Sleep Modes

The standard application execution mode is the CPU mode. After any reset the chip starts in CPU mode. Typical current consumption is about 4 mA (radio off). The chip supports various power modes (sleep modes) to reduce current consumption. To enter in a sleep mode the pwr_timerSleep function is used. In sleep mode various ULP timers can be activated to control the wakeup behaviour. Additionally its possible to force a CPU wake up by activating the wake pins WAKE0 and WAKE1 (WAKE_PIN0_RESET, WAKE_PIN1_RESET). The table shows an overview of the different sleep modes.

Power Mode	Timer controlling wakeup	typical current consumption (see note)	Pin State (DVDD)	Wakeup Event	Wakeup State	Description of the mode
Deep Sleep Mode	WatchdogTimer	100 nA	Undefined DVDD is off	Watchdog, Wake pins	WatchdogReset	Used for weak ambient energy powered, event triggered TX applications
Flywheel Sleep Mode	FlywheelTimer	700 nA	Undefined DVDD is off	Flywheel, Wake pins	FlywheelReset	Used for high precision system timing, lowest duty-cycle synchronous network.
ShortTerm Sleep Mode	ShortTermTimer	3 uA	Undefined DVDD is off	ShortTerm overflow, Wake pins	Continue in application all RAM's (XDATA, DATA, SFR) retained except radio configuration (need to call radio_init()), XTAL off, running on CRCO	Used for short sleep periods that are significantly longer than the XTAL startup time (e.g. between subtelegrams)
Standby	Scheduler (Timer0)	0.9 mA	Defined DVDD is on	WakeupEvents	Continue in application the whole CPU inclusive all RAM's (XDATA, DATA, SFR) is retained, XTAL still running	Used for waiting for an event

Note:

The current consumption values are only informative, please consult the respective user manuals (see References)

Remember that the Watchdog timer is always running and it can't be disabled. It can wake up OR reset the CPU in any sleep mode.

In ShortTerm sleep if the FlyWheel timer is running, it's timeout can also reset the CPU