Patents by Inventor Ian Shaeffer

Ian Shaeffer 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).

  • Publication number: 20180053540
    Abstract: A system has a plurality of memory devices arranged in a fly-by topology, each having on-die termination (ODT) circuitry for connecting to an address and control (RQ) bus. The ODT circuitry of each memory device includes a set of one or more control registers for controlling on-die termination of one or more signal lines of the RQ bus. A first memory device includes a first set of one or more control registers storing a first ODT value, for controlling termination of one or more signal lines of the RQ bus by the ODT circuitry of the first memory device, and a second memory device includes a second set of one or more control registers storing a second ODT value different from the first ODT value, for controlling termination of one or more signal lines of the RQ bus by the ODT circuitry of the second memory device.
    Type: Application
    Filed: July 31, 2017
    Publication date: February 22, 2018
    Inventors: Ian Shaeffer, Kyung Suk Oh
  • Publication number: 20180047436
    Abstract: A memory device comprising a programmable command-and-address (CA) interface and/or a programmable data interface is described. In an operational mode, two or more CA interfaces may be active. In another operational mode, at least one, but not all, CA interfaces may be active. In an operational mode, all of the data interfaces may be active. In another operational mode, at least one, but not all, data interfaces may be active. The memory device can include circuitry to select: an operational mode; a sub-mode within an operational mode; one or more CA interfaces as the active CA interface(s); a main CA interface from multiple active CA interfaces; and/or one or more data interfaces as the active data interfaces. The circuitry may perform these selection(s) based on one or more bits in one or more registers and/or one or more signals received on one or more pins.
    Type: Application
    Filed: June 14, 2017
    Publication date: February 15, 2018
    Applicant: Rambus Inc.
    Inventors: Ian Shaeffer, Lawrence Lai, Fan Ho, David A. Secker, Wayne S. Richardson, Akash Bansal, Brian S. Leibowitz, Kyung Suk Oh
  • Patent number: 9881662
    Abstract: A system that calibrates timing relationships between signals involved in performing write operations is described. This system includes a memory controller which is coupled to a set of memory chips, wherein each memory chip includes a phase detector configured to calibrate a phase relationship between a data-strobe signal and a clock signal received at the memory chip from the memory controller during a write operation. Furthermore, the memory controller is configured to perform one or more write-read-validate operations to calibrate a clock-cycle relationship between the data-strobe signal and the clock signal, wherein the write-read-validate operations involve varying a delay on the data-strobe signal relative to the clock signal by a multiple of a clock period.
    Type: Grant
    Filed: January 13, 2017
    Date of Patent: January 30, 2018
    Assignee: Rambus Inc.
    Inventors: Thomas J. Giovannini, Alok Gupta, Ian Shaeffer, Steven C. Woo
  • Patent number: 9870283
    Abstract: Systems and methods are provided for detecting and correcting address errors in a memory system. In the memory system, a memory device generates an error-detection code based on an address transmitted via an address bus and transmits the error-detection code to a memory controller. The memory controller transmits an error indication to the memory device in response to the error-detection code.
    Type: Grant
    Filed: September 24, 2015
    Date of Patent: January 16, 2018
    Assignee: Rambus Inc.
    Inventors: Ian Shaeffer, Craig E. Hampel
  • Publication number: 20180011805
    Abstract: Apparatus and methods for operation of a memory controller, memory device and system are described. During operation, the memory controller transmits a read command which specifies that a memory device output data accessed from a memory core. This read command contains information which specifies whether the memory device is to commence outputting of a timing reference signal prior to commencing outputting of the data. The memory controller receives the timing reference signal if the information specified that the memory device output the timing reference signal. The memory controller subsequently samples the data output from the memory device based on information provided by the timing reference signal output from the memory device.
    Type: Application
    Filed: April 26, 2017
    Publication date: January 11, 2018
    Inventors: Ian Shaeffer, Thomas J. Giovannini
  • Patent number: 9864707
    Abstract: A memory controller accesses different types of memory devices running at different native rates through the use of a time division multiplexed bus. Data is transferred over the bus at one rate when accessing one type of memory device and at a different rate when accessing another type of memory device. In addition, the memory controller may provide control information (e.g., command and address information) to the different types of memory devices at different rates and, in some cases, time multiplex the control information on a shared bus.
    Type: Grant
    Filed: September 26, 2015
    Date of Patent: January 9, 2018
    Assignee: Rambus Inc.
    Inventor: Ian Shaeffer
  • Patent number: 9865329
    Abstract: Systems, among other embodiments, include topologies (data and/or control/address information) between an integrated circuit buffer device (that may be coupled to a master, such as a memory controller) and a plurality of integrated circuit memory devices. For example, data may be provided between the plurality of integrated circuit memory devices and the integrated circuit buffer device using separate segmented (or point-to-point link) signal paths in response to control/address information provided from the integrated circuit buffer device to the plurality of integrated circuit buffer devices using a single fly-by (or bus) signal path. An integrated circuit buffer device enables configurable effective memory organization of the plurality of integrated circuit memory devices. The memory organization represented by the integrated circuit buffer device to a memory controller may be different than the actual memory organization behind or coupled to the integrated circuit buffer device.
