Phase Displacement, Slip Or Jitter Correction Patents (Class 375/371)
  • Patent number: 8571822
    Abstract: A method for testing an integrated circuit, the method including performing a series of at least three tests, each including: selecting two nodes among at least three nodes for taking a clock signal from an integrated circuit, taking two clock signals at the two selected taking nodes during a test duration, detecting and counting events appearing in a jitter signal between the two clock signals taken, during the test duration, and determining from numbers of events counted a test result proportional to a sum of jitter variances of the two clock signals taken, and at the end of the series of tests, determining by a matrix calculation the jitter variance of each clock signal taken.
    Type: Grant
    Filed: November 18, 2010
    Date of Patent: October 29, 2013
    Assignee: STMicroelectronics (Grenoble 2) SAS
    Inventor: Herve Le-Gall
  • Publication number: 20130279637
    Abstract: Aspects of a method and system for a reference signal (RS) timing loop for OFDM symbol synchronization and tracking may include tracking symbol timing in an Orthogonal Frequency Division Multiplexing (OFDM) signal based on at least a reference symbol set. A receiver timing may be adjusted based on at least the symbol timing. The symbol timing may be tracked by generating an output signal as a function of a guard time ?tg in a phase discrimination feedback loop. The reference symbol (RS) set may be generated in an RS extraction module or circuit, from at least a fast Fourier transform of the received OFDM signal. The receiver timing may be coarsely adjusted and then finely adjusted. The coarse receiver timing adjustment may be based on processing at least a primary synchronization signal and a secondary synchronization signal.
    Type: Application
    Filed: June 18, 2013
    Publication date: October 24, 2013
    Inventor: Mark KENT
  • Patent number: 8565362
    Abstract: A clock recovery apparatus includes a mask generator configured to generate a plurality of time masks using a multi-phase clock signal and a clock recovery unit configured to select one of the time masks to recover a clock from a data stream.
    Type: Grant
    Filed: December 17, 2010
    Date of Patent: October 22, 2013
    Assignee: Dongbu HiTek Co., Ltd.
    Inventor: Sang Seob Kim
  • Patent number: 8564345
    Abstract: Digitally controllable delay lines including fine grain and coarse grain delay elements, and methods and system to calibrate the delay lines in fine grain increments. Calibration may include calibrating a number of fine grain elements for which a combined delay is substantially equal to a delay of a coarse grain element, and calibrating numbers of fine grain and coarse grain elements which a combined delay corresponds to a period of a reference clock. A digitally controlled delay line may be implemented as part of a digital delay locked loop (DLL), and calibration parameters may be provided to a slave DLL having a similarly implemented delay line. A digitally controllable DLL may provide relatively low-power, high-resolution over a spectrum of process, voltage, and temperature variations, and may be implemented in relatively high-speed applications previously reserved for analog DLLs.
    Type: Grant
    Filed: April 1, 2011
    Date of Patent: October 22, 2013
    Assignee: Intel Corporation
    Inventor: Wing K. Yu
  • Patent number: 8565363
    Abstract: A receiver may process a received signal to generate a processed received signal. The receiver may generate, during a sequence estimation process, an estimate of a phase error of the processed received signal. The receiver may generate an estimate of a value of a transmitted symbol corresponding to the received signal based on the estimated phase error. The generation of the estimate of the phase error may comprise generation of one or more phase candidate vectors. The generation of the estimate may comprise calculation of a metric based on the one or more phase candidate vectors. The calculation of the metric may comprise phase shifting the processed received signal based on the estimated phase error resulting in a phase-corrected received signal. The calculation of the metric may comprise calculating a Euclidean distance based on the phase-corrected received signal and one or more symbol candidate vectors.
    Type: Grant
    Filed: January 31, 2013
    Date of Patent: October 22, 2013
    Assignee: MagnaCom Ltd.
    Inventor: Amir Eliaz
  • Patent number: 8564311
    Abstract: A noise suppression method for a capacitance-to-voltage converter varies a sequence of sensing signal edges during a plurality capacitance measurements to produce a number of noise responses. The sensing signal edges are varied in a repetitive rising and falling edge pattern for each sequence. Three or more such sequences can be used, and the sequence with the highest noise is eliminated and the others are averaged. The noise suppression method can be implemented during calibration and then used for a number of normal acquisitions. The noise suppression method can be applied to capacitance-to-voltage converters having monitoring and integration phases.
    Type: Grant
    Filed: July 1, 2010
    Date of Patent: October 22, 2013
    Assignee: STMicroelectronics Asia Pacific Pte Ltd.
