Western Digital Technologies, Inc.

Sandisk Technologies Inc.

Joanna Lai

Nian Niles Yang

Eran Sharon

Idan Alrod

Deepak Raghu

Mark Shlick

Evgeny Mekhanik

Grishma Shah

Dmitry Vaysman

Raghavendra Gopalakrishnan

Henry Chin

Mohan Dunga

Xiying Costa

Changyuan Chen

Bo Lei

Biswajit Ray

Philip David Reusswig

Phil Reusswig

Pitamber Shukla

Abhilash Ravi Kashyap

Mahim Raj Gupta

Chris Yip

Mohsen Purahmad

Zelei Guo

Abuzer Azo Dogan

A data storage device is configured to mark data for refresh in response to determining that a first measured temperature associated with writing the data to the memory exceeds a first threshold. The data storage device is further configured to refresh the marked data in response to determining that a second measured temperature associated with the memory is below a second threshold.

Temperature variation compensation

A storage device having a wide range of operating temperatures is disclosed. Techniques disclosed herein may be used to operate MLC cells at higher temperatures before resorting to thermal throttling. Techniques disclosed herein may be used to operate MLC cells at lower temperatures without needing to pre-heat the storage device. SLC data stored in a first group of memory cells is folded to MLC data stored in a second group of memory cells while an operating temperature is outside a first temperature range. After the operating temperature is within a second temperature range, the data integrity of the MLC data is checked. The SLC data in the first group is folded to MLC data in a third group of memory cells responsive to the MLC data in the second group failing the data integrity check. The foregoing permits the storage device to increase its range in operating temperatures.

Extending operating temperature of storage device

A non-volatile storage system comprises memory cells arranged in groups of memory cells that include programmable select gates and one or more control circuits in communication with the memory cells. The one or more control circuits configured to identify a select gate that needs to be programmed and program the select gate identified to be programmed if a temperature at the non-volatile memory cells is greater than a minimum temperature and defer programming of the select gate identified to be programmed until the temperature at the non-volatile memory cells is greater than the minimum temperature. In some embodiments, the one or more control circuits are configured to perform dummy memory operations on the plurality of non-volatile memory cells to raise the temperature of the non-volatile memory cells in response to determining that the temperature at the non-volatile memory cells is not high enough.

Non-volatile storage system with adjustable select gates as a function of temperature

Technology is described herein for operating non-volatile storage. In one embodiment, the memory system tracks which adjustments to default values for hard bit read reference voltages are most frequently successful to decode data in non-volatile memory cells. In response to a process that uses only hard bits failing to successfully decode data in a group of the non-volatile memory cells, the memory system attempts to decode the data in the group of non-volatile memory cells using dynamic hard bit read reference voltages and dynamic soft bit read reference voltages that correspond to only a subset of the most frequently successful adjustments to the default values for the hard bit read reference voltages. By only using a subset of the most frequently successful adjustments to the default values for the hard bit read reference voltages time and power is saved.

Adaptive hard and soft bit decoding

A non-volatile memory system includes technology for detecting read disturb in open blocks. In one embodiment, the system determines whether a particular block of non-volatile memory cells has been subjected to a minimum number of open block read operations and performs sensing operations for memory cells connected to an open word line of the particular block. The number of errors in the sensed data is determined. If the number of errors is greater than a limit, then the system takes an action to mitigate the read disturb.

Non-volatile memory with read disturb detection for open blocks

A storage system and method for generating block allocation groups based on deterministic data patterns are provided. A storage system is provided comprising a memory comprising a plurality of blocks and a controller. The controller is configured to infer characteristics of the memory from data patterns of data stored in the plurality of blocks; and group the plurality of blocks based on the inferred characteristics of the memory.

Storage system and method for grouping blocks based on deterministic data patterns

Techniques are provided for improving the accuracy of read operations of memory cells, where the threshold voltage of a memory cell can shift depending on when the read operation occurs. In one aspect, read voltages are set and optimized based on a time period since a last sensing operation. A timing device such as an n-bit digital counter may be provided for each block of memory cells to track the time. The counter is set to all 1's when the device is powered on. When a sensing operation occurs, the counter is periodically incremented based on a clock. When a next read operation occurs, the value of the counter is cross-referenced to an optimal set of read voltage shifts. Each block of cells may have its own counter, where the counters are incremented using a local or global clock.

System solution for first read issue using time dependent read voltages

Performance improvement features can improve the performance of read processes under the right conditions. In order to selectively use the performance improvement features, the system conducts active read sampling to obtain information about bit error rate and then enables the performance improvement feature(s) for future read processes based on the information about bit error rate.

Non-volatile storage system with self-test for read performance enhancement feature setup

A storage system and method for using hybrid blocks with sub-block erase operations are provided. In one embodiment, a storage system is provided comprising a memory comprising a block, wherein the block comprises a first sub-block and a second sub-block; and a controller in communication with the memory. The controller is configured to erase the first sub-block, wherein the second sub-block is programmed; and program the first sub-block to fewer bits per cell than the second sub-block is programmed to. Other embodiments are provided.

Storage system and method for using hybrid blocks with sub-block erase operations

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San Jose, CA, United States of America

Joanna Lai