I used the external crystal oscillator (32768HZ) for the real-time clock experiment, but I found that my read time is always 0:0:0 on January 1, 2016. I feel that the real-time clock is not counting.
The following is my program configuration and initialization
Key_Test = 0;
Finally, I found out that it was read on January 1, 2016, 0:00, 0:00.