| 摘要 |
PROBLEM TO BE SOLVED: To realize an information processor capable of realizing memory protection and efficiently using DMA transfer. SOLUTION: An I/O controller 130 connected with an I/O device 135 comprises a DMA controller (DMAC) 133 and an access control unit (ACU) 132. The DMAC 133 executes DMA transfer according to data transfer control information set to a control/status register 134 by a user process. The ACU 132 restricts the execution of DMA transfer by the DMAC 133 based on access control information set to a control/status register 131 by a privilege process to prohibit the access to memory areas other than a memory area to which the user process is accessible by the DMAC 133. COPYRIGHT: (C)2006,JPO&NCIPI
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