| 摘要 |
PROBLEM TO BE SOLVED: To provide a DMA controller capable of effectively preventing leakage of confidential information and of transferring data according to a request from another device to transfer the data, even in the case of confidential information processors of varying confidentiality. SOLUTION: The DMA controller 100 is connected to master devices 103, 105 and slave devices 106-108 by buses and causes data transfers according to transfer requirements sent from each master device for designating a destination and a sender. Each of the master devices and each of the slave devices retain access determination ranks. When the result of determination as to whether or not data transfers are possible based upon the result of comparison between the access determination rank of each master device and the access determination ranks of the slave devices designated as the destination and the sender by the transfer requirements indicates that the data transfer is possible, the DMA controller 104 causes data transfers; when the result indicates that the transfer is not possible, the DMA controller stops the data transfer. COPYRIGHT: (C)2006,JPO&NCIPI
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