Lucent Technologies Inc.

At&t Bell Laboratories

Agere Systems Guardian Corp.

Agere Systems Inc.

Frank P Higgins

Israel Amir

Ilyoung Kim

Yervant Zorian

James Louis Lewandowski

Hai Quang Pham

Jeffrey Jay Nagy

Goh Komoriya

Kenneth H Billingham

Eric Sweetman

Larry Ray Fenstermaker

Dennis J Fitch

Frank Joseph Krainaker

John Burnet Macdonald

John B Macdonald

William Thomas Kenny

A circuit board, for use with a high speed backplane, includes transmitter and receiver with circuitry for correcting for multipath signal errors. A training sequence that is often a pseudo-random signal is transmitted by the transmitter on a first circuit board to a receiver located on a second circuit board. The receiver on the second circuit board includes an analog-to-digital signal converter, an equalizer, and a binary digital-to-analog reconverter for receiving the training sequence. The equalizer preferably comprises a series of connected registers having taps in between, a plurality of individual weighting means attached to each of the taps, and a summing means connected to the weighting means. A training sequence is transmitted from the first circuit board to the receiver on the second circuit board, enabling the receiver to adaptively determine a set of weighting means coefficients for correcting the multipath errors in subsequent signals. Coefficients for the weighting means are then adjusted from the output of the summing means. The method and system described can substantially reduce the cost of backplane fabrication and enhance the performance of the overall system.

Method and system to increase the performance of high-speed backplanes

A content-addressable memory (CAM) has a memory array for storing data, the memory array having E entries each having N data bits and a valid bit. The functionality of the CAM is tested by testing the memory array for read/write functionality. The functionality of a matching function, a priority encoding function, a match flag function, and a multiple match flag function of the CAM is tested. The functionality of an invalidate data function and a valid data restricted search function is also tested.

Testing content-addressable memories

A reconfiguration memory device is provided associated with a main memory array. The reconfiguration memory device generates a spare address in real time corresponding to a faulty address. The reconfiguration memory device is coupled to an address line, so that when address information is received for the main memory array, the address information is also received by the reconfiguration memory device. The reconfiguration memory device is adapted to send an output signal that results in the address in the spare memory address array being addressed, if the received address information corresponds to a stored faulty address. The output signal includes a spare control signal that directs components to look to the output of the spare memory.

Built-in self-test and self-repair methods and devices for computer memories comprising a reconfiguration memory device

A method is provided for determining the location of faulty components in a computer memory array on a chip and for providing a software repair procedure. According to the method, the location of faulty components in a computer memory array is determined by successively reading and writing to locations in the array according to an algorithm. If a faulty component is detected, it is determined whether a spare component in a spare memory array on the chip is available. If a spare component is available, a spare component is designated to correspond to the faulty component. A look up table on the same chip stores information representing the location of the faulty component associated with information representing the location of the corresponding spare component. The method may also include, testing the memory array by successively reading and writing to locations on the memory array according to an algorithm, during which step, when a faulty component with which a spare component is associated is addressed, the look up table is used to identify the spare component corresponding to the faulty component, and the spare component is addressed.

System and method for detecting faults in computer memories using a look up table

A memory device has first and second sets of memory cells. Each of the cells in the second set is a neighboring cell corresponding to a respective cell of the first set. A data generating function generates a first pattern and a second pattern. A controller causes the first pattern to be written in the first set of memory cells, causes each cell in the second set of memory cells to be read simultaneously while the corresponding neighboring cell in the first set of memory cells is being written to, and causes a datum to be read from each cell in the second set of memory cells after the corresponding neighboring cell in the first set of memory cells is written to. An output data evaluator determines whether the data read from the second set of memory cells match the second pattern, and detects a fault in the memory device, if the data read do not match the second pattern.

Method and system for testing multiport memories

Memory test hardware is provided for generating signals for testing a first memory array and a second memory array. The first memory array and the second memory array may be any two of main memory array, a spare memory array, and reconfiguration memory array, or the apparatus may be adapted for testing all three memory arrays. The memory test hardware may include a controller for generating control signals, a data generator coupled to the controller for generating data signals, and an address generator coupled to the controller for generating address signals. The test device may further include an output data evaluator and repair unit for receiving signals from the main memory array and the spare memory array and for detecting faults in those arrays.

