MAX_FANOUT - 2024.1 English

Vivado Design Suite User Guide: Synthesis (UG901)

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2024.1 English

MAX_FANOUT instructs Vivado synthesis on the fanout limits for registers and signals. You can specify this either in RTL or as an input to the project. The value is an integer that indicates what the fanout should be. A value of -1 tells the tool not to perform any replication.

This attribute only works on registers and combinatorial signals.

Note: It replicates the register or the driver that drives the combinatorial signal to achieve the fan outputs, black boxes, EDIF files, and Native Generic Circuit (NGC) files are not supported with this attribute.