Memory/Instruction barriers before writing to the backup SRAM The following code didn't worked because of a missing data barrier before writing to the backup SRAM:HAL_PWR_EnableBkUpAccess();
std::copy(buffer, buffer + num_bytes, BaseAddress + address);
HAL_PWR_DisableBkUpAccess();Adding a DSB, solved the issue for now.HAL_PWR_EnableBkUpAccess();
__DSB();
std::copy(buffer, buffer + num_bytes, BaseAddress + address);
HAL_PWR_DisableBkUpAccess();It is understandable, that the enable BkUp (which is setting a single bit) needs to be fully completed before writing the the actually memory addresses.But for me it is not fully understandable, if a DMB would be enough (it also works) and if I need an additional ISB, so Enable and Disable don't happen just before the actual copy, like so:HAL_PWR_EnableBkUpAccess();
__DSB();
std::copy(buffer, buffer + num_bytes, BaseAddress + address);
__ISB();
HAL_PWR_DisableBkUpAccess();Can someone help me out here, what the correct way would be?
