Why is Slack different after STA in Prime Time compared to PNR output?

Question

Accepted Answer

Slack is different after STA in Prime Time compared to PNR output due to timing optimizations and adjustments made during the Prime Time stage.

During Prime Time, timing optimizations are performed to meet the required timing constraints, which may result in changes to the slack values.
Prime Time stage involves detailed analysis and adjustments to improve timing closure, which can impact slack values.
PNR output is the result of physical implementation without timing optimizations, while STA in Prime Time includes timing optimizations for better performance.
Slack values may decrease or increase after STA in Prime Time compared to PNR output, depending on the specific design changes made during the optimization process.

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