Dynamic Voltage Scaling is performed on automotive micro-controller AURIX from Infineon Technologies. In this micro-controller the core and different IPs operate on the 1.25 V supply rail, so dynamically voltage is changed according to the workload in the micro-controller. DVS is done either using an internal onboard voltage regulator or an external voltage regulator. An External board (KITPF3000FRDMEV), which has a controller and a Power Management Integrated Circuit (PMIC) is used for changing the supply voltage to the micro-controller during DVS using an external voltage regulator. The micro-controller is predicting the workload and according to workload, the control command is sent to the controller (FRDM-KL25) in the kit through I2C communication and then the controller sends the command to adjust the voltage of PMIC (PF3000) through I2C communication. Both current measurements for the internal voltage regulator and external voltage regulator are measured for various loads and latency is measured for various baud rates while using external voltage regulator through I2C protocol.