International Business Machines Corporation

Atmel Corporation

Cadence Design Systems, Inc.

Brian A Worth

Scott Whitney Gould

Frank Ray Keyser, Iii

Terrance John Zittritsch

Allan Robert Bertolet

Eric Ernest Millham

Wendell Ray Larsen

Joseph Andrew Iadanza

Jeanne P Bickford

Frederick Furtek

Steven Paul Hartman

Kim P Clinton

Timothy Shawn Reny

Christine Marie Fuller

Ronald Raymond Palmer

Gulson Yasar

Peter Anton Habitz

Jinjun Xiong

Vikram Iyengar

Sally S Botala

Wayne Kevin Beebe

Michael Richard Ouellette

Paul Steven Zuchowski

Vernon Roberts Norman

Leon Jacob Sigal

David John Craft

Mark Steven Styduhar

William John Livingstone

Amol Anil Joshi

Kenneth Ferguson

John E Barwin, Iii

Frank Ray Keyser Iii

Jason Chung

A method of characterizing an electromigration (EM) parameter for use in an integrated circuit (IC) chip design including, inputting a layout of a wire layer and identifying a signal gate-circuit including electrically parallel paths, connected to an output of the signal gate from the layout. Based on widths for each of the paths, determining a maximum possible current for each of the paths, and calculating an average current for each of the paths. Identifying a path that is most limited in its current carrying capacity by possible EM failure mechanisms, and storing in a design library, a possible maximum current output to the identified limiting path, as the EM parameter.

Identifying and mitigating electromigration failures in signal nets of an integrated circuit chip design

Methods and systems for qualifying a single cell with product path delay analysis are provided. A method includes designing a product using a model from an initial test site. The method also includes creating performance path tests for one or more paths on the product. The method further includes measuring performance path parameters of the product. The method includes determining that the measured performance path parameters match predicted performance path parameters.

Systems and methods for single cell product path delay analysis

A method for providing quality control on wafers running on a manufacturing line is disclosed. The resistances on a group of manufacturing test structures within a wafer running on a wafer manufacturing line are initially measured. Then, an actual distribution value is obtained based on the result of the measured resistances on the group of manufacturing test structures. The difference between the actual distribution value and a predetermined distribution value is recorded. Next, the resistances on a group of design test structures within the wafer are measured. The measured resistances of the group of design test structures are correlated to the measured resistances of the group of manufacturing test structures in order to obtain an offset value. The resistance of an adjustable resistor circuit within the wafer and subsequent wafers running on the wafer manufacturing line are adjusted according to the offset value.

Method and system for providing quality control on wafers running on a manufacturing line

A programmable gate array includes test subsystems for testing various functional subsystems of the programmable gate array. A sequence of test methods, employing the test subsystems, test the functionality of the programmable gate array, taking into account the interdependencies of the various subsystems and accordingly enabling fault isolation therein.

Testable programmable gate array and associated LSSD/deterministic test

A programmable logic cell has four cell input nodes and a plurality of combinational logic circuits. Four inverter circuits are provided for programmably inverting respective input logic signals, each inverter circuit having an inverter input node connected to a respective cell input node for accepting its respective input logic signal therefrom. Each inverter is programmable into a first state wherein a logic signal representing the complement of the input logic signal is provided to the inverter output node, and a second state wherein a logic signal representing the non-complement of the input logic signal is provided to the inverter output node. The inverter circuits buffer their input logic signals in both their first and second states. A first logic gate of the plurality of combinational logic circuits has first and second inputs each connected to a respective output node of one of two of the four inverter circuits, and a second logic gate has first and second inputs each connected to a respective output node of one of the other two of the four inverter circuits. The inverter circuits may be implemented as XNOR gates.

Programmable inverter circuit used in a programmable logic cell

A programmable logic cell has four logic gates, two of which are configurable. The two configurable logic gates are positioned near the logic cell inputs. Each configurable logic gate has two inputs, each input being connected to one of the four logic cell inputs. The remaining two logic gates receive the outputs of the configurable logic gates. Four independent logic cell input nodes are provided, each having associated therewith a programmable input multiplexer. Each input multiplexer can have inputs connected to at least two types of interconnect conductors. The cell also has two output paths, each having associated therewith an independently-controlled output multiplexer. The output of each output multiplexer is connected to an input of the other output multiplexer. Additional features include a multiplexer having inputs connected to two cell input nodes, a select input connected to a third logic cell input node, and an output connected to a cell output node; a system low-skew data (e.g., clock) input available to at least one of the input multiplexers; a flip-flop connected within the logic cell; and internal cell feedback. The preferred method of programming utilizes user-programmed SRAM memory cells.

