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It seems likely that the neonode IR hardware is left powered up, or at least the IR LEDs are active(though perhaps pulsed -I've never read the neonode spec sheet), that the processor drops into a low power sleep mode in between page changes, and an IRQ or NMI is whacked by the neonode hardware to bring the processor out of sleep when a "touch" event is logged. Most microcontrollers also allow for a timed sleep mode where an internal timer counter is allowed to remain powered and clocked until it causes a wakeup by whacking an IRQ internally connected to the timer/counter hardware. That would normally be how you'd handle the wake up to write the screen on a once a minute basis, unless you have an external RTC to whack an interrupt.
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