1)
o
Which operations (write or read) to be performed using write or read control lines.
o
Address of I/O devices that is to be used communicated on data lines.
o
Starting location on memory where information will be read or written to be
communicated on data lines and is stored by DMA interface in its address register.
o
Number of words which are to be read or written is communicated on data lines and
is stored in data count register.
2)
To carry out an input, output or memory-to-memory operation, the host processor
initializes the DMA controller with a count of the number of words to transfer, and the
memory address to use. The CPU then commands the peripheral device to initiate a data
transfer.