| 摘要 |
PROBLEM TO BE SOLVED: To reduce current consumption by decreasing the number of times of supplying a clock for synchronization. SOLUTION: In a non-power-down state of a memory, supply of a clock to a data output circuit is limited to a read-state after receiving a read- command, supply of a clock is not performed at the time of an active state and a write-state. Further, in the best mode, supply of a clock to a data output circuit 40 is started after the number of clocks corresponding to cache latency set after receiving a read-command in a read-state after receiving a read- command, and after output of read-out data from a data output circuit 40 is started, stopped after the number of clocks corresponding to set burst length. Therefore, even in a non-power-down state, the number of times of supplying clocks required for driving a large current can be decreased by supplying clocks only in a period in which read-out data is actually outputted to the outside from the data output circuit 40.
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