| 摘要 |
PURPOSE:To recover a defective memory without having a large chip size, by performing comparison with a defective address for each row address and column address and giving an access to a corresponding redundant memory. CONSTITUTION:A selector AS selects one of row and column addresses given from address buffers Y-ADB and X-ADB, and this selected address is compared with a row or column address of a defective memory that is stored in an address comparator AC. When the coincidence is obtained from this comparison, a corresponding address is delivered from an output selector. Then an access is given to a desired redundant memory of a memory array M-ARY. Thus the defective memory can be recovered without increasing the chip size by making use of a fact that a defective bit is inclined to one of row and column systems. |
