Defektzellen-Reparaturschaltkreis und Verfahren für eine Halbleiterspeichervorrichtung

摘要

A method and circuit for repairing a defective cell of a packaged semiconductor memory device in a package state is described. In a repair mode, a repair mode selecting signal (PMj) is generated and a fuse selecting signal (PAj) corresponding to defective cell information is also generated. The repair mode selecting signal, which is decoded and the fuse selecting signal are analysed on receipt of a repair mode enable clock ( phi MI) and a fuse corresponding to the analyzed result is cut off, thus programming the address of the defective cell. In a normal operation mode, an external input address (Ai) is compared with the program address on receipt of a row address strobe signal. When the two addresses do not correspond to each other, a normal cell is selected. When the two addresses do correspond to each other, a redundant cell is selected. Input terminals may be shared between the two modes.