Semiconductor memory devices and memory systems with enhanced error detection and correction

Abstract

A semiconductor memory device includes a memory cell array, an error correction circuit, an input/output (I/O) gating circuit and a control logic circuit. The memory cell array is coupled to word-line and bit-lines and is divided into sub array blocks. The error correction circuit generates parity data based on main data using an error correction code (ECC). The control logic circuit controls the error correction circuit and the I/O gating circuit based on a command and address. The control logic circuit stores the main data and the parity data in (k+1) target sub array blocks in the second direction among the sub array blocks, and controls the I/O gating circuit such that a portion of the (k+1) target sub array blocks store both of a portion of the main data and a portion of the parity data.