Patents by Inventor David William Boerstler

David William Boerstler 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: 6744326
    Abstract: An oscillator system is provided to have a plurality of delay paths coupled in a loop. The oscillator system also has an improved AC feedforward path coupled in parallel with one or more delay paths in the loop. The AC feedforward path includes first and second parallel sections. The first parallel section has a plurality of parallel branches and is configured for receiving one or more control signals. The plurality of parallel branches is selectively conducted in response to the one or more control signals. The second parallel section is coupled in series with the first parallel section and is configured to remain conducting when any of the plurality of parallel branches becomes conducting. The first and second parallel sections are configured to transmit an AC feedforward signal when conducting.
    Type: Grant
    Filed: October 10, 2002
    Date of Patent: June 1, 2004
    Assignee: International Business Machines Corporation
    Inventor: David William Boerstler
  • Publication number: 20040078613
    Abstract: Disclosed is an electronic chip containing a plurality of electronic circuit partitions, distributed over the area of the chip, each including a processor core and a clock phase domain different from cores in other partitions of the chip. A source of same frequency, but different phase clock signals representing different clock domains, provides different phase signals to adjacent partitions for the purpose of reducing instantaneous magnitude switching currents. Intra-chip communication circuitry distributes control and data signals between partitions.
    Type: Application
    Filed: October 17, 2002
    Publication date: April 22, 2004
    Applicant: International Business Machines Corporation
    Inventors: David William Boerstler, Sang Hoo Dhong, Harm Peter Hofstee, Peichun Peter Liu
  • Publication number: 20040076189
    Abstract: Disclosed is the method of and apparatus for reducing the magnitude of switching occurring at any given time. This is accomplished by grouping circuitry into a plurality of partitions wherein the circuitry in each partition may be operationally switched at times different from circuitry in other partitions. Different phase clock signals are then provided to each partition whereby switching operationally occurs at different times in each of the partitions. An example of circuitry that can utilize this improvement is a main processor or computer utilizing a plurality of auxiliary processor units in its operations.
    Type: Application
    Filed: October 17, 2002
    Publication date: April 22, 2004
    Applicant: International Business Machines Corporation
    Inventors: David William Boerstler, Sang Hoo Dhong, Harm Peter Hofstee, Stephen Douglas Weitzel
  • Patent number: 6724221
    Abstract: In one form of the invention, circuitry having exclusive-OR and latch functionality includes timing circuitry and logic circuitry. The circuitry includes a memory, with first and second memory nodes, for storing a state and its complement, and first and second timing circuitry portions, each operable to receive at least one timing signal, coupled to the respective memory nodes. The logic circuitry includes first and second logic circuitry portions, each of which is operable to receive at least first and second data signals. Each of the logic circuitry portions is coupled in series with a conditionally conductive path of one of the respective first and second timing circuitry portions.
    Type: Grant
    Filed: March 28, 2002
    Date of Patent: April 20, 2004
    Assignee: International Business Machines Corporation
    Inventors: Juan-Antonio Carballo, David William Boerstler, Jeffrey L. Burns, Kevin John Nowka, Li Shi
  • Publication number: 20040070458
    Abstract: An oscillator system is provided to have a plurality of delay paths coupled in a loop. The oscillator system also has an improved AC feedforward path coupled in parallel with one or more delay paths in the loop. The AC feedforward path includes first and second parallel sections. The first parallel section has a plurality of parallel branches and is configured for receiving one or more control signals. The plurality of parallel branches is selectively conducted in response to the one or more control signals. The second parallel section is coupled in series with the first parallel section and is configured to remain conducting when any of the plurality of parallel branches becomes conducting. The first and second parallel sections are configured to transmit an AC feedforward signal when conducting.
