Patents by Inventor Richard W. Hull

Richard W. Hull 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: 7924881
    Abstract: Systems and methods ensure that datagrams retain integrity in light of the problems associated with the internetworking protocol's use of datagram identifiers drawn from a first pool of datagram identifiers. The methods involve controlling the use of datagram identifiers to ensure that only certain identifiers are allowable. A second pool of datagram identifiers is created that is different from the first pool. A datagram identifier is drawn from the second pool and assigned to a datagram in a manner that the datagram identifier is controlled from being reused during the lifetime of the datagram. In alternative embodiments the number of available datagram identifiers is either increased through optional header fields, or reduced through tracking allowed datagram identifiers. A first host notifies a second host of an allowed identifier. The second host uses the allowed identifier as a datagram identifier.
    Type: Grant
    Filed: May 15, 2006
    Date of Patent: April 12, 2011
    Assignee: Rateze Remote Mgmt. L.L.C.
    Inventors: Charles William Frank, Thomas Earl Ludwig, Richard W. Hull, Mark Adams, Rochak Sharma, Adnan Khan, Samuel K. Baughman, Nicholas J. Witchey
  • Patent number: 7028174
    Abstract: A disk drive is disclosed comprising a microprocessor, a non-volatile serial semiconductor memory for storing code segments of a control program, a first semiconductor memory for storing code segments of a loader program, and a second semiconductor memory for receiving the code segments of the control program. When the disk drive is powered on, the microprocessor executes the loader program from the first semiconductor memory to load the control program from the non-volatile serial semiconductor memory into the second semiconductor memory. The microprocessor then executes the control program from the second semiconductor memory.
    Type: Grant
    Filed: September 30, 2002
    Date of Patent: April 11, 2006
    Assignee: Western Digital Technologies, Inc.
    Inventors: Alireza Atai-Azimi, Richard W. Hull, Mark F. Vallis
  • Patent number: 6580573
    Abstract: A disk drive has a channel circuit for demodulating data sectors and servo sectors stored on a rotating medium to provide data-sector data and servo-sector data. The channel circuit transmits the data-sector data and servo-sector data to a disk controller circuit in an order which is different than the order in which they are stored on a rotating medium to allow for demodulation latency while maintaining real-time updates of embedded servo information.
    Type: Grant
    Filed: January 24, 2000
    Date of Patent: June 17, 2003
    Assignee: Western Digital Technologies, Inc.
    Inventors: Richard W. Hull, Hoover K. Jung, Sanjay S. Mathur
  • Patent number: 6519104
    Abstract: A computer system is disclosed comprising a host connected to a disk drive, the disk drive comprising a disk having a disk surface. The disk drive further includes a controller and a channel integrated circuit chip. The controller includes a controller port. The channel integrated circuit chip includes an input for receiving a time-multiplexed analog read signal. The time-multiplexed analog read signal is processed to generate data symbols representing recovered servo data and recovered user data. The channel integrated circuit chip includes a channel port for transferring both the recovered servo data and the recovered user data. The disk drive further includes a communication bus connected between the channel port and the controller port. The channel port transfers both the recovered servo data and the recovered user data to the communication bus. The communication bus transfers both the recovered servo data and the recovered user data to the controller port.
    Type: Grant
    Filed: February 28, 2002
    Date of Patent: February 11, 2003
    Assignee: Western Digital Technologies, Inc.
    Inventors: Robert L. Cloke, David P. Turner, Richard W. Hull, Vafa James Rakshani
  • Patent number: 6487032
    Abstract: A computer system is disclosed comprising a host connected to a disk drive, the disk drive comprising a disk surface having a plurality of tracks arranged in an embedded servo format including servo track segments for storing servo data and data track segments for storing user data. The disk drive includes a read element operative during a user-data read operation for reading data from the disk surface to produce a time-multiplexed analog read signal that during a revolution of the disk represents analog read servo data during each of a first set of time intervals and represents analog read user data during each of a second set of time intervals. The disk drive includes a sampled signal processing circuit that generates a servo state variable while processing the time-multiplexed read signal during the first servo time interval and a user data state variable while processing the time-multiplexed read signal during the first user data time interval.
