Micron Technology Incorporated

Lingming Yang

Nevil N Gajera

Karthik Sarpatwari

Amitava Majumdar

Sandeep Krishna Thirumala

Jessica Chen

Fabio Pellizzer

John Frederic Schreck

Mingdong Cui

Lei Wei

John Christopher M Sancon

Josephine Tiu Hamada

Francesco Douglas Verna-Ketel

Kenneth Richard Surdyk

Marco Sforzin

Paolo Amato

Joseph M McCrate

Yen Chun Lee

Xuan Anh Tran

Methods, systems, and devices for data correction schemes with reduced device overhead are described. A memory system may include a set of memory devices storing data and check codes associated with the data. The memory system may additionally include a single parity device storing parity information associated with the data. During a read operation of a set of data, a controller of the memory system may detect an error in data associated with a first check code, the data including two or more subsets of the set of data received from two or more corresponding memory devices. The controller may generate candidate data corresponding to one of the two or more subsets using the parity information and remaining subsets of the set of data. Then the controller may determine whether the candidate data is correct by comparing the first check code with a check value generated using the candidate data.

Data correction scheme with reduced device overhead

Systems, methods and apparatus to read target memory cells having an associated reference memory cell configured to be representative of drift or changes in the threshold voltages of the target memory cells. The reference cell is programmed to a predetermined threshold level when the target cells are programmed to store data. In response to a command to read the target memory cells, estimation of a drift of the threshold voltage of the reference is performed in parallel with applying an initial voltage pulse to read the target cells. Based on a result of the drift estimation, voltage pulses used to read the target cells can be modified and/or added to account for the drift estimated using the reference cell.

Drift aware read operations

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

The present disclosure includes apparatuses, methods, and systems for performing refresh operations on memory cells. An embodiment includes a memory having a group of memory cells and one or more additional memory cells whose data state is indicative of whether to refresh the group of memory cells, and circuitry configured to apply a first voltage pulse to the group of memory cells to sense a data state of the memory cells of the group, apply, while the first voltage pulse is applied to the group of memory cells, a second voltage pulse having a greater magnitude than the first voltage pulse to the one or more additional memory cells to sense a data state of the one or more additional memory cells, and determine whether to perform a refresh operation on the group of memory cells based on the sensed data state of the one or more additional memory cells.

Performing refresh operations on memory cells

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.

Cache memory with randomized eviction

Systems, methods and apparatus to program a memory cell to have a threshold voltage to a level representative of one value among more than two predetermined values. A first voltage pulse is driven across the memory cell to cause a predetermined current to go through the memory cell. The first voltage pulse is sufficient to program the memory cell to a level representative of a first value. To program the memory cell to a level representative of a second value, a second voltage pulse, different from the first voltage pulse, is driven across the memory cell within a time period of residual poling in the memory cell caused by the first voltage pulse.

Self-selecting memory cells configured to store more than one bit per memory cell

Systems, methods and apparatus to program memory cells to an intermediate state. A first voltage pulse is applied in a first polarity across each respective memory cell among the memory cells to move its threshold voltage in the first polarity to a first voltage region representative of a first value. A second voltage pulse is then applied in a second polarity to further move its threshold voltage in the first polarity to a second voltage region representative of a second value and the intermediate state. A magnitude of the second voltage pulse applied for the memory cells is controlled by increasing the magnitude in increments until the memory cells are sensed to be conductive. Optionally, prior to the first voltage pulse, a third voltage pulse is applied in the second polarity to cancel or reduce a drift in threshold voltages of the respective memory cell.

Programming intermediate state to store data in self-selecting memory cells

An example apparatus includes a three-dimensional (3D) memory array including a sense line and a plurality of vertical stacks. Each respective on of the vertical stacks includes a different respective portion of the sense line, a first memory cell coupled to that portion of the sense line, a second memory cell coupled to that portion of the sense line, a first access line coupled to the first memory cell and a second access line coupled to the second memory cell. The first and second access lines are perpendicular to the sense line.

Three-dimensional memory arrays, and methods of forming the same

An integrated circuit memory device, having: a first wire; a second wire; a memory cell connected between the first wire and the second wire; a first voltage driver connected to the first wire; and a second voltage driver connected to the second wire. During an operation to read the memory cell, the second voltage driver is configured to start ramping up a voltage applied on the second wire after the first voltage driver starts ramping up and holding a voltage applied on the first wire.

Read spike mitigation in integrated circuit memory

Methods, systems, and devices for dynamic read voltage techniques are described. In some examples, a memory device may include one or more partitions made up of multiple disjoint subsets of memory arrays. The memory device may receive a read command to read the one or more partitions and enter a drift determination phase. During the drift determination phase, the memory device may concurrently apply a respective voltage of a set of voltages to each disjoint subset and determine a quantity of memory cells in each disjoint subset that have a threshold voltage below the applied voltage. Based on a comparison between the determined quantity of memory cells and a predetermined quantity of memory cells, the memory device may select a voltage from the set of voltages and utilize the selected voltage to read the one or more partitions.

Dynamic read voltage techniques

The present disclosure includes apparatuses, methods, and systems for performing refresh operations on memory cells. A memory can include a group of memory cells and one or more additional memory cells whose data state is indicative of whether to refresh the group of memory cells. Circuitry is configured to apply a first voltage pulse to the group of memory cells to sense a data state of the memory cells of the group, apply, while the first voltage pulse is applied to the group of memory cells, a second voltage pulse having a greater magnitude than the first voltage pulse to the one or more additional memory cells to sense a data state of the one or more additional memory cells, and determine whether to perform a refresh operation on the group of memory cells based on the sensed data state of the one or more additional memory cells.

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Meridian, ID, United States of America

Lingming Yang