Using Multiple Clocks Patents (Class 327/144)
  • Patent number: 8717072
    Abstract: A semiconductor device includes a comparison unit configured to compare the phases of a plurality of clocks having different frequencies and output a phase comparison signal, a phase inversion control unit configured to generate a phase inversion control signal, and a start control unit configured to generate a start control signal in response to a clock enable signal, wherein the comparison unit is configured to start an operation in response to the start control signal and invert, in response to the phase inversion control signal, a phase of an internal clock generated from one of the plurality of clocks when the plurality of clocks have different phases.
    Type: Grant
    Filed: March 5, 2012
    Date of Patent: May 6, 2014
    Assignee: Hynix Semiconductor Inc.
    Inventor: Jung-Hoon Park
  • Patent number: 8711018
    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: February 28, 2013
    Date of Patent: April 29, 2014
    Assignee: Intel Corporation
    Inventors: Ehud Shoor, Dror Lazar, Assaf Benhamou
  • Patent number: 8704562
    Abstract: An apparatus and method for providing an output signal. The apparatus comprises an input for receiving a reference signal, an oscillator for providing an output signal, and an offset signal generator for frequency multiplying the reference signal to generate an offset signal that has a plurality of frequency products in a plurality of frequency bands. The apparatus further includes a mixer for mixing the offset signal with the output signal to produce a combined signal, an offset frequency selector for controllably selecting a frequency band of the offset signal, and a difference detector for detecting a difference between the reference signal and the combined signal and for providing a control signal to the oscillator based on the detected difference.
    Type: Grant
    Filed: July 16, 2012
    Date of Patent: April 22, 2014
    Assignee: Nanowave Technologies Inc.
    Inventors: Charles William Tremlett Nicholls, Walid Hamdane
  • Patent number: 8704560
    Abstract: A multi-phase signal generators and methods for generating multi-phase signals are described. In one embodiment, a clock generator generates quadrature signals including those having 90, 180, 270 and 360 degrees phase difference with a first signal. The rising edge of an intermediate signal is compared with the rising edges of two of the other signals to generate an UP and DN pulse signal, respectively. The UP and DN signals are used to adjust the delay of a delay line producing the signals to synchronize the signals. In some embodiments, a reset signal generator is used to truncate the UP or DN signal pulse.
    Type: Grant
    Filed: March 16, 2011
    Date of Patent: April 22, 2014
    Assignee: Micron Technology, Inc.
    Inventor: Yantao Ma
  • Patent number: 8707001
    Abstract: Methods and systems for determining a memory access time are provided. A first phase skew is measured between a first clock signal used by a memory and a second clock signal used as a reference clock signal. Then, a second phase skew is measured between a delayed version of the first clock signal output by the memory when the memory completes a given read operation and the second clock signal. The memory access time is determined based on the first and second phase skews.
    Type: Grant
    Filed: December 4, 2008
    Date of Patent: April 22, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Nan Chen, Zhiqin Chen, Varun Verma
  • Publication number: 20140097877
    Abstract: Control circuitry and adjustable clock signal generation circuitry is provided to control the signal transmission rate for electronic devices and systems of electronic devices. The control circuitry may receive status signals indicating current clock rates of a signal transmitting and receiving circuit as well as current processing capacity from the signal receiving circuit. The control circuitry may then generate control signals which control adjustable clock signal generation circuitry. The adjustable clock signal generation circuitry may be used to adjust the rate of generated clock signals for the signal transmitting and receiving circuits which can increase or decrease the signal transmission rate between those circuits.
    Type: Application
    Filed: October 9, 2012
    Publication date: April 10, 2014
    Inventors: Gregg William Baeckler, David W. Mendel
  • Patent number: 8687457
    Abstract: A semiconductor memory device includes a system clock input block configured to be inputted with a system clock, a data clock input block configured to be inputted with a data clock, a first phase detection block configured to compare a phase of the system clock, generate a first phase detection signal, and determine a logic level of a reverse control signal in response to the first phase detection signal, a second phase detection block configured to compare a phase of a clock acquired by delaying the system clock by a correction time, generate a second phase detection signal, and determine a logic level of a clock select signal in response to the first and second phase detection signals, and a clock select block configured to select and output the data clock or a clock acquired by delaying the data clock.
    Type: Grant
    Filed: December 21, 2011
    Date of Patent: April 1, 2014
    Assignee: SK Hynix Inc.
