An application processor and a system on chip (SoC) that incorporates the application processor are provided. The application processor includes a first core configured to process first data per unit time, a second core configured to process second data larger than the first data per unit time, and a lookup table configured to determine whether to activate the first core or the second core based on at least one of an analysis result of a message signal received by a communications processor, a sensing signal supplied to the application processor and a power level supplied to the communications processor.