| 摘要 |
PROBLEM TO BE SOLVED: To quickly perform DMA transfer even in using a memory in which read access is made impossible for a fixed period after releasing self-refresh. SOLUTION: A memory arbiter 120 for receiving requests from one or more read DMACs 111-113, allowing a memory control part 130 to execute operation concerned with these requests, receiving a self-refresh request and a release request for a DDR SDRAM, and allowing the memory control part 130 to execute operation concerned with these requests is provided with access target memory area recognition parts 121-123 for receiving an address to which an access request is to be outputted next and the predicted number of access requests to be outputted within prescribed time from a read DMAC in driving and predicting a memory area to be accessed within the prescribed time in a memory system while referring to the received address and the predicted number of access requests and a copied address specification (function) part 25 for setting an address in which the data of the memory area to be accessed within the prescribed time can be temporarily copied in each read DMAC. COPYRIGHT: (C)2005,JPO&NCIPI
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