STM32F429IIT6 RTC Abnormal please help me!!

[blin.0]

Hi everyone!! I am from Taiwan

I am currently working on a project that records time using STM32F429IIT6

VBAT is connected to the 3.3V output of the power supply.

PDR_ON is connected to VDD

Power on when VDD is powered off

Time will be initialized

Project output is with STM32CUBE

I really don't know what to do.

please help me

[waclawek.jan]

What are the symptoms?

What is the initialization code of RTC?

Did you try to look at some of the example projects related to RTC?

JW

[blin.0]

Hi JW

I am trying to print out the value of RTC_BKP_DR0

The value of the first RTC_BKP_DR0 is 0X32F2

Later I changed the value of RTC_BKP_DR0 to 0X1111

Download to the STM32F429IIT6

After NRST is triggered, RTC_BKP_DR0 is still 0X32F2

But after I cut off VDD, I will re-power it. The value of RTC_BKP_DR0 is 0X1111

VBAT has connected to Super capacitor

I don't know if this is normal

RTC_BKP_DR0 should still be 0X32F2, it should not be 0x1111