| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor memory in which normal operation is the same as a conventional device and screening by burn-in can be performed in shorter time than a conventional one. SOLUTION: A first refresh timer 11 outputs a refresh request signal REFSH1 for normal operation, a second refresh timer 12 outputs a refresh request signal REFSH2 for burn-in. A selector 13 selects refresh request signal according to an external instructor signal, and outputs it to an arbiter 14. Since the frequency of the signal REFRESH2 is higher than that of the signal REFRESH1, a frequency that a DRAM access signalΦW is outputted from a DRAM access signal generation circuit 15 in burn-in mode is made higher than that in normal operation, the DRAM access time in unit time becomes long.
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