Correction For Skew, Phase, Or Rate Patents (Class 713/503)
  • Patent number: 8117482
    Abstract: First and second counter circuits output a signal based on a trigger signal and a clock signal respectively. A selection circuit selects first to fourth signals as the trigger signal, the clock signal, the trigger signal and the clock signal. In a first output mode, an output circuit outputs signals exhibiting normal-phase and reversed-phase PWM waveforms based on both of the signals of the first and second counter circuits. In a second output mode, the output circuit outputs signals that are each based only on either of the signals of the first and second counter circuits.
    Type: Grant
    Filed: November 14, 2008
    Date of Patent: February 14, 2012
    Assignee: Renesas Electronics Corporation
    Inventor: Yasuhiro Takata
  • Patent number: 8117483
    Abstract: A memory controller performs a read test for each of a plurality of memory devices to generate a read delay time of each memory device. There is a prime memory device and a subset of memory devices. For each memory device of the subset, the read delay time for the prime memory device is compared with the read delay time of each memory device of the subset of memory devices to generate a differential delay for each memory device of the subset. For each subset memory device, a write test start time of the prime memory device is combined with a differential delay of each memory device to generate a write test start time for the each memory device. A write test for each memory device uses the write test start time for each subset memory device to generate a write launch time for each subset memory device.
    Type: Grant
    Filed: May 13, 2009
    Date of Patent: February 14, 2012
    Assignee: Freescale Semiconductor, Inc.
    Inventors: James A. Welker, Michael P. George
  • Patent number: 8117485
    Abstract: Provided is a memory system for seamless switching. The memory system includes first through mth chips, where m is a natural number, connected in the form of a daisy chain and configured to transmit at least one of signals and data, a (k?1)th chip of the first through mth chips, where k is a natural number and 2?k?m, configured to output a (k?1)th detection signal corresponding to a phase difference between (k?1)th test data of the (k?1)th chip and kth test data of a kth chip of the first through mth chips, and the kth chip including a clock phase control unit configured to control a phase of a received clock signal and to output the phase-controlled clock signal as a kth clock signal, where the clock phase control unit of the kth chip outputs the kth clock signal in response to the (k?1)th detection signal.
    Type: Grant
    Filed: February 18, 2009
    Date of Patent: February 14, 2012
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Hoe-ju Chung
  • Patent number: 8112655
    Abstract: A memory system is described, where the transmission time of data between memory modules is managed so that the overall time delay between specified points in the memory system is maintained a constant. Each lane of a multilane bus may be separately managed, and a data frame evaluated at the destination module, without a need for deskewing at intermediate modules. The time delay in propagation of the data through a module, which may have a switch to route the data, is reduced by operating the data path through the module at one or more submultiples of the bus serial data rate, and selecting the sampling point of the received data so that variations in time delay due to temperature changes or ageing are accommodated.
    Type: Grant
    Filed: October 3, 2008
    Date of Patent: February 7, 2012
    Assignee: Violin Memory, Inc.
    Inventors: Kevin D. Drucker, James H. Jones, Jon C. R. Bennett
  • Publication number: 20120030500
    Abstract: Embodiments of systems and methods are described for reducing the effects of hysteresis in the operation of data processing circuitry. In this embodiment of the invention, adaptive control circuitry is used to reduce the effects of hysteresis. The embodiment disclosed herein provides significant reduction in the effects of hysteresis and, therefore, a significant reduction in the amount of guard band needed to compensate for hysteresis effects in SOI processes and thereby improving the performance/power characteristics of the circuit.
    Type: Application
    Filed: July 30, 2010
    Publication date: February 2, 2012
    Inventors: Arun Iyer, Bhawna Tomar, Animesh Jain, Krishna Sethupathy Leela
  • Patent number: 8108710
    Abstract: A system and method is presented for reducing skew between the positive and negative components of a differential signal in a high speed communications link. The communications link includes a signal generator producing and transmitting complementary positive and negative signals over separate transmission lines and a receiver receiving the complementary signals. The communication link further includes a skew compensation circuit having a skew detector, a controller, and separate delay and buffer elements for both the positive and negative component of the differential signal. The controller separately controls each of the delay or buffer elements in response to the detected skew between differential signal components.
    Type: Grant
    Filed: January 8, 2009
    Date of Patent: January 31, 2012
    Assignee: Mayo Foundation for Medical Education and Research
    Inventor: Patrick J. Zabinski
  • Patent number: 8099618
    Abstract: A data processing unit having a field of clocked logic cells (PAEs) which is operable in different configuration states and a clock preselecting means for preselecting logic cell clocking. The clock preselecting means is designed in such a way that, depending on the state, a first clock is preselected at least at a first cell (PAE) and an additional clock is preselected at least at an additional cell.
