Why is the timing report difference between Astro and DC

[blueant]

In one case, I found the components of the timing path (same star point, same end point) is difference between Astro's timing-report and DC timing-report. Anyone can tell me why?
Thanks

 

[JesseKing]

Because these two tools use different algorithms to calculat path delay, and the most important thing is path delay reported from dc is load based and path delay in astro is RC based.

 

[clivechen]

Although Astro and DC has different algorithms, but they should get the same result, because they all want to calculate the path delay!

 

[feel_on_on]

DC only estimate time path information!astro count this time path in reality component circuit!so this is the different ! astro is accurate and right!

 

[JesseKing]

Although Astro and DC has different algorithms, but they should get the same result, because they all want to calculate the path delay!

There are certainly different, path delay in dc just contains cell delay, and path delay in astro contains both cell delay and net delay

 

[blueant]

There are certainly different, path delay in dc just contains cell delay, and path delay in astro contains both cell delay and net delay[/quote]

Astro can ignore net delay.

 

[spauls]

DC is not a timing engine it is a synthesis engine , you can compare Prime time and Astro reports , they are almost equivalent

 

[power-twq]

because the wire load model is different between astro and DC.

In one case, I found the components of the timing path (same star point, same end point) is difference between Astro's timing-report and DC timing-report. Anyone can tell me why?
Thanks