nerdexam
CompTIA

SK0-004 · Question #345

Which of the following is a bus mastering method? (Select TWO).

The correct answer is A. A device transfers data directly to the memory. C. A device connects to another device without involving the processor. Bus mastering allows a device to take control of the system bus and transfer data directly to memory or to another device without requiring processor intervention.

Server hardware installation and management

Question

Which of the following is a bus mastering method? (Select TWO).

Options

  • AA device transfers data directly to the memory.
  • BA device handles mediation between the northbridge and the processor.
  • CA device connects to another device without involving the processor.
  • DA device transfers data to the processor and then on to the memory.
  • EA device handles mediation between the southbridge and the processor.

How the community answered

(35 responses)
  • A
    89% (31)
  • B
    3% (1)
  • D
    6% (2)
  • E
    3% (1)

Why each option

Bus mastering allows a device to take control of the system bus and transfer data directly to memory or to another device without requiring processor intervention.

AA device transfers data directly to the memory.Correct

A bus master device can seize control of the bus and write data directly into system memory without routing it through the CPU, which offloads the processor and significantly improves I/O throughput.

BA device handles mediation between the northbridge and the processor.

Mediating between the northbridge and the processor is a chipset-level bridging function, not an operation performed by a peripheral device acting as a bus master.

CA device connects to another device without involving the processor.Correct

Bus mastering also enables direct device-to-device communication on the bus, where one peripheral transfers data to another without the CPU acting as an intermediary, which is a defining characteristic of bus mastering technology.

DA device transfers data to the processor and then on to the memory.

Routing data through the processor first before it reaches memory describes Programmed I/O (PIO), which is the traditional CPU-dependent method and is the conceptual opposite of bus mastering.

EA device handles mediation between the southbridge and the processor.

Mediating between the southbridge and processor is a chipset function unrelated to bus mastering, which specifically concerns peripheral devices taking autonomous control of the bus.

Concept tested: Bus mastering and CPU-independent data transfer

Source: https://learn.microsoft.com/en-us/windows-hardware/drivers/kernel/introduction-to-dma

Topics

#bus mastering#DMA#data transfer#memory architecture

Community Discussion

No community discussion yet for this question.

Sign up to join the discussion
Full SK0-004 Practice