Learning objective
Interrupts: Describe the role of interrupts and interrupt service routines (ISRs); their effect on the Fetch-Execute cycle; and the need to save the volatile environment while the interrupt is being serviced.
Read the explanation, check the common trap, then practise with flashcards and questions.
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Topic
Structure and role of the processor and its components
Subtopic
Interrupts
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Quick explanation
Interrupts: Describe the role of interrupts and interrupt service routines (ISRs); their effect on the Fetch-Execute cycle; and the need to save the volatile environment while the interrupt is being serviced
- This point belongs to Structure and role of the processor and its components, especially Interrupts.
- You need to be able to interrupts: Describe the role of interrupts and interrupt service routines (ISRs); their effect on the Fetch-Execute cycle; and the need to save the volatile environment while the interrupt is being serviced.
- Use the linked flashcards and practice questions to check recall, then practise applying the idea in an exam-style answer.
Why it matters
This objective helps connect Interrupts to exam-style questions, flashcards, and revision notes for Structure and role of the processor and its components.
Quick student answer
What is the primary role of an interrupt?
Direct answer
To request that the processor temporarily deal with an event
Key terms
- Interrupt: A request that causes the processor to temporarily divert from its current program so that it can deal with an event.
- Interrupt service routine (ISR): A routine executed by the processor to service an interrupt.
Common trap
Treating an interrupt as a permanent stop: An interrupt temporarily changes the processor's execution to an ISR. The original program can resume after the interrupt has been serviced.
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Related learning objectives
- The processor and its components: Explain the role and operation of a processor and its major components: • arithmetic logic unit • control unit • clock • general-purpose registers • dedicated registers, including: • program counter • current instruction register • memory address register • memory buffer register • status register.
The processor and its components
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The Fetch-Execute cycle and the role of registers within it
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Addressing modes
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Machine-code/assembly language operations