International Business Machines Corporation

Robert A Proctor

Joseph N Kozhaya

Joseph Natonio

Patrick H Buffet

Gulsun Yasar

Gary S Ditlow

Ivan L Wemple

Ciaran J Brennan

Charles S Chiu

Erich C Schanzenbach

Paul E Dunn

James Patrick Libous

Lu'ay Bakir

Paul D Montane

Rory D Loughran

A method for placing electrostatic discharge clamps within integrated circuit devices is disclosed. A region is initially defined within an integrated circuit design. A list of ESD-susceptible circuits located within the defined region is then generated. The center of gravity of the ESD-susceptible circuits located within the defined region is located. Next, an ESD protection device is placed at the center of gravity of the ESD-susceptible circuits located within the defined region. A determination is made as to whether or not all ESD-susceptible circuits within the list of ESD-susceptible circuits are protected by the placement of the ESD protection device. If so, the process is repeated in other regions until the entire integrated circuit is addressed. Otherwise, the defined region is divided into at least two smaller regions and the process is repeated.

Method for placing electrostatic discharge clamps within integrated circuit devices

A method and system for testing the compliance of a distribution of I/O circuits in a semiconductor chip with voltage (IR) and electromigration (EM) limits. Maximum and average currents for the I/O circuits are calculated. A resistance model for the power distribution network of the chip is created, and the I/O circuit currents are indexed to corresponding nodes in the resistance model. Average current demand of the logic circuitry of the chip is also calculated and indexed to nodes in the resistance model. The resistance model with indexed currents is then solved to determine voltages at the nodes. The voltages are checked for compliance with IR and EM limits, and a report is produced. If violations of the IR and EM limits are detected, the placement of the I/O circuits in the power distribution network may be revised to bring the design into compliance with IR and EM requirements.

Method of power distribution analysis for I/O circuits in ASIC designs

A method of analyzing the power distribution in a chip containing one or more voltage islands, each voltage island having a power distribution network connected to a chip-level power distribution network by one or more voltage translation interface circuits. The method comprising: analyzing the voltage-island power distribution networks independently of the chip-level power distribution network to obtain voltage translation interface circuit currents; using the voltage translation interface circuit currents as input to a model of the chip-level power distribution network to obtain voltage translation interface circuit input voltages; and calculating voltage translation interface circuit output voltages based on the voltage translation interface circuit input voltages, the voltage translation interface circuit currents, and current-voltage characteristics of the voltage translation interface circuits.

Method of analyzing integrated circuit power distribution in chips containing voltage islands

A method of analyzing I/O cell layouts for integrated circuits, such as ASICs, includes defining a proposed I/O cell layout on a selected chip image, providing a set of limit rules for electromigration, IR voltage drop and di/dt noise for the selected chip image, providing characteristics for each I/O cell type used in the proposed I/O cell layout, checking the proposed I/O cell layout by applying the limit rules to the proposed I/O cell layout and reporting all I/O cells used in the proposed I/O cell layout that do not meet the limit rules for the selected chip image.

Fast method of I/O circuit placement and electrical rule checking

A method for improving the crosstalk and time-of-flight performance for signals in an integrated circuit with respect to the package-related wiring. I/O pads in the package-related wiring of a logic design meeting specified crosstalk and time-of-flight constraints are identified using a software tool. The tool produces a graphical display in which the identified I/O pads are highlighted. The tool enables a user to graphically manipulate the display to assign, i.e., establish an electrical connection, between I/O circuits corresponding to the signals and the highlighted I/O pads.

Method of assigning integrated circuit I/O signals in an integrated circuit package

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South Burlington, VT, United States of America

Robert A Proctor