On the K32L2A4S I am confused by its oscillator set up in regards to external crystals.
The FRDM-K32L2A4S has a 32 kHz crystal on the EXTAL/XTAL pins for the RTC.
The data sheet says that the minimum input to the PLL is 8 MHz.
What do you need to do if you want an accurate RTC, for when the system is sleeping, and a accurate system clock when running, when not connected to USB?
From the data sheet and Reference Manual it looks like you can connect a 32 kHz OR a 8 MHz (or higher) crystal, but not both at the same time as they are both on (E)Xtal.
Is there a way to trim the internal osc. with the 32 kHz crystal, like can be done with the AVR?:
"AVR055: Using a 32kHz XTAL for run-time calibration of the internal RC Osc."
https://www.microchip.com//wwwAppNotes/AppNotes.aspx?appnote=en591195
