Patents Assigned to Rambus
  • Patent number: 11238003
    Abstract: The timing of the synchronous interface is controlled by a clock signal driven by a controller. The clock is toggled in order to send a command to a memory device via the interface. If there are no additional commands to be sent via the interface, the controller suspends the clock signal. When the memory device is ready, the memory device drives a signal back to the controller. The timing of this signal is not dependent upon the clock signal. Receipt of this signal by the controller indicates that the memory device is ready and the clock signal should be resumed so that a status of the command can be returned via the interface, or another command issued via the interface.
    Type: Grant
    Filed: January 6, 2020
    Date of Patent: February 1, 2022
    Assignee: Rambus Inc.
    Inventor: Yuanlong Wang
  • Patent number: 11239855
    Abstract: A capacitor-based digital-to-analog-converter produces a level-shifted analog outputs by precharging respective sets of output-generating capacitors to different applied potentials and then floating a common output of the sets of capacitors such that charge is redistributed among the capacitors through the common output to yield, across all the capacitors, a uniform precharge voltage that falls between the different applied potentials.
    Type: Grant
    Filed: February 3, 2021
    Date of Patent: February 1, 2022
    Assignee: Rambus Inc.
    Inventor: Shankar Tangirala
  • Patent number: 11239827
    Abstract: Disclosed is receiver for a noise limited system. A front-end circuit amplifies and band-limits an incoming signal. The amplification increases the signal swing but introduces both thermal and flicker noise. A low-pass band limitation reduces the thermal noise component present at frequencies above what is necessary for correctly receiving the transmitted symbols. This band limited signal is provided to the integrator circuit. The output of the integrator is equalized to reduce the effects of inter-symbol interference and then sampled. The samples are used to apply low frequency equalization (i.e., in response to long and/or unbalanced strings of symbols) to mitigate the effects of DC wander caused by mismatches between the number of symbols of each kind being received.
    Type: Grant
    Filed: November 19, 2020
    Date of Patent: February 1, 2022
    Assignee: Rambus Inc.
    Inventors: Masum Hossain, Carl W. Werner
  • Patent number: 11233678
    Abstract: A high-speed signaling system with adaptive transmit pre-emphasis. A transmit circuit has a plurality of output drivers to output a first signal onto a signal path. A receive circuit is coupled to receive the first signal via the signal path and configured to generate an indication of whether the first signal exceeds a threshold level. A first threshold control circuit is coupled to receive the indication from the receive circuit and configured to adjust the threshold level according to whether the first signal exceeds the threshold level. A drive strength control circuit is coupled to receive the indication from the receive circuit and configured to adjust a drive strength of at least one output driver of the plurality of output drivers according to whether the first signal exceeds the threshold level.
    Type: Grant
    Filed: August 21, 2020
    Date of Patent: January 25, 2022
    Assignee: Rambus Inc.
    Inventors: Vladimir M. Stojanovic, Andrew C. Ho, Anthony Bessios, Fred F. Chen, Elad Alon, Mark A. Horowitz
  • Patent number: 11233589
    Abstract: Described are methods and circuits for margin testing digital receivers. These methods and circuits prevent margins from collapsing in response to erroneously received data and can thus be used in receivers that employ historical data to reduce intersymbol interference (ISI). Some embodiments detect receive errors for input data streams of unknown patterns and can thus be used for in-system margin testing. Such systems can be adapted to dynamically alter system parameters during device operation to maintain adequate margins despite fluctuations in the system noise environment due to e.g. temperature and supply-voltage changes. Also described are methods of plotting and interpreting filtered and unfiltered error data generated by the disclosed methods and circuits. Some embodiments filter error data to facilitate pattern-specific margin testing.
    Type: Grant
    Filed: November 24, 2020
    Date of Patent: January 25, 2022
    Assignee: Rambus Inc.
    Inventors: Andrew Ho, Vladimir Stojanovic, Bruno W. Garlepp, Fred F. Chen
  • Patent number: 11232047
    Abstract: A memory system includes a dynamic random access memory (DRAM) device, a second memory device, and a memory controller circuit. The memory controller circuit is coupled to the DRAM device by a first data channel configured to transfer first data between the memory controller circuit and the DRAM device on behalf of a host, and is also coupled to the DRAM device by a second data channel configured to transfer second data between the memory controller circuit and the DRAM device on behalf of the second memory device while the first data is being transferred across the first data channel.
    Type: Grant
    Filed: May 13, 2020
    Date of Patent: January 25, 2022
    Assignee: Rambus Inc.
