Patents Assigned to Rambus Inc.
  • Patent number: 11720485
    Abstract: A memory device having a DRAM core and a register stores first data in the register before receiving first and second memory access commands via a command interface and before receiving second data via a data interface. The memory device responds to the first memory access command by writing the first data from the register to the DRAM core and responds to the second memory access command by writing the second data from the data interface to the DRAM core.
    Type: Grant
    Filed: April 25, 2022
    Date of Patent: August 8, 2023
    Assignee: Rambus Inc.
    Inventors: Thomas J. Sheffler, Lawrence Lai, Liang Peng, Bohuslav Rychlik
  • Patent number: 11714752
    Abstract: A hybrid volatile/non-volatile memory module employs a relatively fast, durable, and expensive dynamic, random-access memory (DRAM) cache to store a subset of data from a larger amount of relatively slow and inexpensive nonvolatile memory (NVM). A module controller prioritizes accesses to the DRAM cache for improved speed performance and to minimize programming cycles to the NVM. Data is first written to the DRAM cache where it can be accessed (written to and read from) without the aid of the NVM. Data is only written to the NVM when that data is evicted from the DRAM cache to make room for additional data. Mapping tables relating NVM addresses to physical addresses are distributed throughout the DRAM cache using cache line bits that are not used for data.
    Type: Grant
    Filed: March 23, 2022
    Date of Patent: August 1, 2023
    Assignee: Rambus Inc.
    Inventors: Frederick A. Ware, John Eric Linstadt, Christopher Haywood
  • Patent number: 11709736
    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. The memory components can be configured to route data around defective data connections to maintain full capacity and continue to support memory transactions.
    Type: Grant
    Filed: June 22, 2021
    Date of Patent: July 25, 2023
    Assignee: Rambus Inc.
    Inventors: Kenneth L. Wright, Frederick A. Ware
  • Patent number: 11709525
    Abstract: A memory system in which a timing drift that would occur in distribution of a first timing signal for data transport in a memory device is determined by measuring the actual phase delays occurring in a second timing signal that has a frequency lower than that of the first timing signal and is distributed in one or more circuits mimicking the drift characteristics of at least a portion of distribution of the first timing signal. The actual phase delays are determined in the memory device and provided to a memory controller so that the phases of the timing signals used for data transport may be adjusted based on the determined timing drift.
    Type: Grant
    Filed: June 1, 2022
    Date of Patent: July 25, 2023
    Assignee: Rambus Inc.
    Inventors: Jun Kim, Pak Shing Chau, Wayne S. Richardson
  • Patent number: 11711246
    Abstract: A driver circuit of a PAM-N transmitting device transmits a PAM-N signal via a communication channel, wherein N is greater than 2, and the PAM-N signal has N signal levels corresponding to N symbols. A PAM-N receiving device receives the PAM-N signal. The PAM-N receiving device generates distortion information indicative of a level of distortion corresponding to inequalities in voltage differences between the N signal levels. The PAM-N receiving device transmits to the PAM-N transmitting device the distortion information indicative of the level of the distortion. The PAM-N transmitting device receives the distortion information. The PAM-N transmitting device adjusts one or more drive strength parameters of the driver circuit of the PAM-N transmitting device based on the distortion information.
    Type: Grant
    Filed: April 1, 2022
    Date of Patent: July 25, 2023
    Assignee: Rambus Inc.
    Inventor: Reza Navid
  • Patent number: 11710520
    Abstract: A memory module with multiple memory devices includes a buffer system that manages communication between a memory controller and the memory devices. Each memory device supports an access mode and a low-power mode, the latter used to save power for devices that are not immediately needed. The module provides granular power management using a chip-select decoder that decodes chip-select signals from the memory controller into power-state signals that determine which of the memory devices are in which of the modes. Devices can thus be brought out of the low-power mode in relatively small numbers, as needed, to limit power consumption.
    Type: Grant
    Filed: March 23, 2022
    Date of Patent: July 25, 2023
    Assignee: Rambus Inc.
