| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve control efficiency of peripheral equipment by a user process. Ž<P>SOLUTION: A memory access control apparatus 300 receives from a DMA requestor 336 an access request command, which contains an IOID (Input/Output device ID), for a DMA (Direct Memory Access)address space that is a memory area used for a DMA transfer, determines whether the access is permitted or not, and makes the access to be executed if it is permitted. The OS (Operating System) on a PU (Processing Unit) 112 sets in an MMU 334 the correspondence relationship between the logical address space of the user process and the DMA address space. When the user process instructs to access the DMA address space by specifying a logical address, the MMU 334 translates the logical address into a physical address of the DMA address space. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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