98 results about "Memory rank" patented technology

A method and system for decreasing power consumption in memory arrays having usage-driven power management provides decreased power consumption in the memory array of a processing system. Per-page usage information is gathered on memory by a memory controller and periodically evaluated by software. The software distinguishes between more frequently accessed pages and less frequently accessed pages by analyzing the gathered usage information and periodically migrates physical memory pages in order to group less frequently accessed pages and more frequently access pages in separately power-managed memory ranks. When used in conjunction with a usage-driven power management mechanism, the ranks containing the less frequently accessed pages can enter deeper power-saving states and/or any power-saving state for longer periods. Operation may be further enhanced by using packed allocation in the memory ranks containing the less-frequently accessed pages and scattered allocation in the memory ranks having more frequently accessed pages.

A layout for simultaneously sub-accessible memory modules is disclosed. In one embodiment, a memory module includes a printed circuit board having a plurality of sectors, each sector being electrically isolated from the other sectors and having a multi-layer structure. At least one memory device is attached to each sector, the memory devices being organized into a plurality of memory ranks. A driver is attached to the printed circuit board and is operatively coupled to the memory ranks. The driver is adapted to be coupled to a memory interface of the computer system. Because the sectors are electrically-isolated from adjacent sectors, the memory ranks are either individually or simultaneously, or both individually and simultaneously accessible by the driver so that one or more memory devices on a particular sector may be accessed at one time. In an alternate embodiment, the printed circuit board includes a driver sector electrically isolated from the other sectors and having a multi-layer structure, the driver being attached to the driver sector.

The invention refers to a Memory Rank Decoder for a Multi-Rank Dual Inline Memory Module (DIMM) having a predetermined number of DRAM memory chips mounted on a printer circuit board (PCB), wherein each DRAM memory chip comprises a predetermined number of stacked DRAM memory dies which are selectable by a memory rank selection signal (r), wherein the memory rank decoder generates the memory rank selection signal (r) in response to external selection signals applied to the dual inline module (DIMM).

A memory controller uses a power- and performance-aware scheduler which reorders memory commands based on power priorities. Selected memory ranks of the memory device are then powered down based on rank localities of the reordered commands. The highest power priority may be given to memory commands having the same rank as the last command sent to the memory device. Any memory commands having the same power priority can be further sorted based on one or more performance criteria such as an expected latency of the memory commands and an expected ratio of read and write memory commands. To optimize the power-down function, the power-down command is only sent when the selected memory rank is currently idle, the selected memory rank is not already powered down, none of the reordered memory commands correspond to the selected rank, and a currently pending memory command cannot be issued in the current clock cycle.

A memory controller uses a throttling mechanism which estimates a throttling delay for achieving a target power consumption, and periodically blocks all memory commands for a number of clock cycles corresponding to the throttling delay. Idle memory ranks of the memory device are powered down while the memory commands are blocked. A regression model bases the throttling delay on a plurality of operating factors and a plurality of regression coefficients for the operating factors. In the illustrative implementation the operating factors include power consumption, a current number of bank conflicts, a current number of read commands, and a current number of write commands. Different sets of regression coefficients can be programmably stored for use with different system configurations.

A memory subsystem is disclosed. The memory subsystem includes a memory controller coupled to one or more memory modules. Each memory module comprises a buffer coupled to one or more memory ranks. A clock source is coupled to provide a clock signal to each of the memory modules. The memory controller is configured to convey a clock enable (CKE) command to one of the memory modules, the CKE command corresponding to a given memory rank. In response to the CKE command, a memory module buffer associated with the given memory rank is configured to convey a CKE disable signal to the given memory rank. The given memory rank is configured to disable operation of the clock signal within the given memory rank, responsive to the CKE disable signal.

A memory controller includes a state machine that initiates a memory refresh of a DRAM (having a number of banks) by sending thereto a refresh command. Responsive to receiving the command, the DRAM may perform a per-bank refresh in which individual ones of the banks are refreshed in succession, one at a time. Upon receiving a high priority transaction, a determination is made as to the number of memory banks that have currently been refreshed in the per-bank refresh. If the number of banks refreshed is less than a threshold value, the per-bank refresh is aborted.

Improved efficiency of address/data communication over a memory bus. A memory-control device is located between a processor 30 and memory ranks 40a, 40b and controls access to the memory ranks 40a, 40b. A memory-management unit 10 receives and buffers access request from the processor 30 to memory ranks 40a, 40b, and issues access request to a rank-management unit 20 based on scheduling for memory management. A rank-management unit 20 connects the memory ranks 40a, 40b, receives and buffers access request from the memory-management unit 10, and gives access request to a specified memory rank based on scheduling for rank management.

