用PIC单片机内部定时器0，作为16位定时器使用，并开启溢出中断。单片机的外部中断0引脚接开关SW2，并设置为下降沿的触发方式。单片机的UART接口工作于全双工异步模式，1个起始位，8个数据位，1个停止位，波特率为9600，并开启接收中断，与PC机通信。编写程序实现功能：SW2按键按下时，LCD上显示“Timer0 Start”, 定时器0开始工作，然后LCD上显示“Timer0 Working”,当UART接收到PC机发送的命令“P”时，定时器0停止工作，LCD上显示“Timer0 Stop”,并把定时时间发回给PC机。

并使用ICD2仿真器进行程序的烧写和仿真调试。

-PIC microcontroller internal timer 0 as a 16-bit timer, and open the overflow interrupt. MCU external interrupt 0 pin is connected to switch SW2, and set to the falling edge of the trigger. The microcontroller UART interface operates in full-duplex asynchronous mode, one start bit, 8 data bits, 1 stop bit, baud rate of 9600, and open to receive interrupt communication with the PC. Write a program to achieve functional: SW2 button is pressed, the display on the LCD Timer0 Start " to, timer 0 start work, and then displayed on the LCD Timer0 Working"　When UART receives commands sent to the PC, " P" , the timer 0 stop working, the Timer0 Stop " is displayed on the LCD, and the timing time is sent back to the PC. And to use ICD2 emulator for procedural programming and simulation debugging.