Abstract: A method and apparatus for thermal testing of semiconductor chip designs is provided. One embodiment of a novel method for performing thermal testing of a semiconductor chip design includes calculating full-chip temperatures over the semiconductor chip design (e.g., to identify steep thermal gradients) and positioning temperature sensors within a corresponding semiconductor chip in accordance with the calculated full-chip temperatures (e.g., in the regions of steep thermal gradients). Thus, temperature sensors are strategically placed in the regions where they are most likely to be needed, according to calculated temperatures, rather than randomly positioned throughout a test chip.

Abstract: A method and apparatus is described which allows efficient optimization of integrated circuit designs. By performing a global analysis of the circuit and identifying bottleneck nodes, optimization focuses on the nodes most likely to generate the highest return on investment and those that have the highest room for improvement. The identification of bottleneck nodes is seamlessly integrated into the timing analysis of the circuit design. Nodes are given a bottleneck number, which represents how important they are in meeting the objective function. By optimizing in order of highest bottleneck number, the optimization process converges quickly and will not get side-tracked by paths that cannot be improved.

Abstract: Methods of creating a power distribution arrangement with tapered metal wires for a physical design are provided and described. In one embodiment, a method of creating a power distribution arrangement for a physical design of an integrated circuit includes arranging a plurality of metal wires for power distribution in a desired arrangement. Each metal wire has a width. Furthermore, the metal wires are tapered such that the width is thicker in a core edge area of the physical design than in a core center area of the physical design. In other embodiments, a method of creating a power distribution arrangement for a physical design of a current integrated circuit includes arranging a plurality of metal wires for power distribution in a desired arrangement. The metal wires are tapered using a routing congestion profile and/or a voltage drop profile of a prior physical design of a prior integrated circuit.

Abstract: Subtleties of advanced fabrication processes and nano-scale phenomena associated with integrated circuit miniaturization have exposed the insufficiencies of design rules. Such inadequacies have adverse impact on all parts of the integrated circuit creation flow where design rules are used. In addition, segregation of the various layout data modification steps required for deep sub-micrometer manufacturing are resulting in slack and inefficiencies. This invention describes methods to improve integrated circuit creation via the use of a unified model of fabrication processes and circuit elements that can complement or replace design rules. By capturing the interdependence among fabrication processes and circuit elements, the unified model enables efficient layout generation, resulting in better integrated circuits.

Abstract: Methods for floorplanning a hierarchical physical design to improve placement and routing are provided and described. In one embodiment, a method of floorplanning a hierarchical physical design includes arranging a plurality of blocks in a top-level of the hierarchical physical design. Each block includes a plurality of linear edges. Additionally, at least one of the blocks is selected. Furthermore, at least one linear edge of the selected block is rasterized. This rasterization includes converting the linear edge to a stepped-shape edge.

Abstract: A basic Boolean circuit is a transistor circuit commonly used in industry to produce the logic of a particular Boolean gate. A sequence of standard Boolean circuits disposed along the processing path of an integrated circuit define a predetermined truth table representing the relationship of inputs and outputs of the processing path. A reduced-transistor circuit is generated that is defined by the same truth table as the sequence of standard Boolean logic circuits, but is not definable by a sequence of standard Boolean logic circuits. A processing path of an integrated circuit is programmed with the reduced-transistor circuit instead of the sequence of standard Boolean circuits, thereby reducing the time delay of the processing path and the power consumed by the circuit. The reduced-transistor circuit may be generated in response to receiving a programming instruction defining a sequence of Boolean gates.

Abstract: A highlighting system for use with electronic circuit design tools is provided for displaying signal waveforms and Register Transfer Logic (RTL) source code portions corresponding to a selected signal in the same window. The user selects a time and signal to be explored. Based on the selected time and signal, the values of all related signals are identified from a database generated by simulation of RTL source code. Nodes corresponding to the related signals are identified from a gate-level netlist corresponding to the RTL source code and the nodes responsible for the particular value of the selected signal at selected time are identified. The nodes are then mapped on to the RTL source code portions by a process of Instrumentation. The RTL source code portions so identified are then displayed. In particular, the portions of the RTL source code responsible for the particular value or transition in particular value of the signal at the selected time are highlighted.

Abstract: A technique to verify, evaluate, and estimate the performance of an integrated circuit is embodied in a computer software program that is executable by a computer system. To estimate performance, the integrated circuit design is partitioned into strongly coupled components and state points are identified. The technique accurately estimates of the performance (e.g., transient delays) of an integrated circuit, and has fast execution times. The technique is applicable to small circuits having relatively few transistors, and especially well suited for integrated circuits having millions of transistors and components. The technique handles the effects of deep-submicron integrated circuit technology.

Abstract: Methods for generating a padring layout design are described. These methods utilize automation while still allowing customization. Automation is emphasized as much as possible so that more time can be used to solve the various problems that make each padring layout design unique. A framework in which regular patterns can be described, replicated, and tailored is provided. The padring is broken down into zones in which slots having bumps/bond pads areas, I/O cell areas, and/or edge logic cell areas are laid out in a regular pattern through an instantiation process. Edge logic, which is comprised of standard cells, is pulled from the core of the chip because these cells couple directly to I/O cells and are critical for timing.

