NONVOLATILE SEMICONDUCTOR STORAGE DEVICE AND TEST METHOD THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor storage device improving yield by a test mode for switchably setting the number of allowable defective bits.

SOLUTION: The nonvolatile semiconductor storage device including a test circuit includes: an expected value register for holding an expected value; a comparator circuit for detecting matching of data for each transfer unit of test read data and the expected value of the expected value register for each bit; a first decision circuit having a first deciding gate section for deciding a defect of one bit or more in the transfer unit as fail based on the comparison result and a second deciding gate section for deciding a defect of two bits or more in the transfer unit as fail; a second decision circuit for deciding the defect of one bit or less in the transfer unit as fail based on outputs of the first and second deciding gate sections; and a selector for selecting either one of output of the first deciding gate section of the first decision circuit or output of the second decision circuit.

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