TMC-10107: Maximum Fan-out for Signal


Maximum fan-out on wires (in designs using Intel Hyperflex architecture) always prevents Hyper-Retimer from retiming wires, limiting the achievable design performance.

Note: Use of this rule requires that the Report Source Assignments option is On in the Advanced Synthesis Settings dialog box. This option is on by default.


Consider performing the following:

  • Apply the max_fanout attribute to the source register instead of wire.
  • Duplicate the source registers. Refer to DUPLICATE_REGISTER and DUPLICATE_HIERARCHY_DEPTH assignments for automated solutions. Alternatively, you can edit the RTL to create duplicate copies.

    If you edit the RTL, apply the preserve_syn_only attribute to duplicate registers and assign the duplicates to individual instances in the fan-out hierarchy.




Tag Description
synthesis Design rule checks which pertain to the Compiler's Analysis & Synthesis stage.
register-duplication Design rule checks related to duplication of registers in the design, either manually or automatically.

Device Family

  • Intel Agilex®
  • Intel Agilex®
  • Intel®Stratix® 10