A truefalse judgment on a result of speech recognition is made with high accuracy using a less volume of processing. In this comparator, the input and output terminals of a first inverter are short-circuited, and the output become equivalent to the logical threshold voltage of the first inverter. The method comprises executing an application in the non-privileged mode, generating an interrupt to request the services of a privileged function, and transitioning to the privileged mode to execute the privileged function, wherein the privileged function is executed as part of the same thread of execution as the application.