Programmable logic cell

A generalized data decompression engine is incorporated within a field programmable gate array ('FPGA'). The generalized data decompression engine uses a general purpose data decompression technique such as, for example, a Lempel-Ziv type technique. During operation, a compressed configuration bit stream is received by the generalized data decompression engine in the FPGA and is decompressed thereby. A resultant decompressed configuration bit stream is then used to program logic cells within the FPGA.

Method and system for programming a gate array using a compressed

A given interconnect of a programmable gate array includes a programmable repeater circuit that enables selective isolation and testing of a select block of configured circuitry within the programmable gate array. The programmable repeater circuit includes an input node coupled to a first portion of the given interconnect and an output node coupled to a second portion of the given interconnect. A selective buffer circuit selectively outputs a buffered output signal to the output node that is related to a logic state at the input node. A signal storage circuit is also connected to the input node for selectively storing the logic state received from the input node. In a further embodiment, the signal storage circuit comprises an LSSD register. A primary latch of the LSSD register receives data selectively either from the input node, in accordance with a first clock signal, or alternatively from a secondary serial input node, in accordance with a second clock signal. A secondary latch of the LSSD register is selectively coupled, per a third clock signal, to receive and latch therein latched data of the primary latch. Data representative of data latched within the secondary latch is provided at a secondary serial output, and selectively provided at the primary output node when enabled per a programmable enable signal. In yet a further embodiment, the LSSD register is part of a serial scan chain for selectively interfacing an interconnect boundary of the select block of the configured circuitry within the programmable gate array.

Programmable array interconnect latch

A signal distribution architecture for clock and reset signal distribution in a programmable array is disclosed. The architecture includes separate networks for distributing clock and reset signals to logic cells of the array. Each network includes a plurality of column multiplexers for selecting a column clock or reset signal from a plurality of system clock or reset signals. Within each column of logic cells are positioned sector multiplexers for selecting a sector clock or reset signal from a plurality of column clock or reset signals. The clock and reset signals are applied to the combinatorial and sequential logic circuits of each logic cell associated with a given sector multiplexer. A clock gate circuit is controlled cooperatively with an output multiplexer in each logic cell. The networks are designed with features to minimize signal skew including signal source buffering, multiplexer signal buffering and output driver sizing as a function of signal propagation distance.

Low skew multiplexer network and programmable array clock/reset

Programmable array clock/reset resource

A field programmable gate array has a plurality of programmable resources addressable per respective x and y dimensions of an x,y two dimensional array. A memory device provides a plurality of memory units that store configuration data for configuring associated programmable resources of the field programmable gate array. A controller addresses the memory device with an N-bit address for retrieving given configuration data. An address decoder and sequencer divides the N-bit address into first, second, and third portions and employs the first and third portions interchangeably, in accordance with the second portion, for addressing respective x and y dimensions of the plurality of programmable resources for selecting an associated programmable resource to be configured in accordance with the retrieved configuration data.

Memory mapping method and apparatus to fold sparsely populated

A programmable array having programmable logic cells, a programmable interconnect network and a programmable I/O system. Two I/O interfaces are provided for respective logic cells about the perimeter of the array. The I/O interfaces comprise input, output and enable paths. Each of these paths has an associated multiplexer. An I/O routing network is positioned about the perimeter of the array. Conductors connecting the I/O interface multiplexers to the programmable interconnect network also intersect, and can be programmably connected to, buses of the I/O routing network.

Programmable array I/O-routing resource

A signal distribution architecture for clock and reset signal distribution in a programmable array is disclosed. The architecture includes separate networks for distributing clock and reset signals to logic cells of the array. Each network includes a plurality of column multiplexers for selecting a column clock or reset signal from a plurality of system clock or reset signals. Within each column of logic cells are positioned sector multiplexers for selecting a sector clock or reset signal from a plurality of column clock or reset signals. The clock and reset signals are applied to the combinatorial and sequential logic circuits of each logic cell associated with a given sector multiplexer. A clock gate circuit is controlled cooperatively with an output multiplexer in each logic cell. The networks are designed with features to minimize signal skew including signal source buffering, multiplexer signal buffering, and output driver sizing as a function of signal propagation distance.

Growing community of inventors

Milton, VT, United States of America

Brian A Worth