    Inventor: Kusuma Adi Ningrat
  • 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: 8565288
    Abstract: A method for performing delay locked looping upon a received signal which reduces the asymmetry of auto-correlation function resulting from sampling is provided. The received signal is a spread spectrum code signal, and the method includes: generating a plurality of replica spread spectrum code signals according to an estimated code phase delay and phase spacing, the replica spread spectrum code signals having phases respectively different from the phase of the received signal; calculating a spread spectrum code error statistics signal according to the replica spread spectrum code signals and the received signal; and adjusting the estimated code phase delay according to the spread spectrum code error statistics signal and a phase difference between a sampled point of at least one replica spread spectrum code signal and a corresponding signal transition point.
    Type: Grant
    Filed: March 6, 2011
    Date of Patent: October 22, 2013
    Assignee: Realtek Semiconductor Corp.
    Inventors: Kai-Di Wu, Kun-Sui Hou
  • Patent number: 8559580
    Abstract: Techniques are disclosed for asynchronous calibration for eye diagram generation. For example, a method for calibrating a process for generating a data eye associated with a received signal comprises the following steps. Samples of the received signal are obtained for a first unit interval using a first data latch and a roaming latch. A delay offset is determined between the first data latch and the roaming latch by comparing at least one sample obtained using the first data latch and at least one sample obtained using the roaming latch, wherein the delay offset determined by the comparison is used to calibrate the process for generating the data eye associated with the received signal. A similar comparison may be done for a second data latch and used to calibrate the process. The method is able to find the accurate position of each data latch with respect to the roaming latch so as to improve the accuracy of data decoding in a digital receiver, i.e., provide receiver optimization.
    Type: Grant
    Filed: June 30, 2009
    Date of Patent: October 15, 2013
    Assignee: LSI Corporation
    Inventors: Xingdong Dai, Dwight David Daugherty, Max J. Olsen, Lane A. Smith, Geoffrey Zhang
  • Patent number: 8548405
    Abstract: A method of controlling the phases of RF output signals from a number of radio transmitters. A given radio has at least one synthesizer as a source of its RF output signal, and the synthesizer produces an output the phase offset of which relative to a reference signal is controlled by a phase offset command. A path from an antenna port of the radio obtains a fed back RF output signal and a phase difference between the reference signal and the fed back RF output signal is measured. A value of a zero degree phase offset command for the synthesizer is determined such that the phase difference between the reference signal and the fed back RF signal is nominally zero, and the value is stored. A phase offset command for providing a desired phase offset for the RF output signal is then determined based the stored value of the zero degree phase offset command.
    Type: Grant
    Filed: April 25, 2012
    Date of Patent: October 1, 2013
    Assignee: BAE Systems Information and Electronic Systems Integration Inc.
    Inventor: Michael S. Vogas
  • Patent number: 8548111
    Abstract: A sampler circuit comprises a plurality of series-connected sampler cells and a detector circuit. Each successive stage comprises twice the number of sampler cells, in parallel, as the previous stage, and is clocked at half the sampling frequency of the previous stage. Each sampler cell comprises two parallel branches of series-connected clocked inverters. A clocked inverter is operative to invert an applied signal during one phase of an applied sampling clock, and to render a high impedance output during the other sampling clock phase. Successive clocked inverters are clocked with opposite (i.e., positive/negative) versions of the sampling clock. The detector circuit examines the outputs of the last stage of sampler cells, and may for example comprise an OR function to detect a state transition in an applied input signal. The sampler circuit exhibits immunity to metastability and low power consumption.
    Type: Grant
    Filed: August 4, 2011
    Date of Patent: October 1, 2013
    Assignee: ST-Ericsson-SA
    Inventors: Paul Mateman, Johannes Petrus Antonius Frambach
  • Patent number: 8542787
    Abstract: Apparatus and methods are disclosed for adjusting phase of data signals to compensate for phase-offset variations between devices during normal operation. The phase of data signals are adjusted individually in each transmit data unit and receive data unit across multiple data slices with a common set of phase vector clock signals and a corresponding clock cycle count signal. The transmission of signal information between a first device (such as a memory controller) and a second device (such as a memory component) occurs without errors even when the accumulated delays between the first device and second device change by a half symbol time interval or more during operation of the system. The apparatus reduces the circuitry required, such as phase-lock-loops, for individually adjusting the phase of each transmit data unit and receive data unit across multiple data slices, which in turn results in reduction in complexity and cost of the system.
    Type: Grant
    Filed: June 17, 2011
    Date of Patent: September 24, 2013
    Assignee: Rambus Inc.
