Hi Azel,

Your timers don't need to count backwards just to count out fifteen minutes (or whatever interval you specify). Your display might need to increment backwards, count down if you will, but your timer needs only to count off whatever fundamental increment of time you're counting.

I have two suggestions for you. I would suggest that you click on that button on the left of the screen, the blue one that says tutorials, and begin with the 8051 tutorial. It has a good section on timers and how they work.

But first I suggest that you read the instructions of this site before you post again. Right next to the blank where you entered "Need HELP!!!" as a subject, are the instructions which say,



Good luck