Patents by Inventor David P. Chengson

David P. Chengson 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).

  • Patent number: 11156651
    Abstract: Techniques are described for a method for detecting a fault. The method includes receiving, by a receiving electronic device, via a differential pair transmission line, from a transmitting electronic device, an electrical signal. The method further includes converting, by a receiving (Rx) serializer/deserializer (SerDes) operating at the receiving electronic device, the received electrical signal into a received digital electrical signal. The method further includes, determining, by one or more processors, an electrical signature of the received electrical signal from the received digital electrical signal when the received electrical signal is received by the receiving electronic device. The method further includes determining, by the one or more processors, based on the electrical signature, a position of a fault between the receiving electronic device and the transmitting electronic device. The fault causes the received electrical signal to be different than the transmitted electrical signal.
    Type: Grant
    Filed: June 28, 2019
    Date of Patent: October 26, 2021
    Assignee: Juniper Networks, Inc.
    Inventors: David P. Chengson, Ranjeeth Doppalapudi
  • Patent number: 10455690
    Abstract: A printed circuit board (PCB) assembly may include a component capable of sending or receiving high-speed differential signal pairs, a package that is connected to the component, and a PCB connected to the package. The PCB assembly may be used to support a first high-speed differential signal pair that includes a first differential signal and a second differential signal. The first differential signal may be capable of causing crosstalk onto a particular differential signal, of a second high-speed differential signal pair, while propagating through the PCB assembly. A set of interconnects may be used to intelligently route the first differential signal pair within the package and/or within the PCB. The set of interconnects may include a first interconnect to route the first differential signal away from the particular differential signal and a second interconnect to route the second differential signal toward the particular differential signal.
    Type: Grant
    Filed: March 23, 2018
    Date of Patent: October 22, 2019
    Assignee: Juniper Networks, Inc.
    Inventors: David P. Chengson, Ranjeeth Doppalapudi
  • Patent number: 10455691
    Abstract: An apparatus may include via pads and grid array pads associated with facilitating a connection through a package and to a component, and vias that are electrically connected to the via pads, wherein the vias are used to support high-speed differential signal pairs that are capable of causing crosstalk onto other high-speed differential signal pairs while propagating through the package. The apparatus may include interconnects that electrically connect the vias to the grid array pads, and that are capable of routing the high-speed differential signal pairs in a way that offsets the crosstalk that the high-speed differential signal pairs are capable of causing while propagating through the package. The apparatus may include additional interconnects that electrically connect the vias to additional vias that are to be used to facilitate routing the high-speed differential signal pairs to the component, without the high-speed differential signal pairs propagating through a printed circuit board.
    Type: Grant
    Filed: March 23, 2018
    Date of Patent: October 22, 2019
    Assignee: Juniper Networks, Inc.
    Inventor: David P. Chengson
  • Patent number: 10383213
    Abstract: In some examples, an electronic device includes a printed circuit board (PCB) device that includes a first trace electrically connected to a first pad of a first trace via on a first layer and a second trace electrically connected to a second pad of a second trace via on a second layer. In some examples, the PCB device also includes four ground pads on the first layer and an antipad surrounding the two trace vias, where a first ground pad is positioned between the first trace and the second trace, where the first ground pad and the second ground pad are approximately symmetrically positioned about a perpendicular bisector of a line from the first pad to the second pad, and wherein the third ground pad and the fourth ground pad are approximately symmetrically positioned about the perpendicular bisector of the line from the first pad to the second pad.
    Type: Grant
    Filed: February 22, 2019
    Date of Patent: August 13, 2019
    Assignee: Juniper Networks, Inc.
    Inventors: David P. Chengson, Edward C. Chang, Ranjeeth Doppalapudi, Santosh Kumar Pappu
  • Patent number: 10365314
    Abstract: Techniques are described for a method for detecting a fault. The method includes receiving, by a receiving electronic device, via a differential pair transmission line, from a transmitting electronic device, an electrical signal. The method further includes converting, by a receiving (Rx) serializer/deserializer (SerDes) operating at the receiving electronic device, the received electrical signal into a received digital electrical signal. The method further includes, determining, by one or more processors, an electrical signature of the received electrical signal from the received digital electrical signal when the received electrical signal is received by the receiving electronic device. The method further includes determining, by the one or more processors, based on the electrical signature, a position of a fault between the receiving electronic device and the transmitting electronic device. The fault causes the received electrical signal to be different than the transmitted electrical signal.
    Type: Grant
    Filed: December 21, 2016
    Date of Patent: July 30, 2019
    Assignee: Juniper Networks, Inc.
    Inventors: David P. Chengson, Ranjeeth Doppalapudi
  • Patent number: 10231325
    Abstract: In some examples, an electronic device includes a printed circuit board (PCB) device that includes a first trace electrically connected to a first pad of a first trace via on a first layer and a second trace electrically connected to a second pad of a second trace via on a second layer. In some examples, the PCB device also includes four ground pads on the first layer and an antipad surrounding the two trace vias, where a first ground pad is positioned between the first trace and the second trace, where the first ground pad and the second ground pad are approximately symmetrically positioned about a perpendicular bisector of a line from the first pad to the second pad, and wherein the third ground pad and the fourth ground pad are approximately symmetrically positioned about the perpendicular bisector of the line from the first pad to the second pad.