    Inventor: Liji Gopalakrishnan
  • Patent number: 11226897
    Abstract: Disclosed herein are techniques for implementing hybrid memory modules with improved inter-memory data transmission paths. The claimed embodiments address the problem of implementing a hybrid memory module that exhibits improved transmission latencies and power consumption when transmitting data between DRAM devices and NVM devices (e.g., flash devices) during data backup and data restore operations. Some embodiments are directed to approaches for providing a direct data transmission path coupling a non-volatile memory controller and the DRAM devices to transmit data between the DRAM devices and the flash devices. In one or more embodiments, the DRAM devices can be port switched devices, with a first port coupled to the data buffers and a second port coupled to the direct data transmission path. Further, in one or more embodiments, such data buffers can be disabled when transmitting data between the DRAM devices and the flash devices.
    Type: Grant
    Filed: April 23, 2020
    Date of Patent: January 18, 2022
    Assignee: Rambus Inc.
    Inventor: Aws Shallal
  • Patent number: 11226909
    Abstract: Memory controllers, devices, modules, systems and associated methods are disclosed. In one embodiment, an integrated circuit (IC) memory device is disclosed. The memory device includes an array of storage cells and command interface circuitry to receive an internal transfer command. In response to the internal transfer command, transfer logic reads data from a first portion of the array of storage cells, transfers the data as on-chip transfer data, and writes the on-chip transfer data to a second portion of the array of storage cells. In response to the command interface circuitry receiving an interrupt command, the transfer logic pauses the internal transfer operation, and carries out an unrelated memory access operation involving at least the first portion of the array of storage cells or the second portion of the array of storage cells.
    Type: Grant
    Filed: August 20, 2019
    Date of Patent: January 18, 2022
    Assignee: Rambus Inc.
    Inventors: Liji Gopalakrishnan, Frederick A. Ware, Brent S. Haukness
  • Patent number: 11226766
    Abstract: A buffer circuit includes a primary interface, a secondary interface, and an encoder/decoder circuit. The primary interface is configured to communicate on an n-bit channel, wherein n parallel bits on the n-bit channel are coded using data bit inversion (DBI). The secondary interface is configured to communicate with a plurality of integrated circuit devices on a plurality of m-bit channels, each m-bit channel transmitting m parallel bits without using DBI. And the encoder/decoder circuit is configured to translate data words between the n-bit channel of the primary interface and the plurality of m-bit channels of the secondary interface.
    Type: Grant
    Filed: August 12, 2020
    Date of Patent: January 18, 2022
    Assignee: Rambus Inc.
    Inventor: Scott C. Best
  • Patent number: 11227639
    Abstract: A memory device includes a first dynamic random access memory (DRAM) integrated circuit (IC) chip including first memory core circuitry, and first input/output (I/O) circuitry. A second DRAM IC chip is stacked vertically with the first DRAM IC chip. The second DRAM IC chip includes second memory core circuitry, and second I/O circuitry. Solely one of the first DRAM IC chip or the second DRAM IC chip includes a conductive path that electrically couples at least one of the first memory core circuitry or the second memory core circuitry to solely one of the first I/O circuitry or the second I/O circuitry, respectively.
    Type: Grant
    Filed: December 28, 2020
    Date of Patent: January 18, 2022
    Assignee: Rambus Inc.
    Inventor: Thomas Vogelsang
  • Patent number: 11210242
    Abstract: Memory controllers, devices, modules, systems and associated methods are disclosed. In one embodiment, a memory module includes a pin interface for coupling to a bus. The bus has a first width. The module includes at least one storage class memory (SCM) component and at least one DRAM component. The memory module operates in a first mode that utilizes all of the first width, and in a second mode that utilizes less than all of the first width.
    Type: Grant
    Filed: May 29, 2020
    Date of Patent: December 28, 2021
    Assignee: Rambus Inc.
    Inventors: Frederick A. Ware, Kenneth L. Wright, John Eric Linstadt, Craig Hampel
  • Patent number: 11211105
    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: August 6, 2020
    Date of Patent: December 28, 2021
    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: 11210244
    Abstract: A memory controller interfaces with one or more memory devices having configurable width data buses and configurable connectivity between data pins of the memory devices and data pins of the memory controller. Upon initialization of the memory devices, the memory controller automatically discovers the connectivity configuration of the one or more memory devices, including both individually selected and jointly selected devices. After discovering connectivity of the connected devices, the memory controller configures the memory devices according to the discovered connectivity and assigns unique addresses to jointly selected devices.
    Type: Grant
    Filed: April 8, 2020
    Date of Patent: December 28, 2021
    Assignee: Rambus Inc.
    Inventor: John Eric Linstadt
  • Patent number: 11211139
    Abstract: The disclosed embodiments relate to components of a memory system that support timing-drift calibration. In specific embodiments, this memory system contains a memory device (or multiple devices) which includes a clock distribution circuit and an oscillator circuit which can generate a frequency, wherein a change in the frequency is indicative of a timing drift of the clock distribution circuit. The memory device also includes a measurement circuit which is configured to measure the frequency of the oscillator circuit.
