Differential pair length tuning

[Lakshmi]

Hi,
I’m routing differential pair in kicad 5.1.
There are total 4 Diff pair which needs to be almost same length(Each pair).
Is there an option where I can set the trace length for all pair before routing and so that they’ll be almost same length OR
Is it current way of doing draw all the pair and length tune individually?

[cflin]

Since version 1.4, KiCAD has had extensive options to handle differential pairs. In pcb, these options can be found under “Route.” The ‘Differential Pair’ option tries to keep the length of differential pairs the same as you are laying them out. You need to play with the other two options (tuning). Note that in order for KiCAD to recognize a pair as differential, its two net names must be special: They have to end in ‘_P’ and ‘_N’ or ‘+’ and ‘-’, e.g. ‘DATA_P’ and ‘DATA_N’. (It would be great if the overbar over a net name, denoting complementarity, was also accepted…) See the following video for more information: https://duckduckgo.com/?q=kicad+differential+pair&t=canonical&ia=videos&iax=videos&iai=9M8JNaRHqKw

[Lakshmi]

Hi,
I think you’ve not understand my question. Please read again- " **There are total 4 Diff pair which needs to be almost same length(Each pair).
Is there an option where I can set the trace length for all pair before routing and so that they’ll be almost same length **
I know differential pair in kicad works to some extent well I’ve faced few issues also.
You can take a look at the image below,

[Joan_Sparky]

So you’re not dealing with a single pair, but a bus (4x2) that needs tuning?
Might need to change the title or add ‘bus’ to it…

[halachal]

To answer your question: no, you need to route them all first, then you can “tune length” on each pair to get them equal.

[MitjaN]

This might come in handy Length stats: action plugin