What is DMA controller ?

DMA controller is dedicated hardware used for controlling the DMA operation .Usually DMA controller comes in an IC and used to access the memory with out giving load to the memory.

Some Data that is inputed into the processor does not need any processing by cpu ,so this type of  data can be directly applied to the memory with making the cpu to involve on it.

some of the DMA controller commonly used are:

1) 8237 DMA controller

2)8257 DMA controller