Patents Assigned to Rambus
  • Patent number: 9215112
    Abstract: A decision-feedback equalizer (DFE) samples an analog input signal against M references during the same symbol time to produce M speculative samples. Select logic in the DFE then decodes N bits resolved previously for previous symbol times to select one of the M speculative samples as the present resolved bit. The present resolved bit is then stored as the most recent previously resolved bit in preparation for the next symbol time. The select logic can be can be programmable to accommodate process, environmental, and systematic variations.
    Type: Grant
    Filed: November 24, 2010
    Date of Patent: December 15, 2015
    Assignee: Rambus Inc.
    Inventors: Brian S. Leibowitz, Jaeha Kim
  • Patent number: 9214219
    Abstract: Described are dynamic, random-access memories (DRAM) architectures and methods for subdividing memory activation into fractions of a page. Circuitry in support of sub-page activation is placed in the intersections of local wordline drivers and sense-amplifier stripes to allow independent control of adjacent arrays of memory cells without significant area overhead.
    Type: Grant
    Filed: August 27, 2012
    Date of Patent: December 15, 2015
    Assignee: Rambus Inc.
    Inventor: Thomas Vogelsang
  • Patent number: 9213657
    Abstract: Techniques for performing fast timing reacquisition of read timing in a memory controller to support rank switching device are described. During operation, a memory controller receives read data for a read operation, wherein the read data includes a calibration preamble. The memory controller uses the calibration preamble to perform a fast timing reacquisition operation to compensate for a timing drift between a clock path and a data path for the read data. In particular, the memory controller performs the fast timing reacquisition by adjusting a data delay line coupled to a clock path associated with a control loop, wherein the control loop controls a data clock which is used to receive read data at the memory controller.
    Type: Grant
    Filed: August 4, 2011
    Date of Patent: December 15, 2015
    Assignee: Rambus Inc.
    Inventors: Jared L. Zerbe, Ian Shaeffer
  • Patent number: 9208836
    Abstract: Integrated circuit devices transmit data via a shared signaling link in back to back burst intervals without contention and without insertion of performance-degrading bubbles by disabling output drivers during an interval that occurs at an edge or “margin” of a given burst interval and thus at a timing boundary between the back to back burst intervals. In “bit-level margining” embodiments, the driver-disabling operation or “margining” is performed during a portion of each bit interval (i.e., a unit of time allocated to transmission of a bit or other symbol. In “burst-level margining” embodiments, output drivers are disabled over an entire bit interval that occurs at the margin of a given burst interval.
    Type: Grant
    Filed: January 9, 2012
    Date of Patent: December 8, 2015
    Assignee: Rambus Inc.
    Inventor: Frederick A. Ware
  • Patent number: 9209966
    Abstract: This disclosure provides a clock recovery circuit having a phase-locked loop (PLL) with two-point modulation. A binary phase-error signal controls a variable frequency oscillator's (VFO's) feedback path, while a linear phase-error signal controls the PLL outside of that feedback path. The linear phase-error signal is injected using an ultra-low latency delay path. While the binary phase-error signal sets the lock-point of the PLL, the linear phase-error path dominates at high frequencies and also helps reduce dither jitter. Other optional features include an area-efficient hybrid phase detector that generates both the binary and linear phase-error signals, use of a phase interpolator inside the PLL to further smooth dither jitter, recovered clock update filtering for specific data transitions, and support for multi-PAM signaling.
    Type: Grant
    Filed: April 15, 2015
    Date of Patent: December 8, 2015
    Assignee: Rambus Inc.
    Inventors: Masum Hossain, Jared L. Zerbe, Myeong-Jae Park
  • Patent number: 9202572
    Abstract: In response to detecting an event during operation of an integrated-circuit memory device containing charge-storing memory cells, an electric current is enabled to flow through a word line coupled to the charge-storing memory cells for a brief interval to heat the charge-storing memory cells to an annealing temperature range.
    Type: Grant
    Filed: December 5, 2013
    Date of Patent: December 1, 2015
    Assignee: Rambus Inc.
