Introduction to Direct Memory Access (DMA)

We've learned how interrupts relieve the CPU of the burden of polling, but what about the data transfer? A DMA will handle that for us. This lesson shows how. Takeaways: At the completion of this lesson, each student should be able to: • explain the benefits of direct memory access (DMA), • describe the process of cycle stealing, • explain how a cache supports the use of DMA, • list the four things the DMA needs to complete a transfer, and • show how different DMA configurations affect the number of memory cycles stolen per data element transfer. #dma #io #bus