Why net delay is so long ?

[khyu]

One net  delay is 5ns in my critical path .

But the net have only one fanout.

and it is very short net.

Why does it have so long delay

Thank you

[surajc]

HI @khyu 

1. Can you check the hold requirement of this path? 

2. Is there any local congestion around the area where the flop and lut are placed?  ( to check if the tool is trying to avoid the congestion and thus the large delay )

3. Did you try different placer and router directives ? 

[khyu]

1. Can you check the hold requirement of this path? 

The hold slack is 3.541

2. Is there any local congestion around the area where the flop and lut are placed?  ( to check if the tool is trying to avoid the congestion and thus the large delay )

There is no congestion in these two CLB

3. Did you try different placer and router directives ? 

I use the Performance_ExplorePostRoutePhysOpt

Which strategy do you suggestion?

[surajc]

Hi @khyu 

From the hold requirement what I meant was the following.

[khyu]

Hi Surajc:

            My hold requirement is 0

[surajc]

Hi @khyu 

Can you share the post opt dcp with me? 

Let me know so that I can send an ezmove link for securely sharing the design

[khyu]

Hi Surajc:

     Yes , I can share the post route opt dcp file

You can send me the upload link 

[surajc]

HI @khyu 

I checked your design and there are a lot of critical warnings in methodology report.

Please try fixing those and then proceed for implementation.

[khyu]

Hi Surajc:

          Thank you .

I will clear the critical warning and try again

[bitjockey]

If it doesn't violate timing constraints, perhaps the router thought the bits would just like to take the scenic route around the chip?  Go on a lazy Sunday drive around the [IP] block?