Patents by Inventor Lloyd A. Walls

Lloyd A. Walls has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20080093726
    Abstract: A mechanism for continuously referencing signals over multiple layers in laminate packages provides a continuous path for signals from one layer to another while using the ideal voltage reference for all areas of the package and still avoiding discontinuities in the voltage reference. A reference plane adjustment engine analyzes a package design and identifies an ideal top plane for all areas of the package, including areas under particular chip die(s) and areas that are not under a chip die. The reference plane adjustment engine then modifies the package design to reposition ground planes, source voltage planes, signal planes, and vias between layers to maintain a continuous voltage reference regardless of the top layer. The reference plane adjustment engine provides the resulting mixed voltage plane package design to a design analysis engine. A package fabrication system fabricates the package.
    Type: Application
    Filed: October 23, 2006
    Publication date: April 24, 2008
    Inventors: Francesco Preda, Lloyd A. Walls
  • Publication number: 20070215973
    Abstract: A compact resistive thermal sensor is provided for an integrated circuit (IC), wherein different sensor components are placed on different layers of the IC. This allows the lateral area needed for the sensor resistance wire on any particular IC layer to be selectively reduced. In a useful embodiment, a plurality of first linear conductive members are positioned in a first IC layer, in spaced-apart parallel relationship with one another. A plurality of second linear conductive members are similarly positioned in a second IC layer in spaced-apart parallel relationship with one another, and in orthogonal relationship with the first linear members or in parallel with existing wiring channels of the second IC layer. Conductive elements respectively connect the first linear members into a first conductive path, and the second linear members into a second conductive path.
    Type: Application
    Filed: March 14, 2006
    Publication date: September 20, 2007
    Inventors: Aquilur Rahman, Lloyd Walls
  • Patent number: 5635761
    Abstract: Thin-film conductor technology is utilized to form resistors of precisely controlled value within the interior of multi-chip modules to properly terminate network circuits which interconnect one or more chips with either output pin connections or other chips on the multi-chip module. By forming and disposing the resistors within the interior of the multi-chip module, the terminating resistors may be manufactured during the multi-chip module manufacturing process. This approach preserves valuable surface area available for interconnecting the computer chips to the multi-chip module rather than consuming scarce surface area with termination resistors and other circuit elements necessary to adapt the multi-chip module and the other computer chips to each other.
    Type: Grant
    Filed: December 14, 1994
    Date of Patent: June 3, 1997
    Assignee: International Business Machines, Inc.
    Inventors: Tai A. Cao, Herbert I. Stoller, Thanh D. Trinh, Lloyd A. Walls
  • Patent number: 5541535
    Abstract: A CMOS driver/receiver pair is provided which includes a non-inverting buffer in the input path to a differential receiver circuit. The non-inverting buffer allows a plurality of different voltages, and corresponding voltage swings, to be possible. This allows the differential receiver to compare the input voltage received from the transmission line with the output from its associated driver. Therefore, the receiver is capable of determining the voltage level (and the corresponding logic level) input from the transmission at the same time its associated driver is outputting a logic signal to another driver/receiver pair, via the transmission line. A single voltage source is utilized to provide multiple positive voltages to the differential receivers, such that differences in voltage levels which correspond to different logical combinations of "1" and "0" can be determined by the receiver.
    Type: Grant
    Filed: December 16, 1994
    Date of Patent: July 30, 1996
    Assignee: International Business Machines Corporation
    Inventors: Tai A. Cao, Satyajit Dutta, Thai Q. Nguyen, Thanh D. Trinh, Lloyd A. Walls
  • Patent number: 5541534
    Abstract: The present invention facilitates communication of signals from circuitry implemented with a first CMOS technology requiring a first voltage level supply for operation to circuitry implemented with a second CMOS technology requiring a second voltage level supply for operation, wherein the first and second voltage level supplies are not equal. The present invention receives from the circuitry implemented with a first CMOS technology a signal which has a first voltage level that is not acceptable for input into the circuitry implemented with a second CMOS technology. This signal is converted to a second voltage level that is acceptable for input into the circuitry implemented with a second CMOS technology, and then transmitted to the circuitry implemented with a second CMOS technology requiring a second voltage level supply for operation.
