Patent attributes
A cell array has a word line and a bit line coupled to memory cells, and a redundancy word line and a redundancy bit line coupled to redundancy memory cells. A read unit reads data held in the memory cell. A defect detection input unit receives a defect detection signal from a test apparatus. A dummy defect output unit outputs a dummy defect signal during a predetermined period of time after the defect detection input unit receives the defect detection signal. A data output unit inverts a logic of the read data output from the read unit during an activation of the dummy defect signal. Accordingly, an artificial defect can be generated by the semiconductor memory without changing the test apparatus or a test program. As a result of this, a relief efficiency can be enhanced and a test cost can be reduced.