The controller that controls a memory device includes: a processor suitable for controlling the memory device to perform a first soft read operation by using first soft read voltages; and an error correction code (ECC) codec suitable for performing a first soft decision decoding operation based on first soft read data obtained through the first soft read operation, wherein the processor controls the memory device to perform a second soft read operation with an additional read voltage, of second soft read voltages, that is different than any of the first soft read voltages and which is determined based on the first soft read data, according to whether the first soft decision decoding operation failed, and wherein the ECC codec performs a second soft decision decoding operation based on the first soft read data and second soft read data obtained through the second soft read operation.

A storage device including, a plurality of non-volatile memories configured to include a memory cell region including at least one first metal pad; and a peripheral circuit region including at least one second metal pad and vertically connected to the memory cell region by the at least one first metal pad and the at least one second metal pad, and a controller connected to the plurality of non-volatile memories through a plurality of channels and configured to control the plurality of non-volatile memories, wherein the controller selects one of a first read operation mode and a second read operation mode and transfers a read command corresponding to the selected read operation mode to the plurality of non-volatile memories, wherein one sensing operation is performed to identify one program state among program sates in the first read operation mode, and wherein at least two sensing operations are performed to identify the one program state among the program states in the second read operation mode.

A memory device to estimate a bit error count of data retrievable from a group of memory cells. For example, the memory device has a group of memory cells programmed to store a predetermined number of bits per memory cells to be read at a plurality of first voltages. The memory device determines a plurality of calibrated read voltages corresponding to the plurality of first voltages respectively, based on first signal and noise characteristics of the group of memory cells. The first signal and noise characteristics are used to compute second signal and noise characteristics of the group of memory cells for the calibrated read voltages. The second signal and noise characteristics are used in an empirical formula to compute an estimate of the bit error count of data retrievable from the group of memory cells using the calibrated read voltages.

A storage device including, a plurality of non-volatile memories configured to include a memory cell region including at least one first metal pad; and a peripheral circuit region including at least one second metal pad and vertically connected to the memory cell region by the at least one first metal pad and the at least one second metal pad, and a controller connected to the plurality of non-volatile memories through a plurality of channels and configured to control the plurality of non-volatile memories, wherein the controller selects one of a first read operation mode and a second read operation mode and transfers a read command corresponding to the selected read operation mode to the plurality of non-volatile memories, wherein one sensing operation is performed to identify one program state among program sates in the first read operation mode, and wherein at least two sensing operations are performed to identify the one program state among the program states in the second read operation mode.

Methods, systems, and devices for techniques for determining memory cell read offsets are described to support determining voltage offsets and corresponding read voltage levels for one or more memory cell levels using a relationship between read voltage levels and voltage offsets. A memory device may estimate first voltage offsets using a first procedure and may perform a read operation using the first voltage offsets. If a first voltage offset results in a read error for a corresponding memory cell level, the memory device may determine an updated voltage offset using the relationship. The relationship may predict a voltage offset for a given read voltage level, such that the memory device may use the relationship to predict an updated voltage offset for a memory cell level. The memory device may use the updated voltage offset(s) to perform a second read operation for the one or more memory cells.

Nonvolatile memory device includes memory cell region including a first metal pad and a second metal pad, peripheral circuit region including a third metal pad and a fourth metal pad, vertically connected to the memory cell region. The nonvolatile memory device includes a page buffer circuit including page buffers to sense data from selected memory cells, each including two sequential sensing operations to determine one data state, and each of the page buffers including a latch to sequentially store results of the two sequential sensing operations. The nonvolatile memory device includes control circuit in the peripheral circuit region, to control the page buffers to store result of the first read operation, reset the latches after completion of the first read operation, and control the page buffers to perform the second read operation based on a valley determined based on the result of the first read operation.

A memory device to estimate a bit error count of data retrievable from a group of memory cells. For example, the memory device has a group of memory cells programmed to store a predetermined number of bits per memory cells to be read at a plurality of first voltages. The memory device determines a plurality of calibrated read voltages corresponding to the plurality of first voltages respectively, based on first signal and noise characteristics of the group of memory cells. The first signal and noise characteristics are used to compute second signal and noise characteristics of the group of memory cells for the calibrated read voltages. The second signal and noise characteristics are used in an empirical formula to compute an estimate of the bit error count of data retrievable from the group of memory cells using the calibrated read voltages.

Methods, systems, and devices for techniques for determining memory cell read offsets are described to support determining voltage offsets and corresponding read voltage levels for one or more memory cell levels using a relationship between read voltage levels and voltage offsets. A memory device may estimate first voltage offsets using a first procedure and may perform a read operation using the first voltage offsets. If a first voltage offset results in a read error for a corresponding memory cell level, the memory device may determine an updated voltage offset using the relationship. The relationship may predict a voltage offset for a given read voltage level, such that the memory device may use the relationship to predict an updated voltage offset for a memory cell level. The memory device may use the updated voltage offset(s) to perform a second read operation for the one or more memory cells.

The controller that controls a memory device includes: a processor suitable for controlling the memory device to perform a first soft read operation by using first soft read voltages; and an error correction code (ECC) codec suitable for performing a first soft decision decoding operation based on first soft read data obtained through the first soft read operation, wherein the processor controls the memory device to perform a second soft read operation with an additional read voltage, of second soft read voltages, that is different than any of the first soft read voltages and which is determined based on the first soft read data, according to whether the first soft decision decoding operation failed, and wherein the ECC codec performs a second soft decision decoding operation based on the first soft read data and second soft read data obtained through the second soft read operation.

A memory sub-system configured to iterative calibrate read voltages, where higher read voltages are calibrated based on the calibration results of lower read voltages. For example, a memory device initially determines first read voltages of a group of memory cells. The memory device calculates a second read voltage optimized to read the group of memory cells according to first signal and noise characteristics measured based on at least one of the first read voltages. A third read voltage is estimated based on an offset of the second read voltage from a corresponding voltage among the first read voltages. Second signal and noise characteristics of the group of memory cells are measured based on the third read voltage. The memory device then calculates a fourth read voltage optimized to read the group of memory cells according to the second signal and noise characteristics.