| 摘要 |
PURPOSE:To remove a memory access queuing time due to refreshing operation by refreshing the final memory access cycle in a refresh available cycles set up to several times the bank period of a memory access cycle with priority and executing the memory access of other cycles with priority. CONSTITUTION:Dynamic memories 6, 7 are memory banks for respective memory devices and execute memory accessing operation or refreshing operation based on a refresh request signal from AND gates 14, 15 or a memory access request signal from AND gates 12, 13. The refreshing operation is executed with priority in the final memory access cycle out of the refresh available cycles and the memory accessing operation is executed with priority in the other cycles. Banks other than a bank executing the memory accessing operation is capable of executing the refreshing operation. Consequently, the probability of waiting can be reduced even at the time of memory access based on a random address or continuous addresses.
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