Abstract: A method and apparatus for rapidly testing arrays of cells, such as memory devices, in which a limited number of redundancy rows and columns are available for repair. Repairs are to be made by substituting redundant rows and columns for original rows and columns of the array that contain faulty cells. The repair information as to whether a row or a column is to be substituted for a faulty original cell is determined, at least in part, in real time as the cells are being sequentially tested. E.g., a redundant row is assigned to replace any original row in which the number of faulty cells identified thus far in the testing, exceeds the number of redundant columns that have not as yet been assigned. Depending upon the pattern of faults, impossibility of repair may be detected, and the test aborted. Post-test data processing may be necessary to complete the repair information.

Abstract: A method and apparatus for rapidly testing arrays of cells, such as memory devices, in which a limited number of redundant rows and columns are available for repair. Repairs are to be made by substituting redundant rows and columns for original rows and columns of the array that contain faulty cells. The repair information as to whether a row or a column is to be substituted for a faulty original cell is determined, at least in part, in real time as the cells are being sequentially tested. E.g., a redundant row is assigned to replace any original row in which the number of faulty cells identified thus far in the testing, exceeds the number of redundant columns that have not as yet been assigned. Depending upon the pattern of faults, impossibility of repair may be detected, and the test aborted. Post-test data processing may be necessary to complete the repair information.