Sandisk Patent Applications

POWER OFF RECOVERY IN CROSS-POINT MEMORY WITH THRESHOLD SWITCHING SELECTORS

Granted: May 5, 2022
Application Number: 20220139454
In a memory array with a cross-point structure, at each cross-point junction a programmable resistive memory element, such as an MRAM memory cell, is connected in series with a threshold switching selector, such as an ovonic threshold switch. The threshold switching selector switches to a conducting state when a voltage above a threshold voltage is applied. When powered down for extended periods, the threshold voltage can drift upward. If the drift is excessive, this can make the memory…

Soft Data Compression For Non-Volatile Memory

Granted: April 28, 2022
Application Number: 20220129163
An encoder of a storage medium receives, at a plurality of latches respectively associated with a plurality of memory cells, soft data corresponding to data subject to a read operation specified by the a storage controller, compresses the soft data, and stores the compressed soft data in a buffer before transmitting the compressed soft data to the storage controller. Upon the buffer being full, the encoder writes uncompressed soft data back to at least a subset of the plurality of…

MULTI-LEVEL ULTRA-LOW POWER INFERENCE ENGINE ACCELERATOR

Granted: April 7, 2022
Application Number: 20220108759
Non-volatile memory structures for performing compute-in-memory inferencing for neural networks are presented. A memory array is formed according to a crosspoint architecture with a memory cell at each crosspoint junction. The multi-levels memory cells (MLCs) are formed of multiple of ultra-thin dielectric layers separated by metallic layers, where programming of the memory cell is done by selectively breaking down one or more of the dielectric layers by selecting the write voltage…

SIGNAL AMPLIFICATION IN MRAM DURING READING

Granted: April 7, 2022
Application Number: 20220108740
Apparatuses and techniques are described for reading MRAM memory cells. In a cross-point memory array, each conductive line, such as a bit line or word line, is connected to a transistor pair comprising a pMOSFET in parallel with an nMOSFET. When selecting a memory cell to be read, a voltage of a first conductive line may be pulled up using the pMOSFET while a voltage of a second conductive line is pulled down, e.g., to 0 V, using the nMOSFET. This minimizes a capacitance while the…

SIGNAL PRESERVE IN MRAM DURING READING

Granted: April 7, 2022
Application Number: 20220108739
Apparatuses and techniques are described for reading MRAM memory cells. In a cross-point memory array, each conductive line, such as a bit line or word line, is connected to a transistor pair comprising a pMOSFET in parallel with an nMOSFET. When selecting a memory cell to be read, a voltage of a first conductive line may be pulled up using the pMOSFET while a voltage of a second conductive line is pulled down, e.g., to 0 V, using the nMOSFET. This minimizes a capacitance while the…

ULTRALOW POWER INFERENCE ENGINE WITH EXTERNAL MAGNETIC FIELD PROGRAMMING ASSISTANCE

Granted: April 7, 2022
Application Number: 20220108158
An MRAM-based vector multiplication device, such as can be used for inferencing in a neural network, is presented that is ultralow power, low cost, and does not require special on-chip programming. A crosspoint array has an MRAM cell at each crosspoint junction and periphery array circuitry capable of supplying independent input voltages to each word line and reading current on each bit line. Vector multiplication is performed as an in-array multiplication of a vector of input voltages…

NON-VOLATILE MEMORY WITH SWITCHABLE ERASE METHODS

Granted: March 31, 2022
Application Number: 20220101926
To improve the erase process, multiple methods of erasing are utilized. A first method of erasing is relied on at the beginning of life of the memory system. A second method is increasingly relied on as the memory system is used and undergoes many program/erase cycles. In one example, the first method of erase includes applying an erase enable voltage separately to different subsets of the word lines while word lines not receiving the erase enable voltage receive an erase inhibit…

Soft Data Compression For Non-Volatile Memory

Granted: March 24, 2022
Application Number: 20220091752
An encoder of a storage medium encodes data subject to a read operation specified by a storage controller by generating a plurality of symbols representing a soft data stream corresponding to the data subject to the read operation, where each symbol of the plurality of symbols includes (i) a single-bit value number indicating whether the symbol counts 0s or 1s, and (ii) an N-bit count number indicating a bit count associated with the symbol, where N is greater than or equal to two, and…

Tunable and Scalable Command/Address Protocol for Non-Volatile Memory

Granted: March 3, 2022
Application Number: 20220066958
A data storage system includes a storage medium including a plurality of memory cells; a storage controller in communication with the storage medium; and an electrical interface between the storage medium and the storage controller. The electrical interface includes an N-bit data bus; a data strobe; a command latch enable signal; and an address latch enable signal; wherein, while the command latch signal or the address latch enable signal is asserted, the storage medium is configured to:…

MEMORY BLOCK WITH SEPARATELY DRIVEN SOURCE REGIONS TO IMPROVE PERFORMANCE

Granted: February 24, 2022
Application Number: 20220059157
Apparatuses and techniques are described for providing separate source regions in the substrate below a block of memory cells. The source regions can be separately driven by respective voltage drivers to provide benefits such as more uniform program and erase speeds and narrower threshold voltage distributions. In one approach, a single source region is provided and divided into multiple source regions by etching trenches and filling the trenches with an insulating material. Contacts to…