    Inventors: Frederick A. Ware, James E. Harris
  • Patent number: 11706060
    Abstract: A serial receiver combines continuous-time equalization, analog interleaving, and discrete-time gain for rapid, efficient data reception and quantization of a serial, continuous-time signal. A continuous-time equalizer equalizes a received signal. A number N of time-interleaved analog samplers sample the equalized continuous-time signal to provide N streams of analog samples transitioning at rate reduced by 1/N relative to the received signal. A set of N discrete-time variable-gain amplifiers amplify respective streams of analog samples. A quantizer then quantizes the amplified streams of analog samples to produce a digital signal.
    Type: Grant
    Filed: August 30, 2021
    Date of Patent: July 18, 2023
    Assignee: Rambus Inc.
    Inventors: Haidang Lin, Charles Walter Boecker, Masum Hossain
  • Patent number: 11705903
    Abstract: The embodiments herein describe technologies for back-gate biasing of clock trees using a reference generator. A circuit includes a set of clock buffers and a programmable voltage reference generator to apply a voltage to a back gate of a transistor of the set of clock buffers.
    Type: Grant
    Filed: November 15, 2021
    Date of Patent: July 18, 2023
    Assignee: Rambus Inc.
    Inventors: Alain Rousson, Hui Song, Ravi Shivnaraine, Christopher Holdenried, Hector Villacorta
  • Patent number: 11705187
    Abstract: Described are memory modules that support different error detection and correction (EDC) schemes in both single- and multiple-module memory systems. The memory modules are width configurable and support the different EDC schemes for relatively wide and narrow module data widths. Data buffers on the modules support the half-width and full-width modes, and also support time-division-multiplexing to access additional memory components on each module in support of enhanced EDC.
    Type: Grant
    Filed: October 14, 2021
    Date of Patent: July 18, 2023
    Assignee: Rambus Inc.
    Inventors: Frederick A. Ware, John Eric Linstadt, Kenneth L. Wright
  • Patent number: 11706061
    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: January 11, 2022
    Date of Patent: July 18, 2023
    Assignee: Rambus Inc.
    Inventors: Vladimir M. Stojanovic, Andrew C. Ho, Anthony Bessios, Fred F. Chen, Elad Alon, Mark A. Horowitz
  • Patent number: 11687247
    Abstract: Disclosed herein are techniques for implementing high-throughput low-latency hybrid memory modules with improved data backup and restore throughput, enhanced non-volatile memory controller (NVC) resource access, and enhanced mode register setting programmability. Embodiments comprise a command replicator to generate sequences of one or more DRAM read and/or write and/or other commands to be executed in response to certain local commands from a non-volatile memory controller (NVC) during data backup and data restore operations. Other embodiments comprise an access engine to enable an NVC in a host control mode to trigger entry into a special mode and issue commands to access a protected register space. Some embodiments comprise a mode register controller to capture and store the data comprising mode register setting commands issued during a host control mode, such that an NVC can program the DRAM mode registers in an NVC control mode.
    Type: Grant
    Filed: June 4, 2021
    Date of Patent: June 27, 2023
    Assignee: Rambus Inc.
    Inventors: Aws Shallal, Michael Miller, Stephen Horn
  • Patent number: 11689246
    Abstract: A single-ended data transmission system transmits a signal having a signal voltage that is referenced to a power supply voltage and that swings above and below the power supply voltage. The power supply voltage is coupled to a power supply rail that also serves as a signal return path. The signal voltage is derived from two signal supply voltages generated by a pair of charge pumps that draw substantially same amount of current from a power supply.
    Type: Grant
    Filed: June 22, 2021
    Date of Patent: June 27, 2023
    Assignee: Rambus Inc.
    Inventors: John W. Poulton, Frederick A. Ware, Carl W. Werner
  • Patent number: 11683057
    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: November 16, 2021
    Date of Patent: June 20, 2023
    Assignee: Rambus Inc.
    Inventors: Masum Hossain, Nhat Nguyen, Yikui Jen Dong, Arash Zargaran-Yazd, Wendemagegnehu Beyene
  • Patent number: 11681648
    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: December 22, 2021
    Date of Patent: June 20, 2023
    Assignee: Rambus Inc.
