Patents by Inventor John Fifield

John Fifield 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).

  • Patent number: 6195027
    Abstract: A method and structure for decoding n input signals and their complements to one of m output signals is provided. A capacitive network is provided having m output nodes. The output nodes are precharged to a given voltage value. N input signals and their complements are provided each having either a high value or a low value. At least one but less than all of the output nodes are discharged to a value less than the given voltage but greater than ground in output patterns responsive to given input patterns of the true and complement values of the input signals. The output patterns of the discharged nodes is such as to provide one and only one discharged or one and only one undischarged node for any given pattern of input signals. Preferably the capacitive network includes NMOS inversion capacitors.
    Type: Grant
    Filed: April 30, 1999
    Date of Patent: February 27, 2001
    Assignee: International Business Machines Corporation
    Inventors: Claude L. Bertin, John A. Fifield, Russell J. Houghton, Christopher P. Miller, Steven W. Tomashot, William R. Tonti
  • Patent number: 6177807
    Abstract: A processor with a memory send/received control circuit including a bus drive circuit and a detector circuit connected via control bus line to the control input of the memory. A data input line, or output line, or data input/output line is connected between the processor and the memory. A transmission line stub having a length that is incrementally variable is connected to the memory control input side of the control line 14. The impedance Z0 of the transmission line stub is equal to that of the control line and is open circuited at the end which results in voltage doubling to achieve high speed synchronization between control signals and data signals and to ensure valid data at high clock rates.
    Type: Grant
    Filed: May 28, 1999
    Date of Patent: January 23, 2001
    Assignee: International Business Machines Corporation
    Inventors: Claude L. Bertin, John A. Fifield, Erik L. Hedberg, Russell J. Houghton, William R. Tonti
  • Patent number: 6177809
    Abstract: A first, “known good” reference off-chip driver circuit actuated by an initial logic program (IPL) input signal has an output lead connected as one of the inputs to a comparator circuit for providing a reference off-chip driver output signal. A second off-chip driver circuit including a plurality of “n” separate driver circuit paths connected to input signal and produces output signals connected to a common node to provide output driver signals to the common node. The common node is connected to the second input of the comparator circuit for comparison with the reference off-chip driver output signal from the first off-chip driver circuit to determine the operating state of the second off-chip driver circuit with respect to the operating state of the first off-chip driver circuit.
    Type: Grant
    Filed: May 28, 1999
    Date of Patent: January 23, 2001
    Assignee: International Business Machines Corporation
    Inventors: William R. Tonti, Jack A. Mandelman, Anthony R. Bonaccio, Claude L. Bertin, Howard L. Kalter, John A. Fifield
  • Patent number: 6177817
    Abstract: An off-chip driver circuit with compensated current source including a reference current amplifier and an output driver with a pull-up section. The reference current amplifier includes an input voltage Vcmn from an on chip current reference source. A reference current is established in the reference current amplifier by choosing the Beta of transistor in a current path. A feature of the circuit is that an output current is produced in the output lead of the driver circuit that is proportional to the current in the reference current amplifier, but with adjustments made for the supply voltage level and effective transistor channel length, Leff. Another feature of the circuit is that a reference current-voltage is established on the output lead of the reference current amplifier that is primarily determined by a multiple of the reference current but is reduced by a function of the supply voltage. In the circuit the output current of the driver is reduced linearly and predictably with the supply voltage.
    Type: Grant
    Filed: April 1, 1999
    Date of Patent: January 23, 2001
    Assignee: International Business Machines Corporation
    Inventors: John A. Fifield, Russell J. Houghton, Adam B. Wilson
  • Patent number: 6166561
    Abstract: OCD circuitry is provided for an integrated circuit having a split rail power supply providing a first and a second voltage. The OCD circuitry comprises a tristate logic circuit adapted to control the OCD and a detection circuit coupled to the tristate logic circuit and adapted to generate an inactivation signal that inactivates the OCD if the first voltage is low. The detection circuit preferably comprises a comparator that compares the first voltage to the second voltage, and that generates the inactivation signal if the first voltage is less than the second voltage. To prevent the inadvertent inactivation of the OCD circuitry, the detection circuit preferably is provided with a filter that sets a minimum time period that the first voltage must be low before the detection circuit generates the inactivation signal and thus inactivates the OCD circuitry.
