Routing differential pair with same length

The "Electrical constraint set>static phase tolerance" in the constraint manager is what controls this. Click on the button that says"ns" and select "mils". Then type in the tolerance you would like. I usually type in 10 mils. Remember that "10 mils" will give you +/- 10 mils window. So any given diff pair may have 20 mil difference between the two trace lengths. The smaller the tolerance you give the harder it is to hit that "window" when you are sliding the traces around. You can also use delay tune in the single trace mode to "stretch out" the shorter trace so it is a closer match to the longer trace.

Hope this helps

@Padmster

I hope you are telling about Allegro16.5 or 16.6,is it  possible in 16.3 or lower versions? 

Regards

Prashanth 

I'm using 16.5 but I know it is the same back to 16.2. I don't have any versions older than that installed.

Hi,

Thanks for your help, it is not quite the solution I was hoping for.

 The trace loops back on itself, and I am trying to figure out how to have them equal lengths while keeping the same distance from each other across the whole trace. Maybe there is no automatic or eloquent solution for this. 

https://www.dropbox.com/s/8hvuihc4ni19eig/curved_diff_trace.jpg 

The inside trace is always going to be slightly shorter than the outside trace. Unless of course you use delay tune to put a bump in the shorter trace. But at high speeds the bump can be worse than the trace lengths being slightly mismatched.