i am using this small microcontroller ,in the 16 pin QFN package.
I wrote my code mostly at register level,for the first time no libraries-no Processor Expert,so to be better aware of registers and peripherals(and maybe to appreciate more KDS and PE for the next time).
I can successfully put the micro in VLLS3 sleep,the low measured current and the RCM_SRS0_WAKEUPflag are confirming it(NB because of an errata mask 1N86 i need before to clear RTC time invalid flag (TIF)) .
It wakes up periodically as expected by LPTMR0 ,or by a level change on wake up pin.
In case of wake up by pin ,i have the expected LLWU_F1 flag set.
In case of wake up by LPTMR i should expect to have LLWU_F3 MWUF0 flag set,but it remains low,
even if i enable an LLWU interrupt or if i poll after checked the reset register flag RCM_SRS0_WAKEUPflag .
The Reference Manual states:
19.1 Chip-specific LLWU information
This device has no LLWU module wakeup source and uses the external pin inputs only
of LLWU_P4 and LLWU_P7 as wakeup source to the LLWU module. The internal
peripheral interrupt flags are connected to the platform directly.
Hence, only the following registers and fieldsare functional for this device:
• LLWU_PE2: [WUPE7] and [WUPE4]
• LLWU_F1: [WUF7] and [WUF4]
does it mean that the described behavior is normal?
How can i check if LPTMR0 was the reason of wakeup from VLLS3?