Lsi Corporation

Lsi Logic Corporation

Sandeep Bhutani

Weiqing Guo

Qian Cui

Ivan Pavisic

Ranko L Scepanovic

Andrey Nikitin

Cheng-Gang Kong

Aiguo Lu

Hui-Yin Seto

Ilya Viktorovich Lyalin

Payman Zarkesh-Ha

Igor V Kucherenko

William Lau

Andrej Zolotykih

Richard Karl Kirchner

Peter F Lindberg

Prabhakaran Krishnamurthy

Prasad Subbarao

Charutosh Dixit

Robert W Davis

John D Corbeil, Jr

Subramanian Venkateswaran

Jason R Potnick

Oian Cui

Nianging Zhang

Lei Chen

An apparatus and method to characterize a new process using an improved delay calculation. Multiple derating factors are used for different STA sign off corners that have a base corner with two pairs of off-corners. The approach of the present invention does not add any extra work in cell library characterization, while in the mean it increases the accuracy of the delay calculation and the library generation at corners other than standard corners.

Multiple derating factor sets for delay calculation and library generation in multi-corner STA sign-off flow

A system and method are provided for reducing signal skew. The method includes receiving a netlist having components and connections among the components. Each connection has at least one signal wire. A plurality of net groups is identified, each net group including at least some of the connections and for which equivalent routing is desired. For each net group, the method includes systematically routing connection paths between the components for the connections, each connection path extending between an output of one of the components and an input to at least one other of the components and including at least one path fragment. Routing includes, for at least one of the connections of the net group, routing at least one grounded shielding wire in a routing channel adjacent and parallel to at least one of the path fragments of the connection path.

Method and computer program for generating grounded shielding wires for signal wiring

A system and method are provided for reducing the signal delay skew is disclosed, according to a variety of embodiments. One illustrative embodiment of the present disclosure is directed to a method. According to one illustrative embodiment, the method includes receiving an initial netlist having components and connection paths among the components; identifying a first connection path in the initial netlist that comprises path fragments for which there are no equivalent path fragments in a second connection path in the initial netlist; generating a skew-corrected netlist wherein the second connection path is re-routed to have path fragments equivalent to the path fragments of the first connection path; and outputting the skew-corrected netlist.

Method and apparatus for balancing signal delay skew

An improved method for interconnect delay analysis for VLSI circuits reduces a parasitic graph for moment computation by eliminating one or more nodes in the graph. the elimination process is performed based upon the degree of the nodes. By eliminating nodes in this fashion, the computation complexity is significantly reduced. With this elimination process, resistor loops and crossed loops can also be solved. The order in which the nodes are eliminated is optimized using the depth-first-search method on the parasitic graphs, further reducing the computation complexity. The method provides a consistent functional interface, applicable to different circuit model structures. In addition, the method accounts for coupling capacitance between interconnects.

Moment computation algorithms in VLSI system

A system for reducing the signal delay skew is disclosed, according to a variety of embodiments. One illustrative embodiment of the present disclosure is directed to a method. According to one illustrative embodiment, the method includes receiving an initial netlist comprising components and connection paths among the components. The method further includes identifying one or more skew-influencing features in a first connection path in the initial netlist that lack corresponding skew-influencing features in a second connection path in the initial netlist. The method also includes generating a skew-corrected netlist wherein the second connection path includes one or more added skew-influencing features corresponding to those of the first connection path. The method further includes outputting the skew-corrected netlist.

Signal delay skew reduction system

A system, apparatus and method for generating extracted timing model files, such as macro library files, are disclosed. A user interface or data template is provided to an engineer that allows for the population of data within particular fields related to timing characteristics of an IP block, cell or core. Various types of data and fields may be provided into the user interface or data template. The location of relevant files, such as a cell or core netlist, may be provided within the template. Additionally, one or more modes may be selected by the user to define the manner in which the ETM file(s) are to be generated. An ETM file is automatically generated using the information provided in the data template.