    Type: Grant
    Filed: December 22, 2016
    Date of Patent: January 9, 2018
    Assignee: Rambus Inc.
    Inventors: Ian Shaeffer, Ely Tsern, Craig Hampel
  • Patent number: 9858216
    Abstract: A memory system includes a memory controller coupled to multiple memory devices. Each memory device includes an oscillator that generates an internal reference signal that oscillates at a frequency that is a function of physical device structures within the memory device. The frequencies of the internal reference signals are thus device specific. Each memory device develops a shared reference signal from its internal reference signal and communicates the shared reference signal to the common memory controller. The memory controller uses the shared reference signals to recover device-specific frequency information from each memory device, and then communicates with each memory device at a frequency compatible with the corresponding internal reference signal.
    Type: Grant
    Filed: June 6, 2016
    Date of Patent: January 2, 2018
    Assignee: Rambus Inc.
    Inventors: Scott C. Best, Ian Shaeffer
  • Publication number: 20170372768
    Abstract: An integrated circuit includes a physical layer interface having a control timing domain and a data timing domain, and circuits that enable the control timing domain during a change in power conservation mode in response to a first event, and that enable the data timing domain in response to a second event. The control timing domain can include interface circuits coupled to a command and address path, and the data timing domain can include interface circuits coupled to a data path.
    Type: Application
    Filed: June 7, 2017
    Publication date: December 28, 2017
    Inventors: Ian Shaeffer, Lei Luo, Liji Gopalakrishnan
  • Publication number: 20170371827
    Abstract: A memory device or module selects between alternative command ports. Memory systems with memory modules incorporating such memory devices support point-to-point connectivity and efficient interconnect usage for different numbers of modules. The memory devices and modules can be of programmable data widths. Devices on the same module can be configured select different command ports to facilitate memory threading. Modules can likewise be configured to select different command ports for the same purpose.
    Type: Application
    Filed: July 12, 2017
    Publication date: December 28, 2017
    Inventors: Liji Gopalakrishnan, Ian Shaeffer, Yi Lu
  • Publication number: 20170353184
    Abstract: Local on-die termination controllers for effecting termination of a high-speed signaling links simultaneously engage on-die termination structures within multiple integrated-circuit memory devices disposed on the same memory module, and/or within the same integrated-circuit package, and coupled to the high-speed signaling link. A termination control bus is coupled to memory devices on a module, and provides for peer-to-peer communication of termination control signals.
    Type: Application
    Filed: June 21, 2017
    Publication date: December 7, 2017
    Inventor: Ian Shaeffer
  • Patent number: 9824730
    Abstract: A first timing reference signal and a second timing reference signal are sent to a memory device. The second timing reference signal has approximately a quadrature phase relationship with respect to the first timing reference signal. A plurality of serial data patterns are received from the memory device. The transitions of the first timing reference and the second timing reference determining when transitions occur between the bits of the plurality of data patterns. Timing indicators associated with when received transitions occur between the bits of the plurality of data patterns are received from the memory device. The timing indicators are each measured using a single sampler. Based on the timing indicators, a first duty cycle adjustment for the first timing reference signal, a second duty cycle adjustment for the second timing reference signal, and a quadrature phase adjustment are determined and applied.
    Type: Grant
    Filed: August 4, 2016
    Date of Patent: November 21, 2017
    Assignee: Rambus Inc.
    Inventors: Thomas Giovannini, Scott C Best, Lei Luo, Ian Shaeffer
  • Publication number: 20170315935
    Abstract: A multi-rank memory system in which calibration operations are performed between a memory controller and one rank of memory while data is transferred between the controller and other ranks of memory. A memory controller performs a calibration operation that calibrates parameters pertaining to transmission of data via a first data bus between the memory controller and a memory device in a first rank of memory. While the controller performs the calibration operation, the controller also transfers data with a memory device in a second rank of memory via a second data bus.
    Type: Application
    Filed: April 11, 2017
    Publication date: November 2, 2017
    Inventors: Ian Shaeffer, Frederick A. Ware
  • Patent number: 9734879
    Abstract: A memory device comprising a programmable command-and-address (CA) interface and/or a programmable data interface is described. In an operational mode, two or more CA interfaces may be active. In another operational mode, at least one, but not all, CA interfaces may be active. In an operational mode, all of the data interfaces may be active. In another operational mode, at least one, but not all, data interfaces may be active. The memory device can include circuitry to select: an operational mode; a sub-mode within an operational mode; one or more CA interfaces as the active CA interface(s); a main CA interface from multiple active CA interfaces; and/or one or more data interfaces as the active data interfaces. The circuitry may perform these selection(s) based on one or more bits in one or more registers and/or one or more signals received on one or more pins.
