The USERCODE instruction is supported in
the UltraScale FPGAs. This register allows you to specify
a design-specific identification code. The USERCODE can be programmed into the device
and can be read back for verification later. The USERCODE is embedded into the bitstream
during bitstream generation (USERID property) and is valid only after configuration. If
the device is blank or the USERCODE was not programmed, the USERCODE register contains
0xFFFFFFFF .