说明：  C8051F020单片机比较代码，通过它，你会很快熟悉C8051F单片机在比较器上寄存器的配置。稍微修改，即可加入自己的工程。
(Comparing C8051F020 microcontroller code, through it, you' ll quickly become familiar with C8051F MCU on the register in the comparator configuration. Slightly modified, you can add your own project.)