(This is the older material - click here - for current specification content)

7. Problem with Interrupts?

Handling interrupts it a bit like juggling; as long as everything runs smoothly, it is a fine method.

But interrupts have two problems

1. Responding quickly enough (Latency)

For example, a real-time car computer will be dealing with thousands of interrupt requests per second as the engine, brakes, throttle input-output devices demand attention.

You need a skilled engineer to write computer code that can deal with this situation so that every interrupt is handled in time.

2. Too many interrupts (Stack overflow)

What happens when the stack is full because so many interrupts are waiting their turn to run? The answer is a 'stack overflow' that usually crashes the computer.

Sometimes a simple polling system is the way to go for low demand situations so avoiding tricky interrupts.

(see page 2 for polling system).