    Inventors: Craig E. Hampel, Richard E. Perego, Stefanos S. Sidiropoulos, Ely K. Tsern, Fredrick A. Ware
  • Patent number: 8543068
    Abstract: A transceiver node includes a pulse coupled oscillator in an integrated circuit, which can synchronize with other nodes to generate a global clock subsequently used to facilitate synchronous communications between individual nodes. Known potential uses include a low power sensor node radio for an ad-hoc network for military applications and medical applications such as ingestible and implantable radios, self powered radios, and medical monitoring systems such as cardiac and neural monitoring patches.
    Type: Grant
    Filed: August 4, 2008
    Date of Patent: September 24, 2013
    Assignee: Cornell University
    Inventors: Xiao Y. Wang, Alyssa B. Apsel
  • Patent number: 8537949
    Abstract: Transmitter waveform dispersion penalty (“TWDP”) is decreased in a transmitter. A binary data signal is received for transmission over a channel that exhibits TWDP. The data signal is shifted less than a full clock cycle to generate at least one post cursor signal. The post cursor signal is subtracted from the data signal to generate a transmitter output data signal for transmission over the channel. In addition to decreasing TWDP, data dependent jitter is also reduced for data transmission across a channel that exhibits a multi-pole transmission characteristic. A main data signal and at least one cursor signal, which is shifted at least a portion of a clock period from the main data signal, is generated. The cursor signal is filtered to filter out effects based on the second pole of the multi-pole transmission characteristic. The main data signal is subtracted from the filtered cursor signal to generate the transmitter output data signal.
    Type: Grant
    Filed: June 30, 2010
    Date of Patent: September 17, 2013
    Assignee: NetLogic Microsystems, Inc.
    Inventors: Halil Cirit, Stefanos Sidiropoulos
  • Patent number: 8537952
    Abstract: A fractional-N PLL uses separate charge pumps under the control of separate frequency and phase detectors. Phase jitter from an N divider is linearized by the use of a circuit that generates pulses from the output of the N divider. After frequency lock, the frequency detector turns off the frequency charge pump. After phase lock, activity in the phase detector down charge pump is minimized, reducing the overall noise produced by respective phase and frequency detector charge pumps.
    Type: Grant
    Filed: March 7, 2008
    Date of Patent: September 17, 2013
    Assignee: Marvell International Ltd.
    Inventor: Himanshu Arora
  • Patent number: 8537950
    Abstract: Apparatus for controlling the generation of a DC signal at the output of a mixer, so that the DC signal is predictable, enabling a static offset compensation voltage to offset the DC signal. The apparatus comprises a mixer configured to receive a first and a second input signal, the mixer being such as to generate a first DC signal at the output of the mixer when the first and second input signals have the same frequency and a first relative phase, a phase detector for determining the relative phase of the first and second signals, and a phase modifier configured to modify the phase of the second signal relative to the first signal in dependence on the determination of the relative phase between the first and second signals such that the resulting DC signal at the output of the mixer is the first DC signal.
    Type: Grant
    Filed: August 6, 2010
    Date of Patent: September 17, 2013
    Assignee: Cambridge Silicon Radio Limited
    Inventors: Kwangseok Han, Marco Bruno, Stuart Aitken, Steve Jones, Simon Chang, James Digby Yarlet Collier
  • Patent number: 8537956
    Abstract: A demultiplexer circuit separates input data having different data rates into output data. A phase-locked loop circuit generates first clock signals having average frequencies that are based on a frequency of a second clock signal times a fractional, non-integer number. A serializer circuit serializes a set of the output data to generate serial data signals in response to one of the first clock signals generated by the phase-locked loop circuit.
    Type: Grant
    Filed: November 24, 2010
    Date of Patent: September 17, 2013
    Assignee: Altera Corporation
    Inventors: Tien Duc Pham, Leon Zheng, Sergey Shumarayev, Zhi Y. Wong, Paul B. Ekas
  • Patent number: 8537954
    Abstract: The disclosed invention is a technology for producing a recovered clock signal using a multi-mode clock data recovery (CDR) circuit that accommodates a flexible range operating frequencies F and consecutive identical digit requirements CID. In a first mode of operation, a controlled oscillator produces the recovered clock signal, and in a second mode of operation, a phase interpolator produces the recovered clock signal. The multi-mode CDR circuit operates in the first mode if (CID/F) is less than a threshold time value and in the second mode if (CID/F) is greater than the threshold time value.
