UART 处理的是并行数据转换为串行信号和串行信号转换为并行数据。现有的时钟不精确,这就需要用一个远高于波特率的本地时钟信号对输入信号不断采样,以不断让接收器与发送器保持同步。-UART to handle is the parallel data into a serial signal and serial signal is converted to parallel data. Existing imprecise clock, which requires a much higher than the baud rate of the local clock signal for sampling the input signal continuously to continuously allow the receiver to maintain synchronization with the transmitter.