I've been wondering about this for a while, but couldn't find anything about it. What exactly happens after the screen turns off? Does the kernel actually suspend and halt the CPU? If so, how are notifications received while sleeping? Is there a coprocessor involved?
I'm curious. It would be great if someone could point me towards some articles or videos about this.
Your mobile device cannot sleep like your desktop can.
It can however, sleep it’s own way. Typically this involves CPU throttling. Android does enter a “Deep Sleep” state, minimizing all power consumption, and even switching it’s CPU to a completely idle state where it only periodically “wakes” to handle synchronization and other needed tasks.