    Type: Grant
    Filed: October 23, 2008
    Date of Patent: January 17, 2012
    Inventors: Martin Vorbach, Volker Baumgarte
  • Patent number: 8098493
    Abstract: In one example embodiment, a host device includes a host bezel, first and second guides, and a host connector. The host bezel defines an opening configured to receive a pluggable module. A first cutout on one side of the opening and a second cutout on the opposite side of the opening are adapted to receive corresponding guiderails on the module. The first and second guides are coupled to the host bezel and to a host printed circuit board. Each of the first and second guides defines a channel configured to receive the first and second guiderails of the module. The host connector is coupled to the host printed circuit board and is disposed at the back end of the first and second guides. The host connector includes a recessed slot configured to receive a module connector to electrically couple the module to the host printed circuit board.
    Type: Grant
    Filed: September 2, 2008
    Date of Patent: January 17, 2012
    Assignee: Finisar Corporation
    Inventor: Donald A. Ice
  • Publication number: 20120005518
    Abstract: According to one embodiment, there is provided a host controller. The host controller includes a plurality of data input sections and a controller. The plurality of data input sections is configured to repeat an operation of acquiring a plurality of values by sampling a content of read data and additional information accompanying the content with a plurality of clocks of different phases. The controller is configured to adjust phases of the clocks based on the plurality of values acquired by the data input sections.
    Type: Application
    Filed: May 9, 2011
    Publication date: January 5, 2012
    Inventors: Noriyo Fujii, Masayoshi Murayama
  • Patent number: 8090971
    Abstract: The present invention discloses data recovery architecture (CDR) to improve a multi-link system's tolerance to delay mismatches (or skewing effect) in its different links. The architecture is entirely digital and usable in any multi-link transceiver implementation that makes use of a separate clock link and requires timing synchronization between the different data links.
    Type: Grant
    Filed: December 4, 2007
    Date of Patent: January 3, 2012
    Assignee: Synopsys, Inc.
    Inventor: Jose Angelo Rebelo Sarmento
  • Patent number: 8090973
    Abstract: An interconnection system is described where data lanes may be exchanged between lines at intervals along a transmission path so that the differential time delay between bits on a plurality of the lines is reduced when determined at a receiving location. The data lanes may be bound to the lines through the operation of a configurable switch, or by a configurable switch in conjunction with predetermined manufactured connections, or a combination of the techniques. The wiring of a connectorized node module, which may include a memory device, may be configured so that the differential time delay between pairs of input lines of a node, as measured at the output of a node, is reduced.
    Type: Grant
    Filed: November 15, 2010
    Date of Patent: January 3, 2012
    Assignee: Violin Memory, Inc.
    Inventor: Jon C. R. Bennett
  • Patent number: 8073043
    Abstract: A method and a corresponding system for characterizing the performance of a clock and data recovery circuit in a digital transceiver is presented. The method comprises phase modulating a jitter-free data signal by a testing signal having added data jitter and measuring the time the clock and data recovery system takes to achieve bit lock of a phase modulated signal. Data uncorrelated timing jitter corresponding to a user defined probability distribution is included in the jitter testing signal. Utilization of a variable probability distribution in generating data uncorrelated timing jitter, as provided by the present invention, allows for greater flexibility and accuracy in clock and data recovery circuit testing and characterization.
    Type: Grant
    Filed: September 27, 2007
    Date of Patent: December 6, 2011
    Assignee: Integrated Device Technology, Inc.
    Inventors: Xin Liu, Liang Zhang, Jiang Li Xin
  • Patent number: 8073090
    Abstract: A method and system for performing clock calibration and de-skew on a multi-lane high speed serial interface is presented. Each of a plurality of serial lane transceivers associated with an individual bit lane receives a first data frame, comprising a training sequence header pattern. Based on each of the first data frames, the plurality of serial lane transceivers de-skew a plurality of data frames and generate a plurality of event signals. Using the plurality of event signals, a core clock, having a first phase, is adjusted to be phase aligned with the slowest bit lane.
    Type: Grant
    Filed: July 11, 2008
    Date of Patent: December 6, 2011
    Assignee: Integrated Device Technology, Inc.
    Inventors: Liang Zhang, Hui Wang, Yong Wang
  • Publication number: 20110296227
    Abstract: A memory system and method uses stacked memory device dice coupled to each other and to a logic die. The logic die may include a timing correction system that is operable to control the timing at which the logic die receives signals, such as read data signals, from each of the memory device dice. The timing correction controls the timing of the read data or other signals by adjusting the timing of respective strobe signals, such as read strobe signals, that are applied to each of the memory device dice. The memory device dice may transmit read data to the memory device at a time determined by when it receives the respective strobe signals. The timing of each of the strobe signals is adjusted so that the read data or other signals from all of the memory device dice are received at the same time.
