"how can this be working?
mov R0,#43418496
Crystal = 12 Mhz.
Delay is 120 seconds."


120 Seconds!!!!!! eek!

There are no checks about the maximum delay the code can generate, but I might add one. why on earth would you want a 2 minute delay?

The original web page did say this:-

"It can go up to quite high delays (over 20 seconds!). But if you are looking for a delay that long, I suggest you create a routine to do a 1 second delay, then call it repeatedly."

Which is probably good advice :-)

Chris.