Patents Assigned to Rambus Inc.
  • 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: 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: 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: 11693801
    Abstract: This application is directed to a stacked semiconductor device assembly including a plurality of identical stacked integrated circuit (IC) devices. Each IC device further includes a master interface, a channel master circuit, a slave interface, a channel slave circuit, a memory core, and a modal pad configured to receive a selection signal for the IC device to communicate data using one of its channel master circuit or its channel slave circuit. In some implementations, the IC devices include a first IC device and one or more second IC devices. In accordance with the selection signal, the first IC device is configured to communicate read/write data via the channel master circuit of the first IC device, and each of the one or more second IC devices is configured to communicate respective read/write data via the channel slave circuit of the respective second IC device.
    Type: Grant
    Filed: April 11, 2022
    Date of Patent: July 4, 2023
    Assignee: RAMBUS INC.
    Inventor: Scott C. Best
  • Patent number: 11693447
    Abstract: A circuit and method are provided for setting a phase relationship between a first signal and a second signal having a known frequency relationship to a master signal but having an unknown phase relationship to each other. One or more phase signals is generated based on the master signal, the phase signals having different phases from each other. One of these phase signals is selected based on the phase of the first signal and a target phase delay between the first signal and second signal. The second signal is generated based on the phase and frequency of the selected phase signal.
    Type: Grant
    Filed: January 28, 2022
    Date of Patent: July 4, 2023
    Assignee: RAMBUS INC.
    Inventors: Robert Wang, Zhuobin Li, Navid Yaghini, Hemesh Yasotharan, Clifford Ting
  • 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: 11688441
    Abstract: A memory device includes a set of inputs, and a first register that includes a first register field to store a value for enabling application of one of a plurality of command/address (CA) on-die termination (ODT) impedance values to first inputs that receive the CA signals; a second register field to store a value for enabling application of one of a plurality of chip select (CS) ODT impedance values to a second input that receives the CS signal; and a third register field to store a value for enabling application of a clock (CK) ODT impedance value to third inputs that receive the CK signal. The memory device also includes second and third registers to store values for selecting one of the plurality of CA ODT impedance values and one of the plurality of CS ODT impedance values for application to the first inputs and second input, respectively.
    Type: Grant
    Filed: September 27, 2022
    Date of Patent: June 27, 2023
    Assignee: RAMBUS INC.
    Inventors: Ian Shaeffer, Kyung Suk Oh
  • 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: 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: 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: 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: 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: 11681342
    Abstract: A circuit interface includes one or more processors that generate opcodes, a plurality of interface control circuits, each including a respective processing element responsive to the opcodes generated by one or more processors. Each interface control circuit corresponds to a respective link of a plurality of links of a device-to-device interface (DDI), and each link of the plurality of links of the DDI is for transmitting or receiving signals from one or more sources or one or more destinations external to the circuit.
    Type: Grant
    Filed: January 4, 2021
    Date of Patent: June 20, 2023
    Assignee: RAMBUS INC.
    Inventor: Stephen G. Tell
  • 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: 11675657
    Abstract: A memory system employs an addressing scheme to logically divide rows of memory cells into separate contiguous regions, one for data storage and another for error detection and correction (EDC) codes corresponding to that data. Data and corresponding EDC codes are stored in the same row of the same bank. Accessing data and corresponding EDC code in the same row of the same bank advantageously saves power and avoids bank conflicts. The addressing scheme partitions the memory without requiring the requesting processor to have an understanding of the memory partition.
    Type: Grant
    Filed: April 15, 2022
    Date of Patent: June 13, 2023
    Assignee: Rambus Inc.
    Inventors: Frederick A. Ware, John E. Linstadt, Liji Gopalakrishnan
  • 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: 11677487
    Abstract: In a general aspect, a network transmission interface can include, within an egress data path, a physical coding sublayer (PCS) operating in a constant bitrate domain for transmitting data frames on a network link; a timestamp unit configured to insert timestamps in payloads of the frames; a transmission media access control (MAC) unit located at a boundary between the constant bitrate domain and a variable bitrate domain, configured to receive the frames at a variable bitrate, encapsulate the frames, and provide the encapsulated frames at a constant bitrate; a MAC layer security unit located downstream from the timestamp unit, configured to sign and optionally encrypt the payloads and expand each frame with a security tag and an integrity check value (ICV). The timestamp unit and the MAC layer security unit (26b) can both operate in the constant bitrate domain.
    Type: Grant
    Filed: June 28, 2021
    Date of Patent: June 13, 2023
    Assignee: Rambus Inc.
    Inventor: Maksym Demchenko
  • 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
  • Patent number: 11671108
    Abstract: Disclosed is a successive approximation register (SAR) analog to digital converter (ADC) that uses two or more comparators. This allows the output of one comparator to be latched while the other comparators are comparing and switching. Statistical measures are used to correct the offsets of one or more of the comparators. If a statistically significant mismatch in the number of 1's and 0's occurs in a subset of the bits, adjustments to the offsets of one or more of the comparators are made until there is roughly an equal number of 1 and 0 values. This can reduce or eliminate the need for dedicated offset correction cycles.
    Type: Grant
    Filed: April 25, 2022
    Date of Patent: June 6, 2023
    Assignee: Rambus Inc.
    Inventors: Kenneth C. Dyer, Marcus Van Ierssel