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Altera_Forum's avatar
Altera_Forum
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14 years ago

How to set setup and hold time?

I find SDC file doesn't have constraints for input/output setup/hold. Instead, it has constraints of input/output delay. I think the negative value of input delay represents setup time, while ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

When using TQ, I can create "Virtual" and "Virtual Generated" clock.

In my opinion, the Virtual Generated clock should be used in set_input_delay/set_output_delay constraints. Because the Virtual clock doesn't have the information on which port the virtual clock binds with, while the Virtual Generated clock does.

Should I use "Virtual Generated" clock to do set_input_delay constrain?