Abstract:
The present embodiments provide a system that supports self-refreshing operations in a memory device. During operation, the system transitions the memory device from an auto-refresh state, wherein a memory controller controls refreshing operations for the memory device, to a self-refresh state, wherein the memory device controls the refreshing operations. While the memory device is in the self-refresh state, the system sends progress information for the refreshing operations from the memory device to the memory controller. Next, upon returning from the self-refresh state to the auto-refresh state, the system uses the progress information received from the memory device to control the sequencing of subsequent operations by the memory controller.
Abstract:
A memory controller is operable in an error detection/correction mode in which N syndrome values apply to N data words of a data volume, respectively, but a single parity bit is shared across all N data words of the data volume.
Abstract:
In a multirank memory system in which the clock distribution trees of each rank are permitted to drift over a wide range (e.g., low power memory systems), the fine-interleaving of commands between ranks is facilitated through the use of techniques that cause each addressed rank to properly sample commands intended for that rank, notwithstanding the drift. The ability to perform such “microthreading” provides for substantially enhanced memory capacity without sacrificing the performance of single rank systems. This disclosure provides methods, memory controllers, memory devices and system designs adapted to these ends.
Abstract:
In one embodiment, a memory device includes a memory core and input receivers to receive commands and data. The memory device also includes a register to store a value that indicates whether a subset of the input receivers are powered down in response to a control signal. A memory controller transmits commands and data to the memory device. The memory controller also transmits the value to indicate whether a subset of the input receivers of the memory device are powered down in response to the control signal. In addition, in response to a self-fresh command, the memory device defers entry into a self-refresh operation until receipt of the control signal that is received after receiving the self-refresh command.
Abstract:
Bandwidth for information transfers between devices is dynamically changed to accommodate transitions between power modes employed in a system. The bandwidth is changed by selectively enabling and disabling individual control links and data links that carry the information. During a highest bandwidth mode for the system, all of the data and control links are enabled to provide maximum information throughout. During one or more lower bandwidth modes for the system, at least one data link and/or at least one control link is disabled to reduce the power consumption of the devices. At least one data link and at least one control link remain enabled during each low bandwidth mode. For these links, the same signaling rate is used for both bandwidth modes to reduce latency that would otherwise be caused by changing signaling rates. Also, calibration information is generated for disabled links so that these links may be quickly brought back into service.
Abstract:
A memory cell includes a first resistive memory element, a second resistive memory element electrically coupled with the first resistive memory element at a common node, and a switching element comprising an input terminal electrically coupled with the common node, the switching element comprising a driver configured to float during one or more operations.
Abstract:
Row activation operations within a memory component are carried out with respect to subrows instead of complete storage rows to reduce power consumption. Further, instead of activating subrows in response to row commands, subrow activation operations are deferred until receipt of column commands that specify the column operation to be performed and the subrow to be activated.
Abstract:
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.
Abstract:
A multi-chip package includes a logic integrated circuit (IC) die formed with plural memory controller circuits, a first memory IC die and a second memory IC die. The second memory IC die is mounted to the first memory IC die. The first memory IC die and the logic IC die are mounted to one another. The logic IC die includes a serial link interface for coupling to multiple serial links. The first memory die includes a first memory group accessed by a first one of the plural memory controller circuits, and a second memory group accessed by a second one of the plural memory controller circuits.
Abstract:
A memory component includes a memory core comprising dynamic random access memory (DRAM) storage cells and a first circuit to receive external commands. The external commands include a read command that specifies transmitting data accessed from the memory core. The memory component also includes a second circuit to transmit data onto an external bus in response to a read command and pattern register circuitry operable during calibration to provide at least a first data pattern and a second data pattern. During the calibration, a selected one of the first data pattern and the second data pattern is transmitted by the second circuit onto the external bus in response to a read command received during the calibration. Further, at least one of the first and second data patterns is written to the pattern register circuitry in response to a write command received during the calibration.