Erik, thanks for you getting back to me. I asked this question because it is referent to the external interupt INT0 remember? from Keil forum. If I enter PDM, the micro should wake up as soon as the interrupt is detected. These are pulses coming into INT0 about every 2 milliseconds. My question is why the micro does not wake up and after the interrupt is executed goes back to sleep and so forth...It does not do this. However, if I enter Idle mode instead, it works fine. My thought is that probably the pulses counter (variable) is losing its contents when the micro enters PDM...that is just a thought OK?
Thanks
P.D.
Sorry I posted this question twice by mistake