Abstract:
A table may include first and second row addresses that are adjacent an activated row address. A first counter of the first row address may be incremented if the activated row address is not included in the table. A second counter of the second row address may also be incremented if the activated row address is not included in the table. The first row address may be refreshed if the first counter exceeds a counter threshold. The second row address may be refreshed if the second counter exceeds the counter threshold.
Abstract:
A memory subsystem can test a memory device in situ, testing the performance of the device in the system it is built into during production. Thus, the refresh rate can be adjusted specific to the memory device(s) of a specific system, rather than defaulting to a refresh frequency specified by a standard for the memory device(s). A test component embedded within the host memory subsystem can perform a test and identify specific bits or lines of memory that produce errors when a lower frequency refresh rate is used. The system maps out the identified bits or lines to prevent the bits/lines from being used in runtime of the system. The memory subsystem can then set its refresh rate to an adjusted refresh rate at which a threshold number of errors can be removed by mapping out the bits/lines.
Abstract:
Detection logic of a memory subsystem obtains a threshold for a memory device that indicates a number of accesses within a time window that causes risk of data corruption on a physically adjacent row. The detection logic obtains the threshold from a register that stores configuration information for the memory device, and can be a register on the memory device itself and/or can be an entry of a configuration storage device of a memory module to which the memory device belongs. The detection logic determines whether a number of accesses to a row of the memory device exceeds the threshold. In response to detecting the number of accesses exceeds the threshold, the detection logic can generate a trigger to cause the memory device to perform a refresh targeted to a physically adjacent victim row.
Abstract:
A system monitors data accesses to specific rows of memory to determine if a row hammer condition exists. The system can monitor accessed rows of memory to determine if the number of accesses to any of the rows exceeds a threshold associated with risk of data corruption on a row of memory physically adjacent to the row with high access. Based on the monitoring, a memory controller can determine if the number of accesses to a row exceeds the threshold, and indicate address information for the row whose access count reaches the threshold.
Abstract:
The present disclosure describes DRAM architectures and refresh controllers that allow for scheduling of an opportunistic refresh of a DRAM device concurrently with normal row activate command directed toward the DRAM device. Each activate command affords an "opportunity" to refresh another independent row (i.e., a wordline) within a memory device with no scheduling conflict.
Abstract:
In a dynamic random access memory device, receiving refresh commands via a signaling interface and, in response to the refresh commands, refreshing a first row of storage cells at a first refresh rate and refreshing a second row of storage cells at a second, faster refresh rate.
Abstract:
A method, apparatus, and system to enable a partial refresh scheme for DRAM which includes specifying at least a refresh start value, or a refresh start value and a refresh end value, to reduce the number of rows that must be refreshed during a refresh cycle, thus reducing the amount of power consumed during refresh.
Abstract:
A dynamic random access memory (DRAM) content aware refresh system includes a central processing unit (CPU) communicatively coupled to a memory controller having a content aware refresh unit. A main memory includes DRAM organized into a plurality of refresh groups. Each refresh group of the plurality of refresh groups including a different portion of the main memory DRAM is operatively coupled to the content aware refresh unit such that each refresh group of the plurality of refresh groups is refreshed by the memory controller at a selected one of a plurality of refresh rates based on a density of a bit state within each refresh group. A method for refreshing a dynamic random access memory (DRAM) is also described.