Initialize the address register
Initialize the count to 500
LOOP: Load a byte from device
Store in memory at address given by address register
Increment the address register
Decrement the count
If count !=0 go to LOOP
This is a code to transfer 500 B from IO device to Memory
The DMA controller requires 20 clock cycles for initialization and other overheads. Each DMA transfer cycle takes two clock cycles to transfer one byte of data from the device to the memory.
Calculate the
- DMA transfer time .
- % time processor is busy