In addition to the eFUSEs available in the PS, there are 128 eFUSEs available within the PL. Any value can be programmed into these eFUSEs, which are available via the FUSE_USER_128 register. A description of the eFUSEs is provided in the UltraScale Architecture Configuration User Guide (UG570) [Ref 33]. The programming and reading of the eFUSEs is described in the Internal Programming of BBRAM and eFUSEs Application Note (XAPP1283) [Ref 35].