| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor memory in which a redundancy deciding circuit is made small scale, its operation time is shortened, and redundant relieving probability can be improved. SOLUTION: A semiconductor memory divided into plural memory cell blocks according to a row address has a redundancy deciding circuit 50 deciding whether a memory cell array and a redundant memory cell array are divided into plural parts in the direction of column, further, they correspond to a redundant address in which an address externally supplied is recorded or not, and a replacing data holding circuit holding replacing data indicating whether replacement is performed by a redundant memory cell or not for each memory cell array divided in the direction of column, and a word driver drives either of the memory cell array or the redundant memory cell array divided in the direction of column in accordance with an output of the redundancy deciding circuit 50 and output of the replacement data holding circuit. The number of addresses of the redundancy deciding circuit can be decreased, operation speed can be increased, and reduction of relieving probability can be prevented dividing into plural memory cell blocks.
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