HOLE PRE-CHARGE SCHEME USING GATE INDUCED DRAIN LEAKAGE GENERATION

Granted: December 30, 2021
Application Number: 20210408024
A memory device disclosed herein. The memory device comprises: a memory string including a first select transistor, a memory cell transistor, and a second select transistor connected in series; a bit line connected to one end of the first select transistor; a source line connected to one end of the second select transistor; a first select line connected to a gate of the first select transistor; a word line connected to a gate of the memory cell transistor; a second select line connected…

CALIBRATION FOR INTEGRATED MEMORY ASSEMBLY

Granted: December 30, 2021
Application Number: 20210407613
An integrated memory assembly comprises a memory die and a control die bonded to the memory die. The memory die includes a memory structure of non-volatile memory cells. The control die is configured to program user data to and read user data from the memory die based on one or more operational parameters. The control die is configured to calibrate the one or more operational parameters for the memory die. The control die is also configured to perform testing of the memory die using the…

TRIGGERING NEXT STATE VERIFY IN PROGAM LOOP FOR NONVOLATILE MEMORY

Granted: December 30, 2021
Application Number: 20210407605
Apparatus and methods are described to program memory cells and verify stored values programmed into the cells. The next stage in stored memory can be moved to the current verification iteration when certain conditions are met. Verification can include counting bits that exceed a voltage value for a stage being verified to produce a bit count number and determining if the bit count number for the stage being verified meets a threshold value. If the bit count number does not meet the…

LOOP-DEPENDENT SWITCHING BETWEEN PROGRAM-VERIFY TECHNIQUES

Granted: December 30, 2021
Application Number: 20210407604
A storage device for verifying whether memory cells have been programmed. The storage device may be configured to use a verification technique, that is part of a set of verification techniques, to verify data states of a set of memory cells of a selected word line. The one or more verification techniques may be utilized based on an iteration of the verify operation that is to be performed. The storage device may be further configured to perform, using the verification technique, a next…

DYNAMIC TIER SELECTION FOR PROGRAM VERIFY IN NONVOLATILE MEMORY

Granted: December 30, 2021
Application Number: 20210407603
An apparatus includes a memory controller configured to apply selected one or ones of the program verify voltage levels to a single tier of memory cells. A memory controller is configured to: program data into the plurality of memory cells; and perform a program verify operation across multiple voltage levels with a first voltage level of the program verify operation being applied to a single tier that represents all of the tiers in the memory group and a second voltage level of the…

LOOP DEPENDENT PLANE SKEW METHODOLOGY FOR PROGRAM OPERATION

Granted: December 30, 2021
Application Number: 20210407596
An apparatus, disclosed herein, comprises a plurality of planes, each plane of the plurality of planes including a plurality of memory cells and a control circuit coupled to the plurality of memory cells. The control circuit is configured to: determine a position of a program loop in a sequence of program loops performed to complete a programming operation; initiate an inhibit bit line ramping event for the first plane including ramping of a set of bit lines of a first plane up to an…

COMPUTE-IN-MEMORY DEEP NEURAL NETWORK INFERENCE ENGINE USING LOW-RANK APPROXIMATION TECHNIQUE

Granted: December 30, 2021
Application Number: 20210406672
Non-volatile memory structures for performing compute in memory inferencing for neural networks are presented. To improve performance, both in terms of speed and energy consumption, weight matrices are replaced with their singular value decomposition (SVD) and use of a low rank approximations (LRAs). The decomposition matrices can be stored in a single array, with the resultant LRA matrices requiring fewer weight values to be stored. The reduced sizes of the LRA matrices allow for…

PEAK POWER REDUCTION MANAGEMENT IN NON-VOLATILE STORAGE BY DELAYING START TIMES OPERATIONS

Granted: December 30, 2021
Application Number: 20210405920
Power and/or current regulation in non-volatile memory systems is disclosed. Peak power/current usage may be reduced by staggering concurrent program operations in the different semiconductor dies. Each set of one or more semiconductor dies has an earliest permitted start time for its program operation, as well as a number of permitted backup start times. The permitted start times are unique for each set of one or more semiconductor dies. There may be a uniform gap or delay between each…

DYNAMIC STAGGERING FOR PROGRAMMING IN NONVOLATILE MEMORY

Granted: December 30, 2021
Application Number: 20210405891
An apparatus includes a controller and a plurality of memory dies operable connected to and controlled by the controller. Each of the memory dies draws a current from a current source during a program operation. The controller being configured to receive a clock signal from each of the memory dies; count the number of clock signal received to determine a count value; and dynamically stagger at least one of the memory dies relative to the other memory dies when the count value reaches a…

SYSTEM IDLE TIME REDUCTION METHODS AND APPARATUS

Granted: December 23, 2021
Application Number: 20210397372
An apparatus is provided that includes a memory die including a pipeline circuit coupled to a memory structure. The memory die is configured to execute a first command by receiving in the pipeline circuit data to be written to the memory structure, processing the received data in the pipeline circuit and providing the processed data to the memory structure, predicting that the pipeline circuit has completed processing the received data, and ending execution of the first command based on…