Lsi Logic Corporation

Lsi Corporation

Other

Mentor Graphics Corporation

Dusan Petranovic

Ranko L Scepanovic

Nicholas F Pasch

Edwin R Jones

Mario Garza

Nicholas K Eib

Advait Madhav Mogre

Richard D Schinella

Keith K Chao

John V Jensen

Seapahn Megerian

Miodrag Potkonjak

Ivan Pavisic

Stanislav V Aleshin

Roberto Suaya

Rafael Escovar

Salvador Ortiz

Shrinath Thelapurath

Aiguo Lu

Genadij V Belokopitov

Evgenij Egorov

Marina G Medvedeva

Mikhail Grinchuk

Sergei Gashov

Miodrag Potkoniak

Exemplary impedance extraction methods, systems, and apparatus are described herein. In one exemplary embodiment, for instance, a signal-wire segment of a circuit layout is selected. A predetermined number of return paths are identified for the selected signal-wire segment. The selected signal-wire segment and the identified return paths are further segmented into a plurality of bundles, which comprise signal-wire subsegments and one or more associated return-path subsegments that are parallel to and have the same length as the signal-wire subsegments. Loop inductance values and loop resistance values are determined and stored for the signal-wire subsegments in the bundles for at least one frequency of operation. Computer-readable media storing computer-executable instructions for causing a computer to perform any of the disclosed methods or storing data or information created or modified using any of the disclosed techniques are also disclosed.

Extracting high frequency impedance in a circuit design using an electronic design automation tool

A method for developing a circuit is disclosed. The method generally comprises the steps of (A) generating a solution space having a dimension for each of a plurality of parameters for the circuit, (B) evaluating a plurality of instances of the circuit in the solution space through a software simulation, (C) evaluating the instances through a hardware simulation, and (D) updating the instances in response to the software simulation and the hardware simulation to approach an optimum instance of the instances for the circuit.

Decoder using a memory for storing state metrics implementing a decoder trellis

Metacores: design and optimization techniques

A method for decoding an encoded signal. A first step generates a plurality of first precision state metrics for a decoder trellis in response to a plurality of first precision branch metrics. A second step generates a plurality of second precision state metrics for a selected subset of the first precision state metrics in response to a plurality of second precision branch metrics. A third step replaces the selected subset of first precision state metrics with the second precision state metrics. A fourth step stores the first precision state metrics and the second precision state metrics.

Multi-resolution Viterbi decoding technique

A method for optimal placement of cells on a surface of an integrated circuit, comprising the steps of comparing a placement of cells to predetermined cost criteria and moving cells to alternate locations on the surface if necessary to satisfy the cost criteria. The cost criteria include a timing criterion based upon interconnect delay, where interconnect delay is modeled as a RC tree expressed as a function of pin-to-pin distance. The method accounts for driver to sink interconnect delay at the placement level, a novel aspect resulting from use of the RC tree model, which maximally utilizes available net information to produce an optimal timing estimate. Preferred versions utilize a RC tree interconnect delay model that is consistent with timing models used at design levels above placement, such as synthesis, and below placement, such as routing. Additionally, preferred versions can utilize either a constructive placement or iterative improvement placement method.

Timing-driven placement method utilizing novel interconnect delay model

A method and apparatus are provided for generating constraints for an integrated circuit logic re-synthesis algorithm. The method and apparatus receive a netlist of interconnected logic elements, which includes a plurality of nets, wherein each of the nets is coupled between a respective net driver logic element and at least one driven logic element. The method and apparatus also receive a maximum allowable input ramp time specification for the logic elements and an output ramp time specification for the net driver logic elements. A maximum interconnect capacitance constraint is then generated for each of the net driver logic elements based on the output ramp time specification for that net driver logic element and the maximum allowable input ramp time specification.

Placement-based integrated circuit re-synthesis tool using estimated maximum interconnect capacitances

The present invention is a method and apparatus for applying one-dimensional proximity correction to a piece of a mask pattern, by segmenting a first piece of a mask pattern with horizontal dividing lines into a plurality of segments, segmenting a second piece of said mask pattern with said horizontal dividing lines into a second plurality of segments, and applying proximity correction to a first segment from said first plurality of segments taking into consideration a second segment from said second plurality of segments.

Method and apparatus for application of proximity correction with relative segmentation

The present invention is a method and apparatus for applying proximity correction to a piece of a mask pattern, by segmenting the piece into a plurality of segments, and applying proximity correction to a first segment without taking into consideration the other segments of the piece.

Method and apparatus for application of proximity correction with unitary segmentation

An aerial image produced by a mask having transmissive portions is simulated by dividing the transmissive portions of the mask into primitive elements, obtaining a response for each of the primitive elements, and then simulating the aerial image by combining the responses over all of the primitive elements.

Geometric aerial image simulation

The present invention is a method and apparatus for systematically applying proximity corrections to a mask pattern, wherein the pattern is divided into a grid of equally sized grid rectangles, an inner rectangle comprising a plurality of grid rectangles is formed, an outer rectangle comprising a second plurality of grid rectangles and the inner rectangle is formed and proximity correction is applied to the pattern contained within the inner rectangle as a function of the pattern contained within the outer rectangle.

Method and apparatus for general systematic application of proximity correction

Method of proximity correction with relative segmentation

An aerial image produced by a mask having transmissive portions is simulated by dividing the transmissive portions of the mask into primitive elements and obtaining a spatial frequency function corresponding to each of the primitive elements. The spatial frequency functions corresponding to the primitive elements are combined to obtain a transformed mask transmission function, and the transformed mask transmission function is utilized to generate a simulation of the aerial image.

Hybrid aerial image simulation

Integrated circuit chips (IC's) require proper placement of many cells (groups of circuit components) and complex routing of wires to connect the cells. Designing of the IC's require meeting real-world constraints one of which is the performance of the IC, or the period of time required by the integrated circuit to produce the output signals from the time the input signals are available. Typically, the performance of an integrated circuit is determined by the slowest path of the signals, called the critical path. The critical path is usually only a small portion of the IC. The present invention discloses a method and apparatus for transforming the circuits comprising the critical path, thereby increasing the performance of the entire IC. The transformation is performed by segmenting, or blocking, the cells which make up the critical path. Then, each block is transformed, or replaced, with a resynthesized circuit to which both the digital 0 and digital 1 values are provided. The critical path is defined by the fact that the delay at each block is accumulated because each block has to wait for the output signal of the preceding block to use as its input signal. After the resynthesis of the blocks, none of the blocks need to wait for the output signal of its preceding block because each of the resynthesized blocks has the output for all possible inputs values (0 and 1). Thus, the signal delay at each block is not accumulated; rather, the only accumulated delay is the delay of the multiplexors used to select the correct output. The result is a dramatically reduced critical path delay.

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Cupertino, CA, United States of America

Dusan Petranovic