10.3.2.5 Unit ID Regions

  FUID0          : ORIGIN = 0x800FF8,      LENGTH = 0x2
  FUID1          : ORIGIN = 0x800FFA,      LENGTH = 0x2
  FUID2          : ORIGIN = 0x800FFC,      LENGTH = 0x2
  FUID3          : ORIGIN = 0x800FFE,      LENGTH = 0x2

The unit ID regions correspond to locations in program memory that may be programmed with application-specific information.