    Type: Grant
    Filed: February 25, 2002
    Date of Patent: November 26, 2002
    Assignee: Western Digital Technologies, Inc.
    Inventors: Robert L. Cloke, Vafa James Rakshani, Richard W. Hull, David P. Turner
  • Patent number: 6415349
    Abstract: A disk drive has a unified bus forming a signal path for transmitting register data, user data and servo sectors. The unified bus is connected between a channel circuit and a disk controller circuit. The channel circuit has an output stream engine which responds to and provides control signals to multiplex data on the unified bus at various times between demodulated user data, servo sector data and register data.
    Type: Grant
    Filed: January 24, 2000
    Date of Patent: July 2, 2002
    Assignee: Western Digital Technologies, Inc.
    Inventors: Richard W. Hull, Hoover K. Jung, Sanjay S. Mathur
  • Patent number: 6278568
    Abstract: A disk drive includes a disk having a disk surface. The disk surface has a plurality of tracks arranged in an embedded servo format including servo track segments for storing servo data and data track segments for storing user data. Data from the disk surface is read to produce a time-multiplexed analog read signal that during a revolution of the disk represents analog read servo data during each of a first set of time intervals and represents analog read user data during each of a second set of time intervals. The disk drive further includes a controller and a channel integrated circuit chip. The controller includes a controller port. The channel integrated circuit chip includes an input for receiving the time-multiplexed analog read signal. The time-multiplexed analog read signal is processed to generate data symbols representing recovered servo data and recovered user data.
    Type: Grant
    Filed: December 30, 1998
    Date of Patent: August 21, 2001
    Assignee: Western Digital
    Inventors: Robert L. Cloke, Richard W. Hull, Vafa James Rakshani, David P. Turner
  • Patent number: 6178056
    Abstract: A disk drive includes a disk surface having a plurality of tracks arranged in an embedded servo format including servo track segments for storing servo data and data track segments for storing user data. The disk drive includes a read element operative during a user-data read operation for reading data from the disk surface to produce a time-multiplexed analog read signal that during a revolution of the disk represents analog read servo data during each of a first set of time intervals and represents analog read user data during each of a second set of time intervals. The disk drive includes a sampled signal processing circuit that generates a servo state variable while processing the time-multiplexed read signal during the first servo time interval and a user data state variable while processing the time-multiplexed read signal during the first user data time interval.
    Type: Grant
    Filed: April 15, 1999
    Date of Patent: January 23, 2001
    Assignee: Western Digital Corporation
    Inventors: Robert Leslie Cloke, Richard W. Hull, Vafa James Rakshani, David Price Turner
  • Patent number: 6067206
    Abstract: A disk drive controller having a microprocessor and a sampled signal head positioning system measures and stores the relative rotational offsets between heads arranged in a stacked relationship and respective servo wedges on different disk surfaces. The offsets are stored in a table and subsequently applied to a servo wedge detection circuit to ensure that a next sequential wedge is detected after a head switch.
    Type: Grant
    Filed: November 18, 1997
    Date of Patent: May 23, 2000
    Assignee: Western Digital Corporation
    Inventors: Richard W. Hull, David B. Joan, Charles R. Patton, III, Vafa James Rakshani, Charles W. Simmons
  • Patent number: 5956196
    Abstract: A disk drive having an embedded servo disk format preferably having a fixed-number of radial servo sample wedges per track, in which data blocks are located independently of the servo sample wedge locations of any particular track, and can be split around servo sample wedges. Thus, a fraction of a data block, or more than one data block, can be written between consecutive servo sample wedges, beginning almost anywhere in a data wedge. Each data sector has an associated identification (ID) field that includes at least one segment descriptor. Each segment descriptor describes the data segments into which a data block can be split. Provision is made for as many segment descriptors as there can be data segments for a data block. In general, a segment descriptor is a multi-bit digital signal that defines the absolute or relative location of split data segments (or, alternatively, the absolute or relative length of split data segments, from which the location can be determined).
