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 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:
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.
Abstract:
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.
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. The buffer device segments and merges the data transferred between the memory controller that expects a particular memory organization and actual memory organization.
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 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 module comprises a module interface having module data-group ports to communicate data as respective data groups, a command port to receive memory-access commands, a first memory device including a first device data-group port, a second memory device including a second device data-group port, and a signal buffer coupled between the module interface and each of the first and second devices. In a first mode, in response to the memory-access commands, the signal buffer communicates the data group associated with each of the first and second device data-group ports via a respective one of the module data-group ports. In a second mode, in response to the memory-access commands, the signal buffer alternatively communicates the data group associated with the first device data-group port or the data group associated with the second device data-group port via the same one of the module data-group ports.
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:
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. The buffer device segments and merges the data transferred between the memory controller that expects a particular memory organization and actual memory organization.