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Brew low power mode

To preserve battery life, a device will seek to enter BLPM after a short period without user interaction (10 seconds). To enable BLPM, the platform sends the EVT_APP_NO_SLEEP event. Unless one or more applications return TRUE for this event, the device will enter BLPM, which results in a lower clock rate from the processor and may cause operations by applications to complete more slowly.

To keep the device from entering BLPM, applications can return TRUE for the EVT_APP_NO_SLEEP event. Applications should only return TRUE if they are performing an operation that genuinely requires the clock rate of the processor to be at maximum to avoid a degraded experience, for example, when playing back video. If an application is not performing such an operation, then the application must return FALSE to the event.

Note: Backlight behavior is independent of BLPM; the device may enter BLPM with the backlight on or off.

For examples of Brew MP interactions with device power optimization algorithms, see Brew low power mode examples.

Leaving BLPM

The mobile device leaves BLPM whenever a user event occurs. User events include key presses, application starts, and touch events. After a user event, the device does not re-enter BLPM for a specified timeout period, which the OEM can configure. The default timeout period is 30 seconds without receiving a user event. After this time expires, the EVT_APP_NO_SLEEP event code is sent to all loaded applets. If any of them return TRUE to this event code, the timer is reset.

Note: For more information about the EVT_APP_NO_SLEEP event code, refer to the AEEEvent topic in the C/C++ API Reference.