    Type: Application
    Filed: October 10, 2002
    Publication date: April 15, 2004
    Applicant: International Business Machines Corporation
    Inventor: David William Boerstler
  • Publication number: 20040071252
    Abstract: An improved charge pump used in a phase-locked loop includes transient current correction capability by adding a canceling capacitance for each parasitic capacitance associated with a switching device in a charge pump. For each transient current component flowing through the parasitic capacitance, a canceling capacitance is implemented to create a canceling transient current component in the opposite direction such that it cancels out the transient current component. Preferably, an additional switching device is added to implement such a canceling capacitance for each parasitic capacitance.
    Type: Application
    Filed: October 10, 2002
    Publication date: April 15, 2004
    Applicant: International Business Machines Corporation
    Inventor: David William Boerstler
  • Publication number: 20040017872
    Abstract: A lock detector and method is provided for detecting lock between first and second signals. The lock detector includes a pulse generator for receiving the first signal and generating a pulse train from the first signal. Each pulse corresponds to at least one of rising and falling edges of the first signal in each period of the first signal. The lock detector also includes a mask generator for generating a mask signal from the second signal such that the mask signal has a mask state around at least one of rising and falling edges of the second signal in each period of the second signal. Additionally, the lock detector has a logic gate, which receives the pulse train and the mask signal from the pulse generator and the mask generator, respectively. The logic gate generates an incrementing pulse signal by combining the pulse train with the mask signal.
    Type: Application
    Filed: July 25, 2002
    Publication date: January 29, 2004
    Applicant: International Business Machines Corporation
    Inventors: David William Boerstler, Stephen Douglas Weitzel
  • Publication number: 20030184340
    Abstract: In one form of the invention, circuitry having exclusive-OR and latch functionality includes timing circuitry and logic circuitry. The circuitry includes a memory, with first and second memory nodes, for storing a state and its complement, and first and second timing circuitry portions, each operable to receive at least one timing signal, coupled to the respective memory nodes. The logic circuitry includes first and second logic circuitry portions, each of which is operable to receive at least first and second data signals. Each of the logic circuitry portions is coupled in series with a conditionally conductive path of one of the respective first and second timing circuitry portions.
    Type: Application
    Filed: March 28, 2002
    Publication date: October 2, 2003
    Applicant: International Business Machines Corporation
    Inventors: Juan-Antonio Carballo, David William Boerstler, Jeffrey L. Burns, Kevin John Nowka, Li Shi
  • Patent number: 6621358
    Abstract: In a first form, a voltage controlled oscillator includes delay cells connected in a ring, and control elements connected to selectively bypass respective sets of the delay cells. The delay cells are operable to receive respective differential inputs and to generate inverted outputs. The control elements are operable to receive respective differential inputs and to generate non-inverted outputs with variable delays. The control element delays are variable responsive to respective differential control voltages.
    Type: Grant
    Filed: December 17, 2001
    Date of Patent: September 16, 2003
    Assignee: International Business Machines Corporation
    Inventors: Juan-Antonio Carballo, David William Boerstler, Jeffrey L. Burns, Ivan Vo
  • Publication number: 20030112082
    Abstract: In a first form, a voltage controlled oscillator includes delay cells connected in a ring, and control elements connected to selectively bypass respective sets of the delay cells. The delay cells are operable to receive respective differential inputs and to generate inverted outputs. The control elements are operable to receive respective differential inputs and to generate non-inverted outputs with variable delays. The control element delays are variable responsive to respective differential control voltages.
    Type: Application
    Filed: December 17, 2001
    Publication date: June 19, 2003
    Applicant: International Business Machines Corporation
    Inventors: Juan-Antonio Carballo, David William Boerstler, Jeffrey L. Burns, Ivan Vo
  • Patent number: 6573758
    Abstract: In one aspect, circuitry for a digital logic function includes a first pair of input nodes for receiving respective first and second input signals, a second pair of input nodes for receiving respective complements of the first and second input signals, and an output node. The circuitry has a plurality of PFET-NFET pass gates. Such a pass gate has a first conducting electrode of the pass gate PFET connected to a first conducting electrode of the pass gate NFET, providing a first conducting node of the pass gate, and a second conducting electrode of the pass gate PFET connected to a second conducting electrode of the pass gate NFET, providing a second conducting node of the pass gate. The input nodes are connected to first conducting nodes of respective ones of the plurality of pass gates, and the second conducting nodes of the plurality of pass gates are connected to the circuitry output node.
