Hi team :
I would like to share an experience to you . Any comments would be welcome .
The RTC 32.7668KHz clock can only be sourced from an external crystal that is challenged of some space restricted case . The internal reference clock will be required to support RTC at this moment . Of cause , the IRC accuracy maybe not compete with external crystal , but in this case space is the major concern . However , Kinetis RTC not support clock sourced from IRC . We make a workaround to enable RTC reference to IRC . The detail please refer to attachment . The sample code is build with KDS V3.0 for FRDM-K64F .