Hello all, I am writing an RTOS for an XC167 (just for fun, believe it or not :-) ). while running it on the Keil IDE I constantly experience 100% CPU usage. I wrote a preemptive scheduler with a task switching frequency of 1[ms] (driven by GPT1). Is this behavior the result of the way the IDE simulates the processor? or maybe it is a programming mistake of some kind? or maybe it's not a mistake after all? all my tasks implement an infinite loop, of course. I use an interrupt to switch tasks, another for time measurements and another (but it also happens without it) to update user timer (to keep the time measurement latency as low as possible). Kind regards, Tamir Michael