    Type: Grant
    Filed: January 15, 2010
    Date of Patent: September 17, 2013
    Assignee: Altera Corporation
    Inventors: Sergey Y. Shumarayev, Rakesh H. Patel, Wilson Wong, Tim T. Hoang
  • Patent number: 8537951
    Abstract: A network entity and computer program for detecting occurrence of transmission resynchronizations in a network carrying packets subject to variable delays, and adaptively varying the play out time of data packets. The method may include that the packets are received at a network entity and forwarded by delaying them by a jitter protection time, and determining for a predetermined time period a set of arrival time jitter values. A peak to peak value may be determined indicating the largest difference among the values included in the determined set of arrival time jitter values and detecting an out of range condition. The peak to peak value may be compared with the jitter protection time when the out of range condition is detected and detecting that a resynchronization occurred on the basis of the comparing.
    Type: Grant
    Filed: June 26, 2009
    Date of Patent: September 17, 2013
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventor: Arto Mahkonen
  • Patent number: 8537957
    Abstract: A clock synchronizer for generating a local clock signal synchronized to a received clock signal. The clock synchronizer incorporates a reference oscillator providing a reference signal, and a synthesizer circuit arranged to synthesize a local clock signal from the reference signal. The synthesizer circuit comprises a phase-locked-loop circuit, including a phase detector receiving the reference signal, and a controllable divider arranged in a feedback path from a controlled oscillator to the phase detector, the divider being controllable to set a frequency division value N along the path to determine a ratio of the local clock frequency to the reference frequency. The clock synchronizer also incorporates a clock comparison circuit adapted to generate a digital signal indicative of an asynchronism between the local and received clock signals. A control link is arranged to link the clock comparison circuit to the divider.
    Type: Grant
    Filed: May 23, 2011
    Date of Patent: September 17, 2013
    Assignee: Wolfson Microelectronics plc
    Inventor: Paul Lesso
  • Publication number: 20130235962
    Abstract: A multiple input multiple output (MIMO) calibration device (360) for calibrating a phase relationship between at least two signals present on at least two radio frequency (RF) paths coupling a wireless communication unit and the MIMO calibration device (360) is described. The MIMO calibration device (360) is operably coupleable via at least two RF paths between a wireless communication unit and an antenna arrangement (219).
    Type: Application
    Filed: November 15, 2011
    Publication date: September 12, 2013
    Applicant: SOCOWAVE TECHNOLOGIES LIMITED
    Inventors: Conor O'Keefe, Michael O'Brien
  • Patent number: 8532243
    Abstract: A technique that is readily implemented in monolithic integrated circuits includes a method including generating an output clock signal during a presence of a reference clock signal based, at least in part, on a digital control value indicating a phase difference between a feedback signal of a PLL and a reference clock signal. The method includes generating the output clock signal during an absence of the reference clock signal and based, at least in part, on an average digital control word indicating an average value of a number of samples of the digital control value during the presence of the reference clock signal, the number of samples preceding the absence of the reference clock signal by a delay period. The number of samples is selected from a plurality of numbers of samples and the delay period is selected from a plurality of delay periods.
    Type: Grant
    Filed: February 12, 2007
    Date of Patent: September 10, 2013
    Assignee: Silicon Laboratories Inc.
    Inventors: Srisai R. Seethamraju, Jerrell P. Hein, Kenneth Kin Wai Wong, Qicheng Yu
  • Patent number: 8531214
    Abstract: Spread spectrum generators and methods are disclosed. In one implementation, a spread spectrum clock generator includes a phase locked loop generating an output clock according to a first clock and a second clock; a delay line coupled between the first clock and the phase locked loop; a modulation unit providing a modulation signal to control the delay line thereby modulating phase of the first clock, such that frequency of the output clock generated by the phase locked loop varies periodically; a scaling unit scaling the modulation signal from the modulation unit according to a scaling ratio, and outputting to the delay line; and a calibration unit generating an output signal for controlling the scaling ratio.
    Type: Grant
    Filed: January 18, 2013
    Date of Patent: September 10, 2013
    Assignee: MediaTek Inc.
    Inventors: Shang-Ping Chen, Ping-Ying Wang
  • Patent number: 8526554
    Abstract: Apparatus and methods are disclosed, such as those involving deskewing serial data transmissions. One such apparatus includes a plurality of receivers, each of which is configured to receive a serial data stream. Each of the receivers includes a shift register including a plurality of stages arranged in sequence to propagate a stream of characters. Each of the stages is configured to store a character, and shift the character to a next stage in response to a clock signal. The receiver also includes a multiplexer having a plurality of inputs, each of the inputs being electrically coupled to a respective one of the stages of the shift register, and to select one of the stages to generate an output such that the outputs of the multiplexers in the receivers are deskewed.
    Type: Grant
    Filed: March 9, 2011
    Date of Patent: September 3, 2013
    Assignee: Analog Devices, Inc.
