Meander basics EAGLE 9.6.2

[sara.caron]

Hi

I seem to be unable to length match diff pairs between pairs. I select the meander tool, left click one segment, try selecting the diff pair and the resultant is a small window that tells me that the pair is 100% length matched (intra-pair) which they are. Also when the program tells me to select the side to meander the command resets. I am trying to match data diff pairs to a clk data pair. My MISC tab is set to 10 mil for tolerance and the Gap factor is 1 or 1.5 (trying different variables). I was able to get one pair matched to the clock pair but unable to repeat the process. 

I have several designs to perfect the process. Please help by giving some basics.

Running EAGLE 9.6.2

[jorge_garcia · Accepted solution]

Hello @sara.caron.

I hope you're doing well. Welcome to the forum, here are some tips to make the meandering easier to use.

1) In the DRC> Misc tab set the tolerance and the Gap Factor. Tolerance will depend on the technology you are trying to implement. Gap Factor I find is best set to 1, any value larger than 1 could make it difficult to generate small meanders in tight spaces.
2) When adding meanders its best to start the meander from one end then move towards the middle of the trace segment. Avoid angled segments for meandering use the longest horizontal or vertical portion of the diff pair traces.

For your specific use case where you are trying to match to other signals in your design, you need to know the length of the longest signal you want to match to. Let's say for an example the longest trace is 3000 mils, then when you go to meander a diff pair, you click on the meander command and then in the electronics CLI you enter 3000 and press enter (assuming units is mils). Now the meander command will match both members of the diff pair to 3000 instead of the default behavior of matching to the longest member of the diff pair.

Let me know if you have any other questions.

Best Regards,