Using Multiple Clocks Patents (Class 327/144)
  • Patent number: 8384438
    Abstract: A conversion circuit includes a first inverter having an input node configured to receive a single-ended signal and second and third inverters each having respective inputs coupled to an output of the first inverter. A fourth inverter has an input coupled to an output of the second inverter and has an output coupled to a first node. A fifth inverter has an input coupled to the first node and an output coupled to a second node to which an output of the third inverter is coupled. Sixth and seventh inverters are configured to respectively output a differential signal based on the single-ended signal. The sixth inverter has an input coupled to the first node, and the seventh inverter has an input coupled to the second node.
    Type: Grant
    Filed: August 11, 2011
    Date of Patent: February 26, 2013
    Assignee: Initio Corporation
    Inventors: Zhenchang Du, Haiming Tang, Wei Wang
  • Publication number: 20130002300
    Abstract: In embodiments of a serializing transmitter, the serializing transmitter includes one or more multiplexing drive units that each generate a series of output pulses derived from input data signals and multi-phase clock signals. Each of the multiplexing drive units includes a pulse-controlled push-pull output driver that has first and second inputs, and an output coupled to an output of the multiplexing drive unit. Each of the multiplexing drive units also includes a first M:1 (where M is two or more) pulse-generating multiplexer having an output coupled to the first input of the pulse-controlled push-pull output driver, and generating a first series of intermediate pulses at the output; and a second M:1 pulse-generating multiplexer having an output coupled to the second input of the pulse-controlled push-pull output driver, and generating a second series of intermediate pulses at the output.
    Type: Application
    Filed: June 28, 2011
    Publication date: January 3, 2013
    Applicant: MICROSOFT CORPORATION
    Inventor: Alan S. Fiedler
  • Publication number: 20130002298
    Abstract: A D-type flip-flop 2 includes tristate inverter circuitry 4, 6 passing a processing signal through to storage circuitry 8 from where the processing signal passes via a transmission gate 10 to slave storage circuitry 12. A transition detector 16 is coupled to the input node nm of the storage circuitry 8 and serves to generate an error signal if a transition is detected upon that input node during an error detecting period. Other forms of this technique may provide clock gating circuitry.
    Type: Application
    Filed: July 1, 2011
    Publication date: January 3, 2013
    Applicant: ARM Limited
    Inventors: David William Howard, David Michael Bull, Shidhartha Das
  • Patent number: 8344768
    Abstract: A display device includes a skew compensating type data receiving unit for delaying clocks received in response to a program signal, comparing the clocks delayed thus to compensating clocks, setting an internal delay amount according to a result of the comparison, and delaying and forwarding a low voltage differential signals according to the delay amount set thus, a clock receiving unit for delaying the clock received thus by a fixed delay amount and forwarding the clock delayed thus as a compensating clock, a clock generating unit for generating a data restoring clock by using the clock delayed thus, and a data restoring logic for restoring the low voltage differential signal delayed at the data receiving unit in synchronization with the data restoring clock, thereby compensating for an internal skew taking place at the data channel which receives a low voltage differential signal.
    Type: Grant
    Filed: December 21, 2009
    Date of Patent: January 1, 2013
    Assignee: Dongbu HiTek Co., Ltd.
    Inventor: Sang-Seob Kim
  • Patent number: 8340152
    Abstract: An electronic system having a spread spectrum clock is disclosed. A spread spectrum clock source creates and transmits both a spread spectrum clock signal and a modulation signal. A spread spectrum clock generator uses a modulation waveform on the modulation signal to frequency modulate a reference oscillator frequency. A logic unit comprises a Phase Locked Loop that receives the spread spectrum clock signal and the modulation signal and generates a logic unit clock signal.
    Type: Grant
    Filed: July 31, 2008
    Date of Patent: December 25, 2012
    Assignee: International Business Machines Corporation
    Inventors: Mark James Jeanson, Jordan Ross Keuseman, George Russell Zettles, IV
  • Patent number: 8334707
    Abstract: Some embodiments show a storage circuit with fault detection. The storage circuit comprises, first and second fault detection circuits each comprising a first stable state and a second stable state, wherein each of the first and the second fault detection circuits is configured such that a fault signal strength necessary to cause switching from the first stable state to the second stable state is different from a fault signal strength necessary to cause switching from the second stable state to the first stable state.
