PURPOSE: To improve integration by providing redundant memory cells of the same number of unit for every block and providing ROMs storing a position for substitution by quantities corresponding to the number of substitution unit for redundant memory cells of each block.
CONSTITUTION: Since a redundant section test signal is not impressed after writing in a first ROM 21, a second ROM 22 and a selector ROM 26 is finished, when low-order addresses written in a ROM 21 and a ROM 22 is inputted, an output of a column selecting signal from a column decoder 15 is stopped. And output of comparator circuits 23 and 24 are impressed to a first switch and a third switch of a switch column 17 of a redundant section via a selecting ROM 26, and a bit column is connected to a sense amplifier 18. Then, redundant memory cells of the same number of substitution unit for every block are provided, and ROMs storing positions for substitution are provided by quantities corresponding to the number of substitution unit of redundant memory cells for every block, Thereby, a redundant ROM can be miniaturized, and integration can be improved by its reduction.
TAKEMAE YOSHIHIRO
KODAMA YUKINORI