    Inventor: Jung-Hoon Park
  • Patent number: 8674736
    Abstract: A method of synchronizing clock signals may include generating a replicated delay associated with a delay of a clock signal path. The clock signal path may be associated with communication of a slave clock signal by a master block of a circuit to a slave block of the circuit. The method may further include selecting the slave clock signal from one of multiple clock signals based on the replicated delay. Each of the multiple clock signals may have a same frequency and a different phase.
    Type: Grant
    Filed: July 31, 2012
    Date of Patent: March 18, 2014
    Assignee: Fujitsu Limited
    Inventor: Asako Toda
  • Patent number: 8669786
    Abstract: A clock phase shift detector circuit may include a phase detector that receives a first and a second clock signal, whereby the phase detector generates a phase signal based on a phase difference between the first and the second clock signal. A first integrator is coupled to the phase detector, receives the phase signal, and generates an integrated phase signal. A second integrator receives the first clock signal and generates an integrated first clock signal. A comparator is coupled to the first and the second integrator, whereby the comparator receives the integrated phase signal and the integrated first clock signal. The comparator may then generate a control signal that detects a change between the phase difference of the first and the second clock signal and an optimized phase difference based on an amplitude comparison between the integrated phase signal and the integrated first clock signal.
    Type: Grant
    Filed: December 7, 2012
    Date of Patent: March 11, 2014
    Assignee: International Business Machines Corporation
    Inventors: Kai D. Feng, Jong-ru Guo, Trushil N. Shah, Ping-Chuan Wang, Zhijian Yang
  • Patent number: 8665636
    Abstract: According to one embodiment, when a row address of a port A matches a row address of a port B, a memory cell is accessed only from the port A by controlling a word line potential of the port A based on a third clock, and data is exchanged between a bit line of the port A and the port A based on a first clock and data is exchanged between the bit line of the port A and the port B based on a second clock.
    Type: Grant
    Filed: September 20, 2011
    Date of Patent: March 4, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Toshikazu Fukuda
  • Publication number: 20140056085
    Abstract: Semiconductor chips are provided. The semiconductor chip includes a selection phase clock generator and a data input/output portion. The selection phase clock generator is configured to receive an external clock signal and an inversed external clock signal to generate phase clock signals, configured to receive a first external test clock signal and a second external test clock signal to generate test phase clock signals, and configured to output the phase clock signals or the test phase clock signals as selection phase clock signals in response to a test mode signal.
    Type: Application
    Filed: July 17, 2013
    Publication date: February 27, 2014
    Applicant: SK hynix Inc.
    Inventors: Tae Wook KANG, Kwang Jin NA
  • Patent number: 8659332
    Abstract: A signal circuit includes a clock terminal for transmitting a reference clock and a data terminal for transmitting an input/output data. In an embodiment, the frequency of the reference clock is one-eighth of the bit rate of the input/output data.
    Type: Grant
    Filed: January 4, 2012
    Date of Patent: February 25, 2014
    Assignee: Raydium Semiconductor Corporation
    Inventors: Ko-Yang Tso, Hui-Wen Miao, Yann-Hsiung Liang, Chin-Chieh Chao, Ren-Feng Huang
  • Publication number: 20140035635
    Abstract: The invention relates to an apparatus and a method for glitch-free clock switching. In one embodiment this is accomplished by a first clock source, one or more second clock source and a clock switching control device configured to synchronize the receive input clock from the first clock source and the second clock source, and output at least one of the them according to control signal selection.
    Type: Application
    Filed: August 11, 2011
    Publication date: February 6, 2014
    Applicant: Tejas Networks Limited Plot No. 25, JP Software Park
    Inventors: Srinivas Rao, Gajendra Singh Ranka
  • Publication number: 20140036963
    Abstract: A method and arrangement are provided for time synchronization between two geographically separated stationary clocks, such as first and second clocks located respectively at first and second ends of an AC power line. A first representation of an oscillating power line quantity is produced by measuring or recording the power line quantity at the first end of the power line, and time-stamping the first representation by the first clock. A second representation of the same oscillating power line quantity is produced by measuring the power line quantity at the second end of the power line, and time-stamping the second representation by the second clock. The first and second representations are compared to determine a clock offset between the first and second clocks. Based on the comparison, one or both of the first and second clocks are adjusted to reduce the determined clock offset.
