The yellow line is 5V and the blue line is 3.3V. I connected my scope to see if I saw something and the good news that it is not an interference problem at all. I basically have a horrioble ripple situation out from DRV8213. This indicate that my capacitors are not doing its job at all. How this MCU can manage to work at 84Mhz is more of a mystery than why it does not at 168Mhz.