Is it possible to generate an interrupt to wake from Deep Power Down without having a crystal on the RTCX1-2 pins?
The User Manual says, "The RTC interrupt can bring the microcontroller out of Power-down mode when the RTC is operating from its own oscillator on the RTCX1-2 pins. When the RTC interrupt is enabled for wake-up and its selected event occurs, the oscillator wake-up cycle associated with the XTAL1/2 pins is started."
Is there any other way to generate an RTC Interrupt to wake up the µC?
Hi,
In Deep Power-down mode, power is shut off to the entire chip with the exception of the Real-Time Clock, the RESET pin, the WIC, and the RTC backup registers. To optimize power conservation, the user has the additional option of turning off or retaining power to the 32 kHz oscillator. It is also possible to use external circuitry to turn off power to the on-chip regulator via the VDD(REG)(3V3) pins after entering Deep power-down mode. Power to the on-chip regulator must be restored before device operation can be restarted.
Wake-up from Deep power-down mode will occur when an external reset signal is applied, or the RTC interrupt is enabled and an RTC interrupt is generated.
For more details, please check the application note AN10915.
http://cache.nxp.com/documents/application_note/AN10915.zip?fsrch=1&sr=1&pageNum=1
Have a great day,
Sol
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Any other ideas before I chalk this up as a lost cause?