Stats

Locked Locked
Replies 4
Subscribers 165
Views 12923
Members are here 0

Allegro fanout ratsnest connection to ground plane lost after footprint symbol update, but tracks present

Hello,

In Allegro 17.2, I previously had fanout connections to a ground plane for a QFN footprint with no more unconnected ratsnestlines. I changed the footprint symbol and did an update. All over at the connections to the ground and 1.8V power planes I see ratsnests appearing between the pins as if the fanout connections were not there. However, the tracks are still there. (see the picture for pins 12 and 10) To make the ratsnests dissappear, I have to delete the tracks and fanout again. How come? Can I reconnect the tracks automatically?

(I enabled the display design parameter to show the holes and have the ratsnest geometry set to straight)

RFinley over 4 years ago

Select that net and make sure the cline segments and vias are still associated with the same net. The cline segment touching pin 10 may have changed nets.
Cancel
Vote Up 0 Vote Down

Cancel
frank mpbc over 4 years ago in reply to RFinley

"are still associated with the same net."

How? With F4?

Frank
Cancel
Vote Up 0 Vote Down

Cancel
RFinley over 4 years ago in reply to frank mpbc

My approach: make sure you are in etchedit mode, make sure nets are checked in the Find filter. Just hover over it.

If you hover over pin10, away from the cline segment, everything associated with that net will flash. But, if you move to the right and hover over the cline segment, does the pin also flash or highlight?
Cancel
Vote Up 0 Vote Down

Cancel
steve over 4 years ago in reply to RFinley

You can also try a Tools - Derive Connectivity, check the relevant options (first two) and click on OK. This sometimes happens if you have different database units and accuracy between footprints and the board.
Cancel
Vote Up 0 Vote Down

Cancel

Cadence Guidelines

Community Guidelines

The Cadence Design Communities support Cadence users and technologists interacting to exchange ideas, news, technical information, and best practices to solve problems and get the most from Cadence technology. The community is open to everyone, and to provide the most value, we require participants to follow our Community Guidelines that facilitate a quality exchange of ideas and information. By accessing, contributing, using or downloading any materials from the site, you agree to be bound by the full Community Guidelines.