Patents by Inventor Vernon R. Norman
Vernon R. Norman has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 7809054Abstract: Disclosed are a receiver circuit, method and design architecture of a decision feedback equalizer (DFE) Clock-And-Data Recovery (CDR) architecture that utilizes/produces one sample-per-bit in the receiver and reduces bit-error-rate (BER). An integrating receiver is combined with a decision feedback equalizer along with the appropriate (CDR) loop phase detector to maintain a single sample per bit requirement. The incoming voltage is converted to a current and connected to a current summing node. Weighted currents determined by the values of previously detected bits and their respective feedback coefficients are also connected to this node. Additionally, the summed currents is integrated and converted to a voltage. A sampler is utilized to make a bit decision based on the resulting voltage. After sampling, the integrator is reset before analysis of the next bit. The necessary amplification is achieved by maximizing the sensitivity of the latch, using integration in front of the data latch.Type: GrantFiled: April 18, 2006Date of Patent: October 5, 2010Assignee: International Business Machines CorporationInventors: Juan A. Carballo, Hayden C. Cranford, Jr., Gareth J. Nicholls, Vernon R. Norman, Martin L. Schmatz
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Patent number: 7698802Abstract: A method for manufacturing a calibration device for an active circuit on a chip, comprises: providing an active circuit that is capable of exhibiting a desired electrical characteristic; and providing a calibration mechanism on-chip with the active circuit. The calibration mechanism generates a control output and comprises a device under test (DUT) configured as a replica of at least one segment of the active circuit, and which generates a test output that causes finite adjustments to the control output, based on a comparison of the electrical characteristics exhibited by the DUT with a known electrical characteristic. The method further comprises: attaching to each control input terminal of the active circuit a corresponding control output from the calibration mechanism. The control output of the calibration mechanism dynamically adjusts control input applied to devices of the active circuit to force the active circuit to exhibit the desired electrical characteristic.Type: GrantFiled: February 8, 2008Date of Patent: April 20, 2010Assignee: International Business Machines CorporationInventors: Steven M. Clements, William P. Cornwell, Carrie E. Cox, Hayden C. Cranford, Jr., Vernon R. Norman
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Patent number: 7661052Abstract: A method and system for testing a high-speed circuit is disclosed. The method and system include obtaining a high-speed statistical signature of the high-speed circuit using a conventional tester. The method and system further include comparing the high-speed statistical signature of the high-speed circuit to an expected signature. Consequently, it can be determined whether the high-speed circuit functions within the desired parameters.Type: GrantFiled: January 29, 2008Date of Patent: February 9, 2010Assignee: International Business Machines CorporationInventors: Hayden C. Cranford, Jr., Vernon R. Norman, Martin L. Schmatz
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Patent number: 7570071Abstract: Substantially-accurate calibration of output impedance of a device-under-test (DUT) to within a predetermined range of allowable impedance. The DUT is part of a source series terminated (SST) serial link transmitter, in which two branches of parallel transistors each provide an impedance value when particular transistors of the parallel branch are turned on. The impedance value is added to a series-connected resistor to provide the output impedance. The DUT consists of one branch of parallel transistors in series with a resistor. Output impedance of the DUT is compared to the resistance of a reference resistor, and the comparator provides a control signal based on whether the output impedance falls within the pre-set percentage variance of the reference resistance. The control signal is processed by a FSM (finite state machine) that individually turns on or off the transistors within the parallel branch until the DUT impedance value falls within the desired range.Type: GrantFiled: February 8, 2008Date of Patent: August 4, 2009Assignee: International Business Machines CorporationInventors: Steven M. Clements, William P. Cornwell, Carrie E. Cox, Hayden C. Cranford, Jr., Vernon R. Norman
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Patent number: 7539473Abstract: A circuit design, method, and system for tracking VCO calibration without requiring an over-designed divider as in conventional implementation. A filter reset component is added to the inputs of the VCO. A process step is added to the calibration mechanism/process that shorts the filter nodes and thus centers the frequency of the VCO before stepping from one frequency band to the next.Type: GrantFiled: April 26, 2006Date of Patent: May 26, 2009Assignee: International Business Machines CorporationInventors: Hayden C. Cranford, Jr., Stacy J. Garvin, Vernon R. Norman
