Hello all. I am working on this ARM Cortex M4 board and as you can see the MCU runs at 120 MHz. I would like to bring that down to 100 MHz because I am trying to implement a Timer init function and interrupt handler. A basic 1ms heartbeat timer is needed for much of the testing I need to do regarding this board. I found this reference manual for the specific MCU on this board. I've been told I could alter the clock going into the systick or alter the PLL configuration but I am new to this and I am not too sure how to approach this. By the way, I am using Kinetis Design Studio and KSDK. Any and all help is greatly appreciated.