BACKUP SRAM affects the other tasks

[ADank.2]

Hi,

I am using backup sram in stm32f429zi. Data Read write in backup sram section is executing properly and data will retain after power down. But when we do the power UP then my program is not executing from main loop. so my code is not working as required. As soon as I do the hardware reset then my code worked as per requirement and data also retaining in backupsram. so my question is that how can we recognize that the Power is up without using hardware reset?

Thanks,

Anagha

[TDK · Accepted solution]

> But when we do the power UP then my program is not executing from main loop. so my code is not working as required.

Attach a debugger without resetting the chip and see where the code is it. It's executing code somewhere.

The chip always resets after power comes up. No changing that.

I'm assuming you still have VBAT connected, as backup SRAM is lost without any power.

[ADank.2]

Solved!

PDR_ON Pin connected to GND and VDD through resistor. It should be connected to only VDD. So by desoldering the resistor connected between GND and PDR_ON my issue is resolved.