    Type: Grant
    Filed: February 26, 1999
    Date of Patent: December 26, 2000
    Assignee: International Business Machines Corporation
    Inventors: John A. Fifield, Christopher P. Miller
  • Patent number: 6141245
    Abstract: A system and method for reducing impedance loading of semiconductor integrated circuit devices implementing protective device structures that contributes to impedance loading at an I/O pad connection. The method comprises providing a fuse device between the I/O pad connection and the protective device; connecting a current source device associated with each fuse device in the integrated circuit, the current source device connected to one end of the fuse device; providing fuse selection circuit for activating current flow through a selected fuse device between the current source and the I/O connection, the current flow being of an amount sufficient for blowing the fuse and disconnecting the protective device from the circuit structure, thereby reducing impedance loading at the I/O connection.
    Type: Grant
    Filed: April 30, 1999
    Date of Patent: October 31, 2000
    Assignee: International Business Machines Corporation
    Inventors: Claude Louis Bertin, John A. Fifield, Erik Leigh Hedberg, Russell J. Houghton, Timothy Dooling Sullivan, Steven William Tomashot, William Robert Tonti
  • Patent number: 6127866
    Abstract: A circuit and method are provided wherein a receiver receives an input train of pulses. The circuit includes a delay-locked-loop coupled to an output of the receiver. The delay-locked-loop includes a pulse generator responsive to received input train of pulses produced at the output of the receiver for producing first pulses in response to the leading edges of the received input train of pulses and second pulses in response to the trailing edges of received input train of pulses. The leading edge of the first pulse has the same edge type as the leading edge of the second pulse (i.e., the leading edge of the first pulse and the leading edge of the second pulse are either both rising edge types or both falling edges types). The first pulses and the second pulses are combined into a composite input signal comprising the first and second pulses with the leading edge of the first pulse maintaining the same edge type.
    Type: Grant
    Filed: January 28, 1999
    Date of Patent: October 3, 2000
    Assignees: Infineon Technologies North America Corp., International Business Machines Corporation
    Inventors: Albert M. Chu, John A. Fifield, Jason E. Rotella, Jean-Marc Dortu
  • Patent number: 6118318
    Abstract: A self biased differential amplifier has a switching point accurately set according to a reference voltage. DC hysteresis is provided, by a circuit internal to the differential amplifier. The amplifier has an input circuit having first and second series connected transistors, wherein the beta ratio of these first and second transistors is changed by enabling an additional transistor of a hysteresis circuit according to an output state of the differential amplifier. When the output state is "high", the switching point is decreased in order that temporary small drops (due to noise or glitches) in the input signal are ignored. Conversely, when the output state is "low", the switching point is increased in order that temporary small increases in the input signal are ignored.
    Type: Grant
    Filed: May 9, 1997
    Date of Patent: September 12, 2000
    Assignee: International Business Machines Corporation
    Inventors: John A. Fifield, Lawrence G. Heller
  • Patent number: 5873053
    Abstract: Temperatures on a chip, including particular regions of a chip are monitored by sensing changes in sub-threshold conduction of a field effect transistor (FET) integrated on the chip due to changes in charge carrier population distribution with temperature therein. Such changes in sub-threshold current with temperature are preferably detected using a current mirror and two FETs with different channel geometry and slightly different gate voltages such that the currents are equal at a specific design temperature. The slightly different gate voltages are conveniently provided by a low current voltage divider with or without on-chip voltage regulation in which resistor ratios can be accurately and repeatably obtained. Variations from that temperature thus yield large current differences and substantial signal swing which improve noise immunity. Hysteresis can be applied to the output (or amplified output) of the current mirror to obtain bistable thermostat-like action.
