Examples of the present disclosure provide apparatuses and methods for error code calculation. The apparatus can include an array of memory cells that are coupled to sense lines. The apparatus can include a controller configured to control a sensing circuitry, that is coupled to the sense lines, to perform a number of operations without transferring data via an input/output (I/O) lines. The sensing circuitry can be controlled to calculate an error code for data stored in the array of memory cells and compare the error code with an initial error code for the data to determine whether the data has been modified.

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.

Apparatuses and methods for compensating for signal drop in memory. Compensating for signal drop can include applying a first signal to a terminal of a particular transistor and mirroring the first signal to a decoder replica. Compensating for signal drop can also include applying a second signal to a gate of the particular transistor, the second signal comprising a sensing signal and a signal drop on the decoder replica and sensing a state of the particular transistor.

A sense amplifier including a first input transistor having a first input gate and a first drain/source terminal, a second input transistor having a second input gate and a second drain/source terminal, a latch circuit, and a first capacitor. The latch circuit includes a first latch transistor having a third drain/source terminal connected to the first drain/source terminal and a second latch transistor having a fourth drain/source terminal connected to the second drain/source terminal. The first capacitor is connected on one side to the first input gate and on another side to the fourth drain/source terminal to reduce a coupling effect in the sense amplifier.

In a compute-in-memory (“CIM”) system, current signals, indicative of the result of a multiply-and-accumulate operation, from a CIM memory circuit are computed by comparing them with reference currents, which are generated by a current digital-to-analog converter (“DAC”) circuit. The memory circuit can include non-volatile memory (“NVM”) elements, which can be multi-level or two-level NVM elements. The characteristic sizes of the memory elements can be binary weighted to correspond to the respective place values in a multi-bit weight and/or a multi-bit input signal. Alternatively, NVM elements of equal size can be used to drive transistors of binary weighted sizes. The current comparison operation can be carried out at higher speeds than voltage computation. In some embodiments, simple clock-gated switches are used to produce even currents in the current summing branches. The clock-gated switches also serve to limit the time the cell currents are on, thereby reducing static power consumption.

A memory device includes a plurality of sense amplifiers, a plurality of memory cells, a plurality of data lines, a plurality of reference cells, and a connection line. The memory cells are coupled to a plurality of first inputs of the plurality of sense amplifiers respectively. The data lines are coupled to a plurality of second inputs of the plurality of sense amplifiers respectively. The reference cells are arranged in a plurality of columns respectively and coupled to the plurality of data line respectively. Each of the plurality of reference cells includes a plurality of resistive elements. The connection line is coupled to the plurality of data lines. In a read mode, one of the sense amplifiers is configured to access the plurality of resistive elements arranged in at least one of the plurality of columns.

A memory device includes a memory array that includes one or more rows of memory cells and one or more columns of memory cells. The comparator circuitry is operably connected to at least one column of memory cells in the one or more columns of memory cells. The comparator circuitry includes a precompute circuit and a select circuit operably connected to the outputs of the precompute circuit. The precompute circuit is operable to precompute a comparison operation to produce a first precompute signal and a second precompute signal. The select circuit is operable to receive a first cell data signal from a memory cell in the column of memory cells. Based at least on the first cell data signal, the select circuit selects either the first precompute signal or the second precompute signal to output from the comparator circuitry as a signal read from the memory cell.

Apparatuses and methods for compensating for signal drop in memory. Compensating for signal drop can include applying a first signal to a terminal of a particular transistor and mirroring the first signal to a decoder replica. Compensating for signal drop can also include applying a second signal to a gate of the particular transistor, the second signal comprising a sensing signal and a signal drop on the decoder replica and sensing a state of the particular transistor.

A semiconductor device includes: a sense amplifier; a branched line selectively connectable to the amplifier; an array of bit lines connected to corresponding memory cells; and an intra-sense-amplifier recycling arrangement configured to do as follows including: recovering a first charge from a first bit line associated with a first one of the memory cells, the first charge being associated with a preceding first evaluation performed by the sense amplifier; and boosting the branched line to a reference voltage including reusing the first charge to at least partially charge the branched line; and wherein the sense amplifier is configured to make a second evaluation of a stored value in a second memory cell relative to the reference voltage.

In a particular implementation, a circuit comprises: a memory array including a plurality of bit cells, where each of the bit cells are coupled to a respective bit path; a first multiplexer comprising a plurality of column address locations, where each of the plurality of column address locations is coupled to the memory array and corresponds to a respective bit path capacitance; and a variable capacitance circuit coupled to a reference path and configured to substantially match reference path capacitance to each of the respective bit path capacitances.