Micron Technology Incorporated

Ovonyx Memory Technology, LLC

Stmicroelectronics S.r.l.

Umberto Di Vincenzo

Ferdinando Bedeschi

Riccardo Muzzetto

Carlo Lisi

Marco Sforzin

Daniele Vimercati

Michele Maria Venturini

Simone Lombardo

Scott James Derner

Huy Thanh Vo

Hyun Yoo Lee

Efrem Bolandrina

Eric S Carman

Suryanarayana B Tatapudi

Lucia Di Martino

Daniele Balluchi

Christopher John Kawamura

Angelo Visconti

Claudia Palattella

Christophe Vincent Antoine Laurent

Pierguido Garofalo

Christian Caillat

Nicola Del Gatto

Paolo Turbanti

Christopher Johnson Kawamura

Christian Marc Benoit Caillat

A method including storing user data in memory cells of a memory array, storing, in a counter associated to the memory cells, count data corresponding to a number of bits in the user data having a predetermined first logic value, applying a read voltage to the memory cells to read the user data, applying the read voltage to the cells of the counter to read the count data and to provide a target value corresponding to the number of bits in the user data having the first logic value. During the application of the read voltage, the count data and the user data are read simultaneously such that the target value is provided during the reading of the user data. The application of the read voltage is stopped when the number of bits in the user data having the first logic value corresponds to the target value.

Counter-based methods and systems for accessing memory cells

A detection circuit may be configured to receive an input signal indicative of a data state and to detect the data state using charge sharing between two capacitors to achieve detection with threshold compensation. The detection circuit may include semi-latch circuitry and boosting circuitry to expedite the detection, thereby achieving high speed at low power consumption and low circuit size.

Threshold compensated detector for memory sense

Apparatuses, methods, and systems for storing one data value by programming a first memory cell and a second memory cell are disclosed. The first memory cell and the second memory cell may each be programmed to a first data state, a second data state, or a third data state, and the one data value can correspond to a combination of the first data state, the second data state, or the third data state to which the first memory cell and the second memory cell are programmed, where two combinations of the first data state, the second data state, or the third data state to which the first memory cell is programmable and the first data state, the second data state, or the third data state to which the second memory cell is programmable are ineligible to correspond to the one data value.

Storing one data value by programming a first memory cell and a second memory cell

Systems and methods for operating a memory include a sensing circuitry connected to a memory cell through an address decoder, a precharge circuitry configured to be connected to the sensing circuitry during a precharge stage and at least partially disconnected from the sensing circuitry during a sensing stage immediately following the precharge stage, and a reference voltage provided to the precharge circuitry, wherein the reference voltage is mirrored to the memory cell by mirroring a current flowing from the precharge circuitry with a current flowing from the sensing circuitry during the precharge stage.

Cascoded sense amplifiers for self-selecting memory

Apparatuses, methods, and systems for performing sense operations in memory are disclosed. The memory can have a group of memory cells, and circuitry can be configured to perform a sense operation on the group, wherein performing the sense operation includes performing a first sense operation in a first polarity on the group of memory cells to determine a quantity of the memory cells of the group that are in a particular data state, and performing a second sense operation in a second polarity on the group of memory cells to determine a data state of the memory cells of the group. The second polarity is opposite the first polarity, and the second sense operation is a count-based sense operation that uses the determined quantity of memory cells in the particular data state as a counting threshold to determine the data state of the memory cells of the group.

Performing sense operations in memory

A system includes a memory array having pattern cells and data cells. The pattern cells are configured to store only a first logic state. The data cells are configured to store the first logic state or a second logic state. Bias circuitry is configured to apply voltages to the pattern cells and data cells. Sensing circuitry is configured to read the pattern cells. A controller is configured to apply, using the bias circuitry, first voltages to the pattern cells; determine, using the sensing circuitry, that at least a portion of the pattern cells switch; determine, based on the portion of the pattern cells that switch, to refresh a codeword; and apply, using the bias circuitry, the refresh of the codeword.

Refresh determination using memory cell patterns

Methods, systems, and devices for read operations based on a dynamic reference are described. A memory device may include a set of memory cells each associated with a capacitive circuit including a first and second capacitor. After receiving a read command, the memory device may couple each capacitive circuit with a respective memory cell (e.g., to transfer a charge stored by each respective memory cell to a capacitive circuit) and may couple the second capacitor of each capacitive circuit to a reference voltage bus. Thus, a reference voltage on the reference voltage bus may be based on an average charge across the second capacitors of each capacitive circuit. The memory device may then compare a charge stored by the first and second capacitors of each capacitive circuit with the reference voltage bus and may output a set of values stored by the set of memory cells based on the comparing.

