GROUP CLASSIFICATION METHOD FOR SOLID STATE STORAGE DEVICE

摘要

A group classification method includes the following steps. Firstly, a voltage shift parameter table is established. The voltage shift parameter table includes a first positional parameter table corresponding to a first neighboring cell. Then, MN ICI patterns are determined according to N neighboring cells having a significant ICI effect. If the central cell has a first storing state, MN central cell threshold voltage shifts corresponding to the MN ICI patterns are determined according to the voltage shift parameter table, and the first storing state is divided into plural sub-regions. Afterwards, the central cells corresponding to a first number of ICI patterns are classified into a first group of the first storing state. The central cell threshold voltage shifts corresponding to the first number of ICI patterns lie in a first sub-region of the first storing state.

主权项

1. A group classification method for a solid state storage device, the solid state storage device comprising a central cell and plural neighboring cells around the central cell, each of the central cell and the plural neighboring cells being programmable into one of M storing states, N neighboring cells of the plural neighboring cells having a significant ICI effect, the group classification method comprising steps of:
establishing a voltage shift parameter table, wherein the voltage shift parameter table comprises a first positional parameter table corresponding to a first neighboring cell, and the first neighboring cell is one of the N neighboring cells having the significant ICI effect; determining MN ICI patterns according to the N neighboring cells having the significant ICI effect; if the central cell has a first storing state of the M storing states, determining MN central cell threshold voltage shifts corresponding to the MN ICI patterns according to the voltage shift parameter table; dividing the first storing state into plural sub-regions according to the MN central cell threshold voltage shifts; and classifying the central cells corresponding to a first number of ICI patterns into a first group of the first storing state, wherein the central cell threshold voltage shifts corresponding to the first number of ICI patterns lie in a first sub-region of the first storing state.