    Type: Grant
    Filed: December 29, 2008
    Date of Patent: December 18, 2012
    Assignee: Infineon Technologies AG
    Inventor: Thomas Kuenemund
  • Patent number: 8330508
    Abstract: Embodiments of phase-generation circuitry and methods for generating a multiphase signal with duty-cycle correction are generally described herein. The phase-generation circuitry may include a plurality of controllable delay stages arranged in series and phase detector circuitry. Each delay stage may be configured to phase shift a differential signal based on a control signal. The phase detector circuitry may be configured to generate the control signal based on a first time difference and a second time difference. The first time difference may be a time difference between rising edges of a first component of the differential signal and a second component of a phase-shifted signal. The second time difference may be a time difference between falling edges of the first component of the differential signal and the second component of the phase-shifted signal. Other circuits, systems, and methods are described.
    Type: Grant
    Filed: April 23, 2010
    Date of Patent: December 11, 2012
    Assignee: Micron Technology, Inc.
    Inventors: Feng Lin, Roman Andreas Royer
  • Patent number: 8314724
    Abstract: In one embodiment, the present invention includes a de-serializer to receive serial data at a first rate and to output a parallel data frame corresponding to the serial data aligned to a frame alignment boundary in response to a phase control signal received from a feedback loop coupled between the de-serializer and a receiver logic coupled to an output of the de-serializer. Other embodiments are described and claimed.
    Type: Grant
    Filed: December 15, 2010
    Date of Patent: November 20, 2012
    Assignee: Intel Corporation
    Inventors: Ehud Shoor, Dror Lazar, Assaf Benhamou
  • Patent number: 8288967
    Abstract: A LED control circuit and method determine the frequency and duty of a LED driving signal according to a swing control signal and a dimming control signal, respectively. Responsive to the swing control signal, a pulse edge generator generates a clock whose frequency is determined by the swing control signal. Responsive to the clock and the dimming control signal, a duty ratio controller generates the LED driving signal whose frequency is determined by the clock frequency and whose duty is determined by the dimming control signal.
    Type: Grant
    Filed: March 11, 2010
    Date of Patent: October 16, 2012
    Assignee: Richtek Technology Corp.
    Inventor: Jing-Meng Liu
  • Publication number: 20120257463
    Abstract: A driver circuit includes pull-up and pull-down drivers driven by separate pre-drivers operating between different voltage rails. Data signals driving the pull-up driver and the pull-down driver are synchronized, and the pull-up driver and the pull-down driver are coupled together to produce an output signal having a voltage swing based on both the pull-up driver and the pull-down driver.
    Type: Application
    Filed: April 5, 2012
    Publication date: October 11, 2012
    Inventors: Manish JAIN, Navin Kumar Mishra
  • Publication number: 20120229184
    Abstract: An apparatus and method for clock regeneration with low jitter. The method includes the following steps: (a) using a phase lock loop to generate a first clock that is phase locked to a reference clock; (b) using a binary phase detector for generating a phase error signal by detecting a timing difference between the input signal and a second clock; (c) filtering the phase error signal to generate a first control word and a second control word; (d) performing a phase rotation on the first clock by an amount controlled by the first control word to generate the second clock; (e) filtering the second control word to generate a third control word; (f) sampling the third control word to generate a fourth control word using a third clock; and (g) performing a phase rotation on the first clock by an amount controlled by the fourth control word to generate the third clock. Comparable features for performing these steps are provided in the apparatus.
    Type: Application
    Filed: March 10, 2011
    Publication date: September 13, 2012
    Applicant: REALTEK SEMICONDUCTOR CORP.
    Inventors: Chia-Liang Lin, Ger-Chih Chou, Pei-Si Wu
  • Patent number: 8248001
    Abstract: A LED control circuit and method generate a high frequency clock signal with a fixed duty for a LED driver, to supply a switching current to drive a LED to emit light flashing at a modulated high frequency and with a fixed duty. By controlling the flashing LED light within certain flashing frequency range, the circuit and method allow a LED light source for expelling, confusing or trapping insects but serving only an illuminative or decorative purpose to human eyes, due to the difference between human beings and insects in visual perception of flashing frequencies.
    Type: Grant
    Filed: March 19, 2009
    Date of Patent: August 21, 2012
    Assignee: Richtek Technology Corp.
    Inventor: Jing-Meng Liu
  • Patent number: 8228101
    Abstract: Methods, circuits and systems for balanced distribution of source-synchronous clock signals are described. Multiple data sets together with one or more clock signals associated with the multiple data sets may be received at a number of interface devices. The multiple data sets may be captured in a number of data buffers. The clock signals may be programmably distributed to a group of the multiple data buffers that retain the one or more data sets, using a balanced clock network. Additional methods, circuits, and systems are disclosed.
