simulation of one or more cells in the at risk path is performed.

Abstract: Systems and methods are provided for simulating an integrated circuit system. A file representative of an integrated circuit layout is received, the integrated circuit layout including a plurality of cells and characteristics of power supply and ground paths to each cell. A vulnerable cell of the integrated circuit layout based on a vulnerability characteristic of the vulnerable cell. A power analysis of a portion of the integrated circuit layout is performed to determine a plurality of power and ground levels within a timing window for each of a plurality of cells including the vulnerable cell. A timing analysis of the vulnerable cell is performed, where the timing analysis receives a single power level and single ground level for the vulnerable cell and determines a slack level for the vulnerable cell. An at risk path is identified based on the vulnerable cell slack level, and a dynamic power/ground simulation of one or more cells in the at risk path is performed.

Abstract: The present invention relates to a method and apparatus for determining capacitances and charge models for MOS devices to be used in calculating delays in a timing verifier for a circuit. The models are generated by first creating a variety of configurations of MOS devices which vary the inputs to the source, drain, and gate. Such inputs may include rising and falling values as well as constant values at VDD and VSS. Simulations are run on all of the configurations using conditions anticipated for the circuit to be analyzed. Capacitance values obtained from the simulations are used to determine models based upon length and width of the MOS devices using standard curve fitting techniques. Models then can be used for determining delays within the circuit.

Abstract: The present invention relates to a method and apparatus for determining capacitances and charge models for MOS devices to be used in calculating delays in a timing verifier for a circuit. The models are generated by first creating a variety of configurations of MOS devices which vary the inputs to the source, drain, and gate. Such inputs may include rising and falling values as well as constant values at VDD and VSS. Simulations are run on all of the configurations using conditions anticipated for the circuit to be analyzed. Capacitance values obtained from the simulations are used to determine models based upon length and width of the MOS devices using standard curve fitting techniques. Models then can be used for determining delays within the circuit.

Abstract: The present invention relates to a method and apparatus for determining capacitance and charge models for MOS devices to be used in calculating delays in a timing verifier for a circuit. The models are generated by first creating a variety of configurations of MOS devices which vary the inputs to the source, drain, and gate. Such inputs may include rising and falling values as well as constant values at VDD and VSS. Simulations are run on all of the configurations using conditions anticipated for the circuit to be analyzed. Capacitance values obtained from the simulations are used to determine models based upon length and width of the MOS devices using standard curve fitting techniques. Models then can be used for determining delays within the circuit.

Abstract: An efficient method is presented for automatically verifying test patterns devised to detect speed critical faults in electrical circuits, with minimal human intervention. The method provides a controlled momentary inversion of a logic value at a control point within the circuit being tested or simulated, and then checks the measured or simulated circuit's output value. If the momentary logic inversion causes an inverted logic output, then the test pattern under evaluation has been determined to be capable of detecting circuits that have failures due to speed critical problems. With such an arrangement it is possible to determine whether specific test patterns will accurately measure the performance of circuit paths that have potential operating speed related problems.