    Type: Application
    Filed: July 24, 2013
    Publication date: February 6, 2014
    Applicant: ABB RESEARCH LTD
    Inventor: Dacfey DZUNG
  • Patent number: 8643412
    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: Grant
    Filed: February 11, 2011
    Date of Patent: February 4, 2014
    Assignee: Advantest Corporation
    Inventor: Daisuke Watanabe
  • Patent number: 8634503
    Abstract: A clock-data recovery system and method promotes fast adjustment to large phase changes in the incoming data signal. The system can include phase alignment circuitry, clock generator circuitry, time-to-digital converter circuitry, and sampling circuitry. The phase alignment circuitry uses the incoming data signal and a feedback clock signal to generate an output clock signal. The clock generator circuitry uses the output clock signal to generate base phase clock signals of different phases or polarities. The time-to-digital converter circuitry uses the base phase clock signals and the incoming data signal to generate the feedback clock signal. The time-to-digital converter circuitry bases the feedback clock signal on the base phase clock signal that is aligned more closely in phase with the incoming data signal than the other base phase clock signals. The sampling circuitry re-times or recovers the data signal using one or more of the base phase clock signals.
    Type: Grant
    Filed: March 31, 2011
    Date of Patent: January 21, 2014
    Inventors: Brian J. Misek, Robert K. Barnes, Peter J. Meier
  • Patent number: 8629699
    Abstract: A clock data recovery circuit which has a high degree of jitter tolerance and can alleviate increase in the phase number of a multi-phase clock, power consumption, and a semiconductor chip area is provided. Each circuit of plural edge detection circuits comprises a first edge detection circuit and a second edge detection circuit. The first detection circuit detects that a data edge leads in phase more than ?1 phase from an edge detection phase, the second detection circuit detects that the data edge laggs in phase more than +1 phase from the edge detection phase. In response to the first output signal or the second output signal, the edge detection phase is changed by the amount of ?1 phase or +1 phase. When the data edge is detected in the range of ±1 phase, a next edge detection phase is maintained in the current state.
    Type: Grant
    Filed: November 8, 2012
    Date of Patent: January 14, 2014
    Assignee: Renesas Electronics Corporation
    Inventors: Yusuke Wachi, Takayuki Noto, Tomoaki Takahashi, Takashi Kawamoto
  • Patent number: 8620605
    Abstract: A method for detecting and determining a position of faults using reflectometry in a wired electrical network including: injecting a test signal e(t) into a cable in the electrical network, a timing of successive injections being controlled by a synchronization module that generates an emission clock signal and a reception clock signal; retrieving a reflected signal on the cable; sampling the reflected signal at a frequency Fe=1/Te, where Te is a sampling period; counting a number of samples obtained for the reflected signal and comparing the number of samples obtained with a number n predefined as a function of a length of the cable or the electrical network to be diagnosed, where n is an integer; repeating the injecting, the sampling, and the counting steps N times, shifting the emission clock signal by a duration ?; reconstituting the reflected signal from n*N samples obtained; and analyzing the reconstituted reflected signal to detect a fault.
    Type: Grant
    Filed: December 19, 2008
    Date of Patent: December 31, 2013
    Assignee: Commissariat a l'Energie Atomique et aux Energies Alternatives
    Inventors: Julien Guilhemsang, Fabrice Auzanneau, Yannick Bonhomme
  • Patent number: 8612795
    Abstract: One embodiment relates to a clocking network interconnecting an array of transceivers. The clocking network includes first and second series of multiplexers, each multiplexer in the first and second series being adjacent to a transceiver. The first series of multiplexers selectively transmits clock signals in a first direction of the array, and the second series of multiplexers selectively transmits clock signals in a second direction of the array. Another embodiment relates to an integrated circuit with a programmable interface. The integrated circuit includes an array of physical media attachment circuits, phase-locked loop circuits, and a clock distribution network. The clock distribution network is arranged to be programmed into multiple segments. Each segment distributes a clock signal to a bounded range of the physical media attachment circuits in the array. Another embodiment relates to a method of distributing clock signals in an integrated circuit. Other embodiments and features are also disclosed.