    Type: Grant
    Filed: September 27, 2001
    Date of Patent: June 3, 2003
    Assignee: International Business Machines Corporation
    Inventors: David William Boerstler, Juan Antonio Carballo, Robert Kevin Montoye
  • Patent number: 6566921
    Abstract: An apparatus and a method for making high resolution frequency adjustments in a multistage frequency synthesizer. The initial stage of the frequency synthesizer is a conventional phase lock loop connected to a dynamically variable frequency divider. There are one or more intermediate stages that consist of the forward portion of a phase locked loop with feedback through a fixed frequency divider and connected to a dynamically variable frequency divider. The final stage consists of the forward portion of a phase locked loop with feedback through a fixed frequency divider and connected to another fixed frequency divider. By varying the constant of division in the variable frequency dividers in the circuit, fine frequency adjustments can be made very rapidly. The precision of the adjustments depends on the relative values of the frequency dividers and the number of intermediate stages in the system.
    Type: Grant
    Filed: August 3, 2000
    Date of Patent: May 20, 2003
    Assignee: International Business Machines Corporation
    Inventors: David William Boerstler, Mark Edward Dean, Hung Cai Ngo, Andrew Christian Zimmerman
  • Patent number: 6559727
    Abstract: A voltage controlled oscillator is provided comprising a plurality of delay elements serially connected to form a ring and each element within the plurality of elements includes an input and output. The voltage controlled oscillator also includes a set of control elements where each control element within the set of control elements has an input connected to an input of a delay element within the set of delay elements and an output connected to an output of a different delay element within the plurality of delay elements. A control voltage is selectively applied to control elements within the set of control elements to vary the oscillating frequency and phase distribution in proportion to the control voltage.
    Type: Grant
    Filed: November 30, 2000
    Date of Patent: May 6, 2003
    Assignee: International Business Machines Corporation
    Inventor: David William Boerstler
  • Publication number: 20030058001
    Abstract: In one aspect, circuitry for a digital logic function includes a first pair of input nodes for receiving respective first and second input signals, a second pair of input nodes for receiving respective complements of the first and second input signals, and an output node. The circuitry has a plurality of PFET-NFET pass gates. Such a pass gate has a first conducting electrode of the pass gate PFET connected to a first conducting electrode of the pass gate NFET, providing a first conducting node of the pass gate, and a second conducting electrode of the pass gate PFET connected to a second conducting electrode of the pass gate NFET, providing a second conducting node of the pass gate. The input nodes are connected to first conducting nodes of respective ones of the plurality of pass gates, and the second conducting nodes of the plurality of pass gates are connected to the circuitry output node.
    Type: Application
    Filed: September 27, 2001
    Publication date: March 27, 2003
    Applicant: International Business Machiness Corporation
    Inventors: David William Boerstler, Juan Antonio Carballo, Robert Kevin Montoye
  • Patent number: 6529084
    Abstract: A voltage controlled oscillator (VCO) and phase-locked loop (PLL) topologies that allow for low-voltage, high frequency, low-jitter operation are disclosed. The conventional PLL design is modified so as to bifurcate the error signal into AC and DC components. A VCO accepting AC- and DC-component control inputs adjusts its output frequency in accordance with both inputs.
