Forum Discussion
Occasional ContributorAbout Timing Constraints
No, as mentioned, set_input/output_delay specifies external delays so the Fitter knows where to place input or output registers to meet timing on the inputs or timing at the downstream device on outputs. set_max/min_delay is a way of specifically saying to the Fitter "I want this path to have a max delay of x and a min delay of y." Both sets of commands affect how the Fitter places and routes things.
Occasional ContributorThank you for your detailed explanation.
It was very helpful.
I understand that setting "set_max/min_delay" is not normally necessary, and that combinatorial logic delays between paths are included in the set values.
The specified delay value specifies the amount of delay between paths in the same way as "set_input_delay", and does not control the fitting so that the delay between paths is less than the specified value (when "set_max_delay") Am I correct in understanding that it is not?
Sorry for the elementary question, but it would be helpful if you could teach me.
That's all
sstrellSuper Contributor
No, as mentioned, set_input/output_delay specifies external delays so the Fitter knows where to place input or output registers to meet timing on the inputs or timing at the downstream device on outputs. set_max/min_delay is a way of specifically saying to the Fitter "I want this path to have a max delay of x and a min delay of y." Both sets of commands affect how the Fitter places and routes things.
- Yamada1
Thank you for your detailed explanation.
It was very helpful.
Thank you for your prompt response, even though it was an elementary question.