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Publication number: 20090116593Abstract: Aspects of providing automatic adaptation to frequency offsets in high speed serial links are described. First signals for phase adjusts in a receiver link are adjusted by detecting trends in the first signals to generate second signals, the second signals improving a rate of compensation for the frequency offsets by the phase adjusts. An up/down counter is included for counting signals for phase adjustments by a clock-data-recovery loop of a serial receiver. An adder is coupled to the up/down counter and outputs accumulated data indicative of a trend in the phase adjustments. Combinatorial logic coupled to the adder adapts the signals based on the accumulated data.Type: ApplicationFiled: January 6, 2009Publication date: May 7, 2009Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: HAYDEN C. CRANFORD, JR., GARETH JOHN NICHOLLS, BOBAK MODARESS-RAZAVI, VERNON R. NORMAN, MARTIN L. SCHMATZ
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Patent number: 7512177Abstract: Apparatuses and methods comprise a phase shifter, an adjustable capacitance configured to adjust a phase shift of said phase shifter, an arbitrary waveform generator configured to adjust the adjustable capacitance, and a pulse pattern generator coupled to the phase shifter, the phase shifter is configured to control the pulse pattern generator. In one aspect, an adjustable capacitance is at least one varactor diode. In another, a pair of varactor diodes are separated by ?/4 lines, an input and an output of the adjustable capacitance is AC-coupled, and the arbitrary waveform generator is configured to adjust the adjustable capacitance through a gaussian noise signal input to the pair of varactor diodes. A deterministic jitter generator may be coupled to the pulse pattern generator. An open-circuited stub line may be input to the pattern generator, a deterministic jitter content number adjustable varying stub line length.Type: GrantFiled: July 26, 2007Date of Patent: March 31, 2009Assignee: International Business Machines CorporationInventors: Hayden C. Cranford, Jr., Marcel A. Kossel, Vernon R. Norman, Martin L. Schmatz
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Patent number: 7477713Abstract: Aspects of providing automatic adaptation to frequency offsets in high speed serial links are described. First signals for phase adjusts in a receiver link are adjusted by detecting trends in the first signals to generate second signals, the second signals improving a rate of compensation for the frequency offsets by the phase adjusts. An up/down counter is included for counting signals for phase adjustments by a clock-data-recovery loop of a serial receiver. An adder is coupled to the up/down counter and outputs accumulated data indicative of a trend in the phase adjustments. Combinatorial logic coupled to the adder adapts the signals based on the accumulated data.Type: GrantFiled: March 2, 2004Date of Patent: January 13, 2009Assignee: International Business Machines CorporationInventors: Hayden C. Cranford, Jr., Gareth John Nicholls, Bobak Modaress-Razavi, Vernon R. Norman, Martin L. Schmatz
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Publication number: 20080240224Abstract: A design structure embodied in a machine readable storage medium for designing, manufacturing, and/or testing a design of a decision feedback equalizer (DFE) Clock-And-Data Recovery (CDR) architecture that utilizes/produces one sample-per-bit in the receiver and reduces bit-error-rate (BER) is provided. The design generally includes a receiver circuit. The receiver circuit generally includes a decision feedback equalizer (DFE) that produces one sample per bit, and means for automatically self-adjusting the DFE to enable an eye centering process by which peak energy is maintained within the receiver circuit when phase error is a minimum.Type: ApplicationFiled: June 12, 2008Publication date: October 2, 2008Inventors: JUAN A. CARBALLO, Hayden C. Cranford, Gareth J. Nicholls, Vernon R. Norman, Martin L. Schmatz
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Patent number: 7418069Abstract: The invention is directed to a clock data recovery system for resampling a clock signal according to an incoming data signal. The clock data recovery system comprises a clock generator for generating the clock signal and a phase adjustment unit for generating sampling phases dependent on a phase adjustment control signal. It also comprises a data sampling unit operable to generate a stream of input samples and an edge detector for generating therefrom an internal early signal and an internal late signal. A phase adjustment control unit is disposed for generating under use of the early signal and the late signal the phase adjustment control signal. The phase adjustment control unit is feedable with an external early/late signal and/or comprises an output for delivering an export early/late signal.Type: GrantFiled: December 28, 2007Date of Patent: August 26, 2008Assignee: International Business Machines CorporationInventors: Martin Schmatz, Hayden C. Cranford, Vernon R. Norman
