51扩占8155芯片的应用，包括端口、定时器和内部RAM。 内附PROTEUS原理图。-51 extended the application of accounting for 8155 chips

51单片机的8155扩展的proteus仿真，完成数码管显示，LED灯控制，键盘控制等多种功能，仅供参考(51 MCU 8155 extended proteus simulation, the completion of digital tube display, LED light control, keyboard control and other functions, for reference purposes only)