    Type: Grant
    Filed: October 28, 1997
    Date of Patent: September 21, 1999
    Assignee: Western Digital Corporation
    Inventors: Richard W. Hull, Marc E. Acosta, Carl Bonke, Vafa Rakshani, Ronald E. Wilson
  • Patent number: 5600499
    Abstract: A format for embedded servo track identification fields in rotating disk data storage units such as magnetic disk drives. The present invention uses the concept of tri-bits (i.e., three code bits per logical bit) to encode track identification information in servo wedges of embedded servo disk drive systems. More specifically, two particular sets (and their equivalents) of tri-bit codes have been discovered to have optimum characteristics for providing a phase coherent encoding of a Gray code that is simple to translate into straight binary code. The properties of such tri-bit encoding limit error propagation to a single bit, which allows for very reliable track identification during movement of a head transducer across tracks (i.e., "seeks"). A full range of Gray scale codes is available since more than two consecutive logical "0"s can be reliably decoded when encoded using such tri-bits.
    Type: Grant
    Filed: April 9, 1993
    Date of Patent: February 4, 1997
    Assignee: Western Digital Corporation
    Inventors: Marc E. Acosta, Richard W. Hull, Michael Spaur
  • Patent number: 5311376
    Abstract: An integrated servo system for a disk drive employing sector servo positioning information on concentric tracks of a recording medium utilizes a servo burst pattern with three sequentially occurring servo bursts. One burst is positioned to have a maximum amplitude plateau on a track centerline of alternate tracks, and the other two bursts have maximum plateau values at locations between the centerlines of adjacent tracks. The amplitudes of the bursts are sequentially detected by a peak detector and supplied to sample and hold circuitry for measuring their relative amplitudes. Discriminator circuitry utilizes a window to provide two samples of each transition in the servo pattern and compares the samples to detect different fields and events in the pattern.
    Type: Grant
    Filed: June 11, 1991
    Date of Patent: May 10, 1994
    Assignee: Western Digital (Singapore) PTE
    Inventors: David B. Joan, Michael R. Spaur, Richard W. Hull, Takashi Asami, Marshall D. Lee, Robert P. Mento, Min-Hui Wang
  • Patent number: 5115151
    Abstract: A comparator which is used to compare two analog voltages and provide a single ended output comprises three CMOS differential amplifiers. The use of three differential amplifiers provides improved matching of input capacitance, and a reduction in propagation delay over prior art use of a single differential amplifier. The comparator may be adopted for use in certain CMOS processes to extend the maximum operating voltage by limiting the internal node voltages otherwise subject to damage from impact ionization. An alternative embodiment is disclosed for comparing two analog voltages that are outside the power supply voltage range.
    Type: Grant
    Filed: June 8, 1990
    Date of Patent: May 19, 1992
    Assignee: Western Digital Corporation
    Inventors: Richard W. Hull, Timothy G. O'Shaughnessy
  • Patent number: 5017919
    Abstract: A DAC embodied in a CMOS integrated circuit converts a multi-bit digital signal to an analog-current signal. A higher-order portion of the digital signal, e.g., the most significant 5 bits of a byte, are decoded separately from the lower-order portion, e.g., the 3 least significant bits. The DAC includes circuitry for producing a first bias voltage, a first set of current sources each biased by the first bias voltage to produce a switchable current having a unit magnitude, and switching circuitry controlled by the decoded lower-order portion to cause a selected number of the unit-magnitude currents to contribute to the analog-current signal.
