Defect cells - repair circuit and defect cells - method of repair for a semiconductor memory device

摘要

Repair circuit for repairing a defective cell in an encapsulated semiconductor memory device, thea normal cell array (500) for storing data,a redundant cell array (600) for storing of redundant data,a cells selection circuit (400) for selecting a memory cell from the normal or the redundant cell field depending on whether an enable signal (φre) for an access to a redundant cell is present or not, and alsothe repair circuit has with the following components:a repair mode freely administration circuit (100) for the alternative for releasing a of two possible operating states (repair mode or operating mode) of the repair circuit by outputting a first binary release signal for the repair mode (φmi),a defect cells address decoder (200), the only in the reparaturrodus enabled for decoding externally entered defect cells addresses (pm1 .. Pmn) of the normal cell array (500) and for generating a decoder output signal (φrm1 .. φrmn), andcontrol is a control circuit (300), theduring the repair mode, the output signal by the decoder, initialized defect cells address is stored continuously and these speichervor gear with the..