I found some differences between the memory mapping of the Datasheet and the Reference Manual:
DS STM32F4x Rev10 - Memory map pg. 86
Option Bytes 0x1FFE C000 - 0x1FFE C008
Reserved 0x1FFE C00F - 0x1FFE FFFF
/* missing info C008 - C00F -*/
RM STM32F4 Rev16 - Table 6. pg. 77
Option Bytes 0x1FFE C000 - 0x1FFE C00F
Same for bank to on 0x1FFF C000 ...
This defines no problem but which should be referred to?