    Inventor: Michael Hennedy
  • Patent number: 8526528
    Abstract: A communication terminal includes first and second transmitters, which are coupled to produce respective first and second Radio Frequency (RF) signals that are phase-shifted with respect to one another by a beamforming phase offset, and to transmit the RF signals toward a remote communication terminal. The terminal includes a reception subsystem including first and second receivers and a phase correction unit. The first and second receivers are respectively coupled to receive third and fourth RF signals from the remote communication terminal. The phase correction unit is coupled to produce, responsively to the third and fourth RF signals, a phase correction for correcting an error component in the beamforming phase offset.
    Type: Grant
    Filed: May 18, 2012
    Date of Patent: September 3, 2013
    Assignee: Provigent Ltd.
    Inventors: Rafi Ravid, Zohar Montekyo, Ahikam Aharony
  • Patent number: 8520793
    Abstract: A phase detector includes a first sampling unit, a sampling module and a phase determining module. The first sampling unit is arranged for sampling a first data input signal to generate a first data signal according to a first clock signal. The sampling module includes a second sampling unit and a third sampling unit. The second sampling unit is arranged for sampling a second data input signal to generate a second data signal according to a second clock signal. The third sampling unit is arranged for sampling the second data signal to generate a third data signal according to the first clock signal. The phase determining module is arranged for generating a phase detecting result according to the first data signal and the third data signal.
    Type: Grant
    Filed: April 20, 2011
    Date of Patent: August 27, 2013
    Assignee: Faraday Technology Corp.
    Inventors: Chun-Cheng Lin, Ming-Shih Yu
  • Patent number: 8520792
    Abstract: A determining unit of a phase adjusting device determines whether or not a data stream to be detected included in serial transfer data can be detected in each output (first output to fourth output) of a first data obtaining unit and a second data obtaining unit. A phase adjusting unit adjusts a delay amount given to the serial transfer data to be output based on a determination result of the determining unit.
    Type: Grant
    Filed: February 21, 2012
    Date of Patent: August 27, 2013
    Assignee: Nikon Corporation
    Inventor: Daiki Ito
  • Patent number: 8519760
    Abstract: A device characteristic compensation circuit includes a device characteristic detection block configured to detect one or more of a frequency of a clock signal and characteristics of devices, and generate a control code signal according to a detection result; and an internal voltage regulation unit configured to regulate a level of an internal voltage in response to the control code signal and generate a corrected internal voltage.
    Type: Grant
    Filed: August 27, 2011
    Date of Patent: August 27, 2013
    Assignee: SK Hynix Inc.
    Inventors: Ki Han Kim, Hyun Woo Lee
  • Patent number: 8522087
    Abstract: A counter configuration operates in cooperation with a delay configuration such that the counter configuration counts an input interval based on a given clock speed and a given clock interval while the delay configuration provides an enhanced data output that is greater than what would otherwise be provided by the given clock speed. The counter configuration counts responsive to a selected edge in the clock interval. An apparatus in the form of a correction arrangement and an associated method are configured to monitor at least the delay configuration output for detecting a particular time relationship between an endpoint of the input interval and a nearest occurrence of the selected clock edge in the given clock signal that is indicative of at least a potential error in the enhanced data output and determining if the potential error is an actual error for subsequent use in correcting the enhanced data output.
    Type: Grant
    Filed: February 2, 2011
    Date of Patent: August 27, 2013
    Assignee: Micron Technology, Inc.
    Inventors: Larry J. Koudele, Robert B. Eisenhuth
  • Patent number: 8520787
    Abstract: Apparatus and methods are disclosed, such as those involving deskewing serial data transmissions. One such apparatus includes a plurality of receivers, each of which is configured to receive a serial data stream. Each of the receivers includes a shift register including a plurality of stages arranged in sequence to propagate a stream of characters. Each of the stages is configured to store a character, and shift the character to a next stage in response to a clock signal. The receiver also includes a multiplexer having a plurality of inputs, each of the inputs being electrically coupled to a respective one of the stages of the shift register, and to select one of the stages to generate an output such that the outputs of the multiplexers in the receivers are deskewed.
    Type: Grant
    Filed: March 9, 2011
    Date of Patent: August 27, 2013
    Assignee: Analog Devices, Inc.
    Inventor: Michael Hennedy
  • 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
  • Patent number: 8520725
    Abstract: A data equalizing circuit includes an equalizer configured to control a gain of data according to a value of a control code and output a controller gain; and a detection unit configured to divide n cycles of the data into N periods, count data transition frequencies for n/N periods while changing the value of the control code, calculate dispersion values of data transition frequencies for 1/N periods of the data from the data transition frequencies for the n/N periods, and finally output the value of the control code corresponding to a largest dispersion value, wherein n is equal to or greater than 2 and is set such that boundaries of the respective n/N periods of the data have different positions in the 1 UI data.
