26.4.2.3.2 Flash Programming

When programming the Flash, it is written one word at a time. Writing is done by writing a 32-bit word to the desired address in the Flash, after programming has been enabled through the Command bit field in the Control B register (CTRLB.CMD). Writes of bytes or half-words to the Flash are discarded, and a bus error is returned.

Attempting to start a programming on a section that is busy will cause the Programming Error Status bit in the Status register (STATUS.PROGE) and the Error flag in the Interrupt Flag Status and Clear register (INTFLAG.ERROR) to be set.