Abstract: The present invention relates to a method of operating memory cells, comprising reading a previous user data from the memory cells; writing a new user data and merging the new user data with the previous user data into write registers; generating mask register information, and wherein the mask register information indicates bits of the previous user data stored in the memory cells to be switched or not to be switched in their logic values; counting numbers of a first logic value and a second logic value to be written using the mask register information, respectively; storing the numbers of the first logic value and the second logic value into a first counter and a second counter, respectively; and applying a programming pulse to the memory cells according to the mask register information.

Abstract: Methods, systems, and devices for operating a memory cell or cells are described. A capacitor coupled with an access line may be precharged and then boosted such that the charge stored in the capacitor is elevated to a higher voltage with respect to a memory cell. The boosted charge in the capacitor may support sensing operations that would otherwise require a relatively higher voltage. Some embodiments may employ charge amplification between an access line and a sense component, which may amplify signals between the memory cell and the sense component, and reduce charge sharing between these components. Some embodiments may employ “sample-and-hold” operations, which may re-use certain components of a sense component to separately generate a signal and a reference, reducing sensitivity to manufacturing and/or operational tolerances. In some embodiments, sensing may be further improved by employing “self-reference” operations that use a memory cell to generate its own reference.

Abstract: Techniques are described herein for mitigating parasitic signals induced by state transitions during an access operation of a selected memory cell in a memory device. Some memory devices may include a plate that is coupled with memory cells associated with a plurality of digit lines and/or a plurality of word lines. Because the plate is coupled with a plurality of digit lines and/or word lines, unintended coupling between various components of the memory device may occur during an access operation. To mitigate parasitic signals induced by the unintended coupling, the memory device may isolate the selected memory cell from a selected digit line during certain portions of the access operation. The memory device may isolate the selected memory cell when the plate transitions from a first voltage to a second, when the selected digit line transitions from a third voltage to a fourth voltage, or a combination thereof.

Abstract: Methods, systems, and devices for a source follower-based sensing architecture and sensing scheme are described. In one example, a memory device may include a sense circuit that includes two source followers that are coupled to each other and to a sense amplifier. A method of operating the memory device may include transferring a digit line voltage to one of the source followers and transferring a reference voltage to the other source follower. After transferring the digit line voltage and the reference voltage, the source followers may be enabled so that signals representative of the digit line voltage and the reference voltage are transferred from the outputs of the source followers to the sense amplifier for sensing.

Abstract: Methods, systems, and devices for method for setting a reference voltage for read operations are described. A memory device may perform a first read operation on a set of memory cells using a first reference voltage and detect a first codeword based on performing the first read operation using the first reference voltage. The memory device may compare a first quantity of bits of the first codeword having a first logic value (e.g., a logic value ‘1’) with an expected quantity of bits having the first logic value (e.g., the expected quantity of logic value ‘1’s stored by the set of memory cells). The memory device may determine whether to perform a second read operation on the set of memory cells using a second reference voltage different than the first reference voltage (e.g., greater or less than the first reference voltage) based on the comparing.

Abstract: Methods, systems, and devices for sensing techniques for a memory cell are described to enable a latch to sense a logic state of a memory cell. A transistor coupled with a memory cell may boost a first voltage associated with the memory cell to a second voltage via one or more parasitic capacitances of the transistor. The second voltage may be developed on a first node of a sense component, and the second voltage may be shifted to a third voltage at a first node of the sense component by applying a voltage to a shift node coupled with a capacitor of the sense component. Similar boosting and shifting operations may be performed to develop a reference voltage on a second node of the sense component. The sense component may sense the state of the memory cell by comparing with the reference voltage.

Abstract: In a memory device, 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.

Abstract: The present disclosure provides a method, a circuit, and a system for reading memory cells. The method comprises: applying a first voltage with a first polarity to a plurality of the memory cells; applying a second voltage with a second polarity to one or more of said plurality of the memory cells; applying at least a third voltage with the first polarity to one or more of said plurality of the memory cells; detecting electrical responses of memory cells to the first voltage, the second voltage, and the third voltage; and determining a logic state of respective memory cells based on the electrical responses of the memory cells to the first voltage, the second voltage, and the third voltage.

Abstract: The present disclosure relates to a method for reading memory cells, comprising the steps of applying a first read voltage to a plurality of memory cells, detecting first threshold voltages exhibited by the plurality of memory cells in response to application of the first read voltage, based on the first threshold voltages, associating a first logic state to one or more cells of the plurality of memory cells, applying a second read voltage to the plurality of memory cells, wherein the second read voltage has the same polarity of the first read voltage and a higher magnitude than an expected highest threshold voltage of memory cells in the first logic state, detecting second threshold voltages exhibited by the plurality of memory cells in response to application of the second read voltage, based on the second threshold voltages, associating a second logic state to one or more cells of the plurality of memory cells, applying a third read voltage to the plurality of memory cells, wherein the third read voltage h

Abstract: 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.

