If the address do not require FFFFH, does it mean that the area is not programmed?
For (2) under FCU Command Usage, Programming and Erasing the E2 DataFlash Memory in the E2 DataFlash Memory chapter of the User's Manual: Hardware, it states that "If the area accessed... includes addresses that do not require programming, write FFFFh as the programming data for those addresses". If the data to be written to addresses that do not require programming is FFFFh, does this mean that the area is not programmed?
No. The data flash area is written. When FFFFh is set as the programming data for addresses that do not require programming in the programming unit, FFFFh is written. The area is not in an unprogrammed state. The value of E2 DataFlash after an erase is undefined (unprogrammed state). Use the blank check command to check for an erased state.