In Power-save mode, the asynchronoustimer continues to run, allowing the user to maintain a timer base while the rest of the device is sleeping.
在省 电模式下，异步定时器继续运行，允许用户保持一个时间基准，而其余功能模块处于休眠 状态；
2
More precisely, the redisplay occurs after some kind of asynchronous event related to the view, such as a keystroke, a timer completion, or a response to an HTTP request.
Based on the principle of UART, a software method has been presented for asynchronous communication by using interrupt program of timer, and has been implemented in an application project.