    Type: Grant
    Filed: September 14, 2009
    Date of Patent: July 24, 2012
    Assignee: Achronix Semiconductor Corporation
    Inventors: Rahul Nimaiyar, Ravi Sunkavalli
  • Patent number: 8222932
    Abstract: A phase-locked loop includes: a voltage-controlled oscillator (VCO) system receiving one or more control signals and in response thereto generating a PLL output signal; a plurality of phase detectors for comparing a reference signal having a reference frequency to a PLL feedback signal having a PLL feedback frequency derived from the PLL output signal, and in response thereto to output a comparison signal; and a plurality of signal processing paths each connected to an output of a corresponding one of the phase detectors for outputting a phase detection output signal. The signal processing paths have different frequency responses from each other. In operation only one of the phase detectors is activated, and a switching arrangement selectively switches between outputs of the signal processing paths to select the phase detection output signal from the activated phase detector to generate the control signal(s) for the VCO system.
    Type: Grant
    Filed: February 23, 2010
    Date of Patent: July 17, 2012
    Assignee: Agilent Technologies, Inc.
    Inventor: Murat Demirkan
  • Patent number: 8222931
    Abstract: A semiconductor device includes a plurality of synchronization clock generators configured to generate a plurality of synchronization clock signals by mixing phases of first and second source clock signals having an identical frequency, a first clock transmission path configured to sequentially apply the first source clock signal to the plurality of synchronization clock generators by transferring the first source clock signal in a forward direction, a second clock transmission path configured to sequentially apply the second source clock signal to the plurality of synchronization clock generators by transferring the second source clock signal in a backward direction, and a plurality of data output units configured to synchronize a plurality of data with the plurality of synchronization clock signals and outputting the synchronized plurality of data.
    Type: Grant
    Filed: October 7, 2011
    Date of Patent: July 17, 2012
    Assignee: Hynix Semiconductor Inc.
    Inventor: Tae-Kyun Kim
  • Publication number: 20120169383
    Abstract: A first conversion circuit converts a first clock signal based on a signal level of a first voltage into a second clock signal based on a signal level of a second voltage. A flip-flop circuit supplied with the first voltage as an operation voltage latches and outputs a signal, which is based on the signal level of the first voltage, in accordance with the first clock signal. A second conversion circuit supplied with the second voltage as an operation voltage converts a signal level of an input signal, which is based on an output signal of the flip-flop circuit, into the signal level of the second voltage in synchronization with the second clock signal.
    Type: Application
    Filed: December 19, 2011
    Publication date: July 5, 2012
    Applicant: FUJITSU SEMICONDUCTOR LIMITED
    Inventors: Tomoya KAKAMU, Hisao SUZUKI, Yuji SEKIDO
  • Patent number: 8212594
    Abstract: Clock-domain-crossing systems and methods include an integrator that accumulates input samples over multiple clock cycles in a first clock domain to generate an accumulation result. Clock-domain-crossing circuitry samples the accumulation result in the first clock domain after each of a repeating accumulation count to generate a first domain accumulation. The first domain accumulation is sampled in a second clock domain after a time delay to generate a second domain accumulation. The time delay ensures proper setup and hold time parameters for the second clock domain relative to the first clock domain. A differentiator generates output information in the second clock domain by delaying the second domain accumulation and subtracting the delayed second domain accumulation from the second domain accumulation. The systems and methods preserve temporal characteristics of the input information in the first clock domain when it is transferred to the second clock domain as the output information.
    Type: Grant
    Filed: August 11, 2010
    Date of Patent: July 3, 2012
    Assignee: Integrated Device Technology, Inc.
    Inventors: Rohit Singhal, Chris DeMarco
  • Publication number: 20120155206
    Abstract: Such a device is disclosed that includes a control circuit outputting a first clock signal having a first clock cycle in response to a first command signal and outputting a second clock signal having a second clock cycle in response to a second command signal, a first circuit controlled based on the first clock signal, and a second circuit controlled based on the second clock signal.
    Type: Application
    Filed: December 8, 2011
    Publication date: June 21, 2012
    Applicant: Elpida Memory, Inc.
    Inventors: Takuyo KODAMA, Kosuke Goto
  • Patent number: 8204166
    Abstract: An apparatus including a multiplexer configured to provide an output clock selected from a source clock, a destination clock, and a transition clock is provided. The apparatus further includes a phase difference calculation module configured to calculate a phase difference between the source clock and the destination clock and a clock generation module configured to generate a plurality of clocks. The apparatus further includes a clock selection module configured to select one of the plurality of clocks as the transition clock and a control circuit configured to provide: (1) a signal to the clock selection module for selecting one of the plurality of clocks as the transition clock based on the phase difference between the source clock and the destination clock and (2) a signal to the multiplexer to provide as the output clock one of the source clock, the destination clock, or the transition clock.
