| ID: | 3929 |
| From: | ge...@igor2.repo.hu |
| Date: | Mon, 6 Apr 2020 04:40:53 +0200 (CEST) |
| Subject: | Re: [pcb-rnd] drc: Different part of board, different rules |
| in-reply-to: | 3928 from Britton Kerin <br...@gmail.com> |
On Sun, 5 Apr 2020, Britton Kerin wrote: >I have a vague sense that asymmetrical bloating (making only one of >two objects which might be too close bigger, which I think is what is >being proposed here) might not be equivalent to bloating everything >simultaneously, but I haven't thought about it carefully. In a sense yes. In case of zone poly based check or in case of different-clearance-per-net case this will sometimes happen. Zone case: if two objects A and B at the edge of the poly are close then different bloat-check will be done for A-to-B from A, under the zone, and for B-to-A for B, not under the zone. This means if the stricter (non-zone in the BGA fanout example) rule triggers, you get one violaton, B-to-A. Net case: let's say you use 0.3mm rule for signals and 1mm rule for high voltage lines. If two objects, A in a signal net and B in a HV net are getting close, then in the A-to-B check we'd bloat by 0.3mm and in the B-to-A check we'd bloat by 1 mm. So if your distance is 0.2mm both will trigger, if it's 0.6mm only the HV net will trigger and if it's above 1mm neither triggers. > >While on this subject one thing I labored to fix in pcb in the old days >was the bad location reporting for DRC violations, where a violation >involving one long object like a line would get reported at the center >of the object, rather than in the bloat intersection itself. I don't know >if pcb-rnd still has this behavior or not but if so this might be a good >time to fix it :) I see you haven't opened the drc in pcb-rnd yet! This part got a full rewrite. The display remembers much more than just a coordinate. It remembers all offending objects participating in the violation, sorted into two groups (red and blue), so unlike in pcb, you get a meaningful preview that actually tells you what the problem is. The preview boinding box is calculated so that the offending objects are within the view. Center of objects are irrelevant in this. This has happened many months ago to make sure we have the necessary object-listing and GUI infra for the time when we finally have the resources to implement the new DRC algo (which is now). Regards, Igor2
Reply subtree:
3929 Re: [pcb-rnd] drc: Different part of board, different rules from ge...@igor2.repo.hu