RTC off when no external oscillator

[carrielbr]

Good Morning.

I am running RTC MK20DX256VLL10, however to turn off the chip and remove the oscillator 32Khz my RTC stops working. Its detect if the crystal was removed by the User when the chip is not powered (connected only with the RTC battery)?

Thank you

[isaacavila]

Hello Ciao,

Unfortunately, there is not such feature for RTC in K20, there is only a clock monitor that allows user to detect when RTC CLKOUT signal is lost (MCG_C8[CME1] bit), however, it does not apply when MCU is in low power modes or when MCU is not powered up. In other words, It can help you to detect if RTC CLK OUT signal is lost only when MCU is fully powered.

Regards,

Isaac