Apparatus for detecting faults in multiple computer memories

An optical probe is positioned between a pair of connectors positioned substantially adjacent to each other so as to read identifying markings on the face or surface of one of the connectors. The optical probe includes a probe head and an illumination device for projecting light substantially parallel to the face of one of the connectors, i.e., a surface being imaged. The illumination device includes a bifurcated fiber optic cable and a pair of prisms positioned so as to illuminate the surface being imaged from opposite directions. A spectral image representative of light scattered by laser etchings on the surface, or light reflected or absorbed by other markings on the surface is projected by a cylindrical mirror through the path of the light from the illumination device to a camera. The camera displays the image of the surface being imaged on a monitor. The probe head is substantially flat and thin so as to fit between the connectors without damaging the connectors. The probe head is also electrically non-conductive so that it can be used while an electronic system utilizing the connectors is operating.

Optical probe for scanning surfaces within constricted spaces

An apparatus for selective multi-directional illumination of an object, particularly for selective multi-directional imaging of an object, comprises a central mirror selectively rotatable about a central axis for reflecting light arriving along the central axis in selected directions radial to the axis. A plurality of differently tilted mirrors are mounted on an annular member selectively rotatable around the central axis for disposing selected ones of the tilted mirrors in the path of light from the central mirror. The tilted mirrors reflect light onto an object at a direction determined by the angular position of the central mirror and at an angle of elevation determined by the selected tilted mirror. Light reflected from the illuminated object reaches an imaging device along a path retracing the illuminating light whereby the direction of viewing of the imaged object corresponds to the direction of illumination of the object.

Illumination system and method

Human inspection of an object (12) having a light-reflective areas (20) thereon arrayed in individual arrays (21) is enhanced by first capturing the image of selected portions of the arrays via one or more image capture devices (34). The images are processed to create a single image frame in which like portions of like arrays of light-reflective are uniformly spaced and oriented in a two-dimensional array having large scale regularity. The single image frame is then displayed on a display (48) for observation by a human operator (29). Because the displayed image frame of the light-reflective areas has large scale regularity, the operator bility to detect defects associated with missing or misaligned light-reflective areas will be enhanced.

Inspection apparatus and method

A bar code (14) on an object (12) is read a distance from the object by a television camera. The output signal of the camera is thresholded to obtain a binary signal indicative of the image information associated with at least one scan line. This binary signal is written into a FIFO storage device (28) at a rate corresponding to the rate at which the camera images the bar code. Once the binary signal is fully written into the FIFO storage device, the binary signal is read from the FIFO at a second, much slower rate for decoding by a bar code decoder (36). In this way, the image of the bar code can be obtained by a television camera which is capable of imaging the bar code at a distance, while the image information can be decoded by a bar code decoder that operates to perform decoding at a rate much slower than the rate at which the camera acquires information.

Method and apparatus for reading bar codes with a television camera

A three-dimensional image of the surface (12) on an object (14) is obtained in real time by a system (10) which includes first and second reflective surfaces (32,38). The first reflective surface successively reflects a separate one of the first and second lines of light (26,28) onto the surface of the object so that each line of light strikes a first strip of area (34) at an acute angle. The second reflective surface reflects the field of view of a linescan camera (40) onto the object's surface so that the camera captures the image of a second strip of area (41) contiguous with the first strip. The first and second reflective surfaces are rapidly rotated in unison by one or more actuators (50,52) such that the object's surface is spanned by the camera each time the surface is spanned by a successive one of the first and second lines of light. A three-dimensional image of each successive second strip imaged by the camera is obtained from a predetermined relationship between the intensity sensed by the camera for that strip when the corresponding first strip is successively illuminated by the first and second lines of light.

Real-time three-dimensional imaging technique

Inspection of a circuit board (10) to detect missing and misaligned active and passive surface-mounted components (12) and (14), respectively, is accomplished by first illuminating the board with top light to enhance the image of the passive components. The circuit board is then displaced, relative to a linescan camera (28) trained on the board, so that the camera captures the image of successive strips of surface area running across the board perpendicular to its direction of movement. The images captured by the camera (28) are stored and thereafter processed by an image-processing system (33) to determine whether any passive component is missing or misaligned. The circuit board is then illuminated with side light to enhance the image of the active components. The circuit board is again displaced relative to the linescan camera so the camera captures the image of successive strips of surface area on the board. The captured images are stored and then processed by the image-processing system to detect whether any of the active surface-mounted components are missing or misaligned.

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West Trenton, NJ, United States of America

Frank P Higgins