Assume this simple application which contains an interrupt service routine for a timer, which increments a tick variable. The main function sets the necessary status registers. The application exits when 100 interrupts have been generated.

#pragma language = extended
#include <stdio.h>
#include "iorl78.h"
#include <intrinsics.h>

volatile int ticks = 0;
void main (void)
{
  /* Timer setup code */
  __disable_interrupt();        /* Disable all interrupts */
  TMIF00 = 0;                   /* Reset interrupt request flag */
  TMMK00 = 0;                   /* Enable timer interrupts */
  TS0 |= 0;                     /* Start the timer */
  __enable_interrupt();         /* Enable all interrupts */
 
  {
    ticks += 1;
  }
  while (ticks < 100);          /* Endless loop */
  printf("Done\n");
} 

/* Timer interrupt service routine */
#pragma vector = INTTM00_vect
{
  ticks += 1;
}

Add your interrupt service routine to your application source code and add the file to your project.

Build your project and start the simulator.

Choose Simulator>Interrupt Setup to open the Interrupt Setup dialog box. Select the Enable interrupt simulation option to enable interrupt simulation. Click New to open the Edit Interrupt dialog box. For the timer example, verify these settings:

Click OK.

Execute your application. If you have enabled the interrupt properly in your application source code, C-SPY will:

To watch the interrupt in action, choose Simulator>Interrupt Log to open the Interrupt Log window.

From the context menu, available in the Interrupt Log window, choose Enable to enable the logging. If you restart program execution, status information about entrances and exits to and from interrupts will now appear in the Interrupt Log window.

For information about how to get a graphical representation of the interrupts correlated with a time axis, see Timeline window—Interrupt Log graph.