    Type: Grant
    Filed: October 11, 2001
    Date of Patent: March 4, 2003
    Assignee: International Business Machines Corporation
    Inventors: David William Boerstler, Juan-Antonio Carballo, Gary Dale Carpenter, Hung Cai Ngo, Kevin John Nowka
  • Patent number: 6522207
    Abstract: An apparatus and a method for making small frequency adjustments in a frequency synthesizer. The frequency synthesizer consists of the forward portion of a phase locked loop with feedback through a fixed frequency divider and the output of the forward portion of the phase locked loop connected to a dynamically variable frequency divider. By changing the constant of division in the variable frequency divider, the output of the frequency divider can be rapidly changed in small increments. The dynamically variable frequency divider is key to this design. This digital circuit stores the current divisor value and has an input for a new divisor value. When a signal is sent to switch to the new divisor value, the circuit uses an incrementer and associated logic to rapidly change to the new constant of division.
    Type: Grant
    Filed: August 3, 2000
    Date of Patent: February 18, 2003
    Assignee: International Business Machines Corporation
    Inventors: David William Boerstler, Mark Edward Dean, Hung Cai Ngo, Andrew Christian Zimmerman
  • Patent number: 6507228
    Abstract: A latch includes memory and pulldown circuitry coupled to nodes of the memory for pulling one of the nodes down responsive to data. The pulldown circuitry has gating circuitry for gating the pulling down responsive to a clock signal. The latch also has pull up circuitry coupled to the other one of the memory nodes. A first pull up circuitry section is operable to pull the other one of the memory nodes up to a high state responsive to data. The first pull up circuitry section includes second gating circuitry. The second gating circuitry is operable to gate the pulling up of the other one of the memory nodes responsive to a pull up circuitry clock signal. The first pull up circuitry section more quickly pulls up its memory node, so that the two nodes are pulled up and down at more nearly the same time.
    Type: Grant
    Filed: May 3, 2001
    Date of Patent: January 14, 2003
    Assignee: International Business Machines Corporation
    Inventors: David William Boerstler, Osamu Takahashi
  • Patent number: 6501313
    Abstract: A method of controlling a clock signal in a clock distribution network, by detecting an error in a duty cycle of the clock signal, and dynamically adjusting the body voltage of one or more devices in the clock distribution network, based on the detected error. Where the electronic device is a p-type device, the adjustment may be performed by reducing the body voltage of the p-type device with respect to a supply voltage. Where the electronic device is an n-type device, the adjustment may be performed by increasing the body voltage of the n-type device with respect to a reference plane. The invention may be implemented digitally, that is, with the body voltage of the electronic device being adjusted by selectively connecting a body contact of the device to one of several discrete voltages using a multiplexer.
    Type: Grant
    Filed: December 27, 2000
    Date of Patent: December 31, 2002
    Assignee: International Business Machines Corporation
    Inventors: David William Boerstler, Daniel Mark Dreps, Byron Lee Krauter, Hung Cai Ngo
  • Publication number: 20020172312
    Abstract: A system and method for reducing timing uncertainties in a serial data signal A system may comprise a transmitter configured to transmit serial data to a receiver through a transmission medium, e.g., wireless, wired. The receiver may comprise an oscillator configured to generate multiple phases of a clock. The receiver may further comprise a retiming mechanism configured to reduce the timing uncertainties of the serial data received by the receiver by selecting a particular phase of the clock to be asserted to sample the serial data signal. The particular phase may be selected by selecting the appropriate synchronization state/retiming state. A retiming state indicates which particular phase of the clock should be asserted to sample the serial data signal. A synchronization state indicates which particular phase of the clock is the appropriate one to assert at a given transition of the serial data signal.
    Type: Application
    Filed: March 29, 2001
    Publication date: November 21, 2002
    Applicant: International Business Machines Corporation
    Inventor: David William Boerstler
  • Patent number: 6480049
    Abstract: The Sync State outputs are used in combination with the multiple phase outputs to generate and error signal which is operable to generate voltage which controls the frequency of the MVCO and to generate a shifted clock which is divided in a sequential circuit to generate the quadrature clock with a frequency F.
    Type: Grant
    Filed: November 28, 2001
    Date of Patent: November 12, 2002
    Assignee: International Business Machines Corporation
    Inventors: David William Boerstler, Robert Keven Montoye, Kevin John Nowka