I'm using KL05Z32, in a project ( solar cell application ) where the energy saving is important.
I'm using 2 clock configuration: FEI and BLPI and LLS like sleep state.
To test my application I change gradually the voltage from 2.3 to 3.3V while the application run, to simulate the sun.
If PTA7 falling, micro wake-up from LLS and, if there are certain conditions, I change FEI --> BLPI --> RUN --> VLPR to save power.
When micro wake up form LLS I noted that when the voltage exceed 3.08 - 3.1V, any transition to VLPR produce a reset. Micro reset itself every time I try to change in VLPR.
To restore the right condition I must switch off and reduce the voltage (under 3.08 - 3.1V) and switch on the voltage.
If I don't enter in LLS and stay always in RUN, the application run correctly until 3.3V.
(I have another pin electrically connect to PTA7 to sense the interrupt when I am not in sleep state )
Under this voltage it's all right, micro wake-up correctly and the transition to VLPR is correct.
I tried to change in a middle clock configuration: FEI - FBI - BLPI but the problem persist when I change in VLPR.
In FEI core clock is 20Mhz and bus clock is 10Mhz.
In BLPI core clock is 2Mhz and bus clock is 667Khz.
Has anyone had the same problem?