Method of determining deterioration state of memory device and memory system using the same

摘要

A method is provided for determining a deterioration condition of a memory device. The method includes calculating first information corresponding to a number of bits having a first logic value from data obtained by performing a first read operation on target storage region of the memory device using a first reference voltage as a read voltage, and calculating second information corresponding to a number of bits having a second logic value from data obtained by performing a second read operation on the target storage region using a second reference voltage as the read voltage. A deterioration condition of the target storage region is determined based on the first and second information. The first reference voltage is less than a first read voltage by which an erase state of the memory device is distinguished from an adjacent program state, and the second reference voltage is higher than the first read voltage.

主权项

1. A method of determining a deterioration condition of a memory device, the method comprising:
calculating first information corresponding to a number of bits having a first logic value from data obtained by performing a first read operation on a target storage region of the memory device using a first reference voltage as a read voltage; calculating second information corresponding to a number of bits having a second logic value, from data obtained by performing a second read operation on the target storage region of the memory device using a second reference voltage as the read voltage; and determining a deterioration condition of the target storage region of the memory device based on the calculated first information and the calculated second information, wherein the first reference voltage is less than a first read voltage by which an erase state of the memory device is distinguished from a program state adjacent to the erase state, and the second reference voltage is higher than the first read voltage, and wherein determining of the deterioration condition comprises: applying the calculated first information and the calculated second information to a predetermined equation and performing a calculation process; and determining the type of deterioration condition of the target storage region of the memory device based on a result of the calculation process, wherein the predetermined equation is obtained to discriminate among the plurality of types of deterioration conditions based on a distribution of experimentally measured first information and experimentally measured second information.