CPU Serial Port Expansion of Certain Navigation System

In hardware design for a navigation system,the microcontroller can not provide enough UART serial ports to communicate with the navigation sensors.The paper designed a solution based on the C8051F040 microcontroller UART1 serial port expansion method using SP2349.In which,the SP2349 would be the core hardware circuit,and the microcontroller serial port UART1 would be extended to two serial ports,and designed the software that could achieve communication between microcontroller and navigation sensors by use of interrupts.The method solved the contradiction of being lack of the microcontroller serial port during period of communication between single chip and navigation sensors.