    Type: Application
    Filed: August 12, 2011
    Publication date: December 1, 2011
    Applicant: Micron Technology, Inc.
    Inventors: Paul A. LaBerge, Joseph M. Jeddeloh, James B. Johnson
  • Publication number: 20110289340
    Abstract: In a first embodiment of the present invention, a method for dynamically adjusting a system clock of a plurality of system clock-controlled components in a system is provided, the method comprising: detecting the receipt of a command at a non-system clock-controlled component of the system; and adjusting the system clock to a fast speed based on the detecting. This embodiment may also include: determining that the command has been completed; determining that there are no outstanding commands in the plurality of system clock-controlled components; and adjusting the system clock to a slow speed based on the determination that there are no outstanding commands in the plurality of system clock-controlled components.
    Type: Application
    Filed: May 18, 2010
    Publication date: November 24, 2011
    Applicant: PLX TECHNOLOGY, INC.
    Inventor: Philip David ROSE
  • Patent number: 8065553
    Abstract: A semiconductor integrated circuit device has a command decoder for issuing a control command in accordance with a supplied control signal, a DRAM core, and a timing adjusting circuit for supplying the control command, set active for a predetermined period, as a DRAM control signal to the DRAM core. The timing adjusting circuit generates n different clocks that are respectively shifted in phase with respect to a supplied reference clock, and generates the DRAM control signal by setting the control command active in a prescribed operation cycle for only a period starting at a first predetermined clock pulse of a first clock of the n clocks and ending at a second predetermined clock pulse of a second clock of the n clocks. In this way, timing design with relatively high accuracy of adjustment can be done in a short period.
    Type: Grant
    Filed: January 23, 2009
    Date of Patent: November 22, 2011
    Assignee: Fujitsu Limited
    Inventors: Hirotaka Tamura, Hisakatsu Yamaguchi, Shigetoshi Wakayama, Kohtaroh Gotoh, Junji Ogawa
  • Patent number: 8065550
    Abstract: A semiconductor memory device includes a mode register set for establishing information on a delay time, a delay time calculator for calculating an I/O path delay time of a data clock on a basis of a unit period of a system clock, and a delay locked clock generator for reflecting in the data clock a value of subtracting an output of the delay time calculator from the information established in the mode register set.
    Type: Grant
    Filed: December 28, 2007
    Date of Patent: November 22, 2011
    Assignee: Hynix Semiconductor, Inc.
    Inventors: Bo-Kyeom Kim, Sang-Sik Yoon
  • Patent number: 8065551
    Abstract: Disclosed herein are solutions for addressing the problem of skew of data within a byte lane by factors caused external to the integrated circuit or module providing the data. To compensate for such skew, an on-chip delay is added to the data out paths of those bits in the byte lane with otherwise would arrive early to their destinations. Such on-chip delay is provided delay circuits preferably positioned directly before the output buffers/bond pads of the integrated circuit or module. By intentionally delaying some of the outputs from the integrated circuit or module, external skew is compensated for so that all data in the byte lane arrives at the destination at substantially the same time. In a preferred embodiment, the delay circuits are programmable to allow the integrated circuit or module to be freely tailored to environments having different skew considerations, such as different styles of connectors.
    Type: Grant
    Filed: November 5, 2008
    Date of Patent: November 22, 2011
    Assignee: Micron Technology, Inc.
    Inventor: Christopher S. Johnson
  • Patent number: 8060769
    Abstract: There is provided a duplexed field controller. The duplexed field controller includes: first and second control units between which a control authority is switchable; a first application clock that is updated based on a reference clock so as to define a timing of an application operation of the first control unit; a second application clock that is updated based on the reference clock so as to define a timing of an application operation of the second control unit; and an update control unit that bypasses the first update of the second application clock after switching of the control authority, if the first application clock is ahead of the second application clock when the control authority is switched from the first control unit to the second control unit.
    Type: Grant
    Filed: February 4, 2010
    Date of Patent: November 15, 2011
    Assignee: Yokogawa Electric Corporation
    Inventors: Hideharu Yajima, Satoshi Kitamura, Senji Watanabe, Masafumi Kisa, Kazushi Sakamoto, Hiroyuki Takizawa, Kuniharu Akabane, Yoshinori Kobayashi, Kenji Habaguchi, Kiyotaka Kozakai, Mitsuhiro Kurono, Hiroaki Nakajima
  • Patent number: 8060770
    Abstract: A system that includes a clock tree and multiple variable delay components. The system is characterized by including a first set of fuses indicative of identities of variable delay components that belong to a first set of variable delay components, a second set of fuses indicative of delay values of the variable delay components that belong to the first set of variable delay components, and a second set of variable delay components that are set to at least one default delay value. A method for reducing clock skews, the method includes providing a clock tree that includes a set of variable delay components. The method is characterized by selecting a first set of variable delay components in view of timing violations occurring due clock skews, setting delay values of variable delay components that form a first set of variable delay components by programming fuses, and setting delay values of variable delay components that form a second set of variable delay components to at least one default value.