    Type: Grant
    Filed: April 8, 1997
    Date of Patent: February 16, 1999
    Assignee: International Business Machines Corporation
    Inventors: Wilbur D. Pricer, Wendell P. Noble, John A. Fifield, John E. Gersbach
  • Patent number: 5761114
    Abstract: A method and apparatus for using multi-level signals in a gain cell is shown. The method involves of first, storing a value of a multi-level signal in the gain cell. A stepping waveform is then applied to the gain cell and the gain cell outputs a conduction signal when the level of the stepping waveform corresponds to the value of the multilevel signal that is stored within the gain cell. Finally, the value of the multi-level signal is determined through the conduction signal and the corresponding level of the stepping waveform. The gain cell includes an input device, a storage device and a level comparator, which responds to the stepping waveform generated from a stepping signal generator and outputs the conduction signal for determining the value of the multi-level signal stored in the storage device.
    Type: Grant
    Filed: February 19, 1997
    Date of Patent: June 2, 1998
    Assignee: International Business Machines Corporation
    Inventors: Claude L. Bertin, John A. Fifield, Russell J. Houghton, Christopher P. Miller, William R. Tonti
  • Patent number: 5757693
    Abstract: A gain cell in a memory array having read and write bitlines and wordlines, wherein the gain cell comprises a write transistor, a storage node, a read transistor, and a diode is disclosed. The write transistor allows the value of the write bitline to be stored onto the storage node when activated by the write wordline. The read transistor, which allows the stored value to be read, is coupled to the storage node and to the read bitline via the diode. The diode prevents the conduction of the read transistor in the opposite direction, thus preventing read interference from other cells and reducing bitline capacitance.
    Type: Grant
    Filed: February 19, 1997
    Date of Patent: May 26, 1998
    Assignee: International Business Machines Corporation
    Inventors: Russell J. Houghton, Claude L. Bertin, John A. Fifield, Christopher P. Miller, William R. Tonti
  • Patent number: 5638385
    Abstract: A memory device having an on-chip ECC system includes an array of memory cells, some of which have wider transistors than others so that they have faster access speeds. Data bits are written into ordinary memory cells and the check bits are written into the faster cells in order to make up for the delay associated with the calculation of the check bits.
    Type: Grant
    Filed: October 31, 1991
    Date of Patent: June 10, 1997
    Assignee: International Business Machines Corporation
    Inventors: John A. Fifield, Duane E. Galbi, Hsing-San Lee
  • Patent number: 5633605
    Abstract: A dynamic bus system with a central precharge device is disclosed that utilizes a controller circuit with a one-shot generator and write synchronizing circuits in combination with logic output modules having pull-up/down devices. The issuance of the output enable (OE) signals is interlocked with the turn-off of the precharge. Thus, data is written to the dynamic bus only when the precharge device is inactive, avoiding bus collisions. The resulting circuitry not only ensures the precharging of the bus before the data write to the bus, but will allow the synchronized OE signals to be issued during the same clock phase as the precharge signal.
    Type: Grant
    Filed: May 24, 1995
    Date of Patent: May 27, 1997
    Assignee: International Business Machines Corporation
    Inventors: Jeffrey S. Zimmerman, John A. Fifield, Christopher P. Miller, Robert E. Busch
  • Patent number: 5604755
    Abstract: A reset circuit for resetting a memory system following a radiation event includes an error detect circuit for producing an error signal in response to detection of an uncorrectable error in the systems memory arrays, and includes a control circuit for selectively resetting at least select portions of the memory system in response to the error detect signal. All or portions of the memory arrays can be reset by the control circuit, and complete or selective latch reset, or selective power recycling are provided. In one embodiment, the control circuit provides latch reset in response to the error detect signal so as to reset the memory latches without recycling power, and in another embodiment, the control circuit selectively cycles power to independent memory zones of the system to reset only those zones whose memory array is identified as having an uncorrectable error.
    Type: Grant
    Filed: November 20, 1995
    Date of Patent: February 18, 1997
    Assignee: International Business Machine Corp.