Read operations based on a dynamic reference

Methods, systems, and devices for accessing a ferroelectric memory cell are described. In some examples, during a first portion of an access procedure, the voltages of a digit line and word line coupled with the memory cell may be increased while the voltage of a plate coupled with the memory cell is held constant, which may support sensing a logic state stored by the memory cell prior the access procedure, and which may result in a first logic state being written to the memory cell. A voltage of the plate may then be increased, and the digit line may then be coupled with the plate. Because the first logic state was previously written to the memory cell, a target logic state may not need to be subsequently written to the memory cell unless different than the first logic state.

Ferroelectric memory cell access

A method for accessing of memory cells where a set of user data is stored in a plurality of memory cells of the memory array, including: latching a current row address of a selected plurality of memory access; comparing a last row address with the current row address; if the result of the comparison is negative, executing a leakage compensation algorithm through a memory sensing circuitry; if the result of the comparison is positive, waiting for the completion of a write to read procedure on the selected plurality of memory cells.

Methods and systems for improving read and write of memory cells

The present disclosure relates to a memory device comprising an array of memory cells arranged in a multideck configuration comprising a plurality of superimposed decks, a plurality of access lines comprising at least a first plurality of access lines arranged in a first level, a second plurality of access lines arranged in a second level, and a third plurality of access lines arranged in a third level between the first plurality of access lines and the second plurality of access lines, the third plurality of access lines being arranged between two decks of the plurality of decks, a plurality of drivers configured to drive signals to the access lines, and connection elements configured to electrically connect the access lines to the respective drivers. The connections elements and the access lines are arranged so that a single driver of the plurality of drivers is configured to drive at least one access line of each level of the at least three levels. Related memory systems and methods are also disclosed.

Architecture for multideck memory arrays

A variety of applications can include one or more memory devices having one or more memory arrays of memory cells, where each memory cell is a resistive memory cell arranged such that a clamp current for the memory cell can be provided by an access line biasing circuit to the memory cell opposite a coupling of a sense circuit to a digit line to the memory array. The access line biasing circuit and the sense circuit can be operated in a digit line precharge phase and an access line biasing phase of a memory cell of the memory array using a set of switches to control activities for the memory cell in the memory array, the sense circuit, and the access line biasing circuit. A reference current can be provided from the access line biasing circuit to the sense circuit. Additional devices, systems, and methods are discussed.

Current references for memory cells

The present disclosure relates to a method for accessing memory cells comprising: applying an increasing read voltage with a first polarity to the plurality of memory cells; counting a number of switching memory cells in the plurality based on the applying the increasing read voltage; applying a first read voltage with the first polarity based on the number of switched memory cells reaching a threshold number; applying a second read voltage with a second polarity opposite to the first polarity; and determining that a memory cell in the plurality of memory cells has a first logic value based on the memory cell having switched during one of the applying the increasing read voltage and the applying the first read voltage or based on the memory cell not having switched during the applying the second read voltage. A related system is also disclosed.

Method and system for accessing memory cells

Methods and apparatuses with counter-based reading are described. A memory cells of a codeword are accessed and respective voltages are generated. A reference voltage is generated and a logic state of each memory cell is determined based on the reference voltage and the respective generated cell voltage. The reference voltage is modified until a count of memory cells determined to be in a predefined logic state with respect to the last modified reference voltage value meets a criterium. In some embodiments the criterium may be an exact match between the memory cells count and an expected number of memory cells in the predefined logic state. In other embodiments, an error correction (ECC) algorithm may be applied while the difference between the count of cells in the predefined logic state and the expected number of cells in that state does not exceed a detection or correction power of the ECC.

Counter-based read in memory device

Methods and devices for techniques for precharging a memory cell are described. Precharging a memory cell while the memory cell is coupled with its digit line may reduce a total duration of an access operation thereby reducing a latency associated with accessing a memory device. During a read operation, the memory device may select a word line to couple the memory cell with a selected digit line. Further, the memory device may selectively couple the selected digit line with a reference digit line that is to be precharged to a given voltage. A difference in voltage between the selected digit line and the reference digit line at the completion of precharging may represent a signal indicative of a logic state of the memory cell. The memory device may use a capacitor precharged to a first voltage to capture the signal. In some cases, the memory device may continue to perform a self-reference operation using the same memory cell, the selected digit line, and the reference digit line to produce a reference signal using the capacitor precharged to a different voltage. A similar precharging steps may be repeated during the self-reference operation. The selected word line may remain activated during the read operation and the self-reference operation.

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Capriate San Gervasio, Italy

Umberto Di Vincenzo