    Type: Grant
    Filed: February 28, 2012
    Date of Patent: August 27, 2013
    Assignee: SK Hynix Inc.
    Inventors: Chun Seok Jeong, Jae Jin Lee, Chang Sik Yoo, Jang Woo Lee, Seok Joon Kang
  • Patent number: 8514996
    Abstract: A method for clock monitoring in a network is provided. The method comprises receiving a first network clock signal at a network device and comparing the first network clock signal to a local clock signal from a primary oscillator coupled to the network device.
    Type: Grant
    Filed: July 14, 2010
    Date of Patent: August 20, 2013
    Assignee: Honeywell International Inc.
    Inventors: Julie Pollock, Brett D. Oliver, Christopher Brickner
  • Patent number: 8514995
    Abstract: A circuit includes a receiver circuit, a data valid monitor circuit, a clock signal generation circuit, and a phase shift circuit. The receiver circuit is operable to generate a first periodic signal, a sampled data signal based on an input data signal, and a data valid signal based on a predefined number of bits in the sampled data signal. The data valid monitor circuit is operable to generate a count value by counting periods of the first periodic signal. The data valid monitor circuit is operable to generate a phase error signal based on the data valid signal and the count value. The clock signal generation circuit is operable to generate a second periodic signal. The phase shift circuit is operable to generate a third periodic signal based on the second periodic signal and to adjust a phase of the third periodic signal based on the phase error signal.
    Type: Grant
    Filed: April 7, 2011
    Date of Patent: August 20, 2013
    Assignee: Altera Corporation
    Inventors: Boon Hong Oh, Peter Schepers, Da Hai Tang
  • Patent number: 8514920
    Abstract: Methods and apparatus are provided for pseudo asynchronous testing of receive paths in serializer/deserializer (SerDes) devices. A SerDes device is tested by applying a source of serial data to a receive path of the SerDes device during a test mode. The receive path substantially aligns to incoming data using a bit clock. A phase is adjusted during the test mode of the bit clock relative to the source of serial data to evaluate the SerDes device. The source of serial data may be, for example, a reference clock used by a phase locked loop to generate the bit clock. The phase of the bit clock can be directly controlled during the test mode, for example, by a test phase control signal, such as a plurality of interpolation codes that are applied to an interpolator that alters a phase of the bit clock.
    Type: Grant
    Filed: July 26, 2012
    Date of Patent: August 20, 2013
    Assignee: LSI Corporation
    Inventors: Christopher J. Abel, Parag Parikh, Vladimir Sindalovsky
  • Publication number: 20130208839
    Abstract: The invention relates to a method and a system for generating clock signals in a wireless communication device. The method includes generating an uncorrected reference clock signal, generating at least one frequency correction value corresponding to a frequency error in the uncorrected reference clock signal, and generating at least one radio frequency clock signal based on the uncorrected clock signal and the at least one frequency correction value, for receiving and transmitting radio frequency signals. The method further comprise generating, independently of the at least one radio frequency clock signal, a baseband timing signal based on the uncorrected reference clock signal and the at least one frequency correction value, for clocking base-band signal processing circuits.
    Type: Application
    Filed: July 5, 2011
    Publication date: August 15, 2013
    Applicant: TELEFONAKTIEBOLAGET L M ERICSSON (PUBL)
    Inventor: Martin Isberg
  • Patent number: 8509368
    Abstract: Systems and methods that provide clock jitter compensation architectures that improve the performance of direct radio frequency (RF) receivers by injecting a calibration tone into the received radio frequency (RF) signals in order to help identify and then compensate for the clock jitter noise. After injecting the tone, the jitter noise going through the direct RF bandpass sampling receiver is estimated using a narrow bandwidth filter, and the received signals are further processed and demodulated depending on the Nyquist zone of the received signal. The relative modulation factor for the modulation is computed and then applied to the Nyquist zone to de jitter that particular Nyquist zone.
    Type: Grant
    Filed: December 2, 2009
    Date of Patent: August 13, 2013
    Assignee: L-3 Communications Integrated Systems, L.P.
    Inventors: Gerald L. Fudge, Mark A. Chivers, Sujit Ravindran, Alex Yeh
  • Patent number: 8509371
    Abstract: A continuous-rate clock and data recovery circuit includes a delay locked loop with a first integrator and a phase locked loop with a separate integrator. The delay locked loop and the phase locked loop are in a dual loop architecture. The first integrator is a digital accumulator that wraps upon exceeding a maximum or minimum value. The second integrator is a digital accumulator that saturates at its maximum or minimum value.
