The eFUSEs listed in Table: PUF Control eFUSEs control additional PUF behaviors. Table 12-8: PUF Control eFUSEs eFUSE Name Description REG_DIS Disables registrations of the PUF. SYN_INVALID Invalidates the helper data contained in the eFUSEs. SYN_LOCK Prevents modification of the helper data contained in the eFUSEs.