Precautions for Jerry's serial port to receive data by DMA [chapter]

1. receive BUFF Interrupt when full . It should be noted that the data length of a continuous transmission cannot exceed the receiving set by the slave BUFF Otherwise, the length of is greater than BUFF Length data will be lost . 2. Send end interrupt . 3. The timeout is set with the following function （ The third parameter is the count value ）. uart_module_ctrl(&uart1_handle,UART_CMD_OT,0xffff,NULL); TIME_OUT = (1/LSB_CLK)*CNT, The unit is seconds .