A system to improve error control coding may include memory chips of at least two different kinds. The system may also include error control encoder circuitry to substantially encode data for storage in any memory rank. The system may further include error control decoder circuitry to substantially decode encoded data received from any memory rank. The error decoder circuitry is comprised of a slow decoder and a fast decoder.

Embodiments of the inventive concept include a plurality of memory ranks, a buffer chip including a rank remap control section configured to remap a rank from among the plurality of memory ranks of the volatile memory module responsive to a failure of the rank, and a dynamic serial presence detect section configured to dynamically update a stated total capacity of the volatile memory module based at least on the remapped rank. In some embodiments, a memory module includes a plurality of memory ranks, an extra rank in addition to the plurality of memory ranks, the extra rank being a spare rank configured to store a new page corresponding to a failed page from among the plurality of ranks, and a buffer chip including a page remap control section configured to remap the failed page from among the plurality of ranks to the new page in the extra rank.

An apparatus for performing a block operation includes a functional unit, which performs an operation on one or more block operands, and an accumulator memory. The accumulator memory includes two independently interfaced memory banks. A control unit controls the memory banks in the accumulator memory so that each time the operation is performed, an operand is provided from one of the memory banks and a result is stored in the other memory bank. Since the memory banks are independently interfaced, the operand may be provided at the same time as the result is being stored. Additionally, since the result is stored in a different memory bank than the operand, the operation may be restarted if an error occurs.

A memory system and data processing system for controlling memory refresh operations in dynamic random access memories. The memory controller comprises logic that: tracks a time remaining before a scheduled time for performing a high priority, high latency operation a first memory rank of the memory system; responsive to the time remaining reaching a pre-established early notification time before the schedule time for performing the high priority, high latency operation, biases the re-order queue containing memory access operations targeting the plurality of ranks to prioritize scheduling of any first memory access operations that target the first memory rank. The logic further: schedules the first memory access operations to the first memory rank for early completion relative to other memory access operations in the re-order queue that target other memory ranks; and performs the high priority, high latency operation at the first memory rank at the scheduled time.

The invention discloses a kernel-module memory management method for preventing memory leaks and multiple memory releases, and the method comprises the following implementation steps: 1) establishing an array of records; 2) when a kernel module requires a system to allocate memories, adding memory allocation records associated with the allocated memories into the array of records; 3) when the kernel module requires the system to release memories, searching memory allocation records associated with the memories to be released in the array of records, if the associated memory allocation records exist, executing memory release, and cancelling the memory allocation records; and if the associated memory allocation records do not exist, issuing an alarm of 'multiple releases'; and 4) when the kernel module exits, scanning the array of records, if the array of records still has memory allocation records, releasing the memories associated with the memory allocation records one by one according to the memory allocation records, and finally, clearing the array of records. By utilizing the method disclosed by the invention, the kernel modules can be prevented from having the phenomena of memory leaks and multiple memory releases; and the method has the advantages of good memory allocation capability, low congestion degree of an operating system, less occupied resources, small memory-footprint, and good adaptability.

A method and apparatus to efficiently scrub a memory, during a scrub period, of a computer system that has a memory comprising a number of memory elements. Examples of memory elements are memory ranks and banks. A memory rank may further comprise one or more banks. The computer system has a memory controller that receives read requests and write requests from a processor. The memory controller includes a scrub controller configured to output more than one scrub request during a particular request selector cycle. The memory controller includes a request selector that services a read request, a write request, or one of the scrub requests during a request selector cycle.

A computing node which reduces substantially and effectively reduces the power consumed by a memory is provided without affecting the efficiency whereby a processor accesses the memory. The computing node executes a user program sent by a control node. In case of which a message including the capacity of the memory required to execute a user program is received, a memory rank corresponding to the capacity of the required memory is made active by a memory controller before the user program is loaded into the memory.

Embodiments of an apparatus to reduce memory power consumption are presented. In one embodiment, the apparatus comprises a cache memory, a memory, and a control unit. In one embodiment, the memory includes a plurality of memory ranks. The control unit is operable to select one or more memory ranks among the plurality of memory ranks to be idle-prioritized memory ranks such that access frequency to the idle-prioritized memory ranks is reduced.