| 摘要 |
The present invention relates to a semiconductor memory device for preventing deterioration of data stored in a memory cell, caused by word line disturbance, and to a semiconductor memory system comprising the same. The semiconductor memory device comprises: a plurality of normal word lines and a plurality of redundancy word lines arranged adjacent thereto; a detection unit for allowing an active history to detect a normal word line satisfying a predetermined condition, among the normal word lines, as a target word line; and a control unit for sequentially refreshing the normal word lines and the redundancy word lines whenever a refresh command is received, and additionally refreshing the target word line, a word line adjacent to the target word line, and a normal word line adjacent to the redundancy word lines among the normal word lines. |
