I'm using STM32F437IIH6 MCU, it has a 4KB backup SRAM which can be used as EEPROM like memory,
In order to achieve this we need to have a battery (3.3V coin battery) connected to the Vbat pin of the MCU.
I had worked on STM32F40-GEval board(STM32F407 MCU) and was successful in retaining the data in backup SRAM even after powering down the Eval board.
I designed a custom board with STM32F437 and inplemented the same(Battery connection to Vbat pin and all), but was unsuccessful in retaining the memory.
The data write was successful but the moment i switched off the MCU the data was gone.
where am i going wrong?