The concept of utilizing the bus for DMA operations is known as

• Direct memory access (DMA) is a method that allows an input/output (I/O) device to send or receive data directly to or from the main memory, bypassing the CPU to speed up memory operations.
• The process is managed by a chip known as a DMA controller (DMAC).

Types of DMA transfer using a DMA controller:

• Burst or Block Transfer DMA
• Cycle Stealing or Single-Byte Transfer
• Transparent or Hidden DMA Transfer

Cycle Stealing Mode:

• In DMA's cycle stealing mode of operation, the DMA controller puts the CPU on hold for each byte of data to be transferred.

• In this mode, the DMA controller sends a HOLD signal to the microprocessor and waits for the HLDA signal.

• After receiving the HLDA signal, the DMA controller gains control of the system bus and executes only one DMA cycle.

• This concept of utilizing the bus for DMA operations is known as cycle stealing.