| 摘要 |
PURPOSE: A redundancy circuit improving repair efficiency using data lines is provided which employs a switch for selectively separating local data lines to allow redundancy cells in the memory block adjacent to a memory block having a failed cell to be used for repairing the failed cell together with redundancy cells in the memory block having the failed cell. CONSTITUTION: A semiconductor memory device(2) includes at least one redundancy memory block(13,32) that has multiple DQ blocks(10,20,30) sharing a group of global data lines, main memory cell blocks(11,21,31) containing multiple memory cells arranged inside one DQ block, and redundant memory cells for repairing failed cells generated in the main memory blocks. Data of the memory cells is input/output through local data lines and the global data line. The local data lines are selectively separated and connected to replace a failed cell by the redundancy memory cell block included in a DQ block generating the failed cell. In addition, the redundancy memory cell block inside the DQ block adjacent to the DQ block can replace the failed cell.
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