    Type: Grant
    Filed: July 30, 2010
    Date of Patent: December 17, 2013
    Assignee: Altera Corporation
    Inventors: Weiqi Ding, Kumara Tharmalingam
  • Patent number: 8598904
    Abstract: Electrical networks are formed to produce an approximation of at least one desired performance characteristic, based on the recognition that fabrication variations introduce slight differences in electronic sub-networks which were intended to be identical. These fabrication differences are turned to an advantage by providing a pool of sub-networks, and then selectively connecting particular combinations of these sub-networks to implement networks that approximate the desired performance characteristics. The sub-networks are of like kind (e.g., resistors) and have a like measure.
    Type: Grant
    Filed: November 16, 2011
    Date of Patent: December 3, 2013
    Assignee: Analog Devices, Inc.
    Inventors: Arthur J. Kalb, Evaldo M. Miranda
  • Patent number: 8593188
    Abstract: An improved charge pump based phase locked loop where the loop filter resistor noise is reduced by about an order is presented. The voltage controlled oscillator generates a clock signal, and this is input to the phase detector, which, compares the oscillator clock with the reference clock and using the Charge pump it generates a current output proportional to the phase difference. The loop filter converts this proportional current to a voltage and connects it to the oscillator input. The loop filter consists of a capacitor, resistor and the apparatus that bypasses most of the resistor noise.
    Type: Grant
    Filed: May 3, 2012
    Date of Patent: November 26, 2013
    Assignee: Texas Instruments Incorporated
    Inventor: Rajkumar Palwai
  • Patent number: 8587350
    Abstract: A clock generation system for deriving a second clock signal from a first clock signal with a predetermined clock frequency ratio, where the first clock frequency is divided by a first integer, the second clock signal is divided by a second integer, an error signal is generated by comparing the division results, a voltage-controlled oscillator is controlled in dependence on said error signal to generate the second clock signal, and a switch is provided for alternately switching each of the clock signals to a single frequency divider or for alternately switching one of the clock signals to one of two frequency dividers and simultaneously switching the other one of the clock signals to the other one of the two frequency dividers to eliminate errors that may result from processing the two clock signals in different circuit sections.
    Type: Grant
    Filed: February 29, 2012
    Date of Patent: November 19, 2013
    Assignee: Siemens Aktiengesellschaft
    Inventor: George Burcea
  • Patent number: 8587338
    Abstract: Aspects of the disclosure provide a clock gate circuit for generating a clock signal. The clock gate circuit includes a multiplexer and a logic module coupled to the multiplexer. The multiplexer is 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. The logic module includes at least one of an XNOR and an XOR module and is configured to provide an output signal that is responsive to performing at least one of an XNOR and an XOR operation of the output of the multiplexer and an enable signal that enables or disables the clock gate circuit to generate the clock signal.
    Type: Grant
    Filed: July 12, 2011
    Date of Patent: November 19, 2013
    Assignee: Marvell Israel (M.I.S.L) Ltd.
    Inventor: Eitan Rosen
  • Publication number: 20130300466
    Abstract: A system for synchronizing a first clock and a second clock includes a receiver associated with the first clock, configured to receive a remote pulse from the second clock. The remote pulse has a pulse repetition frequency and spectral characteristics that are known to the local clock. The system also includes a local pulse emitter configured to create a local pulse at the first clock, and optics configured to align the local pulse and the remote pulse. The system further includes an interferometer configured to create an interference pattern between the local pulse and the remote pulse. A controller is provided that is configured to calculate a time delay between the first clock and the second clock based on the interference pattern between the local pulse and the remote pulse.
    Type: Application
    Filed: July 10, 2013
    Publication date: November 14, 2013
    Inventors: Steven R. Wilkinson, Neil R. Nelson
  • Patent number: 8581642
    Abstract: A data transfer circuit includes primary data holding circuits that hold input data according to a first clock pulse signal and output data being held; and secondary data holding circuits that hold the output data of the primary data holding circuits according to a second clock pulse asynchronous to the first clock pulse and output data being held. Pulse signal generator generates a pulse signal synchronous with the second clock pulse signal when a pulse edge of the first clock pulse signal and a pulse edge of the second clock pulse signal occur at different timings and generates a pulse signal having the pulse edge the second clock pulse signal removed therefrom when the pulse edge of the the first clock pulse signal and the pulse edge of the the second clock pulse signal occur at the same timing. The secondary data holding circuits hold the output data of the primary data holding circuits synchronously with the pulse signal generated by the pulse signal generator.
