Question

Cycle stealing mode of DMA operation involves:

• A. DMA controller taking over the address, data, and control buses while a block of data is transferred between memory and I/O device.
• B. While the microprocessor is executing a program, an interface circuit takes over control of address, data, and control buses when not in use by the microprocessor.
• C. Data transfer takes place between the I/O device and memory during every alternate clock cycle.
• D. The DMA control waiting for the microprocessor to finish execution of the program and then takes over the buses.

Hint:

Cycle stealing allows efficient data transfer by sharing the bus without fully halting CPU operations.

Answer 1

The Correct Option is C

In cycle stealing mode, the DMA controller temporarily halts the CPU during alternate clock cycles to access the system bus for transferring data between I/O devices and memory. This allows the CPU and DMA controller to share the bus, minimizing performance loss.