一种简单的51的操作系统，设定定时的时间间隔，并为每个任务分配一定时间，当任务就绪时，执行该任务；没有任务就绪时，执行任务调度函数-A simple 51 operating system, set the timing interval, and each task assigned a certain time, when the task is ready, the implementation of the task no task is ready, the implementati