Memory device, memory system, and operating method of compression using position values

Abstract

A memory device includes first and second memory cell arrays each including a plurality of memory cells, a page buffer circuit configured to read first soft decision data including a plurality of sub-segments from the first memory cell array, and a compression circuit configured to perform a first compression operation of generating a first compression segment including a number of position values less than or equal to a first reference number, on each of a plurality of partial segments included in one of the plurality of sub-segments and sequentially perform a plurality of compression operations, which is subsequent to the first compression operation, of generating a next compression segment including a number of position values, which are less than or equal to a reference number corresponding to each compression operation, of position values included in two or more previous compression segments in each compression operation.