More Efficient Data Movement with DMA
Explore how Direct Memory Access (DMA) improves data transfer efficiency by offloading copy tasks from the CPU to a dedicated controller. Understand the drawbacks of programmed I/O and how DMA allows the CPU to run other processes while handling large data movements to and from devices.
We'll cover the following...
We'll cover the following...
Unfortunately, there is one other aspect of our canonical protocol that requires our attention. In particular, when using programmed I/O (PIO) to transfer a large chunk of data to a device, the CPU is once again overburdened with a rather trivial task, and thus wastes a lot of time and effort that could better be spent running other processes. This timeline illustrates the problem:
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