Abstract: A method for modeling integrated circuit designs in a hierarchical design automation system which utilizes a block abstraction including therein set of all database objects (cells, nets, wires, vias, and blockages) that are necessary to achieve accurate placement, routing, extraction, simulation, and verification of the block's ancestors in the hierarchy.

Abstract: A method and apparatus are presented that can analyze the performance of an integrated circuit design at multiple corners, under multiple modes, and for multiple objectives efficiently and simultaneously. The extraction, timing analysis, and optimization functions are integrated into a mechanism that provides a novel problem formulation. A plurality of virtual timing graphs are maintained and updated simultaneously by providing a data structure that can efficiently store operating data for an arbitrary number of conditions at each node. This data structure is populated according to the design, and as optimizations are made, the operating data for all design conditions is updated simultaneously. Timing violations can be reported across all corners and modes. By integrating this multi-corner multi-mode analysis with circuit optimization, a convergent mechanism is provided. In this way, design constraints are evaluated simultaneously for an arbitrary number of design conditions.

Abstract: The present invention is used for guiding formal verification of a circuit design in circuit simulation software to optimize the time required for verification of a circuit design. The invention modifies the analysis region being used for verification in order to optimize the time for verification. The invention allows for manual, semi-automatic, and automatic modification of the analysis region. The modification is done by either expanding or reducing the analysis region or by adding new rules as assumptions to the existing analysis region. The invention also uses the concept of an articulation point for modification of the analysis region. The modification of the analysis region is performed in a manner to optimize time and memory required for verification of the circuit design.

Abstract: A process for reducing cross-talk noise in a VLSI circuit is disclosed. The process identifies a victim net in an integrated circuit and calculates a change in ground capacitance for the victim net to identify a noise amplitude less than or equal to a maximum allowable noise height. The process selects from a library one cell or a grouping of cells having an input capacitance for the victim net closest to the change in ground capacitance. The selected cell or grouping of cells is coupled to the victim net so that its change in ground capacitance provides a noise amplitude less than (or less than or equal to) an allowable maximum noise height that may be a predetermined value. A system for reducing cross-talk noise in a VLSI circuit is also disclosed.

Abstract: Methodology for verifying properties of a circuit model in context of given environmental constraints is disclosed. Verification of a specified property is performed by analyzing only a portion of the circuit model. The present methodology is also directed towards reducing the computation time for verifying the specified property. Further, the present methodology allows the connection of an additional circuit model to the circuit model in a non-intrusive manner. The connection is made without making any modifications to the description of the circuit model. This permits the straightforward specification of related environmental constraints and properties, which makes it possible to verify correct behavior of complex interfaces.

Abstract: A method and apparatus for identifying potential noise failures in an integrated circuit design is described. In one embodiment, the method comprises locating a victim net and an aggressor within the integrated circuit design, modeling the victim net using two ?-type resistor-capacitor (RC) circuits, including determining a coupling between the victim net and the aggressor, and indicating that the integrated circuit design requires modification if modeling the victim net indicates that a potential noise failure may occur in the integrated circuit design.

Abstract: A technique to verify, evaluate, and estimate the performance of an integrated circuit is embodied in a computer software program that is executable by a computer system. Vectors are generated to estimate integrated circuit performance. The technique accurately estimates of the performance (e.g., transient delays) of an integrated circuit, and has fast execution times. The technique is applicable to small circuits having relatively few transistors, and especially well suited for integrated circuits having millions of transistors and components. The technique handles the effects of deep-submicron integrated circuit technology.

Abstract: A fast method of estimating capacitances and wire delays in an integrated circuit design is based on placement information such as that contained in a gate schematic net list from a logic synthesis tool. A simple tree topology called a spine tree is constructed to connect the pins of the net as an approximation of actual connections therein. Capacitance is extracted for this topology assuming a worst case scenario, and Elmore delays are computed for the wire delays based on the worst-case capacitances. The method takes linear time as a function of the number of pins in the net and is much faster than using a Steiner tree method in this context.

Abstract: A software-based system for generating timing constraints for a proposed IC design has a first input as a synthesizable description of the proposed IC, a second input as a clock specification for the proposed IC, and a processing unit accepting the first and second inputs, and determining therefrom as an output, a set of timing constraints to guide implementation of the proposed IC design.

Abstract: A technique to verify, evaluate, and estimate the performance of an integrated circuit is embodied in a computer software program that is executable by a computer system. The technique accurately estimates of the performance (e.g., transient delays) of an integrated circuit, and has fast execution times. The technique includes an incremental recharacterization feature where only portions of the design which have been changed or are new or different will need to be recharacterized during subsequent runs of the software. Portions of the design which are the same need not be recharacterized, and results for those portions from a previous run (stored in a database) are used. This saves execution time since the performance recharacterization or evaluation process is generally more time consuming than a database look up. The technique is applicable to small circuits having relatively few transistors, and especially well suited for integrated circuits having millions of transistors and components.

Abstract: What is disclosed is a method for budgeting timing in a hierarchically decomposed integrated circuit design, which includes: 1) optimizing at least one path through block pins, the optimization resulting in assigned gains for all the cells along said at least one path; 2) performing timing analysis on the at least one path, the timing analysis using the assigned gains in order to generate arrival times for signals at said block pins; and 3) deriving a tinting budget by examining said generated arrival times at said block pins.