Direct memory access

Direct memory access (usually shortened to DMA) is a technology used in Computers and microprocessors. With it, certain hardware components can use parts of the main memory for their applications, without the need to ask the CPU. The CPU will request data from memory once and the DMA will continue to fetch the data, freeing the CPU to do other work. This way, the CPU does not have to request every byte.

Direct Memory Access Media

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  Motherboard of a NeXTcube computer (1990). The two large integrated circuits below the middle of the image are the DMA controller (l.) and - unusual - an extra dedicated DMA controller (r.) for the magneto-optical disc used instead of a hard disk drive in the first series of this computer model.

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  Cache incoherence due to DMA