    Type: Grant
    Filed: September 29, 2009
    Date of Patent: August 13, 2013
    Assignee: Analog Devices, Inc.
    Inventor: John G. Kenney
  • Publication number: 20130202072
    Abstract: The present invention provides method and apparatus for adapting a relatively high data rate second order serdes receiver to receive relatively low data rate serial data, the receiver having jog realignment by and having means for receiving the serial data as a plurality of repeated bits at the high data rate; framing the data as frames of repeated bits of the same value; examining the bits of the frame for the presence of bits which are not of the same value; upon detecting such a presence that is indicative of a framing error jogging the serdes receiver for frame realignment; and supplying to an output of the serdes receiver one of the bits of said same value from each frame at the low data rate.
    Type: Application
    Filed: January 31, 2013
    Publication date: August 8, 2013
    Applicant: TEXAS INSTRUMENTS INCORPORATED
    Inventor: Texas Instruments Incorporated
  • Patent number: 8503592
    Abstract: A communication system and method is disclosed that performs symbol boundary synchronization by generating a symbol alignment estimate from a partial signal correlation; and then refining the symbol alignment estimate via a carrier phase calculation. To generate the symbol alignment estimate, two methods are disclosed. After an estimate is determined, an embodiment provides for refining the symbol alignment estimate via a carrier phase calculation by determining a carrier phase of two adjacent carriers, determining a phase error as directly proportional to an offset from the start of a symbol, determining a phase difference contribution due to a communication channel and device hardware, and counter-rotating the determined carrier phase by an angle of a constellation point at a transmitter.
    Type: Grant
    Filed: February 6, 2012
    Date of Patent: August 6, 2013
    Assignee: Metonoia Technologies, Inc.
    Inventor: Jeffrey C. Strait
  • Patent number: 8503598
    Abstract: An initialization circuit in a delay locked loop ensures that after power up or other reset clock edges are received by a phase detector in the appropriate order for proper operation. After reset of the delay locked loop, the initialization circuit assures that at least one edge of a reference clock is received prior to enabling the phase detector to increase (or decrease) the delay in a delay line. After at least one edge of a feedback clock is received, the initialization circuit enables the phase detector to decrease (or increase) the delay in a delay line.
    Type: Grant
    Filed: June 26, 2012
    Date of Patent: August 6, 2013
    Assignee: MOSAID Technologies Incorporated
    Inventor: Tony Mai
  • Patent number: 8503593
    Abstract: In one aspect, an integrated circuit (IC) system includes a receiver IC configured to receive a first clock signal and includes a feedback circuit configured to provide a feedback signal to a driver IC. The IC system also includes the driver IC configured to receive a second clock signal and includes a waveform generator configured to provide synthesized waveforms from DC to K-band, a serializer/deserializer (SERDES) to receive data from the waveform generator and to provide the signal to the receiver IC and a phase selection circuit to provide a phase selection signal to the first integrated circuit based on the feedback signal. The phase selection signal calibrates the signal from the SERDES and provides phase correction to the SERDES.
    Type: Grant
    Filed: June 23, 2010
    Date of Patent: August 6, 2013
    Assignee: Raytheon Company
    Inventors: David J. Katz, Stephen R. Reid
  • Patent number: 8503594
    Abstract: The present invention includes a method of determining a phase estimate for an input signal having pilot symbols. The method includes receiving a plurality of pilot symbols, and then multiplying two or more pilot symbol slots by corresponding correlator coefficients to correct a phase estimate of the input signal.
    Type: Grant
    Filed: September 5, 2012
    Date of Patent: August 6, 2013
    Assignee: Broadcom Corporation
    Inventors: Tommy Yu, Amy Gayle Hundhausen
  • Patent number: 8503595
    Abstract: The invention relates to a clock generation circuit and a signal reproduction circuit including the clock generation circuit, and, more particularly, the invention provides a data judgment/phase comparison circuit capable of performing both of data judgment and phase comparison by a single-phase clock, and provides a CDR (Clock Data Recovery) circuit including the data judgment/phase comparison circuit. The same data and clock are inputted to two data judging units C_GOOD and C_BAD each having a different data determination period (setup/hold time) required for correctly judging a data, and an output of the data judging unit C_GOOD having a shorter required data determination period is taken as a data output of the data judgment/phase comparison circuit. When the outputs of both of the data judging units are different from each other, a signal Early indicating that a clock phase is too early or a signal Late indicating that the clock phase is too late is outputted.
