摘要:
Statistical timing analysis methods for circuits are described which compensate for circuit elements having correlated timing delays with a high degree of computational efficiency. An quadratic timing model is used to represent each delay element along a circuit path, wherein each element's delay has a first-order relationship to local variations and a second-order relationship to global variations. Propagation of the modeled delays through the circuit is efficiently done via straightforward ADD operations where an input propagates through another element in a circuit path, and via a MAX operation (or an approximation thereof) where two or more inputs merge at an intersection. The inputs to the MAX operator can be tested for gaussianity, and can be processed by the MAX operation (or its approximation) if they are substantially gaussian. Otherwise, they may be stored in a tuple for processing at later points along the circuit path.
摘要:
Statistical timing analysis methods for circuits are described which compensate for circuit elements having correlated timing delays with a high degree of computational efficiency. An extended canonical timing model is used to represent each delay element along a circuit path, wherein the model bears information regarding any correlations that each element has to any other elements in the circuit (and/or to any external global factors, e.g., global temperature variations over the circuit, etc.). The model can be represented in a vectorized format which allows enhancement of computational efficiency, wherein the coefficients of the vectors allow an objective measure of element correlation (and wherein the vectors can be “pruned” by dropping insignificant coefficients to further enhance computational efficiency). A decomposition procedure can be used to decompose correlated elements into uncorrelated elements to allow delays to me more easily propagated through the timing diagram representing the circuit. Finally, a bounded approximation for the output of the MAX operator is described which provides a safely conservative approximation regardless of the linearity of the MAX output.
摘要:
The invention provides a method, system, and program product for accommodating spatially-correlated variation in a process parameter during statistical timing of a circuit. In one embodiment, the method includes dividing an area of the circuit into a plurality of grid cells; associating an independent random variable with each of the plurality of grid cells; and expressing at least one spatially-correlated parameter of a first grid cell as a function of the random variables associated with the first grid cell and at least one neighboring grid cell.
摘要:
Methods and systems for improving operations of a formation tester are disclosed. The formation tester (400) is placed in a wellbore at a location of interest. The formation tester comprises a first isolation pad (402) coupled to a pad carrier (410) and a second isolation pad (404). The first isolation is extendable to substantially seal a probe of the formation tester against a well bore wall. The first isolation pad is then replaced with the second isolation pad if it is determined that the first isolation pad should be replaced with the second isolation pad.
摘要:
Statistical timing analysis methods for circuits having latches and feedback loops are described wherein the circuit yield, and/or the critical cycle mean (the largest cycle mean among all loops in the circuit), may be iteratively calculated with high speed and accuracy, thereby allowing their ready usage in the analysis and validation of proposed circuit designs.
摘要:
A method, system, and computer program product are disclosed for performing statistical leakage power characterization to estimate yield of a circuit in terms of leakage power. According to some approaches, this is performed with consideration of bi-exponential modeling.
摘要:
Statistical timing analysis methods for circuits having latches and feedback loops are described wherein the circuit yield, and/or the critical cycle mean (the largest cycle mean among all loops in the circuit), may be iteratively calculated with high speed and accuracy, thereby allowing their ready usage in the analysis and validation of proposed circuit designs.
摘要:
Statistical timing analysis methods for circuits are described which compensate for circuit elements having correlated timing delays with a high degree of computational efficiency. An extended canonical timing model is used to represent each delay element along a circuit path, wherein the model bears information regarding any correlations that each element has to any other elements in the circuit (and/or to any external global factors, e.g., global temperature variations over the circuit, etc.). The model can be represented in a vectorized format which allows enhancement of computational efficiency, wherein the coefficients of the vectors allow an objective measure of element correlation (and wherein the vectors can be “pruned” by dropping insignificant coefficients to further enhance computational efficiency). A decomposition procedure can be used to decompose correlated elements into uncorrelated elements to allow delays to me more easily propagated through the timing diagram representing the circuit. Finally, a bounded approximation for the output of the MAX operator is described which provides a safely conservative approximation regardless of the linearity of the MAX output.
摘要:
Embodiments of inspection systems and methods are disclosed. One embodiment of an inspection system, among others, comprises logic configured to receive a reference signal and a target signal, the reference signal having first surface displacement information and the target signal having second surface displacement information, said logic configured to determine a correlation coefficient between the first surface displacement information and the second surface displacement information, the correlation coefficient indicating whether an inspected object exhibits a defect.
摘要:
Statistical timing analysis methods for circuits having latches and feedback loops are described wherein the circuit yield, and/or the critical cycle mean (the largest cycle mean among all loops in the circuit), may be iteratively calculated with high speed and accuracy, thereby allowing their ready usage in the analysis and validation of proposed circuit designs.