    Type: Grant
    Filed: February 10, 2011
    Date of Patent: November 12, 2013
    Assignee: Oki Semiconductor Co., Ltd.
    Inventor: Daisuke Kadota
  • Publication number: 20130285719
    Abstract: A system comprising an interface configured to condition a signal associated with a power system; a clock module configured to generate a synchronization signal; and a module coupled to the interface and configured to digitize the signal from the interface; filter the digitized signal; and generate a time-shifted, digitized signal in response to the filtering and the synchronization signal.
    Type: Application
    Filed: May 30, 2012
    Publication date: October 31, 2013
    Inventors: Anthony J. Ranson, Adriano McAvoy
  • Publication number: 20130285718
    Abstract: A semiconductor apparatus includes a control unit configured to generate a first pumping enable signal and a second pumping enable signal which are alternately enabled, in response to an active signal; a first pumping voltage generation unit configured to perform a pumping operation during an enable period of the first pumping enable signal and generate a first pumping voltage; and a second pumping voltage generation unit configured to perform a pumping operation during an enable period of the second pumping enable signal and generate a second pumping voltage.
    Type: Application
    Filed: September 5, 2012
    Publication date: October 31, 2013
    Applicant: SK HYNIX INC.
    Inventor: Jong Hwan KIM
  • Patent number: 8565284
    Abstract: A spread spectrum clock signal generator and an accompanying method provide a spread spectrum clock signal of a reduced electromagnetic interference. The spread spectrum clock signal generator includes (a) a state machine, which maintains a current state of the spread spectrum clock signal generator, receives as input value a next state of the spread spectrum clock signal generator and generates a clock phase selection signal based on the current and next states; (b) a random number generator for generating the next state; and (c) a waveform generation circuit for generating a spread spectrum clock signal based on the clock phase selection signal.
    Type: Grant
    Filed: August 13, 2007
    Date of Patent: October 22, 2013
    Assignee: Intersil Americas Inc.
    Inventors: Paul D. Ta, Wei Wang, Alvin Wang, Peter D. Bradshaw
  • Patent number: 8559576
    Abstract: Embodiments of a synchronization circuit are described. This synchronization circuit includes multiple selectively coupled synchronization stages which are configurable to synchronize data and control signals between a first time domain and a second time domain, where the synchronization can be performed based on asynchronous or synchronous events associated with either the first time domain or the second time domain. Additionally, the synchronization circuit includes control logic, coupled to the synchronization stages, which is configured to adapt a number of synchronization stages used to synchronize the data and the control signals based on an estimate of a probability of metastability persisting to an output of the synchronization circuit during the synchronization.
    Type: Grant
    Filed: August 18, 2008
    Date of Patent: October 15, 2013
    Assignee: Oracle America, Inc.
    Inventors: Tarik Ono, Mark R. Greenstreet
  • Patent number: 8531216
    Abstract: The present invention discloses an electronic apparatus.
    Type: Grant
    Filed: July 24, 2012
    Date of Patent: September 10, 2013
    Assignee: Ralink Technology Corp.
    Inventors: Jin-Xiao Wu, Heng-Chih Lin, Yi-Bin Hsieh
  • Patent number: 8526557
    Abstract: Disclosed herein is a signal transmission system including: a first signal processing section configured to perform signal processing on a basis of a reference signal; a high-frequency reference signal generating section configured to generate and transmit a high-frequency reference signal having a higher frequency than the reference signal such that the high-frequency reference signal is synchronized with the reference signal; a low-frequency reference signal generating section configured to receive the high-frequency reference signal from the high-frequency reference signal generating section, and generate a low-frequency reference signal having a lower frequency than the high-frequency reference signal such that the low-frequency reference signal is synchronized with the received high-frequency reference signal; and a second signal processing section configured to perform signal processing on a basis of the low-frequency reference signal generated by the low-frequency reference signal generating section.
    Type: Grant
    Filed: May 25, 2011
    Date of Patent: September 3, 2013
    Assignee: Sony Corporation
    Inventor: Hidenori Takeuchi
  • Publication number: 20130222021
    Abstract: A transmitting apparatus includes a first circuit to which a base clock and a first clock condition are input, the first circuit outputting a first enable signal based on the base clock and the first clock condition; a second circuit to which the base clock and a second clock condition are input, the second circuit outputting a second enable signal based on the base clock and the second clock condition; a first frame processing circuit receiving a first frame input signal and the first enable signal to output a first frame output signal in synchronization with the first enable signal; and a second frame processing circuit receiving a second frame input signal and the second enable signal to output a second frame output signal in synchronization with the second enable signal.
