# Debjit Sinha

## Debjit Sinha, Hopewell Jct., NY US

Patent application number | Description | Published |
---|---|---|

20110016442 | Method of Performing Static Timing Analysis Considering Abstracted Cell's Interconnect Parasitics - An abstraction model supporting multiple hierarchical levels is inputted into a generalized static timing analysis of a hierarchical IC chip design to analyze and optimize the design of circuits integral to the chip containing a plurality of macro abstracts. An electrical network, synthesized for an internal abstract interconnect segment, is performed only once per macro and is applied to multiple instances of the macro abstract model in the IC chip design. The synthesized electrical network is a resistive capacitive or a resistive inductive capacitive network or a combination thereof. The synthesized electrical network is then used to match impulse response transfer functions of the network and the abstract interconnect segment's timing model. This network is stitched with the electrical parasitics of external interconnect segments connected to macro primary outputs. Various model order reductions are then performed on the electrical parasitics of external interconnects prior to network stitching. A static timing analysis is performed on the final network. | 01-20-2011 |

## Debjit Sinha, Wappingers Falls, NY US

Patent application number | Description | Published |
---|---|---|

20090077515 | Method of Constrained Aggressor Set Selection for Crosstalk Induced Noise - A preliminary static timing analysis run is performed to calculate the delay and slew as well as timing windows for each net in the design, followed by coupling analysis for each given aggressor-victim combination, and to calculate the noise effect on the timing of victim net. Given a set of functional groups that relate the coupled aggressors to each other, the worst set of aggressors are calculated that satisfy the constraints from the functional groups, based on the calculated impact of each aggressor on the victim. Similarly the set of aggressors which contribute to the maximum amount of inductive coupling noise effect on timing are calculated. Furthermore, the coupling noise impact of the reduced set of aggressors on the given victim line and adjust the delay value calculated in the preliminary static timing analysis run. | 03-19-2009 |

20100088658 | METHOD AND APPARATUS FOR EFFICIENT INCREMENTAL STATISTICAL TIMING ANALYSIS AND OPTIMIZATION - In one embodiment, the invention is a method and apparatus for efficient incremental statistical timing analysis and optimization. One embodiment of a method for determining an incremental extrema of n random variables, given a change to at least one of the n random variables, includes obtaining the n random variables, obtaining a first extrema for the n random variables, where the first extrema is an extrema computed prior to the change to the at least one of the n random variables, removing the at least one of the n random variables to form an (n−1) subset, computing a second extrema for the (n−1) subset in accordance with the first extrema and the at least one of the n random variables, and outputting a new extrema of the n random variables incrementally based on the extrema of the (n−1) subset and the at least one of the n random variables that changed. | 04-08-2010 |

20100180243 | Method of Performing Timing Analysis on Integrated Circuit Chips with Consideration of Process Variations - A method for verifying whether a circuit meets timing constraints by performing an incremental static timing analysis in which slack is represented by a distribution that includes sensitivities to various process variables. The slack at an endpoint is computed by propagating the arrival times and required arrival times of paths leading up to the endpoint. The computation of arrival and required arrival times needs the computation of delays of individual gate and wire segments in each path that leads to the endpoint. The mixed mode adds a deterministic timing to the statistical timing (DSTA+SSTA). | 07-15-2010 |

20100211922 | Method of Performing Statistical Timing Abstraction for Hierarchical Timing Analysis of VLSI circuits - A method for performing a hierarchical statistical timing analysis of an integrated circuit (IC) chip design by abstracting one or more macros of the design. The method includes performing a statistical static timing analysis of at least one macro; performing a statistical abstraction of the macro to obtain a statistical abstract model of the macro timing characteristics; applying the statistical abstract model as the timing model for each occurrence of the macro leading to a simplified IC chip design; and performing a hierarchical statistical timing analysis of the simplified chip design. The method achieves a context aware statistical abstraction, where a generated statistical abstract model is instantiated for each macro of the chip during statistical static timing analysis at the chip level, providing a compressed and pruned statistical timing abstraction and reducing the model-size during the statistical abstraction. | 08-19-2010 |

20100269083 | Method of Employing Slew Dependent Pin Capacitances to Capture Interconnect Parasitics During Timing Abstraction of VLSI Circuits - A method for converting interconnect parasitics of an interconnect network into slew dependent pin capacitances utilizes charge matching between predetermined voltage thresholds. During timing abstraction of a macro, parasitics of interconnects connected to the primary inputs are represented as slew dependent pin capacitances in an abstract model being created. Interconnect model order reduction is employed to speed the process. The generated abstract is subsequently used in place of each occurrence of the macro during chip level hierarchical static timing analysis, leading to an enhanced accuracy of the timing analysis of the logic components driving the abstracts. | 10-21-2010 |

20120117527 | PERFORMING STATISTICAL TIMING ANALYSIS WITH NON-SEPARABLE STATISTICAL AND DETERMINISTIC VARIATIONS - In one embodiment, the invention is a method and apparatus for performing statistical timing analysis with non-separable statistical and deterministic variations. One embodiment of a method for performing timing analysis of an integrated circuit chip includes computing delays and slews of chip gates and wires, wherein the delays and slews depend on at least a first process parameter that is deterministic and corner-based and a second process parameter that is statistical and non-separable with the first process parameter, and performing a single timing run using the timing quantity, wherein the single timing run produces arrival times, required arrival times, and timing slacks at outputs, latches, and circuit nodes of the integrated circuit chip. The computed arrival times, required arrival times, and timing slacks can be projected to a corner value of deterministic variations in order to obtain a statistical model of the delays and stews at the corresponding corner. | 05-10-2012 |

