Semiconductor storage device

Abstract

Abstract PURPOSE:To relieve a faulty storage cell effectively, by providing a stand-by storage line to store by a faulty bit circuit in case when an original storage cell is faulty, programming an address of the faulty storage cell, and selectively replacing a stand-by storage cell when said address is supplied. CONSTITUTION:Each bit B consists of a storage line L on which plural storage cells 11 is oriented, and each line L is selected by each line selecting circuits 121-12n at every bit. Between a row selecting circuit 13 having a pair of bit Bi and Bi+1 in-between, and the bit Bi, a stand-by storage line LS2 having an oriented stand-by storage cell 14 is layed out. When the bit B of the storage line L containing a faulty storage cell, a faulty bit storing circuit 20 stores it, and its address is stored in a stand-by selecting circuit 16. When a faulty bit B is selected by the line selecting circuit 12, the stand-by selecting circuit 16 selects a stand-by storage line LS1 to be replaced and to relieve effectively the faulty storage cell by the stand-by storage cells of the smallest number.

Inventors

• 👤 Kiyobumi Ochii
• 👤 落井　清文

Bibliographic Details