EM78系列单片机内部没有异步串行口，所以必须用软件来完成这个工作。在很多实际应用中，我们已经采用了软件实现RS232标准的异步串行通信，结果证明工作非常稳定可靠。用软件完成串行通信，降低了芯片的硬件成本。-EM78 Series MCU internal asynchronous serial port does not have to use the software to complete the job. In many practical applications, we have adopted a software standard RS232 asynchronous serial communication, the result proved very stable and reliable. Complete serial communication software, reducing the cost of hardware chip.