Changing the PWM ON duty based on the supplied DC voltage value makes it possible to control motor speed. This method (PWM duty control) results in lower power consumption compared with controlling the voltage supplied to the motor. Some ROHM DC motor drivers offer two ways of using this PWM: the Standard is to apply PWM signals directly from MCU on F_IN and R_IN pins and the second way is the V_REF Control to apply DC voltage V_REF, this PWM will be created internally from V_REF.