DMA Controller is a hardware device that allows I/O devices to directly access memory with less participation of the processor. DMA controller needs the same old circuits of an interface to communicate with the CPU and Input/Output devices. Fig-1 below shows the block diagram of the DMA controller.
What is the architectural representation of 8257 DMA controller?
Let us have a look at the architectural representation of 8257 DMA controller. It consists of 4 channels that can be utilized over 4 input/output devices. All of the 4 channels can be separately programmed. All the 4 channels hold the 16-bit address and 14-bit counters individually.
What is direct memory access (DMA)?
Direct Memory Access (DMA) : DMA Controller is a hardware device that allows I/O devices to directly access memory with less participation of the processor. DMA controller needs the same old circuits of an interface to communicate with the CPU and Input/Output devices. Fig-1 below shows the block diagram of the DMA controller.