    Type: Grant
    Filed: October 8, 2007
    Date of Patent: June 19, 2012
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Srinivasa R. Bommareddy, Uday Padmanabhan, Samir J. Soni, Koichi E. Nomura, Nicholas F. Jungels, Vivek Bhan
  • Publication number: 20120139591
    Abstract: A first mixer generates a first and a second clock signal having a phase opposite to that of the first clock signal. A second mixer generates a third clock signal having a phase lead angle of 90 degrees with respect to the first clock signal and a fourth clock signal having a phase opposite to that of the third clock signal. An ADC generates a digital signal from a signal that is generated on the basis of a composite signal of a voltage signal formed on the basis of the exclusive OR of the first and the third clock signal and a voltage signal formed on the basis of the exclusive OR of the second and the fourth clock signal. An adder adds the digital signal to the first control signal to generate the second control signal and supplies the second control signal to the second mixer.
    Type: Application
    Filed: February 9, 2012
    Publication date: June 7, 2012
    Applicant: FUJITSU LIMITED
    Inventor: Yoshitomo OZEKI
  • Patent number: 8179173
    Abstract: An electronic circuit for distributing a clock signal to several clock destinations includes phase adjustment circuits for adjusting phase shifts of the clock at the respective one of the clock destinations responsive to a respective DC voltage feedback signal receive from the respective one of the clock destinations; phase detectors for detecting a phase shift of the clock signal at the respective one of the clock destinations according to a nearest neighbor clock destination; loop filters for generating and transmitting respective DC voltage feedback signals; current sources, each configured to receive the respective DC voltage feedback signal and output a respective current to a respective one of the phase adjustment circuits according to said respective DC voltage feedback signals to adjust the phase shift of the clock signal for the respective one of the clock destinations.
    Type: Grant
    Filed: March 12, 2010
    Date of Patent: May 15, 2012
    Assignee: Raytheon Company
    Inventors: Erick M. Hirata, Lloyd F. Linder
  • Patent number: 8174297
    Abstract: An apparatus and method for multi-phase clock generation are disclosed. One embodiment of the apparatus includes a module generating first and second intermediate signals delayed from first edges of a clock signal having a first frequency. Each of the first and second intermediate signals has a second frequency that is half of the first frequency. The first and second intermediate signals have a phase difference of 180° from each other. The apparatus also includes a first delay line delaying the first intermediate signal by a first delay amount; a second delay line delaying the first intermediate signal by a second delay amount; a third delay line delaying the second intermediate signal by a third delay amount; and a fourth delay line delaying the second intermediate signal by a fourth delay amount. The apparatus also includes a closed feedback loop for detecting and adjusting the second and fourth delay amount.
    Type: Grant
    Filed: September 7, 2011
    Date of Patent: May 8, 2012
    Assignee: Micron Technology, Inc.
    Inventor: Jongtae Kwak
  • Publication number: 20120105113
    Abstract: A circuit that transfers data between a first clock domain using a first clock and a second clock domain using a second clock synchronized with the first clock. The circuit comprises a data holding circuit operating at the first clock, an enable signal generation circuit connected to the data holding circuit. Preferably, the data transfer circuit includes an edge signal generation circuit connected to the data holding circuit, the edge signal generation circuit generating an edge signal allowing the data holding circuit to receive and send the data when edges of the first clock and the second clock align, and applying the edge signal to the data holding circuit.
    Type: Application
    Filed: October 6, 2011
    Publication date: May 3, 2012
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Takashi Maeno, Masahiro Murakami
  • Patent number: 8131882
    Abstract: A method for expanding input/output in an embedded system is described in which no additional strobes or enable lines are necessary from the host controller. By controlling the transitions of the signal levels in a specific way when controlling two existing data or select lines, an expansion input and/or output device can generate a strobe and/or enable signal internally. This internal strobe and/or enable signal is then used to store output data or enable input data. The host controller typically utilizes software or firmware to control the data transitions, but no additional wires are needed, and no changes are needed to existing peripheral devices. Thus, an existing system can be expanded when there are no additional control lines available and no unused states in existing signals.
    Type: Grant
    Filed: October 5, 2009
    Date of Patent: March 6, 2012
    Assignee: Schuman Assets Bros. LLC
    Inventor: Stephen Waller Melvin
  • Patent number: 8130014
    Abstract: A data communication network may, include a first sub-network and a second sub-network. The first sub-network may include two or more two master clocks, and a synchronization system connected to the master clocks. The synchronization system may, for determine a time-base for the master clocks and control the master clocks based on the determined time-base. The first sub-network may include one or more slave synchronization data source for generating slave clock synchronization data derived from time information of the master clocks. The second sub-network may include one or more slave clocks and a slave clock time-base controller connected to the slave synchronization data source. The time-base controller may receive the slave clock synchronization data and control one or more of the one or more slave clocks in accordance with the slave clock synchronization data.
