Computer Science I / Input-Output and Peripheral Communication
Practice question · Match the pairs

Match each mechanism or component to what it does.

  • Polling
  • Interrupt
  • Interrupt handler
  • DMA controller
  • Moves a whole block without the CPU touching each byte
  • The CPU repeatedly asks whether the device is ready
  • The device signals the CPU only when it needs attention
  • The short routine run before the CPU resumes its work
Hints
  1. Two of these describe who takes the initiative, the CPU or the device.
  2. One is a piece of code and one is a piece of hardware.
Show the answer
  • Polling → The CPU repeatedly asks whether the device is ready
  • Interrupt → The device signals the CPU only when it needs attention
  • Interrupt handler → The short routine run before the CPU resumes its work
  • DMA controller → Moves a whole block without the CPU touching each byte
Why

Polling puts the CPU in charge of asking; an interrupt puts the device in charge of telling. The handler is the code run on arrival; the DMA controller is separate hardware that does the bulk copying. The shift from asking to being told is the central idea of the lesson.

Read the lesson: Input-Output and Peripheral Communication →

Practise Input-Output and Peripheral Communication

The app has 5 more questions on this lesson, and keeps your place in the course. Computer Science I is free to start.

Start Computer Science I free Get it onGoogle Play

More questions on Input-Output and Peripheral Communication