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Observer
Observer
5,531 Views
Registered: ‎06-11-2009

the warning in "generate post_map simulation model" in ise

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i have made a simple ADR,and done the post_simulation in modelsim.but the result is indeterminate state.

and i found there was a warning when i execute "generate post_map simulation model" in ise.the warning is :

 "NCD is not completely routed, some delays may be inaccurate".

so how can i do with the warning?can it be the reason of the wrong result of post_simulation in modelsim?

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Observer
Observer
6,681 Views
Registered: ‎06-11-2009

thanks very much!!

now i have passed the timing simulation . i t's really the problem of my testbench. :)

View solution in original post

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Professor
Professor
5,525 Views
Registered: ‎08-14-2007

I think you always get this warning with post-map simulation.  Basically it says your timing

won't be as accurate as a post P&R simulation.  If your behavioral simulation was running

properly, you may have some timing problems, including possibly setup or hold violations

due to testbench timing.

-- Gabor
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Observer
Observer
5,512 Views
Registered: ‎06-11-2009

Thank you!

do you mean it's may be the problem of my testbench ? sorry it's the first time for me to do the post_time simulation ,i have much thing to learn.

thank you for your help ! :)

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Professor
Professor
5,504 Views
Registered: ‎08-14-2007

It's possible for a testbench to work with behavioral simulation but not with timing

simulation.  For example if you have synchronous inputs to the unit under test

and the test bench changes them one "delta" after the rising clock edge, the

behavioral simulation will always capture these signals properly, however a timing

simulation may require some non-zero amount of hold time and the "delta"

really represents zero hold time.  Setup and hold violations should show up as

warning messages during simulation.

 

Theoretically if you have constrained all paths in your design (this is a rare case)

and have met timing constraints, the timing simulation should match the behavioral

simulation IF the test bench timing conforms to the constraints as well.

 

HTH,

Gabor

-- Gabor
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Observer
Observer
6,682 Views
Registered: ‎06-11-2009

thanks very much!!

now i have passed the timing simulation . i t's really the problem of my testbench. :)

View solution in original post

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