18.2.4 Alternate System Configuration

To provide better data retention for the configuration data (compared to the data retention of the rest of the device Flash), each set of DEVCFGx, FBCFG0 registers are duplicated in an alternate set. This improves the chances of correct system configuration out of Reset. In the event of an uncorrectable error in a word (ECC DED), the Flash controller uses the alternate set to obtain the correct data.