Methods, systems, and devices related to auto-referenced memory cell read techniques are described. The auto-referenced read may encode user data to include a certain number bits having a first logic state prior to storing the user data in memory cells. Subsequently, reading the encoded user data may be carried out by applying a read voltage to the memory cells while monitoring a series of switching events by activating a subset of the memory cells having the first logic state. The auto-referenced read may identify a particular switching event that correlates to a median threshold voltage value of the subset of the memory cells. Then, the auto-referenced read may determine a reference voltage that takes into account a statistical property of threshold voltage distribution of the subset of the memory cells. The auto-referenced read may identify a time duration to maintain the read voltage based on determining the reference voltage. When the time duration expires, the auto-referenced read may determine that the memory cells that have been activated correspond to the first logic state.

A memory device includes multiple word lines. A method of operating the memory device includes: performing a first dummy read operation, with respect to first memory cells connected to a first word line among the word lines, by applying a dummy read voltage, having an offset level of a first level, to the first word line; determining, based on a result of the performing of the first dummy read operation, degradation of a threshold voltage distribution of the first memory cells; adjusting an offset level of the dummy read voltage as a second level, based on a result of the determining of the threshold voltage distribution; and performing a second dummy read operation with respect to second memory cells connected to a second word line among the word lines, by applying a dummy read voltage, having the offset level adjusted as the second level, to the second word line among the word lines.

A computer-implemented method, according to one approach, is for calibrating read voltages associated with a block of memory having more than one word-line therein. The computer-implemented method includes: for each of the word-lines in the block: calculating an absolute shift value for a reference read voltage associated with the given word-line. A relative shift value is also determined for each of the remaining read voltages associated with the given word-line, and the relative shift values are determined with respect to the reference read voltage. Moreover, each of the read voltages associated with the given word-line are adjusted using the absolute shift value and each of the respective relative shift values.

A computer-implemented method, according to one approach, includes: using a first calibration scheme to calibrate the given page in the block by calculating a first number of independent read voltage offset values for the given page. An attempt is made to read the calibrated given page, and in response to determining that an error correction code failure occurred when attempting to read the calibrated given page, a second calibration scheme is used to recalibrate the given page in the block. The second calibration scheme is configured to calculate a second number of independent read voltage offset values for the given page. An attempt to read the recalibrated given page is also made. In response to determining that an error correction code failure did occur when attempting to read the recalibrated given page, one or more instructions to relocate data stored in the given page are sent.

A method for operating a data storage device includes determining appropriateness of a first read bias for adjacent target threshold voltage distributions among threshold voltage distributions for a plurality of memory cells; and if it is determined that the first read bias is inappropriate, determining a second read bias.

The present disclosure relates to partially written superblock treatment. An example apparatus includes a memory device operable as a multiplane memory resource including blocks organized as superblocks. The memory device is configured to maintain, internal to the memory device, included in a status of an open superblock, a page indicator corresponding to a last written page of the open superblock. The memory device is further configured, responsive to receipt, from a controller, of a read request to a page of the open superblock, determine from page map information maintained internal to the memory device and from the indicator of the last written page, which of a number of different read trim sets to use to read the page of the open superblock corresponding to the read request.

Methods, systems, and devices related to auto-referenced memory cell read techniques are described. The auto-referenced read may encode user data to include a certain number bits having a first logic state prior to storing the user data in memory cells. Subsequently, reading the encoded user data may be carried out by applying a read voltage to the memory cells while monitoring a series of switching events by activating a subset of the memory cells having the first logic state. The auto-referenced read may identify a particular switching event that correlates to a median threshold voltage value of the subset of the memory cells. Then, the auto-referenced read may determine a reference voltage that takes into account a statistical property of threshold voltage distribution of the subset of the memory cells. The auto-referenced read may identify a time duration to maintain the read voltage based on determining the reference voltage. When the time duration expires, the auto-referenced read may determine that the memory cells that have been activated correspond to the first logic state.

A computer-implemented method, according to one approach, is for calibrating read voltages for a block of memory. The computer-implemented method includes: determining a current operating state of a block which includes more than one word-line therein, and where more than one read voltage is associated with each of the word-lines. Moreover, for each of the word-lines in the block: one of the read voltages associated with the given word-line is selected as a reference read voltage, and an absolute shift value is calculated for the reference read voltage. A relative shift value is determined for each of the remaining read voltages associated with the given word-line, where the relative shift values are determined with respect to the reference read voltage. Furthermore, each of the read voltages associated with the given word-line are adjusted using the absolute shift value and each of the respective relative shift values.

A flash memory comprising a first plurality of memory cells, each memory cell of the first plurality of memory cells selectively connected to a first input of a comparator. A second plurality of memory cells selectively connected to a second input of the comparator, wherein a first number of the second plurality of memory cells are in an erased state, wherein a second number of the second plurality of memory cells are in a written state, wherein each memory cell of the first plurality of memory cells and each memory cell of the second plurality of memory cells has a first cell capacitance, and wherein the sum of the first number and the second number is at least three.

A nonvolatile memory device may include a page buffer including a plurality of latch sets that latch each page datum of selected memory cells among a plurality of memory cells according to each of read signal sets including at least one read signal, and a control logic configured to detect a degradation level of the memory cells and determine a read parameter applied to at least one of the read signal sets based on the detected degradation level.