Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Maxim-Integrated/max32657/FCR/FRQCNTCTRL#0x0
CMP_CLKSEL=RTC
Frequency Counter Control Register.
Start Compare.
Compared Clock Select.
0 (RTC): RTC.
2 (EXT_GPIO): External GPIO.
3 (INRO): INRO.
https://github.com/analogdevicesinc/msdk