| 摘要 |
PROBLEM TO BE SOLVED: To achieve the prefetch of a DDR3 by using a 3MAT system of a DDR2.SOLUTION: A semiconductor device comprises: first, second and third memory mats disposed in a word line direction; a first local IO extended from almost the central part in a word line direction of the second memory mat to the first memory mat; a second local IO extended to the third memory mat; a first Y switch signal line for redundant bit line selection disposed in the second memory mat, and extended in a bit line direction; a second Y switch signal line for redundant bit line selection extended in the bit line direction; a Y switch signal line for separation bit line selection extended in the bit line direction, and allowed to pass between the first local IO and the second local IO; and a Y switch signal line for dummy bit line selection disposed so as to be positioned at the opposite side of the Y switch signal line for separation bit line selection with respect to the second Y switch signal line for redundant bit line selection, and extended in the bit line direction. |