    Type: Grant
    Filed: December 20, 2016
    Date of Patent: March 12, 2019
    Assignee: Juniper Networks, Inc.
    Inventors: David P. Chengson, Edward C. Chang, Ranjeeth Doppalapudi, Santosh Kumar Pappu
  • Patent number: 10069596
    Abstract: In an example of this disclosure, a method may include receiving, by a bit error location analyzer, a split information signal at a second data rate derived from an information signal at a first data rate. In this example, the second data rate is less than the first data rate, and the bit error location analyzer may be incapable of performing error analysis at the first data rate The method may include performing error analysis, by the bit error location analyzer, on information represented by the split information signal. In some examples, performing error analysis may include comparing the information represented by the split information signal to an information seed to determine a plurality of bit error locations in the information represented by the split information signal relative to the information seed.
    Type: Grant
    Filed: December 22, 2016
    Date of Patent: September 4, 2018
    Assignee: Juniper Networks, Inc.
    Inventors: David P. Chengson, Granthana Kattehalli Rangaswamy, David James Ofelt, Edward C. Priest, Bhavesh Patel
  • Patent number: 9237003
    Abstract: In general, techniques are described that insert one or more bits into a digital bit stream to maintain an overall transition density in the digital bit stream. Maintaining the overall transition density facilitates the generation of a recovered clock by a phase-locked loop (PLL) circuit of a receiver. For example, when a data transition ratio for a portion of the digital bit stream is less than a desired data transition ratio, the techniques insert additional bits to increase the overall transition density of the digital bit stream.
    Type: Grant
    Filed: August 5, 2011
    Date of Patent: January 12, 2016
    Assignee: Juniper Networks, Inc.
    Inventors: David P. Chengson, Chang-Hong Wu
  • Publication number: 20130215911
    Abstract: A multi-interface bus allows for different bus standards to be implemented over the same set of physical bus lines. More particularly, in one implementation, the system includes a first circuit board, a second circuit board, and a bus connecting the first and second circuit boards. The second circuit board is configured to communicate with the first circuit board using either a synchronous or an asynchronous bus protocol determined based on a bus protocol used by the first circuit board.
    Type: Application
    Filed: March 22, 2013
    Publication date: August 22, 2013
    Applicant: Juniper Networks, Inc.
    Inventors: David P. Chengson, Jaya Bandyopadhyay
  • Patent number: 8508248
    Abstract: A device provides a time domain reflectometry (TDR) or a vector network analyzer (VNA) test signal to a via test area provided on a printed circuit board (PCB), where the via test area includes vias and via stubs formed in the vias. The device also receives a reflected signal from each via in the via test area of the PCB, and compares the reflected signal from each via to a minimum impedance threshold. The device further provides, for display, an indication of passing for the PCB, when the reflected signals from the vias are greater than the minimum impedance threshold.
    Type: Grant
    Filed: February 10, 2011
    Date of Patent: August 13, 2013
    Assignee: Juniper Networks, Inc.
    Inventor: David P. Chengson
  • Patent number: 8452908
    Abstract: A device applies synchronous clocking across a first component and a second component of the device, and designates a particular serial link, from a group of serial links, as a master serial link. The device also designates the remaining serial links as slave serial links, provides, via the master serial link, an encoded data stream, and provides, via the slave serial links, un-encoded and scrambled data streams.
    Type: Grant
    Filed: December 29, 2009
    Date of Patent: May 28, 2013
    Assignee: Juniper Networks, Inc.
    Inventors: David P. Chengson, Chang-Hong Wu
  • Patent number: 8411695
    Abstract: A multi-interface bus allows for different bus standards to be implemented over the same set of physical bus lines. More particularly, in one implementation, the system includes a first circuit board, a second circuit board, and a bus connecting the first and second circuit boards. The second circuit board is configured to communicate with the first circuit board using either a synchronous or an asynchronous bus protocol determined based on a bus protocol used by the first circuit board.
    Type: Grant
    Filed: May 23, 2005
    Date of Patent: April 2, 2013
    Assignee: Juniper Networks, Inc.
    Inventors: David P. Chengson, Jaya Bandyopadhyay
  • Patent number: 8164392
    Abstract: An isolation switch is used to isolate the output of an oscillator, during startup of the oscillator, from the circuitry that uses the periodic signal generated by the oscillator. In one implementation, a device may include an oscillator to generate a periodic signal and a switch connected to receive an output of the oscillator. The switch may include a control input that controls whether the switch is in an open or closed state. Switch control circuit may control the switch so that the switch is in an open state during startup of the oscillator and the switch is in a closed state thereafter.
    Type: Grant
    Filed: April 26, 2010
    Date of Patent: April 24, 2012
    Assignee: Juniper Networks, Inc.
