Author Topic: "The routing start point violates DRC" error when routing differential pair  (Read 937 times)

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Offline JJallingTopic starter

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Hi all,

I'm designing a board for the RPi CM4/CM5 module in KiCad. I have some differential pair traces that I want to route from the module, to a connector. With my current layer stack, the differential pair is .12mm trace, .2mm gap and .4mm clearance. When I try to start routing the differential pair, I get the error "The routing start point violates DRC", which it does because of the spacing on the connector for the RPi module.
Is there a way to ignore constraints locally on a board, ie. on the RPi connector, so I can get the PCIe lanes routed?

Thanks in advance,

BR Jonas
 

Offline Doctorandus_P

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Re: "The routing start point violates DRC" error when routing differential pair
« Reply #1 on: September 24, 2024, 03:38:09 pm »
Yes, you can for example make a custom rule to modify or ignore parameters inside a rule area, or simply inside the courtyard of a footprint. But there are (minor) bugs in this area that interact with how the interactive router works. The final DRC check is reliable though
 
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Offline JJallingTopic starter

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Re: "The routing start point violates DRC" error when routing differential pair
« Reply #2 on: September 25, 2024, 05:55:41 am »
Excellent! Thanks for pointing me in the right direction.

BR Jonas
 


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