Generation of an extracted timing model file

A method of determining whether voltage from an aggressor net exceeds a voltage threshold on a victim net design in an integrated circuit design. Probabilistic noise from the aggressor net on the victim net is calculated. The probabilistic noise is checked against the voltage threshold, and the victim net design is passed when the probabilistic noise does not exceed the voltage threshold. When the probabilistic noise does exceed the threshold, then an effective noise at a desired mean time to failure is computed, and the effective noise is checked against the voltage threshold. The victim net design is passed when the effective noise does not exceed the voltage threshold, and failed when the effective noise does exceed the threshold.

Probabilistic noise analysis

A system, apparatus and method for generating and validating extracted timing model files, such as macro library files, are disclosed. A user interface or data template is provided to an engineer that allows for the population of data within particular fields related to timing characteristics of an IP block, cell or core. An extracted timing model file is generated and a validation procedure is performed. This validation procedure may include comparing the information with the file to a test bench have a plurality of test points. In particular, data provided by the engineer is checked against multiple criteria to ensure that this data is valid and/or falls within an appropriate value range constraints. After the validation procedure has completed, the engineer is provided a summary of the validation results.

Verification of an extracted timing model file

An improved method for interconnect delay analysis for VLSI circuits reduces a parasitic graph for moment computation by eliminating one or more nodes in the graph. The elimination process is performed based upon the degree of the nodes. By eliminating nodes in this fashion, the computation complexity is significantly reduced. With this elimination process, resistor loops and crossed loops can also be solved. The order in which the nodes are eliminated is optimized using the depth-first-search method on the parasitic graphs, further reducing the computation complexity. The method provides a consistent functional interface, applicable to different circuit model structures. In addition, the method accounts for coupling capacitance between interconnects.

Reducing a parasitic graph in moment computation algorithms in VLSI systems

A system for estimating stage delay in an integrated circuit design includes steps of receiving as input an integrated circuit design including a single stage having at least two inputs, an output, and an interconnect connected to the output; calculating a separate interconnect delay for the interconnect as a function of an input ramptime for each of the inputs; adding a gate delay of each of the inputs to the separate interconnect delay calculated as a function of the input ramptime to estimate a stage delay for each of the inputs; and generating as output the stage delay for each of the inputs.

System for avoiding false path pessimism in estimating net delay for an integrated circuit design

A method for determining a timing margin to be applied in an integrated circuit timing design. Circuit simulator path delays and static timing analysis tool path delays are determined for the integrated circuit timing design. The circuit simulator path delays are plotted in a first plot versus a percentage difference between the circuit simulator path delays and the static timing analysis tool path delays, and in a second plot are plotted versus a numerical difference between the circuit simulator path delays and the static timing analysis tool path delays. A first point is identified on the second plot having a largest numerical difference, and the circuit simulator path delay for the first point is identified. A corresponding point on the first plot having the circuit simulator path delay is found, and the percentage difference for the corresponding point is identified. A combination of both the circuit simulator path delay and the percentage difference is used as the timing margin.

Frequency dependent timing margin

A method of computing output delay in a mathematical model of an integrated circuit by sorting cells of original design of an the integrated circuit in a topological order. The original output delays for the sorted cells in the original design are computed in the topological order, to produce original output ramp times. The original output ramp times are propagated and original output delays are computed, and the original output ramp time and original output load for each cell is stored. The cells of the original design are modified to produce a modified design. For each modified cell in the topological order, a new output delay and a new output ramp time are computed and compared to the original output ramp time on the modified cell. When the new output ramp time substantially equals the original output ramp time for a modified cell, the calculations of the modified output ramp time for cells that are further down in the topological order are stopped. Otherwise the calculations of the modified output ramp time for cells that are further down in the topological order are continued until a cell is reached where the new output ramp time substantially equals the original output ramp time.

Delay computation speed up and incrementality

A method for accounting for negative bias temperature instability in a rise delay of a circuit design, the method comprising the steps of create a cell and net model library with original rise numbers, construct the circuit design from the cell and net models, for each cell and net in the circuit design, calculate an original rise delay, apply a negative bias temperature instability model to determine a parameter shift, determine a new rise number from the parameter shift, and calculate a new rise delay by original rise delay* (original rise number)/(new rise number).

Growing community of inventors

Pleasanton, CA, United States of America

Sandeep Bhutani