    Inventors: David P. Chengson, Victor Do
  • Publication number: 20110267073
    Abstract: A system for testing link performance margin in a network device includes one or more daughter cards having a driver to transmit a signal and a receiver to receive the signal, and a midplane including a channel to transmit the signal from the driver to the receiver. The system includes multiple connector assemblies to connect the one or more daughter cards to the midplane, where each of the multiple connector assemblies includes a different known crosstalk margin value. A bit error rate tester is connected to a link between the driver and the receiver, and the multiple connector assemblies are interchangeably included in the link to approximate different signal-to-noise ratio margins for the tested link.
    Type: Application
    Filed: April 29, 2010
    Publication date: November 3, 2011
    Applicant: Juniper Networks, Inc.
    Inventors: David P. CHENGSON, Granthana Rangaswamy
  • Publication number: 20110260769
    Abstract: An isolation switch is used to isolate the output of an oscillator, during startup of the oscillator, from the circuitry that uses the periodic signal generated by the oscillator. In one implementation, a device may include an oscillator to generate a periodic signal and a switch connected to receive an output of the oscillator. The switch may include a control input that controls whether the switch is in an open or closed state. Switch control circuit may control the switch so that the switch is in an open state during startup of the oscillator and the switch is in a closed state thereafter.
    Type: Application
    Filed: April 26, 2010
    Publication date: October 27, 2011
    Applicant: JUNIPER NETWORKS, INC.
    Inventors: David P. CHENGSON, Victor DO
  • Publication number: 20110161544
    Abstract: A device applies synchronous clocking across a first component and a second component of the device, and designates a particular serial link, from a group of serial links, as a master serial link. The device also designates the remaining serial links as slave serial links, provides, via the master serial link, an encoded data stream, and provides, via the slave serial links, un-encoded and scrambled data streams.
    Type: Application
    Filed: December 29, 2009
    Publication date: June 30, 2011
    Applicant: JUNIPER NETWORKS, INC.
    Inventors: David P. Chengson, Chang-Hong Wu
  • Patent number: 5999437
    Abstract: A processor-inclusive memory module (PIMM) is disclosed. In one embodiment of the present invention, the PIMM includes a printed circuit board having first and second opposing surfaces. The printed circuit board also has an address line formed therein. A first SRAM is mounted on the first surface of the printed circuit board. The present PIMM is further comprised of a second SRAM mounted on the second surface of the printed circuit board. The second SRAM is mounted on the second surface of the printed circuit board directly opposite the first SRAM mounted on the first surface of the printed circuit board. The first and second SRAMs are coupled to the address line by respective cache buses. A processor is also mounted on the first surface of the printed circuit board, and is coupled to the address line. In one embodiment of the invention, a heat sink is thermally coupled to the processor. The processor has a plurality of contact pads disposed thereon.
    Type: Grant
    Filed: January 27, 1997
    Date of Patent: December 7, 1999
    Assignee: Silicon Graphics, Inc.
    Inventors: David P. Chengson, William L. Schmidt, Unmesh Agarwala, Alan D. Foster, Edward C. Priest, John C. Manton, Ali Mira
  • Patent number: 5867419
    Abstract: A processor-inclusive memory module (PIMM) is disclosed. In one embodiment of the present invention, the PIMM includes a printed circuit board having first and second opposing surfaces. The printed circuit board also has an address line formed therein. A first SRAM is mounted on the first surface of the printed circuit board. The present PIMM is further comprised of a second SRAM mounted on the second surface of the printed circuit board. The second SRAM is mounted on the second surface of the printed circuit board directly opposite the first SRAM mounted on the first surface of the printed circuit board. The first and second SRAMs are coupled to the address line by respective cache buses. A processor is also mounted on the first surface of the printed circuit board, and is coupled to the address line. In one embodiment of the invention, a heat sink is thermally coupled to the processor. The processor has a plurality of contact pads disposed thereon.
    Type: Grant
    Filed: July 29, 1997
    Date of Patent: February 2, 1999
    Assignee: Silicon Graphics, Inc.
    Inventors: David P. Chengson, William L. Schmidt, Unmesh Agarwala, Alan D. Foster, Edward C. Priest, John C. Manton, Ali Mira
  • Patent number: 5811997
    Abstract: A multi-configurable HSTL/LVCMOS/Open-Drain output driver circuit includes push-pull and open-drain transistors that are selectively enabled/disabled depending upon the desired mode of operation.
    Type: Grant
    Filed: April 26, 1996
    Date of Patent: September 22, 1998
    Assignee: Silicon Graphics, Inc.
    Inventors: David P. Chengson, Robert A. Conrad
  • Patent number: 5790612
    Abstract: The present invention incorporates a variable delay circuit to add delay to a clock signal. In a preferred embodiment of the present invention, the delay is determined and fixed by a circuit employing the concept of a lock-and-leave circuit. This has the effect of fine tuning the delay determined by the lock-and-leave circuit. Mode bits allow a user to control the rate at which fine tuning occurs. Three update rates are provided in a preferred embodiment of the present invention. They are slow, medium, and fast.
    Type: Grant
    Filed: February 29, 1996
    Date of Patent: August 4, 1998
    Assignee: Silicon Graphics, Inc.
    Inventors: David P. Chengson, Hansel A. Collins, Edward C. Priest, Scott W. Alvarez