C Interrupts concept



What are Interrupts?

  • Interrupts are messages to the Pentium chip.
  • Interrupt is used to halt current activity and perform our requested job.
  • When we generate an interrupt, the CPU suspends it current operation.
  • CPU performs the job we requested, finishes our job and resumes its suspended job.
  • We are interrupting the CPU, that is why, we call it interrupts!

What is Interrupt in c Programming language

Explanation Of Interrupt :

  1. Suppose we have sample C Program to execute , Consider following code
  2. int main()
    {
    int num1,num2,sum;
    
    printf("Enter the number 1 : ");
    scanf("%d",&num1);
    
    printf("Enter the number 2 : ");
    scanf("%d",&num2);
    
    sum = num1 + num2;
    
    printf("Sum : %d",sum);
    return(0);
    }
    

    Above program is handed over to CPU for execution then CPU starts executing this program.While Executing Following Statement CPU is waiting for input from the user –

    scanf("%d",&num1);
    
  3. Then Current Program execution is halted and Control is given to the IO device i.e Keyboard to Enter the number.
  4. As soon as User Enters the number , the CPU resumes execution of the remaining code.
  5. The process of halting the Program execution in between is called interrupt.