    Type: Grant
    Filed: November 2, 2005
    Date of Patent: November 15, 2011
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Dan Kuzmin, Michael Priel, Michael Zimin
  • Patent number: 8055930
    Abstract: An integrated circuit device may include a main clock signal input pad configured to receive a main clock signal having a main clock frequency, a high speed clock signal input pad configured to receive a high speed clock signal having a high speed clock frequency greater than the main clock frequency, a frequency divider, and a phase controller. The frequency divider may be configured to generate a plurality of preliminary internal clock signals responsive to the high speed clock signal wherein each of the preliminary internal clock signals has the same main clock frequency and a different phase.
    Type: Grant
    Filed: August 26, 2008
    Date of Patent: November 8, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Seungjun Bae, JinGook Kim, Kwangil Park, Daehyun Chung
  • Patent number: 8050372
    Abstract: A clock-data recovery circuit includes a plurality of input ports and a code generation circuit. The plurality of input ports generates sampling clock signals based on digital control codes and samples input data signals based on the sampling clock signals to generate output data signals and phase detection signals, respectively. The code generation circuit generates the digital control codes based on the phase detection signals received from the input ports during a training mode.
    Type: Grant
    Filed: May 15, 2008
    Date of Patent: November 1, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Kyong-Su Lee
  • Patent number: 8051320
    Abstract: The present invention provides a clock ratio controller for dynamic voltage and frequency scaled digital systems, and applications thereof. In an embodiment, a digital system is provided that includes a first digital circuit that operates at a first rate determined by a first clock signal and a second digital circuit that operates at a second rate determined by a second clock signal. The first digital circuit is coupled to the second digital circuit by a bus that is used for communications between the first digital circuit and the second digital circuit. A clock ratio controller is used to adjust the frequency of the first clock signal and/or the second clock signal in response to a power management signal without causing a loss of synchronization between the first digital circuit and the second digital circuit.
    Type: Grant
    Filed: December 12, 2007
    Date of Patent: November 1, 2011
    Assignee: MIPS Technologies, Inc.
    Inventor: Matthias Knoth
  • Patent number: 8045663
    Abstract: A data transmission/reception system can lessen a skew between data and clock signal by substantially reducing a data reception error. The data transmission/reception system using a first clock signal and a second clock signal having a phase difference corresponding to a half of data bit period as compared with the first clock signal includes a skew information extracting unit and a timing control unit. The skew information extracting unit obtains and outputs skew edge information data necessary for a skew removal by sampling data transmitted in a training operating mode as one of the first and second clock signals in a receiving side. The timing control unit receives the skew edge information data through a transmitting side, and compares its phase with a phase of the transmitted data and controls a timing between transmission data and a transmission sampling clock signal applied to a transmission output unit according to the phase comparison result.
    Type: Grant
    Filed: February 12, 2008
    Date of Patent: October 25, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Seung-Jun Bae, Kwang-Il Park, Seong-jin Jang
  • Patent number: 8041983
    Abstract: A method for optimizing signal operating parameters for a signal sent over a data transmission channel through a programmable logic device (PLD) is provided. A transmit test pattern is generated and is associated with a set of signal operating parameters for the transmission and receiving of the test pattern over a data transmission channel. The data transmission channel loops from a transmit port to a receive port of the PLD. A determination of whether the received test pattern matches the transmit test pattern is performed. The match results and the set of signal operating parameters are recorded. At least one of the signal operating parameters of the set of signal operating parameters is modified through a processor of the PLD. Another transmit pattern is transmitted and received according to the modified set of signal operating parameters and the results are recorded. Methods for optimizing data transfer into a PLD and corresponding apparatuses are included.
    Type: Grant
    Filed: September 24, 2008
    Date of Patent: October 18, 2011
    Assignee: Altera Corporation
    Inventor: San Wong
  • Patent number: 8037340
    Abstract: An apparatus and method for micro-tuning an effective clock frequency of a core in a microprocessor. The apparatus includes a microprocessor having at least one core with logic configured to transition between states, a clock signal coupled to the microprocessor, the clock signal having a predetermined clock frequency based on a worst-case clock frequency and a predetermined clock period. The apparatus further including at least one voltage drop sensor coupled to the core, the sensor being configured to generate an output signal for detecting a voltage drop in the core and to determine whether or not the output signal is detected within the clock period and, if the output signal is not detected, the sensor dynamically adjusts the clock period of the clock signal provided to the core to allow more time to complete state transitions, such that, dynamically adjusting the clock period effectively changes an effective core clock frequency.
