ActiveRoute and Glossing Enhancements

ActiveRoute is new, automated interactive routing technology, introduced in Altium Designer 17.0. ActiveRoute works with the designer to rapidly route selected connections. Rather than allowing an autorouter to do its best at routing the entire board, ActiveRoute acknowledges the reality that board design is a highly interactive process, where the best results are produced by skilled designers using powerful tools, under their control.

Learn more about ActiveRoute

Complementing ActiveRoute, the new Glossing engine carefully analyzes selected routes, neatening and shortening them. The updated Glossing engine also delivers a new Retrace Selected command, use this to update the selected routes to the current routing rule settings - now you can fatten up that existing power routing, or update that differential pair to new width and gap settings.

Both ActiveRoute and Glossing continue to be developed, with a number of enhancements in this release.

Improved Designer Control

One of the great challenges with interactive software tools is interfacing those tools to the designer's fingertips, so they can easily and fluidly move from interactively routing through a tight area of the board, and then apply ActiveRoute's algorithms to route what remains. For this to happen, it must be easy to select the connections or routes of interest.

Selection Techniques

Use the following techniques to select connections or existing routes:

To Select	Use Mouse + Keys	Outcome
Connections		ActiveRoute will route with the Preferred rule setting.
Existing Routes		ActiveRoute will route using the width of the selected track.
Additional objects	+ combinations shown above	Retains current selection, as additional objects are selected.
Other objects in the net		First press of Tab adds other objects on layer(s) the selected object touches. Second press of Tab adds all same-net objects on other layers. Continue to press Tab to cycle through the available selection states.

For example, if you select the connection lines for a differential pair and run ActiveRoute, it will apply the Preferred rule width value to the tracks that it places. Alternatively, if you select the last-placed track segments of a partially routed differential pair and run ActiveRoute, ActiveRoute will respect that, and complete the routing at that width. 

Glossing and the Route Guide

The Route Guide feature allows the designer to draft a preferred path for a selected set of connections, ActiveRoute then attempts to route those connections within that path. The Route Guide feature has been enhanced to support a greater maximum width of 5 times the width required to satisfy the route width + clearance of the selected connections. Post route glossing has also been enhanced to follow the Route Guide path, attempting to keep the glossed routes within the designer-defined Route Guide path.

Continuing the push to better follow the designer's requirements, glossing now produces cleaner pad entries that better respect the intent of the applicable design rules. Glossing also leaves sub-net jumpers in situ, and when there are room-based width rules, the locations where the existing routes cross the room boundary and change their width, are also retained.

To summarize, the following glossing improvements have been made for this release:

• Updated selection principles:
  • Previously, to gloss only a section of a routed net you would select a track at either end of the section; in this release you can also select a pin or a via to signify an end of the desired section.
• Glossing now respects the route guide and attempts to gloss within the route guide area
• Repair dangerous pad entries:
  • Gloss does not automatically comply with the SMT rules (SMD Entry & SMD To Corner), because they tend to encourage unnecessary jogs and circuitous routing.
  • If the rules are present then it tries to recognize dangerous situations, such as the potential for solder bridging, and adjusts its behavior based on these rules.
  • For this to occur the Corner option must be disabled in SMD Entry rule, and the SMD To Corner rule must have a suitable setting.
  • Rule deviations: Gloss will keep the track segment orthogonal with the pad edge being exited from, but will not necessarily keep it centered within that edge. Gloss will also allow the track segment to exit from the side of the pad, if the SMD to Corner distance and other applicable rules can be satisfied.
• Apply the Preferred gap where possible, when glossing a differential pair:
  • If a diffpair was routed with the gap other than the Diff Pair Routing rule Preferred value, Gloss will attempt to change it to use the Preferred gap.
  • It will, however, narrow it down as needed to ensure DRC-free passage in tight zones, and balanced pad entries at the ends.
  • This behavior is applied to the zipped portion of the pair (where the sides are at Max Gap or less from each other).
  • Caveat: Gloss does not handle an unreasonably large Max Gap.
• Support for Subnet Jumpers:
  • Gloss now treats Subnet Jumper tracks as fixed.
• Support for room-based rules:
  • Gloss now adheres to Clearance and Diff Pair Routing rules scoped to rooms.
  • Gloss allows the route to change width as it it enters a room, it will attempt to preserve the original widths used both outside and within the room.
  • If there is a width change at a room boundary, Gloss will leave the boundary-crossing at the existing location.

More Detailed Messaging

The level of feedback displayed in the Messages panel has been expanded to better detail what ActiveRoute has done, what has not been done, and why.

Retrace your Routes

Building on the capabilities that Glossing brings, this release of Altium Designer see the introduction of a new command - Route » Retrace Selected. Where Glossing attempts to shorten the overall route length and reduce the number of corners, Retrace re-applies the preferred width and clearance requirements to an existing route. Now you can easily decrease or increase the routed width of a selected set of nets, or even the width and gap of differential pairs. Retrace works exactly as its name implies, running along the selected routes, updating them to the current rule specifications. Because it does this on an individual net or pair level it will attempt to maintain clearances, but is not able to push surrounding routes if more room is required. In this situation, the rule updates are only applied to those route segments that do not create a violation.

To summarize:

• Retrace is similar to Gloss (and uses the same engine internally), the differences are:
  • Gloss preserves the width; Retrace changes it to the Preferred value.
  • Gloss produces the shortest possible result, often radically deviating from the original; Retrace approximately follows the original.
• Use the same selection principles as Gloss to select the routes to be Retraced.
• Use Retrace to update the selection and apply the applicable preferred Width rule.
• Modifies selected routes as needed to avoid poor quality corners and pad entries, while preserving the general route geometry.
• Use Retrace to update the diff pair gap:
  • Will update the zipped portion of the pair (where the sides are at Max Gap or less from each other), changing the gap to Preferred.
  • To reduce the gap in a routed pair, change the Diff Pair Routing rule so that the Preferred Gap is the desired gap, and the Max Gap is the old Preferred Gap value, then run Retrace.
  • Caveat: Retrace does not handle an unreasonably large Max Gap.
  • Note: if the new Preferred settings are larger than the current width/gap, Retrace may fail to reach its goal without creating violations. In such cases it will use smaller values to avoid creating violations. No pushing of obstructions is performed.

Retrace uses the Differential Pair Routing rule settings in the following way:

• Min Gap - the minimum gap that is allowed during retrace. This is only used if necessary, the default is the Preferred Gap.
• Preferred Gap - the separation that retrace will attempt to achieve, dropping down to no less than Min Gap if necessary. 
• Max Gap - used to determine which sections of the pair will be retraced, only those sections that are currently zipped (where the sides are at Max Gap or less from each other), are attempted. That means the new Max Gap must be at least as large as the actual gap used in the current routing.