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Altera_Forum
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13 years ago

constraining push button input using TimeQuest

Dear All, have a push-button input to one of the pins in the FPGA. This passes through 2 flip-flops to get into FPGA clock domain. How can I specify this correctly in the TimeQuest? I do not wa...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
13 years ago

Do you want a constraint? Since it's going to occur asynchronously, I don't think there's anything that would be correct, and why you have two registers, since the first could go metastable. Most people do nothing, while some add a set_false_path to it so it doesn't show up as unconstrained.