    Type: Grant
    Filed: November 28, 2007
    Date of Patent: October 11, 2011
    Assignee: International Business Machines Corporation
    Inventors: Daeik Kim, Jonghae Kim, Moon Ju Kim, James Randal Moulic
  • Patent number: 8037336
    Abstract: The present disclosure provides a spread spectrum clock generation system having a digitally controlled phase locked loop (PLL) and a digital frequency profile generator to create a near optimal frequency modulation profile for the purpose of achieving spectral flatness in the output frequency modulated clock. The circuit is combined with a multilevel error feedback noise shaping structure that provides the required noise transfer function for the quantization noise but maintains a unity gain all pass signal transfer function. This arrangement offers minimal degradation of the in-band signal-to-noise ratio (SNR) at the cost of higher out-of-band noise.
    Type: Grant
    Filed: May 15, 2007
    Date of Patent: October 11, 2011
    Assignee: STMicroelectronics PVT, Ltd.
    Inventor: Nitin Chawla
  • Publication number: 20110246810
    Abstract: In at least some embodiments, an electronic device includes a processor and a memory coupled to the processor. The electronic device also includes a serial communication link controller coupled to the processor, the serial communication link controller supporting dynamic reconfiguration of a plurality of communication link bundles. The serial communication link controller receives an input clock and generates first and second clock signals based on the input clock, the first and second clock signals having different clock rates and being provided to each of a plurality of communication link bundles.
    Type: Application
    Filed: December 16, 2008
    Publication date: October 6, 2011
    Inventors: Robert E. Wessel, Peter D. Maroni
  • Patent number: 8031252
    Abstract: A solid-state image-capturing device which has built in an image-capturing area including a light receiving element provided on a semiconductor substrate, a substrate bias circuit, and a clamp circuit for receiving output of the substrate bias circuit and applying the output of the substrate bias circuit to the semiconductor substrate in accordance with a substrate pulse, comprises a substrate bias control circuit for controlling so as to reduce an electric current of the clamp circuit during a predetermined period.
    Type: Grant
    Filed: September 15, 2009
    Date of Patent: October 4, 2011
    Assignee: Sony Corporation
    Inventors: Masahiro Segami, Kenji Nakayama, Isao Hirota
  • Publication number: 20110239035
    Abstract: A method and a device for generating a clock signal determine a number of pulses to be discarded from each predetermined cycle of a reference clock signal in order to obtain, on average, a target frequency. A masking pattern is created for discarding the number of pulses to be discarded from each predetermined cycle of the reference clock signal. The clock signal, which includes the target frequency, is generated by discarding the number of pulses from the reference clock signal using the masking pattern.
    Type: Application
    Filed: June 6, 2011
    Publication date: September 29, 2011
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Chi-ho CHA, Hoon-sang JIN
  • Publication number: 20110239034
    Abstract: There is provided a transmission apparatus including: a clock generator; a first circuit including first data processors to process input data based on a first input clock, the first data processors electrically connected in series each transmitting data processed thereby and the first input clock to the next first data processor, the first input clock of the beginning first data processor being one of the clocks generated by the clock generator; a second circuit including: second data processors same as the first data processors; and phase adjusters each to adjust a phase of the second input clock and transmitting the second input clock adjusted thereby to the next second data processor; phase comparators each to compare phases of the first input clock and the second input clock; and a delay controller to control the phase adjusters, based on comparison results of the phase comparators.
    Type: Application
    Filed: March 3, 2011
    Publication date: September 29, 2011
    Applicant: FUJITSU LIMITED
    Inventor: Hayato OKUDA
  • Patent number: 8028186
    Abstract: An interconnection system is described where data lanes may be exchanged between lines at intervals along a transmission path so that the differential time delay between bits on a plurality of the lines is reduced when determined at a receiving location. The data lanes may be bound to the lines through the operation of a configurable switch, or by a configurable switch in conjunction with predetermined manufactured connections, or a combination of the techniques. The wiring of a connectorized node module, which may include a memory device, may be configured so that the differential time delay between pairs of input lines of a node, as measured at the output of a node, is reduced.
    Type: Grant
    Filed: October 17, 2007
    Date of Patent: September 27, 2011
    Assignee: Violin Memory, Inc.
