Task 3 - Interrupts -- Subroutines of the nether world?

When I was first hired as an instructor in Computer Engineering, I was told that I had to teach a course on microprocessors. The first thing I asked was "Will I have to teach interrupts?" After being told "Yes", I was no longer a happy camper despite my experience.

That's the sort of feeling that interrupts generate. They have the reputation of lurking around inside the processor just waiting to jump out at the programmer at the most inconvenient time and shout "Got You!".

Interrupts, at that time, make me just as uneasy as you probably feel about them now. Then one day, quite suddenly while I was teaching a lesson in class, I realized interrupts were just subroutines with a difference. The thought was so obvious, and made understanding interrupts so easy (to me), that I could not understand why I had ever perceived interrupts as being a problem!

Subroutines, or functions as they are often called in higher level languages such as "C", are covered in HVZ. There is also an introduction about the basics of subroutines in these Web pages.

In laboratory 3, we are going to investigate basic interrupt handling on CISC and RISC processors. By treating interrupts, or rather interrupt service routines, as subroutines with a difference much of the mystery and fear associated with interrupt handling should disappear.


The steps to be followed during Task 3



Last modified: July 22, 1996 01:20 PM by M. Smith.
Copyright -- M. R. Smith