SEMICONDUCTOR MEMORY

PROBLEM TO BE SOLVED: To improve the column saving probability of a DRAM, etc., which is provided with plural memory arrays of multi-bit constitution including redundancy bit lines in which every prescribed number arrays is simultaneously turned into an active state. SOLUTION: A dynamic type RAM, etc., provided with plural memory arrays stores saving addresses of bit lines, compares them with access addresses when accessing, and turns a hit signal into a valid level selectively when those addresses match with each other. One of the memory addresses where the saving addresses are brought into active state at the same time is assigned to a redundancy bit line, then each redundancy bit line serves effectively for the saving of a defective bit line.