基于p/o口中断的3位按键输入多个数据，使用p1.0，p1.1，p1.2管脚输入按键信号，通过模拟同步串口控制3个7段共阴极数码管-Based on the p/o mouth interrupted the three key input more data, use p1.0, p1.1, p1.2 tube feet enter key signal, through the simulation synchronous serial control three of seven sect