I am using the KL25Z on the FRDM board. The clock is running at the default frequency of 20.97MHz. Is there is an easy way to change it to 48MHz? I see there is a function SystemCoreClockUpdate() and there are also macro definition for the MCG_MODE with MCG_MODE_FBI the one I need.
However, I cannot find (or understand) documentation on how to use these definitions.
Thanks for any help.
SystemInit() is provided as a means for configuring chip and board specific settings which are outside of the scope of a general solution, and unknowns. Going to be highly dependent on input clocks, pins and peripherals for external memories, etc and design choices you've made.
The code should setup your system, and the variable should reflect your expectations of what that should achieve.