What Is Dma?

By Author: Kevin Lewis
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DMA is Direct Memory Access.

DMA is a system that allows memory to be controlled without passing through the CPU.

Under most situations, the CPU handles the movement of memory for security and stability reasons. However, DMA can be enabled for certain operations, such as reading from a CD-ROM, so that the data read from the CD is not passed through the CPU but is instead pulled off of the CD and put directly into a memory location for use.

Although DMA is not always used, it has its uses. When it is enabled, the process of DMA overrides the CPU for handling the memory. This helps to solve some errors that occur for items when they are transferred through the CPU. Such errors include audio and video that is being read off of a CD-ROM. Occasionally, errors occur which can cause audio to be scratchy or video to be distorted. Under situations such as these, DMA can be a useful system since it works around these errors by bypassing the CPU.