    Inventor: Jon C. R. Bennett
  • Patent number: 8024599
    Abstract: A system and method for digital communication wherein a host provides a host clock and a clockless device transmits to the host a bit stream synchronized according to the clock at a data rate that is an integer multiple of the clock rate. A training mechanism using training data detects time skew between host clock and bit stream, and a digital skew compensation mechanism compensates, substantially in real time, for the skew and for variations in the skew that may occur with the passage of time, in accordance with a vote among at least three samples of a bit of the bit stream, subsequent sampling being retarded or advanced if, respectively, an early or late sample is in disagreement with the vote. Preferably, the compensation value is selected from at least four possible compensation values, and can be stored in a memory to hasten subsequent restarts of the system.
    Type: Grant
    Filed: March 7, 2008
    Date of Patent: September 20, 2011
    Assignee: SanDisk IL Ltd
    Inventor: Tuvia Liran
  • Publication number: 20110225443
    Abstract: The present image forming apparatus includes a first control unit and a second control unit driven by built-in clock oscillators to realize the distributed control. The first control unit generates, using a first timer driven by the built-in clock oscillator of the first control unit, a pulse signal corresponding to a predetermined clock rate and outputs the pulse signal to the second control unit. The second control unit measures, using a second timer driven by the built-in clock oscillator of the second control unit, a pulse width of the pulse signal outputted from the first control unit, and calculates a correction coefficient using reference pulse width corresponding to the predetermined clock rate and the measured pulse width. The processing unit processes using the calculated correction coefficient.
    Type: Application
    Filed: March 7, 2011
    Publication date: September 15, 2011
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Keita Takahashi, Atsushi Otani, Shoji Takeda, Satoru Yamamoto, Hirotaka Seki
  • Patent number: 8020026
    Abstract: The present invention relates to providing a system clock signal that is based on either a first clock signal that is capable of being frequency-corrected or a second clock signal that is not capable of being frequency-corrected, depending on system needs. When the system clock signal is based on the second clock signal, all or part of the circuitry that provides the first clock signal may be disabled or powered-down to reduce power consumption. A multiplexer may be used to select either the first or the second clock signal to provide the system clock signal to system circuitry. The system circuitry may be intolerant of phase-jumps in the system clock signal; therefore, before the multiplexer transitions between the first and the second clock signals, the first clock signal may be phase-adjusted to bring it into phase-alignment with the second clock signal.
    Type: Grant
    Filed: February 29, 2008
    Date of Patent: September 13, 2011
    Assignee: RF Micro Devices, Inc.
    Inventors: Nadim Khlat, Navid Foroudi
  • Patent number: 8020021
    Abstract: Method of controlling a wind power system comprising a plurality of system elements, the wind power system including a plurality of data processors distributed in the system elements, the method includes the steps of: synchronizing at least a part of the data processors to at least one reference signal distributed to the data processors from a time synchronization arrangement, associating the data processors with local clock generation circuitries, wherein the local clock generation circuitries associated with data processors of a first subset of the data processors have a peak-to-peak tracking jitter higher than or equal to a predetermined threshold value and wherein a second subset of the data processors have a peak-to-peak tracking jitter less than the predetermined threshold value, controlling at least one of said system elements at least partly by mechanism of a data processor from said first or second subset of data processors.
    Type: Grant
    Filed: May 25, 2010
    Date of Patent: September 13, 2011
    Assignee: Vestas Wind Systems A/S
    Inventor: John Bengtson
  • Patent number: 8020023
    Abstract: Exemplary systems and methods include a distribution device that maintains a clock rate and distributes a series of tasks to a group of execution devices. Each task has a plurality of samples per frame associated with a time stamp indicating when the task is to be executed. The execution devices execute the series of tasks at the times indicated and adjust the number of samples per frame in relation to the clock rate maintained by the distribution device.
    Type: Grant
    Filed: May 9, 2007
    Date of Patent: September 13, 2011
    Assignee: Sonos, Inc.
    Inventors: Nicholas A. J. Millington, Michael Ericson
  • Patent number: 8010825
    Abstract: A jitter reduction circuit includes a signal line transmitting a first signal and having a plurality of sections, and a plurality of delay lines transmitting a second signal and provided in one-to-one correspondence to the sections of the signal line, wherein the plurality of delay lines is configured such that a delay of the second signal on a given one of the delay lines is set to a first delay in response to a first level of the first signal in a corresponding one of the sections, and is set to a second delay in response to a second level of the first signal in the corresponding one of the sections.
    Type: Grant
    Filed: August 30, 2007
    Date of Patent: August 30, 2011
    Assignee: Fujitsu Limited
    Inventor: Hirotaka Tamura
  • Patent number: 8005130
    Abstract: A transmitting and receiving technique in which a load on data signal lines is reduced while maintaining a communication quality, thereby making it possible to improve the throughput of data channels. In a transceiver, a transmitter side has an encoder circuit that transmits a bit sequence obtained by encoding link information to a clock signal line, and a receiver side has a clock and data recovery circuit 17 that extracts a clock component from a signal received from the clock signal line, a decoder circuit 19 that decodes the extracted signal to reproduce the link information, and a bit deskew circuit 21 that adjusts a skew that is lower than one bit on the basis of a clock component.
