SWCU194 March 2023 CC1314R10 , CC1354P10 , CC1354R10 , CC2674P10 , CC2674R10
The Key Store Written Area register (CRYPTO:KEYWRITTENAREA) shows which areas of the key store RAM contain valid written keys.
When a new key must be written to the key store on a location that is already occupied by a valid key, this key area must be cleared first. Clear the key area by writing this register before the new key is written to the key store memory.
Trying to write to a key area that already contains a valid key is not allowed and results in an error.
For more details, see Section 12.7.