    Inventors: Gary B. Bronner, Brent S. Haukness, Mark A. Horowitz, Mark D. Kellam, Fariborz Assaderaghi
  • Patent number: 9195602
    Abstract: A memory system is disclosed comprising a memory controller and a first set of volatile memory devices defining a first memory hierarchy. The first set of volatile memory devices are disposed on at least one first memory module, which is coupled to the memory controller in a daisy-chained configuration. A first integrated circuit buffer device is included on the module. The system has a second set of nonvolatile memory devices defining a second memory hierarchy. The second set of nonvolatile memory devices are disposed on at least one second memory module, which is coupled to the at least one first memory module in a daisy-chained configuration. The second module includes a second integrated circuit buffer device. The system is configured such that signals transmitted between the memory controller and the second memory hierarchy pass through the first memory hierarchy.
    Type: Grant
    Filed: March 19, 2008
    Date of Patent: November 24, 2015
    Assignee: Rambus Inc.
    Inventors: Craig Hampel, Mark Horowitz
  • Publication number: 20150331732
    Abstract: An integrated circuit memory device is disclosed. The memory device includes at least one group of storage cells. Logic derives a count of error code correction events for each of the at least one group of storage cells. Storage stores the count. A memory control interface selectively communicates the count to a memory controller.
    Type: Application
    Filed: May 8, 2015
    Publication date: November 19, 2015
    Applicant: Rambus Inc.
    Inventors: Thomas J. Giovannini, Kurt T. Knorpp
  • Publication number: 20150332746
    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: July 29, 2015
    Publication date: November 19, 2015
    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: 9191243
    Abstract: Described are on-die termination (ODT) systems and methods that facilitate high-speed communication between a driver die and a receiver die interconnected via one or more signal transmission lines. An ODT control system in accordance with one embodiment calibrates and maintains termination resistances and drive currents to produce optimal output swing voltages. Comparison circuitry employed to calibrate the reference resistance is also used to calibrate the drive current. Termination elements in some embodiments are divided into two adjustable resistive portions, both of which are designed to minimize capacitive loading. One portion is optimized to produce a relatively high range of adjustment, while the other is optimized for fine-tuning and glitch-free switching.
    Type: Grant
    Filed: September 25, 2012
    Date of Patent: November 17, 2015
    Assignee: Rambus Inc.
    Inventors: Huy M. Nguyen, Vijay Gadde, Benedict Lau
  • Patent number: 9183166
    Abstract: An expandable memory system that enables a fixed signaling bandwidth to be configurably re-allocated among dedicated memory channels. Memory channels having progressively reduced widths are dedicated to respective memory sockets, thus enabling point-to-point signaling with respect to each memory socket without signal-compromising traversal of unloaded sockets or costly replication of a full-width memory channel for each socket.
    Type: Grant
    Filed: October 4, 2010
    Date of Patent: November 10, 2015
    Assignee: Rambus Inc.
    Inventors: Ian Shaeffer, Arun Vaidyanath, Sanku Mukherjee
  • Patent number: 9183920
    Abstract: The embodiments described herein describe technologies for using the memory modules in different modes of operation, such as in a standard multi-drop mode or as in a dynamic point-to-point (DPP) mode (also referred to herein as an enhanced mode). The memory modules can also be inserted in the sockets of the memory system in different configurations.
    Type: Grant
    Filed: December 19, 2014
    Date of Patent: November 10, 2015
    Assignee: Rambus Inc.
    Inventors: Frederick A. Ware, Suresh Rajan, Scott C. Best
  • Patent number: 9185311
    Abstract: A split-counter architecture is implemented within an image sensor system. A first counter within an image sensor region counts image data from pixel regions within the image sensor region, and outputs the most significant bits of the image data to a second counter external to the image sensor region, reducing the bandwidth required between the image sensor region and the second counter, and reducing the size of the counters within the image sensor region.
    Type: Grant
    Filed: July 29, 2013
    Date of Patent: November 10, 2015
    Assignee: Rambus Inc.
