Stats

More Content

VIA to VIA spacing isn't true in allegro cadence.

mrcuongcon

I set the VIA to VIA spacing in allegro cadence (v17.2) to 1mil, but allegro not show error in some case.

(1)(2) Via pad to VIA pad ovelap ( but VIA drill not overlap) -> Cadence show error -> OK

(3) Via pad to VIA pad overlap, and Drill via to Drill via overlap too ( but not all part of Via Drill) -> cadence not show error, not OK

(4) Overlapping two VIA ( all part of VIA ) -> cadence show error -> OK.

Pls see detailed in attached picture

https://drive.google.com/file/d/1tq6xxt0YuE3uD2WyMIXe2cW23tzmv3L4/view?usp=drive_link

So, in case (3), is there an issues of allegro cadence?

Parents
  • +1

    Hello,

    When two same net Vias overlap each other they will generated a DRC until the center of one via crosses over the pad of the other via.  At that point the Vias will be considered directly connected.so a DRC Error is not seen.  If you want to see a DRC in this situation you will need to change Pad-Pad Connect under Physical to not allow direct connections, NOT_ALLOWED. (Default is set to ALL ALLOWED.)  See images below.

    Hope this helps,
    Mike Catrambone

Reply
  • +1

    Hello,

    When two same net Vias overlap each other they will generated a DRC until the center of one via crosses over the pad of the other via.  At that point the Vias will be considered directly connected.so a DRC Error is not seen.  If you want to see a DRC in this situation you will need to change Pad-Pad Connect under Physical to not allow direct connections, NOT_ALLOWED. (Default is set to ALL ALLOWED.)  See images below.

    Hope this helps,
    Mike Catrambone

Children
No Data
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.