    Type: Application
    Filed: February 19, 2013
    Publication date: August 29, 2013
    Applicant: FUJITSU LIMITED
    Inventor: Fujitsu Limited
  • Patent number: 8520789
    Abstract: The present invention relates to the communication field and discloses a method and an apparatus for implementing pulse synchronization, so that the control on a single-chip multi-channel device can be simplified. A method for implementing pulse synchronization includes: when a cycle count value corresponding to a reference symbol port of the multiple ports reaches a length of a predetermined pulse cycle, obtaining, by a microprocessor, cycle count values corresponding to the multiple ports; obtaining lengths of temporary synchronization cycles of the multiple ports according to the length of the predetermined pulse cycle and the cycle count values corresponding to the multiple ports; and sending the lengths of the temporary synchronization cycles to logic circuits corresponding to the multiple ports. Embodiments of the present invention are mainly applied in communication systems to output pulse symbols synchronously.
    Type: Grant
    Filed: May 18, 2012
    Date of Patent: August 27, 2013
    Assignee: Huawei Technologies Co., Ltd.
    Inventors: Yang Li, Matthew Leung, Tin Yau Fung
  • Publication number: 20130207698
    Abstract: A clock distribution system for a multi-bit latch. The clock distribution system may include a plurality of branches, each connected to a common clock input. Each branch may be driven by an input clock buffer. Each branch may be connected to clock inputs of a predetermined number of latch stages within the multi-bit latch. A predetermined number of clock branches may include a clock output buffer. The number of clock output buffers may be less than the total number of latch stages. In this manner the clock distribution system may reduce the feed through capacitance of the latch stages, which may mitigate the latch transition skew for each latch stage.
    Type: Application
    Filed: February 9, 2012
    Publication date: August 15, 2013
    Applicant: ANALOG DEVICES, INC.
    Inventor: Hyungil CHAE
  • Patent number: 8498373
    Abstract: A count value generator includes an input for receiving a synchronizing count value, a counter configured to increment at a local frequency, the local frequency being faster than the synchronizing frequency, and an interpolator for determining a frequency ratio between the local frequency and the synchronizing frequency and for determining an increment value for the counter dependent on a relative amount of a maximum value of the counter with respect to the frequency ratio is disclosed. The counter generates a count value including a predetermined number of bits representing integer values and output as the lower order bits of the output count value and additional lower order bits that represent fractional portions of the integer values. The counter includes output circuitry for outputting the synchronizing count value and the predetermined number of bits representing integer values generated by the counter as the lower order bits of the count value.
    Type: Grant
    Filed: January 12, 2012
    Date of Patent: July 30, 2013
    Assignee: ARM Limited
    Inventors: John Michael Horley, Sheldon James Woodhouse, Michael John Williams, Sheshadri Kalkunte, Andrew Christopher Rose
  • Patent number: 8493123
    Abstract: A system for synchronizing a first clock and a second clock includes a receiver associated with the first clock, configured to receive a remote pulse from the second clock. The remote pulse has a pulse repetition frequency and spectral characteristics that are known to the local clock. The system also includes a local pulse emitter configured to create a local pulse at the first clock, and optics configured to align the local pulse and the remote pulse. The system further includes an interferometer configured to create an interference pattern between the local pulse and the remote pulse. A controller is provided that is configured to calculate a time delay between the first clock and the second clock based on the interference pattern between the local pulse and the remote pulse.
    Type: Grant
    Filed: December 15, 2010
    Date of Patent: July 23, 2013
    Assignee: Raytheon Company
    Inventors: Steven R. Wilkinson, Neil R. Nelson
  • Patent number: 8466727
    Abstract: A method for detecting a disturbance of the state of a synchronous flip-flop of master-slave type including two bistable circuits in series, in which the bistable circuits are triggered by two first signals different from each other, and the level of an intermediary junction point between the two bistable circuits is compared both to the level present at the input of the master-slave flip-flop and to the level present at the output, which results in two second signals providing an indication as to the presence of a possible disturbance.
