| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor memory device which can obtain redundancy saving fuse blown-out information without increasing the chip size, and provide a method of reading the redundancy saving address. SOLUTION: Setting up a normal operation mode by using mode signals MOD, "H" data are written by sequentially specifying the whole address of a memory cell block 1 using row address signals RADR. Since the replacement signals REP1 are output when the row address signals RADR match the redundancy saving address set up in the fuse circuits 21, 22, the data "H" are written in a redundancy memory cell instead of a normal memory cell. Then, when "L" is written in the whole address by setting up a test mode, "L" is written in a normal memory cell, and the redundancy memory cell is not changed and remains in "H". Thus, by reading the data of the whole address in the normal mode, the address the data "H" are read can be decided as the redundancy saving address. COPYRIGHT: (C)2005,JPO&NCIPI
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