内容：通过中断接口P3.2连接的独立按键测试，按一次P1口的LED灯反向，

这里使用边沿触发，所以一直按键不松开和一次按键效果相同，区

别于电平触发-Content: The interrupt interface connected to an independent P3.2 key test, according to a P1 port LED lights reverse, where the use of edge-triggered, so they do not release the buttons and a button the same effect, different from the level-triggered