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Publication number: 20080150599Abstract: Apparatuses and methods comprise a phase shifter, an adjustable capacitance configured to adjust a phase shift of said phase shifter, an arbitrary waveform generator configured to adjust the adjustable capacitance, and a pulse pattern generator coupled to the phase shifter, the phase shifter is configured to control the pulse pattern generator. In one aspect, an adjustable capacitance is at least one varactor diode. In another, a pair of varactor diodes are separated by ?/4 lines, an input and an output of the adjustable capacitance is AC-coupled, and the arbitrary waveform generator is configured to adjust the adjustable capacitance through a gaussian noise signal input to the pair of varactor diodes. A deterministic jitter generator may be coupled to the pulse pattern generator. An open-circuited stub line may be input to the pattern generator, a deterministic jitter content number adjustable varying stub line length.Type: ApplicationFiled: July 26, 2007Publication date: June 26, 2008Applicant: International Business Machines CorporationInventors: Hayden C. Cranford, Marcel A. Kossel, Vernon R. Norman, Martin L. Schmatz
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Publication number: 20080133164Abstract: A method and system for testing a high-speed circuit is disclosed. The method and system include obtaining a high-speed statistical signature of the high-speed circuit using a conventional tester. The method and system further include comparing the high-speed statistical signature of the high-speed circuit to an expected signature. Consequently, it can be determined whether the high-speed circuit functions within the desired parameters.Type: ApplicationFiled: January 29, 2008Publication date: June 5, 2008Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Hayden C. Cranford, Vernon R. Norman, Martin L. Schmatz
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Publication number: 20080122452Abstract: Substantially-accurate calibration of output impedance of a device-under-test (DUT) to within a predetermined range of allowable impedance. The DUT is part of a source series terminated (SST) serial link transmitter, in which two branches of parallel transistors each provide an impedance value when particular transistors of the parallel branch are turned on. The impedance value is added to a series-connected resistor to provide the output impedance. The DUT consists of one branch of parallel transistors in series with a resistor. Output impedance of the DUT is compared to the resistance of a reference resistor, and the comparator provides a control signal based on whether the output impedance falls within the pre-set percentage variance of the reference resistance. The control signal is processed by a FSM (finite state machine) that individually turns on or off the transistors within the parallel branch until the DUT impedance value falls within the desired range.Type: ApplicationFiled: February 8, 2008Publication date: May 29, 2008Inventors: Steven M. Clements, William P. Cornwell, Carrie E. Cox, Hayden C. Cranford, Vernon R. Norman
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Publication number: 20080120838Abstract: Substantially-accurate calibration of output impedance of a device-under-test (DUT) to within a predetermined range of allowable impedance. The DUT is part of a source series terminated (SST) serial link transmitter, in which two branches of parallel transistors each provide an impedance value when particular transistors of the parallel branch are turned on. The impedance value is added to a series-connected resistor to provide the output impedance. The DUT consists of one branch of parallel transistors in series with a resistor. Output impedance of the DUT is compared to the resistance of a reference resistor, and the comparator provides a control signal based on whether the output impedance falls within the pre-set percentage variance of the reference resistance. The control signal is processed by a FSM (finite state machine) that individually turns on or off the transistors within the parallel branch until the DUT impedance value falls within the desired range.Type: ApplicationFiled: February 8, 2008Publication date: May 29, 2008Inventors: Steven M. Clements, William P. Cornwell, Carrie E. Cox, Hayden C. Cranford, Vernon R. Norman
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Patent number: 7368902Abstract: Substantially-accurate calibration of output impedance of a device-under-test (DUT) to within a predetermined range of allowable impedance. The DUT is part of a source series terminated (SST) serial link transmitter, in which two branches of parallel transistors each provide an impedance value when particular transistors of the parallel branch are turned on. The impedance value is added to a series-connected resistor to provide the output impedance. The DUT consists of one branch of parallel transistors in series with a resistor. Output impedance of the DUT is compared to the resistance of a reference resistor, and the comparator provides a control signal based on whether the output impedance falls within the pre-set percentage variance of the reference resistance. The control signal is processed by a FSM (finite state machine) that individually turns on or off the transistors within the parallel branch until the DUT impedance value falls within the desired range.Type: GrantFiled: October 28, 2005Date of Patent: May 6, 2008Assignee: International Business Machines CorporationInventors: Steven M. Clements, William P. Cornwell, Carrie E. Cox, Hayden C. Cranford, Jr., Vernon R. Norman
