Embedded system is a big category, and single chip microcomputer is one of the important subcategories. As the name implies, an embedded system is a system embedded in other systems. For example, the attitude control system embedded in the automobile system can make the automobile driving safer and more effective; The introduction of automatic control system in the power supply system can make the power supply work more stable. The attitude control system and power automatic control system here belong to embedded systems. The system composed of single chip microcomputer is generally used for automation and industrial control functions. These functions are generally not used independently and need to be used in coordination with other systems. Therefore, in a broad sense, the application of single chip microcomputer generally belongs to a branch of embedded system. At present, due to the wide application of embedded systems, non-single-chip embedded systems such as mobile phones have emerged. Adding application processors to the basic functions of mobile phones (calls and short messages) makes them more powerful. However, due to the manufacturing process, high-end mobile phones can not be fully integrated (the integration is the cottage), but they also belong to a branch of embedded systems.