After I init the RTC for backup mode, the first time I set the date/time via the S command, the ALFAT saves it. But any subsequent update via the S command doesn’t get saved (even though I get the !00 response). What gives?
Your reference schematic (and your User Manual) say to use a crystal with a 12.5pf load capacitance along with 18pf caps. But per the STM32F205RBT6 manual, you should ‘never’ use a crystal with that value load capacitance (they recommend Cl <= 7pf with 8pf caps). Please explain.