Internal interrupt

Updated: 11/12/2023 by Computer Hope
internal interrupt

Sometimes called a software interrupt, an internal interrupt is a type of interrupt produced by a software instruction. More specifically, they are generated in a computer's microprocessor when certain conditions are met while a program is loaded. In a practical sense, internal interrupts help manage the flow of tasks and ensure that the processor can handle various events and exceptions during program execution.

As the name implies, internal interrupts are related to specific events in a system. For example, a divide by zero error or an attempt to execute an illegal instruction can trigger them. When such events occur, the processor temporarily stops its current task, saves its state, and transfers control to a specific interrupt-handling routine. This routine then addresses the interruption cause and allows the system to respond appropriately.

Examples of internal interrupts

Below are some events that cause an internal interrupt.

  • Dividing by Zero - If a program tries to divide a number by zero, the processor can generate an interrupt to handle the error.
  • Illegal Instruction - When the processor encounters an instruction that it cannot execute or that violates the architecture's instruction set, an interrupt is generated.
  • Floating-Point Errors - Floating-point arithmetic can sometimes involve errors, such as overflow or underflow, which can lead to interrupts.
  • Debugging Events - During software development, programmers may use debugging tools that generate interrupts for breakpoints, moving through code, etc.
  • Timer Interrupts - Periodic interrupts generated by an internal timer can be used for tasks like scheduling and timekeeping.
  • Privileged Instruction - If a user-level program attempts to execute an instruction requiring higher privilege levels, an interrupt is generated.

Debugging, Execute, Fault, Illegal Operation, Interrupt handler, Page fault, Software terms