    Type: Grant
    Filed: March 19, 2020
    Date of Patent: December 28, 2021
    Assignee: Rambus Inc.
    Inventors: Yohan U. Frans, Wayne F. Ellis, Akash Bansal
  • Patent number: 11210240
    Abstract: System and method for improved transferring of data involving memory device systems. A memory appliance (MA) comprising a plurality of memory modules is configured to store data within the plurality of memory modules and further configured to receive data commands from the first server and a second server coupled to the MA. The data commands may include direction memory access commands such that the MA can service the data commands while bypassing a host controller of the MA.
    Type: Grant
    Filed: October 7, 2019
    Date of Patent: December 28, 2021
    Assignee: Rambus Inc.
    Inventors: Vlad Fruchter, Keith Lowery, George Michael Uhler, Steven Woo, Chi-Ming (Philip) Yeung, Ronald Lee
  • Patent number: 11211114
    Abstract: A memory system includes dynamic random-access memory (DRAM) components that include interconnected and redundant component data interfaces. The redundant interfaces facilitate memory interconnect topologies that accommodate considerably more DRAM components per memory channel than do traditional memory systems, and thus offer considerably more memory capacity per channel, without concomitant reductions in signaling speeds. Each DRAM component includes multiplexers that allow either of the data interfaces to write data to or read data from a common set of memory banks, and to selectively relay write and read data to and from other components, bypassing the local banks. Delay elements can impose selected read/write delays to align read and write transactions from and to disparate DRAM components.
    Type: Grant
    Filed: July 3, 2019
    Date of Patent: December 28, 2021
    Assignee: Rambus Inc.
    Inventors: Frederick A. Ware, Ely K. Tsern, John E. Linstadt, Thomas J. Giovannini, Scott C. Best, Kenneth L. Wright
  • Patent number: 11211960
    Abstract: Decision feedback equalization (DFE) is used to help reduce inter-symbol interference (ISI) from a data signal received via a band-limited (or otherwise non-ideal) channel. A first PAM-4 DFE architecture has low latency from the output of the samplers to the application of the first DFE tap feedback to the input signal. This is accomplished by not decoding the sampler outputs in order to generate the feedback signal for the first DFE tap. Rather, weighted versions of the raw sampler outputs are applied directly to the input signal without further analog or digital processing. Additional PAM-4 DFE architectures use the current symbol in addition to previous symbol(s) to determine the DFE feedback signal. Another architecture transmits PAM-4 signaling using non-uniform pre-emphasis. The non-uniform pre-emphasis allows a speculative DFE receiver to resolve the transmitted PAM-4 signals with fewer comparators/samplers.
    Type: Grant
    Filed: December 8, 2020
    Date of Patent: December 28, 2021
    Assignee: Rambus Inc.
    Inventors: Masum Hossain, Nhat Nguyen, Yikui Jen Dong, Arash Zargaran-Yazd, Wendemagegnehu Beyene
  • Patent number: 11206020
    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: May 21, 2020
    Date of Patent: December 21, 2021
    Assignee: Rambus Inc.
    Inventor: Ian Shaeffer
  • Patent number: 11206031
    Abstract: A phase rotator receives control signals and thermometer coded signals that specifies the phase of an output signal. The phase rotator may be used, for example, by a clock and data recovery (CDR) circuit to continually rotate the phase of a clock to compensate for phase/frequency mismatches between received data and the clock. The control signals determine the phase quadrant (i.e., 0°-90°, 90°-180°, etc.) of the output signal. The thermometer coded signals determine the phase of the output signal within a quadrant by steering a set of bias currents between two or more nodes. The set of bias currents are selected to reduce the non-linearity between the thermometer coded value and the phase of the output signal.
    Type: Grant
    Filed: October 28, 2020
    Date of Patent: December 21, 2021
    Assignee: Rambus Inc.
    Inventors: Marcus Van Ierssel, Dominic DiClemente
  • Patent number: 11204825
    Abstract: A memory device is disclosed that includes a row of storage locations that form plural columns. The plural columns include data columns to store data and a tag column to store tag information associated with error locations in the data columns. Each data column is associated with an error correction location including an error code bit location. Logic retrieves and stores the tag information associated with the row in response to activation of the row. A bit error in an accessed data column is repaired by a spare bit location based on the tag information.
    Type: Grant
    Filed: February 13, 2020
    Date of Patent: December 21, 2021
    Assignee: Rambus Inc.
    Inventors: Frederick A. Ware, Brent Haukness