Abstract: A counter can have a number of sensing components. Each respective sensing component can be configured to sense a respective event and can include a respective first capacitor configured to be selectively coupled to a second capacitor in response to the respective sensing component sensing the respective event. The second capacitor can be configured to be charged to a voltage by each respective first capacitor that is selectively coupled to the second capacitor. The counter can have a comparator with a first input coupled to the second capacitor and a second input coupled to a reference voltage corresponding to a threshold quantity of events. The comparator can be configured to output a signal indicative of the threshold quantity of events being sensed in response to the voltage of the second capacitor being greater than or equal to the reference voltage.

Abstract: Techniques, systems, and devices for time-resolved access of memory cells in a memory array are described herein. During a sense portion of a read operation, a selected memory cell may be charged to a predetermined voltage level. A logic state stored on the selected memory cell may be identified based on a duration between the beginning of the charging and when selected memory cell reaches the predetermined voltage level. In some examples, time-varying signals may be used to indicate the logic state based on the duration of the charging. In some examples, the duration of the charging may be based on a polarization state of the selected memory cell, a dielectric charge state of the selected state, or both a polarization state and a dielectric charge state of the selected memory cell.

Abstract: The present disclosure includes apparatuses, methods, and systems for charge separation for memory sensing. An embodiment includes applying a sensing voltage to a memory cell, and determining a data state of the memory cell based, at least in part, on a comparison of an amount of charge discharged by the memory cell while the sensing voltage is being applied to the memory cell before a particular reference time and an amount of charge discharged by the memory cell while the sensing voltage is being applied to the memory cell after the particular reference time.

Abstract: Methods, systems, devices, and techniques for read operations are described. In some examples, a memory device may include a first transistor (e.g., memory node transistor) configured to receive a precharge voltage at a first gate and output first voltage based on a threshold of the first transistor to a reference node via a first switch. The device may include a second transistor (e.g., a reference node transistor) configured to receive a precharge voltage and output a second voltage based on a threshold of the second transistor to a memory node via a second switch. The first voltage may be modified by a reference voltage and input to the second transistor. The second voltage may be modified by a voltage stored on a memory cell and input to the first transistor. The first and second transistor may output third and fourth voltages to be sampled to a latch.

Abstract: 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.

Abstract: Methods and devices for reading a memory cell using a sense amplifier with split capacitors is described. The sense amplifier may include a first capacitor and a second capacitor that may be configured to provide a larger capacitance during certain portions of a read operation and a lower capacitance during other portions of the read operation. In some cases, the first capacitor and the second capacitor are configured to be coupled in parallel between a signal node and a voltage source during a first portion of the read operation to provide a higher capacitance. The first capacitor may be decoupled from the second capacitor during a second portion of the read operation to provide a lower capacitance during the second portion.

Abstract: Methods, systems, and apparatuses for full bias sensing in a memory array are described. Various embodiments of an access operation of a cell in a array may be timed to allow residual charge of a middle electrode between the cell and a selection component to discharge. Access operations may also be timed to allow residual charge of middle electrodes associated with other cells to be discharged. In conjunction with an access operation for a target cell, a residual charge of a middle electrode of another cell may be discharged, and the target cell may then be accessed. A capacitor in electronic communication with a cell may be charged and a logic state of the cell determined based on the charge of the capacitor. The timing for charging the capacitor may be related to the time for discharging a middle electrode of the cell or another cell.

Abstract: Methods, systems, and devices for operating a ferroelectric memory cell or cells are described. A ground reference scheme may be employed in a digit line voltage sensing operation. A positive voltage may be applied to a memory cell; and after a voltage of the digit line of the cell has reached a threshold, a negative voltage may be applied to cause the digit line voltages to center around ground before a read operation. In another example, a first voltage may be applied to a memory cell and then a second voltage that is equal to an inverse of the first voltage may be applied to a reference capacitor that is in electronic communication with a digit line of the memory cell to cause the digit line voltages to center around ground before a read operation.

Abstract: Methods, systems, and devices for operating a memory cell or cells are described. A capacitor coupled with an access line may be precharged and then boosted such that the charge stored in the capacitor is elevated to a higher voltage with respect to a memory cell. The boosted charge in the capacitor may support sensing operations that would otherwise require a relatively higher voltage. Some embodiments may employ charge amplification between an access line and a sense component, which may amplify signals between the memory cell and the sense component, and reduce charge sharing between these components. Some embodiments may employ “sample-and-hold” operations, which may re-use certain components of a sense component to separately generate a signal and a reference, reducing sensitivity to manufacturing and/or operational tolerances. In some embodiments, sensing may be further improved by employing “self-reference” operations that use a memory cell to generate its own reference.

Abstract: A counter can have a number of sensing components. Each respective sensing component can be configured to sense a respective event and can include a respective first capacitor configured to be selectively coupled to a second capacitor in response to the respective sensing component sensing the respective event. The second capacitor can be configured to be charged to a voltage by each respective first capacitor that is selectively coupled to the second capacitor. The counter can have a comparator with a first input coupled to the second capacitor and a second input coupled to a reference voltage corresponding to a threshold quantity of events. The comparator can be configured to output a signal indicative of the threshold quantity of events being sensed in response to the voltage of the second capacitor being greater than or equal to the reference voltage.