| 摘要 |
<P>PROBLEM TO BE SOLVED: To secure the appropriate buffer amount of a DMA buffer. <P>SOLUTION: A channel related information acquisition part 21 acquires the stream transfer rate and CPU processing time of the stream data of a DMA object device and a processing time necessary for completing reading from a DMA buffer as transfer time variation factors, and a determination logic execution part 23 determines the presence/absence of the buffer shortage of the DMA buffer from the transfer time variation factors and management object elements set for every DMA channel, and a buffer increase/decrease determination part 24 controls the increase/decrease of the buffer amount of the DMA buffer in accordance with the presence/absence of the buffer shortage of the DMA buffer. When it is not possible to increase the buffer amount of the DMA buffer although the buffer shortage of the DMA buffer is present, the use of a DMA channel whose priority is low is restricted based on the priority of the DMA channel. <P>COPYRIGHT: (C)2012,JPO&INPIT |