    Type: Grant
    Filed: October 31, 2006
    Date of Patent: March 6, 2012
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Florian Bogenberger, Mathias Rausch
  • Patent number: 8125251
    Abstract: A semiconductor device includes a clock input block to receive a system clock and a data clock, a clock frequency dividing block to generate a plurality of multi-phase data frequency division clocks each of which has the phase difference of a predetermined size by dividing a frequency of the data clock and to determine whether or not phases of the plurality of multi-phase data frequency division clocks are reversed in response to a frequency division control signal, and a first phase detecting block to detect a phase of the system clock based on a phase of a first selected clock that is predetermined among the plurality of multi-phase data frequency division clocks and to determine a logic level of the frequency division control signal in response to the detected result.
    Type: Grant
    Filed: December 3, 2009
    Date of Patent: February 28, 2012
    Assignee: Hynix Semiconductor
    Inventor: Jung-Hoon Park
  • Patent number: 8115524
    Abstract: A semiconductor device for applying an auto clock alignment training mode to reduce the time required for a clock alignment training operation. The semiconductor device adjusts the entry time of the auto clock alignment training mode to prevent the clock alignment training operation from malfunctioning. The semiconductor device includes a clock division block configured to divide a data clock to generate a data division clock, a phase multiplex block configured to generate a plurality of multiple data division clocks in response to the data division clock, a logic level control block configured to set a period, in which a division control signal is changeable, depending on the data division clock, and a first phase detection block configured to detect a phase of a system clock on the basis of the multiple data division clocks in the period, and to generate the division control signal corresponding to a detection result.
    Type: Grant
    Filed: December 3, 2009
    Date of Patent: February 14, 2012
    Assignee: Hynix Semiconductor Inc.
    Inventors: Young-Ran Kim, Jung-Hoon Park
  • Publication number: 20120025878
    Abstract: A semiconductor device includes a plurality of synchronization clock generators configured to generate a plurality of synchronization clock signals by mixing phases of first and second source clock signals having an identical frequency, a first clock transmission path configured to sequentially apply the first source clock signal to the plurality of synchronization clock generators by transferring the first source clock signal in a forward direction, a second clock transmission path configured to sequentially apply the second source clock signal to the plurality of synchronization clock generators by transferring the second source clock signal in a backward direction, and a plurality of data output units configured to synchronize a plurality of data with the plurality of synchronization clock signals and outputting the synchronized plurality of data.
    Type: Application
    Filed: October 7, 2011
    Publication date: February 2, 2012
    Inventor: Tae-Kyun KIM
  • Patent number: 8098786
    Abstract: In a reception apparatus 1, a multiphase sampling clock signal is generated by a sampling clock signal generation circuit 40, based on a clock signal which has been phase-adjusted by a phase adjustment circuit 50. The data of each of the bits of a serial data signal is sampled and output by a sampler block circuit 30n, with timing indicated by the sampling clock signal. The amount of phase adjustment of the clock signal in the phase adjustment circuit 50 is set such that the delay time from generation of the multiphase sampling clock signal in the sampling clock signal generation circuit 40 until indication of the sampling timing by the sampling clock signal in the sampler block circuit 30n is canceled.
    Type: Grant
    Filed: February 8, 2008
    Date of Patent: January 17, 2012
    Assignee: Thine Electronics, Inc.
    Inventors: Kazuyuki Omote, Ryutaro Saito
  • Patent number: 8085069
    Abstract: A starting apparatus includes: a storage unit storing an identifier; a rectifying unit rectifying a reception signal; a generating unit comparing the reception signal rectified in the rectifying unit to a reference signal and generating a digital signal from the reception signal; a judging unit judging whether or not the digital signal contains information of the identifier; a reference changing unit changing the reference signal when the judging unit judges that the reception signal does not contain information of the identifier; and a start instructing unit instructing start of an electric appliance when the judging unit judges that the reception signal contains information of the identifier.
    Type: Grant
    Filed: September 16, 2009
    Date of Patent: December 27, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shoji Otaka, Toshiyuki Umeda, Shigeyasu Iwata, Takafumi Sakamoto, Tsuyoshi Kogawa, Koji Ogura, Makoto Tsuruta, Yu Kaneko, Nobuhiko Sugasawa
  • Patent number: 8085817
    Abstract: A clock synchronization buffer for a counter clock flow pipelined circuit including a cascade of processing modules that receive data from a previous module and provide output results to a following module. The clock synchronization buffer receives a clock input signal and provides clock signals to a local processing module and to the next pipeline stage. The clock synchronization buffer includes a selectable delay stage that receives a clock input signal and a delay select signal and outputs a clock signal having a selected delay. An amplifier connected to the selectable delay stage provides the delayed clock signal to a local processing module that corresponds to the clock synchronization buffer circuit. An inverting amplifier connected to the selectable delay stage provides the delayed clock signal to the next pipeline stage. A clock synchronization controller synchronizes the phases of reference clock input and synchronized clock input signals.