20130036395 | EFFICIENT SLACK PROJECTION FOR TRUNCATED DISTRIBUTIONS - Aspects of the present invention provide solutions for projecting slack in an integrated circuit. A statistical static timing analysis (SSTA) is computed to get a set of Gaussian distributions over a plurality of variation sources in the integrated circuit. Based on the Gaussian distributions, a truncated subset and a remainder subset of the Gaussian distributions are identified. Then data factors that represent a ratio between the remainder subset and the truncated subset are obtained. These data factors are applied to the SSTA to root sum square (RSS) project the slack for the integrated circuit that takes into account the absence of the truncated subset. | 02-07-2013 |

20130145333 | STATISTICAL CLOCK CYCLE COMPUTATION - Systems and methods for statistical clock cycle computation and closing timing of an integrated circuit design to a maximum clock cycle or period. The method includes loading a design and timing model for at least one circuit path of an integrated circuit or a region of the integrated circuit into a computing device. The method further includes performing a statistical static timing analysis (SSTA) of the at least one circuit path using the loaded design and timing model to obtain slack canonical data. The method further includes calculating a maximum circuit clock cycle for the integrated circuit or the specified region of the integrated circuit in linear canonical form based upon the slack canonical data obtained from the SSTA. | 06-06-2013 |

20130159953 | PERFORMING STATISTICAL TIMING ANALYSIS WITH NON-SEPARABLE STATISTICAL AND DETERMINISTIC VARIATIONS - In one embodiment, the invention is a method and apparatus for performing statistical timing analysis with non-separable statistical and deterministic variations. One embodiment of a method for performing timing analysis of an integrated circuit chip includes computing delays and slews of chip gates and wires, wherein the delays and slews depend on at least a first process parameter that is deterministic and corner-based and a second process parameter that is statistical and non-separable with the first process parameter, and performing a single timing run using the timing quantity, wherein the single timing run produces arrival times, required arrival times, and timing slacks at outputs, latches, and circuit nodes of the integrated circuit chip. The computed arrival times, required arrival times, and timing slacks can be projected to a corner value of deterministic variations in order to obtain a statistical model of the delays and slews at the corresponding corner. | 06-20-2013 |

20140040844 | Method for Achieving An Efficient Statistical Optimization of Integrated Circuits - Method for performing timing closure of integrated circuits in the presence of manufacturing and environmental variations. The starting design is analyzed using statistical static timing analysis to determine timing violations. Each timing violation in its statistical canonical form is examined. In a first aspect of the invention, the canonical failing slack is inspected to determine what type of move is most likely to fix the timing violation taking into account all relevant manufacturing and environmental variations. In a second aspect of the invention, pre-characterized moves such as insertion of delay pad cells are evaluated for their ability to fix the timing violation without triggering timing, and the best move or set of moves is selected. | 02-06-2014 |

## Debjit Sinha, Wappinger Falls, NY US

Patent application number | Description | Published |
---|---|---|

20090119037 | SYSTEM AND METHODS FOR DYNAMIC POWER ESTIMATION FOR A DIGITAL CIRCUIT - A method for dynamic timing-dependent power estimation for a digital circuit having coupled interconnects and at least two gates. In one embodiment, the method includes the steps of capturing information on relative switching activities and timing dependence for the coupled interconnects in the digital circuit, estimating the probabilities associated with switching activities and timing dependence for each gate in the digital circuit from the captured information, and obtaining dynamic power estimation of the digital circuit from the estimations of the probabilities. | 05-07-2009 |

20140096100 | METHOD OF SHARING AND RE-USING TIMING MODELS IN A CHIP ACROSS MULTIPLE VOLTAGE DOMAINS - A method and a system for timing analysis of a VLSI circuit or chip design considering manufacturing and environmental variations, where the design includes multiple instances of a gate or macro instantiated at more than one voltage domain by sharing and re-using abstracts. The timing analysis of the chip includes a macro abstract instantiated in a voltage domain different from the domain during abstract generation. Timing models are re-used across chip voltage domains or across chip designs. Moreover, a statistical timing analysis of a chip design takes into consideration the voltage domains wherein at least one timing abstract model generation time voltage domain condition differs from the macro instantiation domain in the chip. The invention further provides sharing and re-using the statistical timing models or abstracts. | 04-03-2014 |

20140149956 | CORNER SPECIFIC NORMALIZATION OF STATIC TIMING ANALYSIS - A method and a system for expressing results of a timing analysis of an integrated circuit (IC) chip design as relative values to drive efficient chip design closure include: using a computer, performing the timing analysis to compute timing results of the chip design across at least two design corners; applying corner specific normalization equations to the timing analysis results from each of the at least two corners to obtain normalized timing results; and using the timing results ordered and filtered by the normalized timing results of the IC chip design for the design closure prior to chip manufacture. The slacks are normalized to provide insight into the degree of difficulty of the required fixes for that slack across corners. Given multiple analyses, the slacks are fixed in a correct order across corners and paths, avoiding inefficient circuit solutions or cost greater design effort. | 05-29-2014 |