Rambus Inc.

Intel Corporation

Thomas J Giovannini

Ian P Shaeffer

John Eric Linstadt

Frederick Abbott Ware

Scott C Best

Steven Cameron Woo

Alok Gupta

Chi-Ming Yeung

Henry Stracovsky

Yoshie Nakabayashi

Ely K Tsern

Catherine Yuhjung Chen

Kenneth Lee Wright

Lei Luo

Abhijit Mukun Abhyankar

Andrew M Fuller

Robert E Palmer

Michael D Bucher

Thoai Thai Le

Catherine Chen

Craig Edward Hampel

John Yan

Huy M Nguyen

Masum Hossain

Vijay Gadde

David A Secker

Kambiz Kaviani

Ming Li

Ravindranath T Kollipara

Barry William Daly

Todd W Bystrom

Donald R Mullen

Arun Vaidyanath

Craig Schulz

Song Quan Shang

Gevorg Nahapetian

Chih-Hao Chen

Adrian F Torres

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.

Protocol including selective output by memory of a timing reference signal

Described are integrated circuits for equalizing parallel write-data and address signals from a memory controller. The integrated circuits each include a set of decision-feedback equalizers, one equalizer for each received signal. Each equalizer in a set has a main sampler and a monitor sampler, each of which samples the respective input signal on edges of a timing-reference signal (e.g. a clock or strobe) that is common to the set. The main sampler samples the input signal relative to a reference. The monitor sampler samples the input signal relative to an adjustable threshold calibrated to monitor one or more levels of the input signal. A feedback network adjusts the respective input signal responsive to one or more tap values that can be adjusted to equalize the signal. An adaptive tap-value generator for one or a collection of the equalizers adjusts the tap value or values as a function of least-mean squares of errors to one or more of the sampler input ports.

Circuits and methods for self-adaptive decision-feedback equalization in a memory system

Described are motherboards with memory-module sockets that accept legacy memory modules for backward compatibility or accept a greater number of configurable modules in support of increased memory capacity. The configurable modules can be backward compatible with legacy motherboards. Equipped with the configurable modules, the motherboards support memory systems with high signaling rates and capacities.

High-performance, high-capacity memory systems and modules

During system initialization, each data buffer device and/or memory device on a memory module is configured with a unique (at least to the module) device identification number. In order to access a single device (rather than multiple buffers and/or memory devices), a target identification number is written to all of the devices using a command bus connected to all of the data buffer devices or memory devices, respectively. The devices whose respective device identification numbers do not match the target identification number are configured to ignore future command bus transactions (at least until the debug mode is turned off.) The selected device that is configured with a device identification number matching the target identification number is configured to respond to command bus transactions.

Memory module register access

A memory system supports single- and dual-memory-module configurations, both supporting point-to-point communication between a host (e.g., a memory controller) and the memory module or modules. Each memory module includes an address-buffer component, data-buffer components, and two sets of memory dies, each set termed a 'timing rank,' that can be accessed independently. The one memory module is configured in a wide mode for the single-memory-module configuration, in which case both timing ranks work together, as a “package rank,” to communicate full-width data. Each of two memory modules are configured in a narrow mode for the dual-memory-module configuration, in which case one timing rank from each memory module communicates data in parallel to appear to the host as single package ranks. The data-buffer components support separate and configurable write and read delays for the different timing ranks on each module to provide read and write leveling within and between memory modules.

Memory modules and systems with variable-width data ranks and configurable data-rank timing

System and method for training and performing operations (e.g., read and write operations) on a double buffered memory topology. In some embodiments, eight DIMMs are coupled to a single channel. The training and operations schemes are configured with timing and signaling to allow training and operations with the double buffered memory topology. In some embodiments, the double buffered memory topology includes one or more buffers on a system board (e.g., motherboard).

Training and operations with a double buffered memory topology

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.

Method and apparatus for calibrating write timing in a memory system

A first-in-first-out (FIFO) storage structure within an integrated-circuit component is loaded with qualification values corresponding to respective pairs of edges expected within a timing strobe signal transmitted to the integrated-circuit component. The qualification values are sequentially output from the FIFO storage structure during respective cycles of the timing strobe signal and a gate signal is either asserted or deasserted during the respective cycles of the timing strobe signal according to the qualification values output from the FIFO storage structure.

Signal receiver with skew-tolerant strobe gating

A first sequence of data bits is shifted into storage elements of a signal receiver during a first sequence of bit-time intervals, and a memory access command indicates that a second sequence of data bits is to be received within the signal receiver during a second sequence of bit-time intervals. Contents of the shift-register storage elements are conditionally overwritten with a predetermined set of seed bits, depending on whether one or more bit-time intervals will transpire between the first and second sequences of bit-time intervals. Equalization signals generated based, at least in part, on contents of the shift-register storage elements are used to adjust respective signal levels representative of one or more bits of the second sequence of data bits.

Burst-tolerant decision feedback equalization

A mother board topology including a processor operable to be coupled to one or more communication channels for communicating commands. The topology includes a first communication channel electrically coupling a first set of two or more dual in-line memory modules (DIMMs) and a first primary data buffer on a mother board. The topology includes a second communication channel electrically coupling a second set of two or more DIMMs and a second primary data buffer on the mother board. The topology includes a third channel electrically coupling the first primary data buffer, the primary second data buffer, and the processor.

Memory system design using buffer(s) on a mother board

The embodiments described herein describe technologies of dynamic random access memory (DRAM) components for high-performance, high-capacity registered memory modules, such as registered dual in-line memory modules (RDIMMs). One DRAM component may include a set of memory cells and steering logic. The steering logic may include a first data interface and a second data interface. The first and second data interfaces are selectively coupled to a controller component in a first mode and the first data interface is selectively coupled to the controller component in a second mode and the second data interface is selectively coupled to a second DRAM component in the second mode.

Dynamic random access memory (DRAM) component for high-performance, high-capacity registered memory modules

Protocol including a command-specified timing reference signal

A memory system supports single- and dual-memory-module configurations, both supporting point-to-point communication between a host (e.g., a memory controller) and the memory module or modules. Each memory module includes an address-buffer component, data-buffer components, and two sets of memory dies, each set termed a 'timing rank,' that can be accessed independently. The one memory module is configured in a wide mode for the single-memory-module configuration, in which case both timing ranks work together, as a 'package rank,' to communicate full-width data. Each of two memory modules are configured in a narrow mode for the dual-memory-module configuration, in which case one timing rank from each memory module communicates data in parallel to appear to the host as single package ranks. The data-buffer components support separate and configurable write and read delays for the different timing ranks on each module to provide read and write leveling within and between memory modules.

Data-buffer component with variable-width data ranks and configurable data-rank timing

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San Jose, CA, United States of America

Thomas J Giovannini