    Type: Grant
    Filed: October 16, 2009
    Date of Patent: December 27, 2011
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Douglas Jai Fouts, Brian Lee Luke
  • Publication number: 20110309865
    Abstract: In some embodiments, a synchronizing circuit includes at least one synchronization device that operates at a lower clock frequency than another synchronization device in the synchronization circuit. In at least one embodiment of the invention, a method includes sampling a first signal at a first frequency to thereby generate a plurality of sampled versions of the first signal. The first frequency is a frequency of a clock signal divided by N. N is a number greater than one. The method includes sampling a second signal at the frequency of the clock signal. The second signal is based on sequentially selected ones of the plurality of sampled versions of the first signal to thereby generate an output version of the first signal.
    Type: Application
    Filed: June 18, 2010
    Publication date: December 22, 2011
    Inventor: Ioan Cordos
  • Publication number: 20110298502
    Abstract: A clock-switching circuit having at least two inputs for receiving at least two different clock sources, an output for providing a selected one of the clock sources, and a switch for selecting the one of the inputs to provide on the output, the switch including elements that, prevent the providing of a truncated version of any of the clock sources on the output, always provide a clock signal on the output, and always maintain phase alignment and pulse ratio of the clock sources on the output.
    Type: Application
    Filed: July 1, 2010
    Publication date: December 8, 2011
    Applicant: LSI CORPORATION
    Inventors: Hao Qiong Chen, Wen Zhu
  • Patent number: 8072273
    Abstract: A synchronized clock system, for use with an electronic system having several system nodes requiring a synchronized clock signal. The clock system may be formed in either discrete form or in integrated form, or in any combination, and includes a first synch bus and a second synch bus, isolated from the first synch bus, and at least one pair and preferably several pairs of SXO modules connected to the busses in alternating fashion. Each of the system nodes is connected at a different one of any number of arbitrarily selected connection points anywhere along the first bus. The points along the busses at which the SXO modules are connected are spaced roughly equidistantly apart. The system nodes are connected to the bus by means of signal conditioning circuits, which may include correction circuits, an amplifier, a frequency multiplier, a logic translator and a fan buffer.
    Type: Grant
    Filed: October 8, 2010
    Date of Patent: December 6, 2011
    Assignee: NEL Frequency Controls, Inc.
    Inventors: Roman Boroditsky, Jorge Gomez
  • Publication number: 20110291712
    Abstract: A gate-line drive circuit is driven by three clock signals of different phases, and includes a plurality of cascade-connected unit shift registers. In a normal operation, activation periods of the three clock signals do not overlap one another. However, the two clock signals of them are simultaneously activated at the beginning of a frame period. A unit shift register of the first stage is adapted to activate an output signal in accordance with the simultaneous activation of the two clock signals.
    Type: Application
    Filed: February 8, 2011
    Publication date: December 1, 2011
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventor: Youichi TOBITA
  • Publication number: 20110286400
    Abstract: A method for sending and receiving a clock and an apparatus for transmitting the clock. Several kinds of clocks are encoded and framed at a sending port so that the clocks needed by all modes of base stations are transmitted in one pair of interconnecting lines. A receiving port can precisely recover the needed clock out. This not only reduces the number of interconnecting lines on the backboard and improves flexibility, but also avoids that the clock decoded out by the receiving port might be imprecise.
    Type: Application
    Filed: September 24, 2009
    Publication date: November 24, 2011
    Applicant: ZTE CORPORATION
    Inventor: Xiaoming Fu
  • Publication number: 20110285431
    Abstract: A synchronizer circuit for transferring data from a source clock domain to a target clock domain. A first latch in the target clock domain may capture a data value corresponding to current data received from the source clock domain. Under certain conditions, the first latch may enter into a metastable, or undefined logic state. A second latch may remain stable, and store a previous value corresponding to data that has most recently been transferred from the source clock domain to the target clock domain. The respective values output by the two latches may be compared by a detection circuit, and a value derived from the output value of the first latch and corresponding to the current data may be written to an output latch if the current data differs from the stored previous value. The detection circuit may also provide a defined logical value to the output latch even if the first latch is in a metastable state.
