Hi:
I have known the function of set_max_fanout,but I don't understand how to confirm the parameter which following set_max_fanout.please help me! thank you!連結已複製
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That's the max fanout value. So if a register has a fanout of 35, and you do that assignment, you'll end up with 5 copies, 4 that have a fanout of 8 and 1 that has a fanout of 3. The following might help:
http://www.alterawiki.com/wiki/register_duplication_for_timing_closureAre you talking about an ASIC?
Max fanout is your constraint that you would manually enter to help timing. You can enter whatever value you want. The main purpose is to help the fitter place logic closer together, and hence achieve better timing.