Differential Pair Routing Improvements (New Feature Summary)

Differential Pair routing is rapidly moving from the bleeding-edge to the every-day, with more and more designs using technologies like high-speed serial interfaces. Helping to ensure that Altium Designer's differential pair routing capabilities continue to deliver the design functionality that you need, the following improvements have been made in this area.

Dynamically display the clearance boundaries during differential pair routing.

Setup and Rule Improvements

Easier Net Length Length Matching Within a Differential Pair

• The Matched Net Lengths design rule Constraints have been simplified, with the Within Differential Pair Length option checking for differences between the nets in each pair targeted by the rule scope.

Defining a new Differential Pair Class via the PCB panel

• If you attempted to use the right-click menu in the PCB panel to add a new Differential Pair Class, the Edit Object Class dialog that popped up was empty, it now lists all existing differential pairs as Non-Members, ready for you to define a new class.

Query Builder enhanced to include Belongs to Differential Pair Class as a Condition

• The Query Builder now includes Belongs to Differential Pair Class in the Condition Type/Operator drop down.

Setting the Preferred and Max Values in a Differential Pairs Routing Rule

• It is no longer possible to inadvertantly enter a Preferred value that exceeds the Maximum value in the Differential Pairs Routing rule.

Differential Pair Rules and Precision Round Off

• When toggling the display units from mils to mm, AND when the Metric Display Precision is set to 3, a rounding error was being introduced. If the Metric Display Precision is set to 4, then the rounding error would not occur.

Routing Improvements

Improved Interactive Length Tuning

• It is not unusual to have multiple rules targeting a differential pair, for example one for the pair length and another specifying the allowable difference in length between pair members. The Interactive Length Tuning dialog now displays all applicable rules, allowing you to select the rule you want applied during this tuning event. Press Tab during tuning to access the dialog.

Differential Pair Length Tuning of xSignals

• If the nets in a differential pair are within xSignals, and the applicable Matched Net Lengths design rule targets those xSignals, those pairs can now be length tuned.

Optimization of Connection Lines for Differential Pairs

• The automatic connection line optimizer now attaches the connection lines to the correct source or target pad.

Arcs in Differential Pairs

• Arcs in Differential Pairs no longer cause false Uncoupled-Length-Violations.

Clip to target length option for Interactive Differential Pair Length Tuning

• Differential pair length tuning, with the Target Length set to Manual and the Clip to target length option enabled, now functions correctly. Note that the amplitude is adjusted if required so that the target length can be met.

Display of Routes during Interactive Differential Pair Length Tuning

• After launching the Interactive Diff Pair Length Tuning command and clicking to select the diff pair, the existing routing could disappear, remaining invisible until the cursor was moved. When the cursor was moved the existing routing would reappear, but masked (when it should not be). The routing now displays correctly during length tuning.

Length Tuning with the Mitered with Lines Style

• During length tuning, using the Mitered with Lines tuning style, occasionally one net in the pair would route directly from the cursor to a random point further along the routing, creating a short circuit. This no longer occurs.