DMA dada transfer:

 DMA dada  transfer:

1. For some  application, such  as  transferring  dada  bytes to  memory  form  magnetic  or optical  disk, however, the  dada  bytes  are coming  in from  the  disk  faster  then  they  can  be  read in  with  program  instruction. In a case like this we use a dedicated Hardware device called a direct memory access (DMA) controller to manage the data transfer.
2. The DMA controller temporarily borrows the address bus, data bus, and control bus from the microprocessor and transfer the data by directly from the disk controller to a series of memory location.
3. A DMA controller can also transfer data from memory to a port.