    Type: Grant
    Filed: February 13, 1995
    Date of Patent: July 30, 1996
    Assignee: International Business Machines Corporation
    Inventors: Tai Cao, Satyajit Dutta, Thai Q. Nguyen, Thanh D. Trinh, Lloyd A. Walls
  • Patent number: 5534812
    Abstract: The present invention includes an output circuit for a driver on a first chip that will cause an unterminated transmission line to create a predetermined voltage reflection. This reflection will then be added to the output of the driver circuit to obtain a voltage level capable of switching the receiver circuit, located on a second chip. Further, the impedance of the driver can be varied to adjust the voltage level of the signal being transmitted to the receiver, in order to reduce noise margins and cause the receiver to switch more quickly. Additionally, the transmission line impedance can also be modified to create overshoot, thereby allowing chips with dissimilar voltage levels to communicate with one another.
    Type: Grant
    Filed: April 21, 1995
    Date of Patent: July 9, 1996
    Assignee: International Business Machines Corporation
    Inventors: Tai A. Cao, Satyajit Dutta, Thai Q. Nguyen, Thanh D. Trinh, Lloyd A. Walls
  • Patent number: 5530377
    Abstract: A method and apparatus for providing active termination of a transmission line is accomplished by providing a pair of complementary transistors operably coupled to the transmission line, wherein one of the transistors provides the active termination impedance when the transmission line is in a first state, and the other transistor provides the active termination when the transistor is in a second state. The complementary pair of transistors may be gated such that when it is desired to remove the active termination from the circuit, it can be done. The line driver/receiver reduces part count by commonly using circuitry in the active termination stage and the receiver stage.
    Type: Grant
    Filed: July 5, 1995
    Date of Patent: June 25, 1996
    Assignee: International Business Machines Corporation
    Inventor: Lloyd A. Walls
  • Patent number: 5506457
    Abstract: An electronic switch circuit switches out bad decoupling capacitors on a high speed integrated circuit chip. The circuit comprises a control device that operates in the subthreshold or off device state to detect leakage in a decoupling capacitor. This control device operates in a low impedance state if the capacitor is good and in a high impedance sate if the capacitor is bad. A feedback circuit is connected from an internal node of the capacitor to a gate of the control device so that once a state of the capacitor is detected it can be stored on the gate of the control device. A single external signal source shared by a group of capacitors activates the control device to detect leakage in the capacitor. The circuit operates to switch out capacitors that fail during normal operation.
    Type: Grant
    Filed: April 7, 1995
    Date of Patent: April 9, 1996
    Assignee: International Business Machines Corporation
    Inventors: Byron L. Krauter, Peter J. Klim, Tak H. Ning, Stanley E. Schuster, Lloyd A. Walls
  • Patent number: 4862077
    Abstract: A probe card apparatus and method which allows reconfiguration of the probing circuits. A first probe card member has a plurality of incomplete probing circuits which are associated with a plurality of contact holes. An adapter ring member, having a plurality of T-shaped conductive lines terminated in contact holes, is removably mounted in close proximity to the first probe card member. Spring-loaded contact pins provide contact between the members such that the T-shaped conductive lines are used to complete the probing circuit. The T-shaped conductive lines are severable lines, and discrete electronic components can be connected between respective contact holes. As the adapter ring member is of a removably attachable construction, the entire probe card circuitry is reconfigurable by a simple change of the adaptor ring.
    Type: Grant
    Filed: February 13, 1989
    Date of Patent: August 29, 1989
    Assignee: International Business Machines Corporation
    Inventors: Timothy A. Horel, Edward S. Hoyt, Lloyd A. Walls
  • Patent number: 4459609
    Abstract: A dense memory is provided which includes a one device random access memory cell using charge fill and spill techniques wherein a potential well under a storage node is filled with charge and the excess charge above a predetermined level is spilled to a diffusion or drain region connected to a sense line through a channel region controlled by pulses on a word line. One bit or two or more bits of information may be stored in the potential well at any given instant of time. Depending upon the value of the increment of voltage applied to the storage node or electrode, a given analog charge packet is stored in a potential well formed under the storage electrode. Information is read by applying a voltage to the word line to turn on the channel region and then stepping down the voltage on the storage electrode in fractional, preferably one half, increments. Charge from a charge packet spilled from the potential well under the storage electrode is detected by a sensing circuit connected to the sense line.
    Type: Grant
    Filed: September 14, 1981
    Date of Patent: July 10, 1984
    Assignee: International Business Machines Corporation
    Inventors: John A. Fifield, Lawrence G. Heller, Lloyd A. Walls