内有C51语言和C语言以及汇编语言的对比，单片机内部资源、扩展资源及其编程；有应用实例，通过实例，读者可以在工作中进行类比编程，又可以开阔思路，提高实际工作能力。-There C51 language and C language and assembly language contrast, MCU internal resources, expansion of resources and their programming　are examples of application, by example, readers can draw an analogy in the work program, but also the broad ideas, enhance practical ability to work.