    Type: Grant
    Filed: July 28, 2009
    Date of Patent: June 18, 2013
    Assignee: STMicroelectronics (Rousset) SAS
    Inventors: Frédéric Bancel, Philippe Roquelaure
  • Patent number: 8466723
    Abstract: A data processing system comprises a plurality of sub-circuits, a clock generator provided with a control circuit, a pool of oscillator circuits comprising at least three oscillator circuits, and a multiplexing circuit coupled between the pool and clock inputs of the sub-circuits. The multiplexing circuit has a control input coupled to a control output of the control circuit. The multiplexing circuit is configured to couple any selectable one of the oscillator circuits in the pool to a clock input of each of the sub-circuits. The control circuit is configured to set the frequencies of respective ones of the clock circuit by controlling the multiplexing circuit to supply clock signals derived from selected ones of the oscillator circuits to the sub-circuits.
    Type: Grant
    Filed: September 25, 2008
    Date of Patent: June 18, 2013
    Assignee: Synopsys, Inc.
    Inventors: Peter Klapproth, Greg Ehmann, Neal Wingen
  • Patent number: 8462034
    Abstract: A synchronizing circuit compatible with a quad switching scheme in a digital-to-analog converter (DAC) to synchronize turning on or off of switches for steering current to a differential output. The synchronizing circuit receives signals from a decoder and synchronizes control signals to the switches by a clock signal. In one embodiment, the synchronizing circuit includes a predictor circuit and a latch circuit. The latch circuit may include four sets of cross-coupled inverters where a set of cross-coupled inverters are activated at a time. By using the synchronizing circuit in conjunction with the quad switching scheme, linearity of analog output from the DAC can be improved and data dependent noise in the analog output can be removed or reduced.
    Type: Grant
    Filed: July 14, 2011
    Date of Patent: June 11, 2013
    Assignee: Synopsys, Inc.
    Inventors: Bruno M. S. Santos, Antonio I. R. Leal, Carlos M. A. Azeredo-Leme
  • Patent number: 8451034
    Abstract: A second latch latches the output data of a first latch using a third clock having the same frequency as that of a first clock. A third latch latches the output data of the second latch using a second clock having a frequency N (N represents an integer) times that of the first clock and the third clock. The second clock and the third clock have a frequency division/multiplication relation therebetween.
    Type: Grant
    Filed: July 25, 2008
    Date of Patent: May 28, 2013
    Assignee: Advantest Corporation
    Inventors: Tasuku Fujibe, Masakatsu Suda
  • Publication number: 20130120033
    Abstract: A charge domain filter (CDF) is provided. The CDF includes a switched-capacitor network (SCN) and a clock generator. An input of the SCN receives an input signal. The SCN samples the input signal according to clock signals with different phases. The clock generator is coupled to the SCN for providing the clock signals. The clock generator adjusts phase differences of the clock signals or pulse widths of the clock signals in accordance with a control signal.
    Type: Application
    Filed: December 23, 2011
    Publication date: May 16, 2013
    Applicant: INDUSTRIAL TECHNOLOGY RESEARCH INSTITUTE
    Inventor: Ming-Feng Huang
  • Patent number: 8442178
    Abstract: A linear phase detector includes an up/down pulse generator operating in response to received data signals and a recovered clock signal. The phase detector generates up and down pulses that have pulse widths proportional to the phase differences between transitions of the received data signals and edges of the recovered clock signal. By generating up and down pulses using a linear phase detector in proportion to a phase error, data signals are effectively recovered, even data signals with significant jitter.
    Type: Grant
    Filed: June 3, 2011
    Date of Patent: May 14, 2013
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Chul-Woo Kim, Seok-Soo Yoon, Young-Ho Kwak, In-Ho Lee, Ki-Hong Kim
  • Patent number: 8421783
    Abstract: A variation in threshold may be suppressed by structuring an analog switch by a MOS transistor and forming a signal synchronized to a clock by making the clock which is a common signal in continuity or discontinuity. An object of the present invention is to reduce the variation in the signal synchronized to the clock by the variation in threshold of the MOS transistor in a circuit which is synchronized to the clock.
