Patent ID: 7386853

Claim:
A computer readable medium containing an operating system for controlling operation of a central processing unit (CPU) of a microcomputer, comprising: first means for managing a plurality of tasks, wherein said plurality of tasks are switched among a running state, a ready state and a third state including at least one of a waiting state and a suspended state; and second means for switching said CPU to a low-power-consumption (LPC) mode if there is no task in the running state and no task in the ready state, wherein the switching of said CPU to the LPC mode is determined based on a predetermined allowable minimum time length of the LPC mode and an amount of time left before a task in the third state is switched to the ready state if the task is in the third state and the amount of time left before the task is switched to the ready state is known, wherein a duration of the LPC mode is set so as to be shorter than said amount of time left before the task in the third state is switched to the ready state.