Programming the device's non-volatile memory (RRAM) and User Information Configuration Registers (UICR) is managed through the Resistive Random-Access Memory Controller (RRAMC). In devices that have a key management unit (KMU), the KMU provisions assets into the SICR by copying data and permission policies from RAM to SICR.
When RRAMC write is enabled, you can write to the non-volatile memory or UICR. Only word-aligned writes are allowed when programming the UICR.