I have defined LVDS signals in Constraint Manager and routed LVDS pair from chip to connector but there is some mismatch in length of positive and negative signal. When I do tuning it applies to both signals and as a result only one signal achieve target length and other signal still have mismatch in length as before. Is it possible to apply tuning to only one signal (not both) ?
Which version are you using? In VX.1.2 (May have been in VX.1 also) you can use "Manual Saw Tune" to tune one side of a diff pair. If you are on an older version of Mentor, there was a tool included in the Smart Utilities that worked pretty good, but I think the "Manual Saw Tune" works much better once you get the hang of it.