| 摘要 |
PROBLEM TO BE SOLVED: To shorten a time required for testing self-refresh-operation of a semiconductor memory having a plurality of self-refresh modes of which refresh- regions are different. SOLUTION: First, the prescribed data is written in all memory regions. Next, after a self-mode is set, a self-refresh signal/TSRC for test is made 'L' and an internal row control signal IPAS is made 'H', then, a column control signal/TCAS for test is made 'L' and the prescribed data is written in a memory cell selected by a refresh-count address CNT and a column address TCADR for test in a period in which a connection enable-signal of a data line and a sense amplifier is 'H'. Such operation as the above is repeated in accordance with a refresh-count address. Next, data of all memory regions are read, and it is checked that write is performed only in a set region.
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