Need for Direct Memory Acess

Question

What is the need of DMA?. What are the advantages of using DMA than normal transfer?. I searched it but not getting clarity. Any help, thanks in advance.

Answer 1

You can think of a DMA transfer as hardware pulling data from directly from memory vs having the CPU fetch data from memory and push it to the hardware.

It's like having a merchant take money from your wallet directly instead of you taking money out of your wallet and giving it to the merchant.

Obviously, the advantage of this is that there's less load on the CPU which means it can go do other things while the transfer is happening.

Answer 2

How about checking out what DMA is here to start with.

http://en.wikipedia.org/wiki/Direct_memory_access