my project is used nrf51822 mcu, it contains SIM, when the mcu is reading SIM data, and at the same, I take out theSIM, and the 51822's pin which is link with SIM is can't control,the IO is unnormal.
Well, think about it: you say this happens when you pull out the "SIM" (you still haven't confirmed exactly what that is).
It sounds like you are doing this when the system is "live"; ie, fully powered and active - yes?
So what steps have you taken to ensure that there are no nasty glitches or other transients when you do this ... ?
