| 摘要 |
PROBLEM TO BE SOLVED: To reduce a testing time of a nonvolatile memory in which a multi-valued storage is carried out. SOLUTION: The semiconductor memory has a plurality of memory banks and data buffers for storing information of two or more bits as a storage unit. In a test mode, control data which classify values having one value and values having other values among the values for every storage unit of the information held by the data buffers, are transferred to sense latches of the memory banks in parallel, and in the memory banks to which the control data is transferred, a decision is made whether the state obtained in a bit line by a selection of specified word lines coincides with the state obtained in the bit line on the basis of the transferred control data. Excluding the memory banks which the noncoincident result is received, the decision is made by transferring the control data in parallel to the sense latch of the corresponding memory bank, for classifying the values having separate one value and the values having other values among the values for every storage unit of the information held by the corresponding data buffer, then the discrimination of the memory banks which are made to be noncoincident in the result of decision, is attained from outside. COPYRIGHT: (C)2007,JPO&INPIT
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