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Patent number: 7349498Abstract: A system and method is disclosed for evaluating a data group of oversampled bits to detect edge transitions and for improving use of information available from a sampled data while maintaining acceptable noise rejection. An edge detection system for receiving a serial data stream includes a sampler for collecting a sample pattern from the serial data stream, the sample pattern including a succession of a plurality of data samples from the data stream with the plurality of data samples including multiple samples during a bit time associated with the data stream; a memory, coupled to the sampler, for storing one or more successive sample patterns; and a correlator, coupled to the memory, for producing a sample condition signal using a set of predefined patterns by comparing the stored sampled patterns to the predefined patterns.Type: GrantFiled: October 7, 2002Date of Patent: March 25, 2008Assignee: International Business Machines CorporationInventors: Hayden C Cranford, Jr., Vernon R. Norman, Martin L. Schmatz
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Patent number: 7340660Abstract: A method and system for testing a high-speed circuit is disclosed. The method and system include obtaining a high-speed statistical signature of the high-speed circuit using a conventional tester. The method and system further include comparing the high-speed statistical signature of the high-speed circuit to an expected signature. Consequently, it can be determined whether the high-speed circuit functions within the desired parameters.Type: GrantFiled: October 7, 2003Date of Patent: March 4, 2008Assignee: International Business Machines CorporationInventors: Hayden C. Cranford, Jr., Vernon R. Norman, Martin L. Schmatz
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Patent number: 7317777Abstract: A system and method for tracking/adapting phase or frequency changes in an incoming serial data stream that may contain significant amounts of noise and/or jitter and may contain relatively long periods of successive univalue data bits. The method includes digitally sampling a received data stream at predefined intervals to produce a data set; estimating when logic transitions occur in the data set; detecting a timing trend represented by the estimated logic transitions; and adjusting a frequency of the first clock so that the timing trend averages approximately zero over a plurality of logic transitions.Type: GrantFiled: October 7, 2002Date of Patent: January 8, 2008Assignee: International Business Machines CorporationInventors: Hayden C Cranford, Jr., Vernon R. Norman, Martin L. Schmatz
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Patent number: 7315594Abstract: The invention is directed to a clock data recovery system for resampling a clock signal to an incoming data signal. The clock data recovery system comprises a clock generator for generating the clock signal and a phase adjustment unit for generating sampling phases dependant on a phase adjustment control signal. It also comprises a data sampling unit operable to generate a stream of input samples and an edge detector for generating therefrom an internal early signal and an internal late signal. A phase adjustment control unit is disposed for generating under use of the early signal and the late signal the phase adjustment control signal. The phase adjustment control unit is feedable with an external early/late signal and/or comprises an output for delivering an export early/late signal.Type: GrantFiled: July 15, 2002Date of Patent: January 1, 2008Assignee: International Business Machines CorporationInventors: Martin Schmatz, Hayden C. Cranford, Vernon R. Norman
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Patent number: 7295604Abstract: The method for determining jitter of a signal in a serial link according to the invention comprising the following steps: First, a section of the signal transmitted via a transmission channel is sampled at different sampling times. The total number of edges in the section is determined. The neighboring sample values are analyzed and from that a statistical value is formed. From the statistical value and the total number of edges a figure of merit is determined. Finally, by means of a look-up table or a jitter-versus-figure of merit curve, the total jitter corresponding to the figure of merit is derived.Type: GrantFiled: November 24, 2003Date of Patent: November 13, 2007Assignee: International Business Machines CorporationInventors: Hayden C. Cranford, Jr., Marcel A. Kossel, Vernon R. Norman, Martin L. Schmatz