    Type: Grant
    Filed: July 13, 2007
    Date of Patent: August 23, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Hidehiro Toyoda, Tatsuya Saito, Hiroki Yamashita, Norio Chujo
  • Publication number: 20110202781
    Abstract: A system and method for loop timing update of energy efficient physical layer devices using subset communication techniques. During a quiet period during which a subset of communication channels are transitioned from an active mode to a low-power mode, circuitry in the active channel can be designed to track, on behalf of the inactive channels, the phase drift due to the frequency offset. This tracking of the frequency estimation error would reduce the time required to perform a timing update for the communication channels when transitioning back to the active mode.
    Type: Application
    Filed: March 29, 2010
    Publication date: August 18, 2011
    Applicant: Broadcom Corporation
    Inventors: Peiqing Wang, Linghsiao Wang, Mehmet Tazebay, Scott Powell
  • Publication number: 20110197088
    Abstract: A method and system for providing an improved compliance clock service are described. An example method comprises establishing a system compliance clock (SCC) for a storage system that provides a compliant storage service, and establishing, for a volume in the storage system, a volume compliance clock (VCC). A current value of the SCC may be periodically updated based on hardware ticks monitored at the associated storage node. The volume compliance clock is to update its value based on a current value of the SCC.
    Type: Application
    Filed: February 5, 2010
    Publication date: August 11, 2011
    Applicant: NetApp, Inc.
    Inventors: Mohit Kumar, Anuja Jaiswal, Jayesh Gada
  • Patent number: 7996699
    Abstract: Multiple media devices are synchronized in a multi-media system having a computer system, a plurality of media devices, and a display system. Each media device to be synchronized receives a front-end synchronization signal that periodically increments a front-end counter. The front-end counter represents an unadjusted system time (UST). The media device obtains a frame of data to be displayed from a computer system. The media device also receives a back-end synchronization signal that periodically increments a back-end counter each time a frame of data is to be displayed. The back-end counter represents a media stream count (MSC). UST and MSC data are periodically transmitted to the computer system for analysis and use by a synchronization algorithm. Specifically, UST is transmitted to the computer system each time a frame of data is obtained, and a UST/MSC pair is transmitted to the computer system each time a frame of data is displayed.
    Type: Grant
    Filed: April 11, 2005
    Date of Patent: August 9, 2011
    Assignee: Graphics Properties Holdings, Inc.
    Inventors: Michael K. Poimboeuf, Francis S. Bernard, Kevin A. Smith, Parkson Wong, Todd S. Stock, William R. Lawson
  • Patent number: 7996701
    Abstract: Automated clock relationship detection may quickly and reliably detect a clock relationship with minimal latency while reducing problems due to metastability occurring at a solitary instant or extended over multiple clock periods. Automated clock relationship detection between two clocks may comprise (a) a shift register synchronizer that reduces the possibility of metastability while capturing and temporarily storing samples of the first clock in response to cycles of the second clock and (b) an evaluator that processes the samples to determine the relationship. A clock relationship detector may also determine the relationship of two clocks by arbitrating a plurality of preliminary determinations of the relationship. Delays may be applied so that each of several detectors receives a clock at a different time, which may avoid metastability in the majority of detectors. The relationship may be used to reliably determine an operating mode of logic driven by one of the clocks.
    Type: Grant
    Filed: February 13, 2008
    Date of Patent: August 9, 2011
    Assignee: Integrated Device Technologies, Inc.
    Inventor: Ming-Tsun Hsieh
  • Publication number: 20110185218
    Abstract: A method, system, and computer program product are provided for adjusting write timing in a memory device based on a training signal. For instance, the method can include configuring the memory device in a training mode of operation. The method can also include determining a write timing window between a signal on a data bus and a write clock signal based on the training signal. Further, the method includes adjusting a phase difference between the signal on the data bus and the write clock signal based on the write timing window. The memory device can recover data on the data bus based on the adjusted phase difference.
    Type: Application
    Filed: July 30, 2010
    Publication date: July 28, 2011
    Applicant: Advanced Micro Devices, Inc.
