What would happen on the timing analysis if user set a negative value on the set_input_delay constraint?

User can either set the negative value on the -max option or on the -min option:

1. Setting a negative value for the -max option of the set_input_delay:

When user set a value of the set_input_delay for the -max option, this applies to the setup analysis. A positive value means it will add to the data path delay and therefore tighten the path requirements for setup. Thus, decreasing the slack.

On the other hand, a negative value means it will subtract to the data path delay and therefore loosen the path requirements for setup. Thus, increasing the slack.

Setup Slack = Required Time - Arrival Time

Timing calculations example of a positive max input delay on the constraint:

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What would happen on the timing analysis if user set a negative value on the set_input_delay constraint?

What would happen on the timing analysis if user set a negative value on the set_input_delay constraint?

Related Articles

Diamond: Why is the HOLD_OFFSET on the timing report a negative value when using the INPUT_DELAY option on the INPUT_SETUP preference?

<div>Lattice Radiant version 2022.1 and 2023.1: Why does the Radiant Timing Report indicate an unconstrained path for path with applied constraint such as <i>set_input_delay</i>?<br></div>

Diamond: How does Timing Analysis use the CLKOFFSET value of the INPUT_SETUP preference?

Radiant: How does the user set constraints for a MII interface?

Radiant: How does the user interpret the Single Clock Domain table entries on the Clock Summary section of the Place &amp; Route Timing Analysis Report?

Radiant: How does the user interpret the Single Clock Domain table entries on the Clock Summary section of the Place & Route Timing Analysis Report?