    Type: Grant
    Filed: June 6, 1990
    Date of Patent: May 21, 1991
    Assignee: Western Digital Corporation
    Inventors: Richard W. Hull, Timothy G. O'Shaughnessy
  • Patent number: 4947063
    Abstract: The transient noise generated at the output drivers of an integrated circuit chip is reduced by maintaining an increasing ramp shaped current through each output driver during the entire transition interval between binary states of a capacitive load. A capacitor fed by a fixed current source is connected across the input of each output driver stage. The fixed current source and capacitor are so selected as to generate across the input of each output driver stage a linear ramp shaped control voltage that regulates the charging/discharging current through the output driver stage and package inductance in the described manner. A specially designed bias circuit reduces the sensitivity of the resulting transient noise to process variations and operating conditions. A feedback connection from the package inductance to the bias control circuit for the fixed current source adjusts the fixed current inversely with the transient noise.
    Type: Grant
    Filed: February 26, 1988
    Date of Patent: August 7, 1990
    Assignee: Western Digital Corporation
    Inventors: Timothy G. O'Shaughnessy, David K. Chung, Richard W. Hull, Kenneth W. Ouyang, Victor G. Pierotti, Joseph A. Souza
  • Patent number: 4859873
    Abstract: A Schmitt trigger circuit with independently biased threshold sections includes a drive disabling switch for blocking one of the threshold sections from driving a logic node toward a predetermined logic state. The drive disabling switch is selectively operated so that unidirectional sensitivity to the crossing of a threshold level belonging to its corresponding one threshold section is obtained.
    Type: Grant
    Filed: July 17, 1987
    Date of Patent: August 22, 1989
    Assignee: Western Digital Corporation
    Inventors: Timothy G. O'Shaughnessy, Richard W. Hull
  • Patent number: 4808884
    Abstract: A digital data separator operates to separate data pulses from clock pulses in MFM encoded signals read from a magnetic disk system. The data separator includes a digital phase-locked loop system incorporating a variable length shift register which functions as a variable oscillator and programmed state machines which control the operation of the shift register and provides filtering functions. The state machines filter high frequency noise components from the incoming data signals and enables the system to accurately track frequency variations in the data stream while providing high tolerance to high frequency noise.
    Type: Grant
    Filed: December 2, 1985
    Date of Patent: February 28, 1989
    Assignee: Western Digital Corporation
    Inventors: Richard W. Hull, Donald E. Tolsch, James H. P. Wang
  • Patent number: 4706045
    Abstract: A voltage controlled oscillator (VCO) has an LC tank circuit which is pumped by two out-of-phase feedback components. The combined effect of the two out-of-phase feedback components results in an effective feedback signal that is a function of the ratio of the magnitude of the two out-of-phase coponents. The magnitude of one of these feedback components is controlled by a CMOS subthreshold Gilbert multiplier. The frequency of oscillation of an oscillating signal within the LC tank circuit changes according to a control voltage applied to the Gilbert multiplier.
    Type: Grant
    Filed: December 10, 1986
    Date of Patent: November 10, 1987
    Assignee: Western Digital Corporation
    Inventors: Kenneth W. Ouyang, Richard W. Hull
  • Patent number: 4519086
    Abstract: A metal oxide semiconductor (MOS) phase lock loop data synchronization circuit, for use in conjuction with an integrated circuit disk controller device, comprising a temperature, process, and voltage compensated MOS voltage controlled oscillator (VCO), a three-bit counter, and a phase detector circuit. The phase detector circuit compares a decoded clock signal output from the VCO with incoming data from a disk device to detect phase differences between the frequency of the VCO and the actual frequency of the incoming data. The phase detector produces voltage signals in response to any such phase differences, which are coupled to the VCO and alter the frequency output of the VCO to match the frequency of the incoming data. The counter provides a system read-clock, which is fully synchronized with the incoming data, to an integrated circuit disk controller device which further processes the data.
    Type: Grant
    Filed: June 16, 1982
    Date of Patent: May 21, 1985
    Assignee: Western Digital Corporation
    Inventors: Richard W. Hull, Leonard Teslenko