    Inventor: Yuanlong Wang
  • Patent number: 11682448
    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: June 28, 2022
    Date of Patent: June 20, 2023
    Assignee: Rambus Inc.
    Inventors: Thomas J. Giovannini, Alok Gupta, Ian Shaeffer, Steven C. Woo
  • Patent number: 11683050
    Abstract: Memory controllers, devices and associated methods are disclosed. In one embodiment, a memory controller includes write circuitry to transmit write data to a memory device, the write circuitry includes a write error detection correction (EDC) encoder to generate first error information associated with the write data. Data bus inversion (DBI) circuitry conditionally inverts data bits associated with each of the write data words based on threshold criteria. Read circuitry receives read data from the memory device. The read circuitry includes a read EDC encoder to generate second error information associated with the received read data. Logic evaluates the first and second error information and conditionally reverse-inverts at least a portion of the read data based on the decoding.
    Type: Grant
    Filed: May 13, 2022
    Date of Patent: June 20, 2023
    Assignee: Rambus Inc.
    Inventors: Frederick A. Ware, John Eric Linstadt
  • Patent number: 11683206
    Abstract: A multi-PAM equalizer receives an input signal distorted by inter-symbol interference (ISI) and expressing a series of symbols each representing one of four pulse amplitudes to convey two binary bits of data per symbol. High-order circuitry resolves the most-significant bit (MSB) of each two-bit symbol, whereas low-order circuitry 115 resolves the immediate least-significant bit (LSB). The MSB is used without the LSB for timing recovery and to calculate tap values for both MSB and LSB evaluation.
    Type: Grant
    Filed: May 18, 2021
    Date of Patent: June 20, 2023
    Assignee: Rambus Inc.
    Inventors: Masum Hossain, Nhat Nguyen, Charles Walter Boecker
  • Patent number: 11681632
    Abstract: A memory controller includes logic circuitry to generate a first data address identifying a location in a first external memory array for storing first data, a first tag address identifying a location in a second external memory array for storing a first tag, a second data address identifying a location in the second external memory array for storing second data, and a second tag address identifying a location in the first external memory array for storing a second tag. The memory controller includes an interface that transfers the first data address and the first tag address for a first set of memory operations in the first and the second external memory arrays. The interface transfers the second data address and the second tag address for a second set of memory operations in the first and the second external memory arrays.
    Type: Grant
    Filed: October 6, 2020
    Date of Patent: June 20, 2023
    Assignee: Rambus Inc.
    Inventor: Frederick A. Ware
  • Patent number: 11677571
    Abstract: A physically unclonable function circuit (PUF) is used to generate a fingerprint value based on the uniqueness of the physical characteristics (e.g., resistance, capacitance, connectivity, etc.) of a tamper prevention (i.e., shielding) structure that includes through-silicon vias and metallization on the backside of the integrated circuit. The physical characteristics depend on random physical factors introduced during manufacturing. This causes the chip-to-chip variations in these physical characteristics to be unpredictable and uncontrollable which makes more difficult to duplicate, clone, or modify the structure without changing the fingerprint value. By including the through-silicon vias and metallization on the backside of the integrated circuit as part of the PUF, the backside of the chip can be protected from modifications that can be used to help learn the secure cryptographic keys and/or circumvent the secure cryptographic (or other) circuitry.
    Type: Grant
    Filed: November 30, 2017
    Date of Patent: June 13, 2023
    Assignee: Rambus Inc.
    Inventor: Scott C. Best
  • Patent number: 11677391
    Abstract: A latency controller within an integrated circuit device retimes command-stream-triggered control and timing signals into endpoint timing domains having respective time-varying phase offsets relative to a reference clock by iteratively estimating and logging the phase offsets independently of commands streaming into the integrated circuit device.
    Type: Grant
    Filed: January 26, 2022
    Date of Patent: June 13, 2023
    Assignee: Rambus Inc.
    Inventors: Robert E. Palmer, Andrew M. Fuller, William F. Stonecypher