    Inventor: Jie Shen
  • Patent number: 9178726
    Abstract: A multi-phase partial response receiver supports various incoming data rates by sampling PrDFE output values at a selected one of at least two clock phases. The receiver includes a calibration circuit that performs a timing analysis of critical data paths in the circuit, and this analysis is then used to select the particular clock phase used to latch the output values. These techniques permit the multiplexer outputs from for each phase of the partial response receiver to directly drive selection of a multiplexer for the ensuing phase, i.e., by avoiding regions of instability or uncertainty in the respective multiplexer outputs.
    Type: Grant
    Filed: April 15, 2015
    Date of Patent: November 3, 2015
    Assignee: Rambus Inc.
    Inventors: Chintan S. Thakkar, Kun-Yung Chang, Ting Wu
  • Patent number: 9177632
    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: May 18, 2015
    Date of Patent: November 3, 2015
    Assignee: Rambus Inc.
    Inventors: Thomas J. Giovannini, Alok Gupta, Ian Shaeffer, Steven C. Woo
  • Patent number: 9176903
    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: Grant
    Filed: November 7, 2011
    Date of Patent: November 3, 2015
    Assignee: Rambus Inc.
    Inventors: Ian Shaeffer, Frederick A. Ware
  • Patent number: 9178688
    Abstract: A receiver is equipped with an adaptive phase-offset controller and associated timing-calibration circuitry that together shift the timing for a data sampler and a digital equalizer. The sample and equalizer timing is shifted to a position with less residual inter-symbol interference (ISI) energy relative to the current symbol. The shifted position may be calculated using a measure of signal quality, such as a receiver bit-error rate or a comparison of filter-tap values, to optimize the timing of data recovery.
    Type: Grant
    Filed: August 29, 2013
    Date of Patent: November 3, 2015
    Assignee: Rambus Inc.
    Inventors: Qi Lin, Brian Leibowitz, Hae-Chang Lee, Jihong Ren, Kyung Suk Oh, Jared L. Zerbe
  • Patent number: 9177655
    Abstract: A nonvolatile memory device that uses pulsed control and rest periods to mitigate the formation of defect precursors. A first embodiment uses pulsed bitline control, where the coupling between a memory cell channel and a reference voltage is pulsed when it is desired to change state in the associated memory cell. Each pulse may be chosen to be less than about 20 nanoseconds, while a “rest period” between pulses can be on the order of about a hundred nanoseconds or greater. Because bitline control is used, very short rise times can be enabled, enabling generation of pulse durations of 50 nanoseconds or less. In other embodiments, these methods may also be more generally applied to other conductors (e.g., wordline or substrate well, for program or erase operations); segmented wordlines or bitlines may also be used, to minimize RC loading and enable sufficiently short rise times to make pulses robust.
    Type: Grant
    Filed: January 1, 2014
    Date of Patent: November 3, 2015
    Assignee: Rambus Inc.
    Inventors: Mark D. Kellam, Brent Steven Haukness, Gary B. Bronner, Kevin Donnelly
  • Patent number: 9176908
    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: November 23, 2010
    Date of Patent: November 3, 2015
    Assignee: Rambus Inc.
    Inventor: Ian Shaeffer
  • Patent number: 9170364
    Abstract: A lighting assembly includes a light source to emit on-axis light rays at smaller angles relative to an optical axis of the light source, and off-axis light rays at larger angles relative to the optical axis and spectrally different from the on-axis light rays. The lighting assembly additionally includes a light guide having a light input edge adjacent the light source and opposed major surfaces between which light from the light source propagates by total internal reflection. The light input edge has an edge feature aligned with the light source to receive light therefrom. The edge feature specularly redirects the on-axis light rays and the off-axis light rays differently to increase overlap between the on-axis light rays and the off-axis light rays within the light guide. The increased overlap reduces spatial color variation of light extracted from the light guide between locations at different angles from the optical axis.
    Type: Grant
    Filed: December 4, 2013
    Date of Patent: October 27, 2015
    Assignee: Rambus Delaware LLC
    Inventors: Robert M Ezell, Martin E Ligas, Timothy A McCollum, Gregg M Podojil