    Type: Application
    Filed: June 2, 2011
    Publication date: November 24, 2011
    Inventors: Bo Tang, Edgardo F. Klass
  • Patent number: 8058900
    Abstract: Aspects of the disclosure provide a clock gate circuit for generating a clock signal. The clock gate circuit can include a multiplexer configured to receive a first logic signal at a first data input, a second logic signal at a second data input, and a reference clock signal at a selector input, and to output the clock signal having a logic state selected from one of the first logic signal or the second logic signal based on transitions of the reference clock signal. Further, the clock gate circuit can include a logic module coupled to the multiplexer and configured to output the first logic signal and the second logic signal based on an enable signal and the output of the multiplexer.
    Type: Grant
    Filed: April 14, 2009
    Date of Patent: November 15, 2011
    Assignee: Marvell Israel (M.I.S.L) Ltd.
    Inventor: Eitan Rosen
  • Patent number: 8060654
    Abstract: A data communication network may include two or more master clocks, and a synchronization system connected to the master clocks. The synchronization system may determine a time-base for the master clocks. The synchronization system may control the master clocks according to the determined time-base. The data communication network may include one or more slave clocks. The slave clocks may be controlled by a slave clock time-base controller based on time information of a single selected master clock selected from the master clocks.
    Type: Grant
    Filed: May 14, 2007
    Date of Patent: November 15, 2011
    Assignee: Freescale Semiconductor, Inc
    Inventors: Florian Bogenberger, Mathias Rausch
  • 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: 8035429
    Abstract: A semiconductor device includes a plurality of synchronization clock generators configured to generate a plurality of synchronization clock signals by mixing phases of first and second source clock signals having an identical frequency, a first clock transmission path configured to sequentially apply the first source clock signal to the plurality of synchronization clock generators by transferring the first source clock signal in a forward direction, a second clock transmission path configured to sequentially apply the second source clock signal to the plurality of synchronization clock generators by transferring the second source clock signal in a backward direction, and a plurality of data output units configured to synchronize a plurality of data with the plurality of synchronization clock signals and outputting the synchronized plurality of data.
    Type: Grant
    Filed: June 18, 2009
    Date of Patent: October 11, 2011
    Assignee: Hynix Semiconductor Inc.
    Inventor: Tae-Kyun Kim
  • Patent number: 8026747
    Abstract: An apparatus and method for multi-phase clock generation are disclosed. One embodiment of the apparatus includes a module generating first and second intermediate signals delayed from first edges of a clock signal having a first frequency. Each of the first and second intermediate signals has a second frequency that is half of the first frequency. The first and second intermediate signals have a phase difference of 180° from each other. The apparatus also includes a first delay line delaying the first intermediate signal by a first delay amount; a second delay line delaying the first intermediate signal by a second delay amount; a third delay line delaying the second intermediate signal by a third delay amount; and a fourth delay line delaying the second intermediate signal by a fourth delay amount. The apparatus also includes a closed feedback loop for detecting and adjusting the second and fourth delay amount.
    Type: Grant
    Filed: December 8, 2009
    Date of Patent: September 27, 2011
    Assignee: Micron Technology, Inc.
    Inventor: Jongtae Kwak
  • Patent number: 8024686
    Abstract: Methods and apparatuses for retiming of multirate system for clock period minimization with a polynomial time without sub-optimality. In an embodiment, a normalized factor vector for the nodes of multirate graph is introduced, allowing the formulation of the multirate graph retiming constraints to a form similar to a single rate graph. In an aspect, the retiming constraints are formulated to allowed the usage of linear programming methodology instead of integer linear programming, thus significantly reducing the complexity of the solving algorithm. The present methodology also uses multirate constraints, avoiding unfolding to single rate equivalent, thus avoiding graph size increase. In a preferred embodiment, the parameters of the multirate system are normalized to the normalized factor vector, providing efficient algorithm in term of computational time and memory usage, without any sub-optimality.
    Type: Grant
    Filed: November 25, 2008
    Date of Patent: September 20, 2011
    Assignee: Synopsys, Inc.
    Inventors: Mustafa Ispir, Levent Oktem
  • Patent number: 8022741
    Abstract: A digital electronic device is provided with a first and second sequential logic unit (SS1, SS2), each for receiving an input signal (D) and for outputting a first and second output signal (Q, QF), respectively. The electronic device furthermore comprises a comparator unit (C) for comparing the first and second output signals (Q, QF) and an adaptive clock generator unit (ACG) for generating a first and second internal clock (CK, CKF) for the first and second sequential logic unit (SS1, SS2), respectively. In a self-tuning mode, the adaptive clock generator unit (ACG) is adapted to delay the first and second internal clock signals (CK, CKF) with respect to the other internal clock signal (CKF). The delay induced by the adaptive control generator unit (ACG) is dependent on the result of the comparison unit (C). In a normal operation mode the adaptive control generator unit (ACG) is adapted to maintain the delay between the first and second internal clock signals constant.
