Semiconductor memory devices, memory systems including the same and method of correcting errors in the same

Abstract

A semiconductor memory device includes a memory cell array in which a plurality of memory cells are arranged. The semiconductor memory device includes an error correcting code (ECC) circuit configured to generate parity data based on main data, write a codeword including the main data and the parity data in the memory cell array, read the codeword from a selected memory cell row to generate syndromes, and correct errors in the read codeword on a per symbol basis based on the syndromes. The main data includes first data of a first memory cell of the selected memory cell row and second data of a second memory cell of the selected memory cell row. The first data and the second data are assigned to one symbol of a plurality of symbols, and the first memory cell and the second memory cell are adjacent to each other in the memory cell array.