    Inventors: Aaron John Nygren, Ming-Ju Edward Lee, Shadi M. Barakat, Xiaoling Xu, Toan Duc Pham, Warren Fritz Kruger
  • Patent number: 7987382
    Abstract: One inventive aspect relates to a digital sub-circuit suitable for embedding in an at least partially digital circuit for minimizing the influence of another digital sub-circuit on the at least partially digital circuit, the other digital sub-circuit being part of the at least partially digital circuit. The influence of the other digital sub-circuit may, for example, be the introduction of ground bounce by switching of the other digital sub-circuit. Another inventive aspect relates to an at least partially digital circuit comprising such a digital sub-circuit for minimizing the influence of another digital sub-circuit to the at least partially digital circuit and to a method for reducing the influence of another digital sub-circuit to an at least partially digital circuit.
    Type: Grant
    Filed: July 13, 2006
    Date of Patent: July 26, 2011
    Assignee: IMEC
    Inventor: Mustafa Badaroglu
  • Patent number: 7983374
    Abstract: A method and apparatus for varying an output clock signal frequency to match the frequency of an output data signal frequency for a SERDES circuit while maintaining a constant input clock frequency is shown. According to this method and apparatus, a PMA rate signal may control the frequency of the output clock while a datastrobe signal may be used to control the frequency of the data signal. Accordingly, the apparatus and methods may be used to produce an output data signal and a clock signal having frequencies that may be lower than the frequency of the input clock signal.
    Type: Grant
    Filed: September 28, 2007
    Date of Patent: July 19, 2011
    Assignee: Integrated Device Technology, Inc.
    Inventors: Leon Lei, Han Bi
  • Patent number: 7983770
    Abstract: An arrangement for controlling a system generated noise level such that the same is adapted to an actual ambient noise level of the system environment. Internal noise generators will thus not run at a needlessly lowered rate than actually needed. For instance, by permitting a fan to run at a generally higher speed, the system will not needlessly undergo significant internal temperature increases. By the same token, CPU performance, to the extent that it represents a noise generator, will not be needlessly throttled.
    Type: Grant
    Filed: April 30, 2007
    Date of Patent: July 19, 2011
    Assignee: Lenovo (Singapore) Pte. Ltd.
    Inventors: John K. Langgood, Thomas F. Lewis, Kevin M. Reinberg, Kevin S. Vernon
  • Patent number: 7984321
    Abstract: A data transfer control device includes an OUT-transfer transmitter circuit which transmits OUT data by driving a serial signal line, a clock-transfer transmitter circuit which transmits a clock signal CLK by driving a serial signal line, a PLL circuit which generates the clock signal CLK, and a power-down setting circuit which sets a power-down mode. In a first power-down mode, the OUT-transfer transmitter circuit is set to the power-down mode, and the clock-transfer transmitter circuit is set to the power-down mode to stop a system clock signal of a target-side data transfer control device. In a second power-down mode, the OUT-transfer transmitter circuit is set to the power-down mode without setting the clock-transfer transmitter circuit to the power-down mode.
    Type: Grant
    Filed: June 20, 2007
    Date of Patent: July 19, 2011
    Assignee: Seiko Epson Corporation
    Inventors: Yukinari Shibata, Nobuyuki Saito, Tomonaga Hasegawa, Takuya Ishida
  • Patent number: 7979732
    Abstract: A method, system, and computer program product are provided for achieving timing closure in a clocked logic circuit. For each local clock buffer in a set of local clock buffers, a logic synthesis tool determines a clock control signal input from a set of clock control signal inputs that will drive a clock control signal to the local clock buffer at a target frequency such that a first timing constraint may be met. The operation performed by the logic synthesis tool forms a determined clock control signal input. Responsive to the logic synthesis tool determining the determined clock control signal input, the logic synthesis tool couples the local clock buffer to the determined clock control signal input that drives the clock control signal to the local clock buffer at the target frequency to achieve timing closure in the clocked logic circuit.
    Type: Grant
    Filed: July 3, 2007
    Date of Patent: July 12, 2011
    Assignee: International Business Machines Corporation
    Inventors: Lawrence D. Curley, John M. Isakson, Arjen Mets, Travis W. Pouarz, Thomas E. Rosser, Kristen M. Tucker
  • Patent number: 7975161
    Abstract: A processing system includes a bus and a processor whose core is constrained to have one or more core clock signal frequencies no lower than a predetermined multiple of the lowest of one or more bus clock signal frequencies. In a power-save mode, the processor is able to generate one or more core clock signals at frequencies such that the lowest core clock signal frequency is lower than the predetermined multiple of the lowest of the one or more bus clock signal frequencies in performance mode. The processor is able to achieve this by generating the one or more bus clock signals so that the lowest of the bus clock signal frequencies in power-save mode is lower than the lowest of the bus clock signal frequencies in performance mode.
    Type: Grant
    Filed: October 2, 2007
    Date of Patent: July 5, 2011
    Assignee: Intel Corporation
    Inventor: Opher Kahn