Patent ID: 11567527

Abstract:
A circuit comprises a power controller, a real-time clock (RTC) sub-system, and a processing sub-system. The RTC sub-system includes an alarm register storing a predetermined time for a task, and provides an early warning countdown and a scheduled event signal. The processing sub-system includes a processor, a preemptive wakeup circuit, and a component coupled to the processor and configured to execute the task with the processor. The preemptive wakeup circuit comprises a selector logic circuit, a comparator, and a wakeup initiation circuit. The selector logic circuit receives latency values indicative of wakeup times for a clock generator and the component, and outputs a longest wakeup time to the comparator, which indicates when the early warning countdown and the longest wakeup time are equal. The wakeup initiation circuit generates a clock request and disables the sleep mode indicator. The power controller provides a clock signal and wakes the component.