New PCB Length Tuning Patterns (New Feature Summary)
This document is no longer available beyond version 21.0. Information can now be found here: Length Tuning for version 24
Length matching is a critical element of high-speed design, usually solved by carefully tuning the lengths of critical routes. This release sees the introduction of new Trombone and Sawtooth tuning patterns, and improvements to the Accordion pattern.
New and Improved Tuning Patterns
This release sees extensive improvements to both single-sided and differential pair length tuning capabilities. New Trombone and Sawtooth tuning patterns have been added, which introduce the concept of a tuning sleeve. The sleeve concept simplifies moving and reshaping the tuning pattern, allowing you to slide the tuning pattern along the original route path and around bends.
New Tuning Patterns
Length tuning now supports all three popular tuning patterns: Trombone, Sawtooth, and Accordion.
Press Tab after launching the Length Tuning command to choose the pattern.
- Press Tab after launching the Length Tuning command
and choose the required Pattern in the Interactive Length Tuning mode of the Properties panel, before you start length tuning a net.
Working with the New Tuning Patterns
For the Trombone and Sawtooth patterns, the polygonal area that the pattern is constructed within an envelope that can be thought of as a sleeve. Click to select a placed pattern and display the sleeve.
The trombone and sawtooth patterns are built within a sleeve shape, which supports a variety of shape-change behaviors.
There a number of different movement and size-change behaviors available, depending on where you click and hold on the sleeve. There are three zones where you can click and drag, these are shown in the image above.
- Click and Drag on Zone 1 or 2 to lengthen or widen the pattern. Note that it is not necessary to click on a handle to resize the pattern, use anywhere along the sleeve edge.
- Click and Drag on Zone 3 to freely move the pattern along or perpendicular to the original route path.
- Edit the properties of the selected pattern(s) in the Properties panel.
The Shift and Ctrl shortcuts can be included during a click and drag action, modifying the behavior in the following ways:
- Shift + Click and Drag on Zone 1 or 3 to slide the pattern along the original route path, maintaining the pattern's lateral distribution across the route path.
- Ctrl + Click and Drag on Zone 2 or 3 to move the pattern perpendicular to the original route path.
Sawtooth Pattern Properties
- Angle - slope of the leading and trailing tooth edges, relative to the original route path of the net being tuned.
- Tooth Width - width of the top of the tooth.
- Actual Height - current tooth height, measured from the centerline of the original route path being tuned, to the centerline of the tooth's top track segment. Press Tab during placement to edit the Actual Height value.
- Min Height - minimum allowable tooth height.
- Min Joint - minimum length of the first colinear track segment placed before the first tooth is created.
- Single Side - create the tuning pattern so that it only projects in one direction from the original route path. Press the S shortcut during placement or interactive editing to toggle the option on or off.
- Fixed Size - fixes the Sawtooth Height to the current height, and removes any teeth that are not at that fixed size.
Trombone Pattern Properties
- Space - the distance between the centerlines of adjacent trombone switchback paths. Press the 3 or 4 shortcut keys to interactively decrease or increase the Space, in increments of Space Step.
- (Space) Step - this is the amount the Space value is changed when the 3 or the 4 shortcut key is pressed during trombone placement or interactive editing.
- Miter - percentage that the corners of the tuning pattern are mitered when the Style is Mitered Lines or Mitered Arcs. Press the 1 or 2 shortcut keys to interactively decrease or increase the Miter, in increments of Miter Step.
- (Miter) Step - this is the amount the Miter value is changed when the 1 or 2 shortcut keys are pressed during trombone placement or interactive editing.
- Style - style of the trombone corners, choose between Mitered Lines, Mitered Arcs or Rounded. The Style is changed by pressing the Spacebar shortcut key during trombone placement or interactive editing.
- Single Side - create the tuning pattern so that it only projects in one direction from the original route path. Press the S shortcut during placement or interactive editing to toggle the option on or off.
Rotate an Accordion Pattern
The PCB editor's accordion pattern has been updated to support the rotation of a placed accordion pattern.
To rotate a selected accordion, hold Ctrl then:
- Click and drag on either end of the accordion selection box to pivot around the opposite end of the accordion.
- Click and drag on either side of the accordion selection box to pivot around the center of the accordion.
- Press the R key during rotation to toggle (on/off) the rotation to snap in 45-degree increments.
Automatic Net Length Tuning
In the Research list, status is In Progress
Assuming that this is the mode where tuning is enabled during interactive routing (Shift+A to toggle it on/off). Currently uses the original, pre-union tuning accordions that are just a collection of tracks and arcs.
Track Dragging
Preferred Clearance Support
In the research list, current status is "In progress"
Any Angle Routing for Differential Pairs
Move to the research list, now flagged as suggested for AD22
Glossing Improvements
Avoid acute angles for Any Angle Pad Entry ROUTING-2890
Suspended? Ticket is not accessible (Jira says "We couldn't connect to that issue")
3D PCB Routing on Surface
Moved to suspended list
GCS & Bugcrunch fixes
New Advanced Settings
PCB.TraceTuning.DisableFilling Disables filling in external tuning.
PCB.TraceTuning.FillingStrength Controls pattern shape: 0 - strict, 1 - with bumps.
Legacy.PCB.UseRewrittenGloss Use new rewritten gloss.
Legacy.PCB.DragVia Use pre-AD20.0 via dragging behavior.
PCB.UseOldDataModel Enable old PCB data model implementation
PCB.DynamicPour Enable dynamic polygon pour feature
PCB.UseMesh2dTriangulation Enable Mesh2d Triangulation
PCB.SplitPlanes.Pouring Enable Split Planes polygon pouring
Legacy.PCB.RigidFlex Enable legacy Rigid Flex
PCB.Polygons.OptimalVoidRotation Polygons optimal void rotation