Micron Technology Incorporated

Sandeep Krishna Thirumala

Nevil N Gajera

Amitava Majumdar

Lingming Yang

Karthik Sarpatwari

Systems, apparatuses, and methods related to a memory controller for performing row access tracking to mitigate row hammer attacks. A memory controller comprises a dual cache system including a direct mapped cache and a victim cache. The direct mapped cache functions as the main cache while a fully associative victim cache is used to reduce hammer attacks to targeted rows. The direct mapped cache performs an aliasing operation to map at least a portion of data stored in a memory device to the direct mapped cache. The direct mapped cache also uses a plurality of counters operatively coupled to the direct mapped cache to track and monitor the number of activations of the data stored in the direct mapped cache. The memory controller proactively refreshes all adjacent rows in the memory device when the respective counter of the direct mapped cache exceeds a predetermined threshold.

Dual cache for row hammer mitigation

Systems, apparatuses, and methods can include a multi-stage cache for providing high reliability, availability, and serviceability (RAS). The multi-stage cache memory comprises a shadow DRAM, which is provided on a volatile main memory module, coupled to a memory controller cache, which is provided on a memory controller. During a first write operation, the memory controller writes data with a strong error correcting code (ECC) from the memory controller cache to the shadow DRAM without writing a RAID (Redundant Arrays of Inexpensive Disks) parity data. During a second write operation, the memory controller writes the data with the strong ECC and writes the RAID parity data from the shadow DRAM to a memory device provided on the volatile main memory module.

Shadow DRAM with CRC+RAID architecture, system and method for high RAS feature in a CXL drive

Provided is a memory system comprising a plurality of memory channels each having a parity bit, a redundant array of independent devices (RAID) parity channel, and a controller of the memory system. The controller is configured to receive a block of data for storage in the memory channels and determine at least one of (i) when a data traffic demand on the memory channels is high and (ii) when a data traffic demand on the memory channels is low. Upon determining the data traffic demand is low, writing the block of data for storage in the memory channels and concurrently updating the parity bits and the RAID parity channel for the stored block of data. Upon determining the data traffic demand is high, only writing the data for storage in the memory channels.

Instant write scheme with delayed parity/raid

Provided is a memory system including a plurality of memory submodules and a controller. Each submodule comprises a plurality of memory channels, each channel having a parity bit and a redundant array of independent devices (RAID) parity channel. The controller is configured to receive a block of data for storage in the plurality of memory submodules and determine whether a level of data traffic demand for a first of the plurality of submodules is high or low. When the data traffic demand is low, (i) writing a portion of the block of data in the first of the plurality of submodules and (ii) concurrently updating the parity bit and the RAID parity channel associated with the block of data. When the data traffic demand is high, (i) only writing the portion of the block of data in the first of the plurality of submodules and (ii) deferring updating of the parity bits and the RAID parity channel associated with the block of data.

Method and memory system for writing data to dram submodules based on the data traffic demand

This document describes apparatuses and techniques for cache memory with randomized eviction. In various aspects, a cache memory randomly selects a cache line for eviction and/or replacement. The cache memory may also support multi-occupancy whereby the cache memory enters data reused from another cache line to replace the data of the randomly evicted cache line. By so doing, the cache memory may operate in a nondeterministic fashion, which may increase a probability of data remaining in the cache memory for subsequent requests.

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Boise, ID, United States of America

Sandeep Krishna Thirumala