    Type: Grant
    Filed: July 29, 2015
    Date of Patent: August 15, 2017
    Assignee: RAMBUS INC.
    Inventors: Ian Shaeffer, Lawrence Lai, Fan Ho, David A. Secker, Wayne S. Richardson, Akash Bansal, Brian S. Leibowitz, Kyung Suk Oh
  • Patent number: 9734112
    Abstract: A memory device or module selects between alternative command ports. Memory systems with memory modules incorporating such memory devices support point-to-point connectivity and efficient interconnect usage for different numbers of modules. The memory devices and modules can be of programmable data widths. Devices on the same module can be configured select different command ports to facilitate memory threading. Modules can likewise be configured to select different command ports for the same purpose.
    Type: Grant
    Filed: February 23, 2016
    Date of Patent: August 15, 2017
    Assignee: Rambus Inc.
    Inventors: Liji Gopalakrishnan, Ian Shaeffer, Yi Lu
  • Patent number: 9734921
    Abstract: A memory device (100) includes an extra column (114) of repair memory tiles. These repair memory tiles are accessed at the same time, and in the same manner as the main array of memory tiles. The output of the repair column is substituted for the output of a column of the main array (112). The main array column that is substituted is determined by tags (121) stored externally to the memory device. The external tags are queried with a partial address of the access. If the address of the access corresponds to an address in the external tags, the tag information is supplied to the memory device. The tag information determines which column in the main array is replaced by the output of the repair column. Since each column of the main array supplies one bit during the access, the repair column enables cell-by-cell replacement of main array cells.
    Type: Grant
    Filed: October 31, 2013
    Date of Patent: August 15, 2017
    Assignee: Rambus Inc.
    Inventors: Frederick A. Ware, Suresh Rajan, Ian Shaeffer
  • Patent number: 9721629
    Abstract: A system has a plurality of memory devices arranged in a fly-by topology, each having on-die termination (ODT) circuitry for connecting to an address and control (RQ) bus. The ODT circuitry of each memory device includes a set of one or more control registers for controlling on-die termination of one or more signal lines of the RQ bus. A first memory device includes a first set of one or more control registers storing a first ODT value, for controlling termination of one or more signal lines of the RQ bus by the ODT circuitry of the first memory device, and a second memory device includes a second set of one or more control registers storing a second ODT value different from the first ODT value, for controlling termination of one or more signal lines of the RQ bus by the ODT circuitry of the second memory device.
    Type: Grant
    Filed: December 29, 2016
    Date of Patent: August 1, 2017
    Assignee: RAMBUS INC.
    Inventors: Ian Shaeffer, Kyung Suk Oh
  • Publication number: 20170200489
    Abstract: A system that calibrates timing relationships between signals involved in performing write operations is described. This system includes a memory controller which is coupled to a set of memory chips, wherein each memory chip includes a phase detector configured to calibrate a phase relationship between a data-strobe signal and a clock signal received at the memory chip from the memory controller during a write operation. Furthermore, the memory controller is configured to perform one or more write-read-validate operations to calibrate a clock-cycle relationship between the data-strobe signal and the clock signal, wherein the write-read-validate operations involve varying a delay on the data-strobe signal relative to the clock signal by a multiple of a clock period.
    Type: Application
    Filed: January 13, 2017
    Publication date: July 13, 2017
    Inventors: Thomas J. Giovannini, Alok Gupta, Ian Shaeffer, Steven C. Woo
  • Patent number: 9703503
    Abstract: In a reconfigurable data strobe-based memory system, data strobes may be re-tasked in different modes of operation. For example, in one mode of operation a differential data strobe may be used as a timing reference for a given set of data signals. In a second mode of operation, one of the components of the differential data strobe may be used as a timing reference for a first portion of the set of data signals and the other component used as a timing reference for a second portion of the set of data signals. Different data mask-related schemes also may be invoked for different modes of operation. For example, in a first mode of operation a memory controller may generate a data mask signal to prevent a portion of a set of data from being written to a memory array. Then, in a second mode of operation the memory controller may invoke a coded value replacement scheme or a data strobe transition inhibition scheme to prevent a portion of a set of data from being written to a memory array.
    Type: Grant
    Filed: October 8, 2014
    Date of Patent: July 11, 2017
    Assignee: Rambus Inc.
    Inventors: Ian Shaeffer, Frederick Ware, Craig E. Hampel
  • Patent number: 9705498
    Abstract: Local on-die termination controllers for effecting termination of a high-speed signaling links simultaneously engage on-die termination structures within multiple integrated-circuit memory devices disposed on the same memory module, and/or within the same integrated-circuit package, and coupled to the high-speed signaling link. A termination control bus is coupled to memory devices on a module, and provides for peer-to-peer communication of termination control signals.
    Type: Grant
    Filed: June 21, 2016
    Date of Patent: July 11, 2017
    Assignee: Rambus Inc.
    Inventor: Ian Shaeffer