| 摘要 |
PURPOSE:To reduce power consumption at the time of refreshing and to suppress unnecessary noise generation by performing refreshing action for only a bank requiring maintenance of stored contents out of already used banks and a bank being used. CONSTITUTION:The above described device is designed so as to pass a dummy cycle for only a bank requiring maintenance of stored contents and a bank being used, and perform a normal refreshing action corresponding to the using state of banks in which bank A, bank B, bank C, and bank D are used in order. For example, in using the bank B, the device always passes a dummy cycle and then performs a normal refreshing action. For the bank A already used, however, if maintenance of stored contents is necessary, the device passes the dummy cycle and performs the refreshing action; if said maintenance of the stored contents is unnecessary, the device performs no dummy cycle or refreshing action, thereby the power consumption at the time of refreshing is reduced considerably. |
