I'm confused concerning the RTC clocking. I want to input an externally-supplied 32kHz clock signal into EXTAL0 and run the KL25 in FEE mode. I also want the RTC to operate, both in run and in Stop mode. What is confusing to me is the following:
1) Both the OSC and the RTC peripherals contain register flags which control oscillator on/off and loading capacitors. However, in the KL25 there is only one oscillator (there is no separate RTC oscillator like in the K series devices). The system oscillator is controlled by the OSC0_CR register flags. So, what are the RTC register flags in RTC_CR controlling?
2) Suppose I set the system oscillator in bypass mode, and input a 32kHz signal into EXTAL0. I can also configure the system oscillator to remain on in low-power modes. Can I then run the RTC using the OSC32KCLK input clock?