    Inventors: Claude L. Bertin, Charles E. Drake, John A. Fifield, Erik Hedberg
  • Patent number: 5581567
    Abstract: A memory system that provides extra data bits without utilizing storage capacity. A first data word is fetched from memory and corrected to remove any single-bit errors. A second data word (which is a subset of the first data word as corrected) is then fetched, and new data correction bits (parity or ECC check bits) is generated for the second data word. Both the second data word and the newly-generated data correction bits are output. This structure amortizes the expense of in-system data correction over a greater data output, and over a smaller storage capacity relative to the data output.
    Type: Grant
    Filed: March 9, 1995
    Date of Patent: December 3, 1996
    Assignee: International Business Machines Corporation
    Inventors: Chin-Long Chen, John A. Fifield, Howard L. Kalter, Willem B. van der Hoeven
  • Patent number: 5561694
    Abstract: A driver circuit provides for selectively changing the state of an output signal, such as a pre-charged dynamic bus signal. The circuit detects whether or not the data is the opposite state as the pre-charged bus signal, and if so, it drives the bus to the appropriate state. The output from the circuit is self-timed when data can be driven onto the bus as soon as data is valid, i.e., data propagates from the input of the circuit to the bus without depending on a clock or other timing edge.
    Type: Grant
    Filed: July 26, 1995
    Date of Patent: October 1, 1996
    Assignee: International Business Machines Corporation
    Inventors: John A. Fifield, Glenn P. Giacalone, Peter J. Jenkins
  • Patent number: 5550488
    Abstract: A self-timed tri-state driver circuit for a dual-rail differential input and single-ended output is disclosed. The circuit generates a tri-state mode in response to an Output Enable (OE) input pulsing low. The OE signal input is driven high to place the driver circuit into a ready state. The circuit is maintained in a tri-state mode until data appears at the inputs. Once a data signal is received after the tri-state circuit is in the ready state, the output immediately outputs this signal. Therefore, the output of the driver is self-timed from the arrival of the data.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: August 27, 1996
    Assignee: International Business Machines Corporation
    Inventors: John A. Fifield, Lawrence G. Heller
  • Patent number: 5535226
    Abstract: In one aspect, a memory device employing device-level error correction tracks the status of the error correction in terms of whether error correction is active or inactive, whether an uncorrectable error beyond the capability of the device-level correction is detected, whether a recovery option from an uncorrectable error is active and whether the recovery option has been reset. In another aspect, a diagnostic method for determining a status for one or more aspects of device-level error correction employed by a memory device is provided. In the diagnostic method, the status is determined for the one or more aspects, a flag is set based on the status, the flag is latched, a diagnostic code is input into the memory device and the latched flag is read.
    Type: Grant
    Filed: May 31, 1994
    Date of Patent: July 9, 1996
    Assignee: International Business Machines Corporation
    Inventors: Charles E. Drake, John A. Fifield, Richard D. Wheeler, Barry J. Wolford
  • Patent number: 5532622
    Abstract: A transition detector circuit produces an output pulse upon detection of a transition at any one of several input nodes using a single delay path so all input transitions produce the same output pulse width and with only one gate delay in the circuit. The circuit includes precharging means, coupled between the plurality of transitioning inputs and the output node, for charging the output node high. The precharging means comprises stacked field effect transistor (FET) devices, each having a gate connected to a respective one of the transitioning inputs. A first charging device for charging the output node high is coupled to the output node. A second charging device for discharging the output node low is coupled to the output node. A single delay means, coupled between the plurality of transitioning inputs and both the first and second charging devices, both turns off the first charging device and turns on the second charging device.
    Type: Grant
    Filed: April 24, 1995
    Date of Patent: July 2, 1996
    Assignee: International Business Machines Corporation
    Inventors: Mark A. Beiley, John A. Fifield
  • Patent number: D442703
    Type: Grant
    Filed: January 19, 2000
    Date of Patent: May 22, 2001
    Assignee: CRH Oldcastle Inc.
    Inventor: John Fifield