22.3.2 Alternate System Configuration Words
In the PIC32CX-BZ3 family of devices, the configuration words select various device configurations and are located at physical addresses from 0x00805F80 (FBCFG7).
If an unrecoverable ECC error occurs when reading the configuration words, the alternate configuration words are used to configure the device from Boot Flash memory. This configuration can be identical to the primary configuration words or different to operate in another condition. The alternate configuration words are located at physical addresses from 0x00805E80 (ALTFBCFG7). To flag that an ECC error has occurred, the BCFGERR (RCON[27]) bit is set.
If uncorrectable ECC errors are found in both primary and alternate words, the BCFGFAIL (RCON[26]) bit is set and the default configuration is used.
After programming the configuration words, the user application must reset the device to ensure the configuration data is reloaded with the new programmed values.