Abstract: A first timing reference signal and a second timing reference signal are sent to a memory device. The second timing reference signal has approximately a quadrature phase relationship with respect to the first timing reference signal. A plurality of serial data patterns are received from the memory device. The transitions of the first timing reference and the second timing reference determining when transitions occur between the bits of the plurality of data patterns. Timing indicators associated with when received transitions occur between the bits of the plurality of data patterns are received from the memory device. The timing indicators are each measured using a single sampler. Based on the timing indicators, a first duty cycle adjustment for the first timing reference signal, a second duty cycle adjustment for the second timing reference signal, and a quadrature phase adjustment are determined and applied.

Abstract: Described are memory modules that include a configurable signal buffer that manages communication between memory devices and a memory controller. The buffer can be configured to support threading to reduce access granularity, the frequency of row-activation, or both. The buffer can translate controller commands to access information of a specified granularity into subcommands seeking to access information of reduced granularity. The reduced-granularity information can then be combined, as by concatenation, and conveyed to the memory controller as information of the specified granularity.

Abstract: A memory system includes a memory controller coupled to multiple memory devices. Each memory device includes an oscillator that generates an internal reference signal that oscillates at a frequency that is a function of physical device structures within the memory device. The frequencies of the internal reference signals are thus device specific. Each memory device develops a shared reference signal from its internal reference signal and communicates the shared reference signal to the common memory controller. The memory controller uses the shared reference signals to recover device-specific frequency information from each memory device, and then communicates with each memory device at a frequency compatible with the corresponding internal reference signal.

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.

Abstract: Systems, among other embodiments, include topologies (data and/or control/address information) between an integrated circuit buffer device (that may be coupled to a master, such as a memory controller) and a plurality of integrated circuit memory devices. For example, data may be provided between the plurality of integrated circuit memory devices and the integrated circuit buffer device using separate segmented (or point-to-point link) signal paths in response to control/address information provided from the integrated circuit buffer device to the plurality of integrated circuit buffer devices using a single fly-by (or bus) signal path. An integrated circuit buffer device enables configurable effective memory organization of the plurality of integrated circuit memory devices. The memory organization represented by the integrated circuit buffer device to a memory controller may be different than the actual memory organization behind or coupled to the integrated circuit buffer device.

Abstract: An embodiment is directed to an integrated circuit device having programmable input capacitance. For example, a programmable register of a memory device may store a value representative of an adjustment to the input capacitance value of a control pin. An embodiment is directed to controlling the skew of a synchronous memory system by allowing programmability of the lighter loaded pins in order to increase their load to match the more heavily loaded pins. By matching lighter loaded pins to more heavily loaded pins, the system exhibits improved synchronization of propagation delays of the control and address pins. In addition, an embodiment provides the ability to vary the loading depending on how many ranks are on the device.

Abstract: A memory device or module selects between alternative command ports. Memory systems with memory modules incorporating such memory devices support point-to-point connectivity and efficient interconnect usage for different numbers of modules. The memory devices and modules can be of programmable data widths. Devices on the same module can be configured select different command ports to facilitate memory threading. Modules can likewise be configured to select different command ports for the same purpose.

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.

Abstract: The disclosed embodiments relate to the design of a memory system which includes a set of one or more memory modules, wherein each memory module in the set has a clamshell configuration, wherein pairs of opposing memory packages containing memory chips are located on opposite sides of the memory module. The memory system also includes a multi-drop path containing signal lines which pass through the set of memory modules, and are coupled to memory packages in the set of memory modules. For a given signal line in the multi-drop path, a first memory package and a second memory package that comprise a given pair of opposing memory packages are coupled to the given signal line at a first location and a second location, respectively, wherein the first location and the second location are separated from each other by a distance d1 along the given signal line.

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.

Abstract: A system has a plurality of memory devices arranged in a fly-by topology, each having on-die termination (ODT) circuitry for connecting to an address and control (RQ) bus. The ODT circuitry of each memory device includes a set of one or more control registers for controlling on-die termination of one or more signal lines of the RQ bus. A first memory device includes a first set of one or more control registers storing a first ODT value, for controlling termination of one or more signal lines of the RQ bus by the ODT circuitry of the first memory device, and a second memory device includes a second set of one or more control registers storing a second ODT value different from the first ODT value, for controlling termination of one or more signal lines of the RQ bus by the ODT circuitry of the second memory device.

Abstract: A memory device or module selects between alternative command ports. Memory systems with memory modules incorporating such memory devices support point-to-point connectivity and efficient interconnect usage for different numbers of modules. The memory devices and modules can be of programmable data widths. Devices on the same module can be configured select different command ports to facilitate memory threading. Modules can likewise be configured to select different command ports for the same purpose.

Abstract: Described are memory modules that include a configurable signal buffer that manages communication between memory devices and a memory controller. The buffer can be configured to support threading to reduce access granularity, the frequency of row-activation, or both. The buffer can translate controller commands to access information of a specified granularity into subcommands seeking to access information of reduced granularity. The reduced-granularity information can then be combined, as by concatenation, and conveyed to the memory controller as information of the specified granularity.

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.

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.

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.

Abstract: Systems and methods are provided for detecting and correcting address errors in a memory system. In the memory system, a memory device generates an error-detection code based on an address transmitted via an address bus and transmits the error-detection code to a memory controller. The memory controller transmits an error indication to the memory device in response to the error-detection code.

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.

Abstract: An integrated circuit includes a physical layer interface having a control timing domain and a data timing domain, and circuits that enable the control timing domain during a change in power conservation mode in response to a first event, and that enable the data timing domain in response to a second event. The control timing domain can include interface circuits coupled to a command and address path, and the data timing domain can include interface circuits coupled to a data path.

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.