Power Mode Switching Process
Typically (for example, when Bluetooth LE and peripherals are used at the same time), the system switches between the power modes as described below.
- Power on the system and launch a cold boot.
- The system enters active mode.
- If there is no logic task to be processed, the system goes into the Check Sleep step, to check whether the system is in idle state.
- If the check result is “Yes”, compare the remaining system idle time (the sleep time left for Bluetooth LE Timer, Sleep Timer, or RTC) with the warm boot duration.
- If the remaining idle time is shorter than the warm boot duration, the system will enter idle mode.
- If longer, the system will enter sleep mode, and wait to be woken up.
- If the check result is “No”, the system remains in active mode.
Note:
Boot time and high boot current are required for the system to enter the warm boot process from sleep mode. When the sleep time is relatively short (for example, shorter than 2s), the reduction in power consumption after the system enters sleep mode is hardly noticeable. Therefore, to ensure overall performance, it is recommended for the system to enter sleep mode only when the sleep time is relatively long, so that the average power consumption can be reduced.
