| 摘要 |
PROBLEM TO BE SOLVED: To improve area efficiency of a redundant circuit by sharply reducing the number of all spare elements without reducing relives efficiency of a defective memory cells of a DRAM. SOLUTION: This device is provided with first spare elements SWL, provided respectively in plural normal banks BANK0-BANK15 in which a memory cell array is divided into plural sections, second spare elements SWL provided in spare banks BANKKBP which is separate from the normal banks, plural first space decodes SRD0-SRD3 selecting and driving the first spare elements, second spare elements SRD0-SRD3 selecting and driving the second spare elements, and replacement control circuits FS0a-FS27a, RWL0N1, RWL0N2, SRDact0- SRDact3 allotting selectively the second spare elements to arbitrary banks in plural normal banks. |
