摘要 |
A semiconductor memory device of the present invention provides, in a memory having an hierarchical bit line structure, a test mode which causes all switches for selecting hierarchical bit lines and a main bit line in an activated memory array to be connected all the time. With this configuration, it is possible to perform a disturb refresh test on a memory cell arrays basis regardless of the hierarchical bit line structure. Possibility of an erroneous read-out, which may be caused by connecting each of the hierarchical bit lines to one another and a consequent increase in a bit line load capacity, may be prevented by providing a timing control such that the switches are connected after a normal mode operation.
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