    Type: Grant
    Filed: July 23, 2012
    Date of Patent: April 16, 2013
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventor: Yukio Tanaka Tanaka
  • Patent number: 8416900
    Abstract: A method and circuit for dynamically changing the frequency of clock signals. The method including: detecting an edge of a first clock signal operating at a first frequency using a second clock signal operating at a second frequency; detecting an edge of the second clock signal using the first clock signal; detecting coincident edges of the first and the second clock signals; and changing the second frequency to a third frequency different from the second frequency upon detection of the coincident edges.
    Type: Grant
    Filed: January 15, 2009
    Date of Patent: April 9, 2013
    Assignee: International Business Machines Corporation
    Inventors: David Wills Milton, Jason Edward Rotella
  • Patent number: 8415995
    Abstract: An electric circuit includes a first circuit, a second circuit, a synchronization detection circuit, a storage circuit, and a correction circuit. The first clock is configured to operate with a first clock, the second circuit is configured to operate with a second clock which is different in frequency from the first clock, and the synchronization detection circuit is configured to detect synchronization of the first and second clocks. The storage circuit is configured to store an output noise pattern of the second circuit, based on the synchronization detected by the synchronization detection circuit, and the correction circuit is configured to correct an output of the second circuit by using the output noise pattern.
    Type: Grant
    Filed: March 11, 2011
    Date of Patent: April 9, 2013
    Assignee: Fujitsu Limited
    Inventor: Tomio Sato
  • Patent number: 8410834
    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: Grant
    Filed: March 10, 2011
    Date of Patent: April 2, 2013
    Assignee: Realtek Semiconductor Corp.
    Inventors: Chia-Liang Lin, Gerchih Chou, Pei-Si Wu
  • Patent number: 8405533
    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: March 26, 2013
    Assignee: Intel Corporation
    Inventors: Ehud Shoor, Dror Lazar, Assaf Benhamou
  • Patent number: 8400188
    Abstract: A variety of edge-detection related devices, methods and systems are implemented in various fashions. One implementation is directed to an edge detector circuit for detecting an edge of an input signal and producing an output level-sensitive signal that is synchronous to a clock signal having an active edge corresponding to a transition from a first-signal level to a second-signal level. A first flip-flop has the input signal as a clock input and produces an internal level-sensitive signal and is reset by the output level-sensitive signal. Logic passes the level-sensitive signal when the clock signal is at the second-signal level and blocks the internal level-sensitive signal when the clock signal is at the first-signal level. A second flip-flop is set by the passed internal level-sensitive signal to produce the output level-sensitive signal. The second flip-flop is cleared in response to the output level-sensitive signal, a reset input and the clock signal.
    Type: Grant
    Filed: March 16, 2009
    Date of Patent: March 19, 2013
    Assignee: NXP B.V.
    Inventor: Robert de Gruijl
  • Patent number: 8390358
    Abstract: Integrated jitter compliant clock signal generation apparatus and methods are provided. Input signals having different frequencies are used to generate respective clock signals having closely spaced frequencies. The input signals might be generated, for example, in adjacent Phase Locked Loops (PLLs) which receive reference clock signals. The reference clock signals, or signals from which the reference clock signals originate, are also closely spaced. The closely spaced reference clock signals are effectively separated for cleanup and then brought back together to provide the closely spaced clock signals. This allows cleanup of the closely spaced reference clock signals to occur at staggered and more widely spaced frequencies. These techniques could also be applied to reference clock signals which are harmonically related and are used to generate harmonically related output clock signals.
    Type: Grant
    Filed: October 7, 2010
    Date of Patent: March 5, 2013
    Assignee: Cortina Systems, Inc.
    Inventors: Shawn Scouten, Malcolm Stevens, Kevin Parker
  • Publication number: 20130049827
    Abstract: There is provided a clock distribution network for synchronizing global clock signals within a 3D chip stack having two or more strata. On each of the two or more strata, the clock distribution network includes a clock grid having a plurality of sectors for providing the global clock signals to various chip locations, a multiple-level buffered clock tree for driving the clock grid and including at least a root and a plurality of clock buffers, and one or more multiplexers for providing the global clock signals to at least a portion of the buffered clock tree. Inputs of at least some of the plurality of clock buffers on each of the two or more strata are shorted together using chip-to-chip interconnects to reduce skewing of the global clock signals with respect to the various chip locations.
    Type: Application
    Filed: August 25, 2011
    Publication date: February 28, 2013
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: THOMAS J. BUCELOT, LIANG-TECK PANG, PHILLIP J. RESTLE