用外部中断输入引脚RB0/INT接收连接在该引脚上的按键信息。每检测到一次按键就对8位计数器COUNT　　加1，将COUNT的值直接送给8个发光二极管显示。

　　单片机复位后，COUNT的初始值为二进制数00000000B，对应的8只发光二极管都不亮。当按键RB0/INT被按下时，COUNT的值加1，发光二极管D0点亮，以表示二进制数00000001B。然后松开按键之后，如果再次按下RB0/INT时，COUNT的值加1，发光二极管D1点亮，以表示二进制数00000010B……，以此类推。通过观测8个发光二极管显示的二进制的COUNT的值，判断中断次数计数的准确性。-External interrupt the input pin RB0/INT receive key information is connected to the pin. Each detected keys on the 8-bit counter COUNT plus 1, the value of COUNT sent directly to eight light-emitting diode display. Processor reset, the initial of COUNT value binary number 00000000B not bright the corresponding eight light-emitting diode. When is pressed key RB0/INT, the value of COUNT plus 1, the light emitting diode D0 is lit, in order to represent a binary number 00000001B. Then release the button when pressed again RB0/INT the value of COUNT plus 1, light-emitting diode D1 is lit to represent a binary number 00000010B ..., and so on. The judge interrupted the accuracy of the count of the number of times through the observation of eight light-emitting diode display binary value of COUNT.