    Type: Grant
    Filed: January 31, 2008
    Date of Patent: September 20, 2011
    Assignee: NXP B.V.
    Inventor: Vincent Huard
  • Publication number: 20110221485
    Abstract: The present invention discloses a time synchronization method and apparatus. The method comprises: each net element node locks a clock synchronization signal of its upper-level net element node through a physical channel, and a clock synchronization network is established; and each net element node performs time counting by using the locked clock synchronization signal and performs time compensation according to the time counting through a time synchronization protocol to realize time synchronization. Through the present invention, each net element node performs the time counting by using the locked clock signal, and performs the time compensation according to the time counting to realize the time synchronization, thus the problem that the accumulative effect of phase transfer results in very obvious phase delay in the related technologies is solved, so as to reduce the phase delay and realize high precision, high interference resistance and reliability.
    Type: Application
    Filed: May 25, 2009
    Publication date: September 15, 2011
    Applicant: ZTE CORPORATION
    Inventors: Li He, Zhiyong Yu, Hui Su
  • Patent number: 8008954
    Abstract: Multi-phase signal generators and methods for generating multi-phase signals are described. In one embodiment, the clock generator generates quadrature clock signals including those having 90, 180, 270 and 360 degrees phase difference with a first clock signal. One of the intermediate clock signals may be used as an enable signal to guide locking of all signals. For example, the 180 degree clock signal may be inverted and used as an enable signal to guide locking of the initial and 360 degree signals in a single phase adjustment procedure. The 0 and 360 degree signals may be delayed before their phase is compared to compensate for duty cycle error in the clock signals.
    Type: Grant
    Filed: October 3, 2008
    Date of Patent: August 30, 2011
    Assignee: Micron Technology, Inc.
    Inventor: Yantao Ma
  • Publication number: 20110199134
    Abstract: Provided is a test apparatus that tests a device under test, comprising a phase comparing section that compares a phase of an internal clock generated in the test apparatus and a phase of a clock superimposed on a device signal output by the device under test; an adjusting section that adjusts a phase shift amount of the internal clock with respect to the device signal, based on the phase comparison result; an acquiring section that acquires the device signal according to the internal clock whose phase shift amount with respect to the device signal is adjusted; and an inhibiting section that inhibits change of the phase shift amount based on the phase comparison result, for at least a portion of a period during which the clock is not superimposed on the device signal. Also provided is a test method relating to the test apparatus.
    Type: Application
    Filed: February 11, 2011
    Publication date: August 18, 2011
    Applicant: ADVANTEST CORPORATION
    Inventor: Daisuke WATANABE
  • Patent number: 7990296
    Abstract: Techniques are provided to serialize and delay parallel input data signals and are particularly useful for low power applications. In one example, a device includes a plurality of data input ports adapted to receive N parallel single-ended input data signals, and a clock input port adapted to receive a clock signal substantially synchronized with the parallel single-ended input data signals. The device also includes a cell adapted to serialize the parallel single-ended input data signals to provide N/2 first serial differential output data signals in response to the clock signal, delay the parallel single-ended input data signals, and serialize the delayed parallel single-ended input data signals to provide N/2 delayed second serial differential output data signals in response to the clock signal. The delayed second serial differential output data signals are delayed relative to the first serial differential output data signals. The device also includes a plurality of output ports.
    Type: Grant
    Filed: March 10, 2010
    Date of Patent: August 2, 2011
    Assignee: SMSC Holdings S.a.r.l.
    Inventors: Heng Wang, Hongming An, CongQing Xiong
  • 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: RE43489
    Abstract: Systems and methods for converting a digital input data stream from a first sample rate to a second, fixed sample rate using a combination of hardware and software components. In one embodiment, a system includes a rate estimator configured to estimate the sample rate of an input data stream, a phase selection unit configured to select a phase for interpolation of a set of polyphase filter coefficients based on the estimated sample rate, a coefficient interpolator configured to interpolate the filter coefficients based on the selected phase, and a convolution unit configured to convolve the interpolated filter coefficients with samples of the input data stream to produce samples of a re-sampled output data stream. One or more hardware or software components are shared between multiple channels that can process data streams having independently variable sample rates.
    Type: Grant
    Filed: January 23, 2009
    Date of Patent: June 26, 2012
    Assignee: D2Audio Corporation
    Inventors: Jack B. Andersen, Larry E. Hand, Daniel L. W. Chieng, Joel W. Page, Wilson E. Taylor, Tonya Andersen