关于变量定义的问题

只看该作者 · 2016-4-13 15:51

struct  Time_Device
{
unsigned char TimeMS;//毫秒
unsigned char TimeS;//秒
unsigned char time_flag;//定时标志位
unsigned char Start_time;//定时器开始计时标志位
};

union Time_REG
{
  unsigned long int  all;
  struct Time_Device  chars;
};

union Time_REG time_A,time_B,time_C,time_D,time_E,time_F;
这个变量层层嵌套，看的我云里雾里，有大神解释下吗