| 摘要 |
PROBLEM TO BE SOLVED: To provide a means for shortening a reset time from a deep stand-by mode to a stand-by mode in a device using virtual SRAM set to the deep stand-by mode and the stand-by mode. SOLUTION: When the semiconductor storage device is changed over from the deep stand-by mode to the stand-by mode, timers 12, 14 are started, and they output a constant cycle timer output TN necessary for self-refresh, and a timing signal TR of a cycle shorter than the refresh cycle, respectively. A counter 15 starts counting the output TR of the timer 14 directly after the deep stand-by mode has been changed over to the stand-by mode, and outputs a change-over signal C when the count value coincides with a set value. A multiplexer 17 is controlled by the output of the counter 15, and selects TR before the count value of the counter 15 coincides with the set value, and selects and outputs TN in the following stand-by mode.
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