Performance in reading memory cells affected by neighboring memory cells

A method for data storage, comprising:

• in a storage device comprising multiple memory cells arranged in multiple Word Lines (WLs), the memory cells store data in Np programming levels of threshold voltage values, defining NRv threshold-sets, wherein each of the threshold-sets comprises Ns read thresholds that define Ns+1 zones of threshold voltage values for each respective threshold-set;
• reading a data page Ns times, from a target WL comprising multiple target memory cells, to produce Ns respective readouts, wherein each of the Ns readouts is read using a set of NRv read thresholds each selected from the NRv threshold-sets, and wherein the target page was encoded for storage using an Error Correction Code (ECC);
• identifying Np neighbor programming levels to which the memory cells in one or more neighbor WLs to the target WL, are programmed, and making a classification of the target memory cells in the target WL into a plurality of cell-groups, wherein each of the cell-groups is associated with (i) a respective threshold-set and (ii) a respective neighbor programming level;
• for each zone calculating Np Log likelihood Ratio (LLR) values, for the respective Np neighbor programming levels;
• assigning the calculated LLR values to the target memory cells whose threshold voltages fall in that zone;
• and
• recovering the target page by applying to the assigned LLR values soft decoding for decoding the ECC.

A storage device, comprising:

• multiple memory cells arranged in multiple Word Lines (WLs), configured to store data in Np programming levels of threshold voltage values;
• and
• circuitry configured to:
• read a neighbor page from a neighbor WL of a target WL that stores a target page encoded using ECC to be read, and classify the memory cells in the target WL into multiple cell-groups based on the Np neighbor programming levels to which the memory cells in the neighbor WL are programmed;
• calculate multiple respective sets of optimal read thresholds for each of the multiple cell-groups;
• read the target WL using each of the multiple sets of the optimal read thresholds, and combine bits read from the memory cells of the respective cell-groups to produce a combined page;
• assign LLR values to the bits of the combined page per zone and neighbor programming level;
• and
• recover the target page by applying to the bits of the combined page, with the assigned LLR values, soft decoding for decoding the ECC.

A method for data storage, comprising:

• in a storage device comprising multiple memory cells arranged in multiple Word Lines (WLs), the memory cells store data in Np programming levels of threshold voltage values,
• reading a neighbor page from a neighbor WL of a target WL that stores a target page encoded using ECC to be read, and classifying the memory cells in the target WL into multiple cell-groups based on the Np neighbor programming levels to which the memory cells in the neighbor WL are programmed;
• calculating multiple respective sets of optimal read thresholds for each of the multiple cell-groups;
• reading the target WL using each of the multiple sets of the optimal read thresholds, and combining bits read from the memory cells of the respective cell-groups to produce a combined page;
• assigning LLR values to the bits of the combined page per zone and neighbor programming level;
• and
• recovering the target page by applying to the bits of the combined page, with the assigned LLR values, soft decoding for decoding the ECC.