    Type: Grant
    Filed: September 29, 2009
    Date of Patent: August 6, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Koji Fukuda, Hiroki Yamashita
  • Patent number: 8498370
    Abstract: The present invention discloses a method and apparatus for addressing the issue of clock skew in a data signal while making efficient use of space on an integrated chip (IC) by utilizing a physical delay line controlled by a state machine in conjunction with pre-requisite chip architecture. The pre-requisite chip architecture samples the incoming data signal in response to a clocking signal input from the physical delay line; the physical delay line responds to commands from the state machine to increment the delay of the physical delay line to produce samples which describe the incoming data signal and delineate its data valid window.
    Type: Grant
    Filed: December 14, 2009
    Date of Patent: July 30, 2013
    Assignee: Altera Canada Co.
    Inventors: Wally Haas, Mutema John Pittman
  • Publication number: 20130188657
    Abstract: An electronic device includes a transmission module communicatively coupled to a synchronizer. The transmission module is configured to transform received data for transmission, receive a first instruction from the synchronizer, based on the instruction adjust the phase of a clock signal used to time the transformation of the received data, and send the adjusted clock signal to the synchronizer. The synchronizer is configured to receive the adjusted clock signal, receive a data signal comprising a frequency and a phase of data to be transmitted, based on the adjusted clock signal and the data signal, determine a second instruction for the transmission module, and provide the second instruction to the transmission module.
    Type: Application
    Filed: January 20, 2012
    Publication date: July 25, 2013
    Applicant: FUJITSU LIMITED
    Inventors: Nikola Nedovic, Shuo-Chun Kao
  • Publication number: 20130188762
    Abstract: The disclosed clock-data recovery architecture includes out-of-lock (including false lock) detection. Out-of-lock detection is accomplished by sampling retimed/recovered data with positive and negative edges of the received data. In example embodiments, an out-of-lock condition is determined either by detecting the occurrence of, or counting, missed edges corresponding to the failure of received data sampling to detect corresponding positive/negative edges of the retimed/recovered data.
    Type: Application
    Filed: January 21, 2013
    Publication date: July 25, 2013
    Applicant: Texas Instruments Incorporated
    Inventor: Texas Instruments Incorporated
  • Patent number: 8494092
    Abstract: In described embodiments, a receiver includes a clock and data recovery (CDR) module with a voltage control oscillator (VCO) and a Sigma-Delta modulator in an integral loop control of the VCO. Providing finer resolution by the Sigma-Delta modulator reduces quantization noise in the integral control loop when compared to a loop without a Sigma-Delta modulator in the integral loop. Sigma-Delta modulation within the integral loop control of a VCO-based CDR reduces effective quantization of the VCO integral word control, allowing the proportional loop control compensation to i) reduce effective quantization of the VCO integral word control and, ii) enhance receiver jitter tolerance in presence of periodic-jitter, serial data whose frequency is offset from the nominal rate and serial data whose nominal frequency is modulated by a spread spectrum clock.
    Type: Grant
    Filed: April 7, 2011
    Date of Patent: July 23, 2013
    Assignee: LSI Corporation
    Inventors: Vladimir Sindalovsky, Lane Smith, Shawn Logan
  • Patent number: 8494104
    Abstract: A NICAM audio signal re-sampler may include a non-linear interpolator configured to interpolate in a non-linear manner between sequential digital samples that are based on a stream of demodulated NICAM audio samples. A phase differential calculator may be included that compares phase information at different resolutions.
    Type: Grant
    Filed: September 19, 2011
    Date of Patent: July 23, 2013
    Assignee: THAT Corporation
    Inventors: Roger R. Darr, Matthew F. Easley, Matthew S. Barnhill
  • Patent number: 8494011
    Abstract: An apparatus and method are described for compensating for frequency and phase variations of electronic components by processing packet delay values. In one embodiment, a packet delay determination module determines packet delay values based on time values associated with a first and a second electronic component. A packet delay selection module selects a subset of the packet delay values based on the maximum frequency drift of the first electronic component. A statistical parameter determination module evaluates a first and a second parameter based on portions of the subset of packet delay values. A validation module validates the parameters when each portion the subset of packet delay values includes a minimum of at least two packet delay values. An adjustment module compensates for at least one of a frequency variation and a phase variation of the first electronic component based on the parameters if the parameters are both validated.
    Type: Grant
    Filed: September 13, 2012
    Date of Patent: July 23, 2013
    Assignee: Juniper Networks, Inc.
    Inventors: Charles F. Barry, Meenakshi S. Subramanian, Feng Frank Pan, Tian Alan Shen, Philip Kruzinski, Guochun George Zhao, DeviPrasad Natesan, David R. Jorgensen