设计程序使一个LED发光管以0.6秒为周期闪烁，即发光管每0.3秒点亮或熄灭一次。

分析题目要求，主要涉及两方面的操作，即控制LED发光管的亮灭以及定时0.3秒。对于LED发光管，只用一个IO就可以控制了（例如使用IOA0）；而对于0.3秒定时，我们可以利用TimerA定时器轻易地实现。-The design process of a LED to LED blinking 0.6 seconds for the cycle, that is, every 0.3 seconds LED lit or extinguished once. Analysis of the subject requirements, mainly related to two aspects of the operation, that is, control LED LED light out as well as the timing of 0.3 seconds. The LED light-emitting tube, only one can control the IO (such as the use of IOA0)　and for 0.3 seconds from time to time, we can use to easily achieve TimerA timer.