51单片机的串口程序，使得51单片机的UART口每接收PC机发送的一个字符，加1回送给PC机。包含实现上述功能的电路原理图（1页）

使用原理图上用到的晶振，给出了计算波特率的步骤。波特率可以是2400、4800、9600给出了设计程序的步骤或画出程序的流程图-51 Single-chip serial procedures, making 51 MCU UART port for each PC, sent to receive a character, plus a gift back to PC. To achieve the above functions with circuit diagram (a) The use of schematic diagram on the use of crystal, is given for calculating the baud rate step. Baud rate can be 2400,4800,9600 gives the design process flow chart of steps or procedures to draw