Patent ID: 9128703
Filing Date: 2015-09-08
Classification: G06F,Y02D

Abstract:
1. A method for placing an e-book reader into a low power mode, the method comprising: transitioning a processor from an active mode to an idle mode when no task is scheduled to execute on the processor; setting a timer interrupt interval based on when a next task is to be executed; adjusting a reference counter in a kernel executing on the processor, the adjusting comprising: entering a wait mode during the timer interrupt interval when the reference counter is greater than zero, the wait mode comprising stopping a clock for the processor while leaving the device active; entering a quiescent doze mode during the timer interrupt interval when the reference counter is zero, the quiescent doze mode including: gating an external memory interface clock associated with an external memory interface that provides access to an external memory; and placing the external memory into self refresh; and waiting for an interrupt before resuming the active mode.