On Wed, Aug 9, 2017 at 7:23 AM, Luke Kenneth Casson Leighton lkcl@lkcl.net wrote:
next set...
wiggles.jpg is the layer 6 length-matching area: HX2N/P is the one that's the longest, it snakes back on itself. i length-matched all 3 signal pairs to 56.413, and left the CK lines at 57.134 just to give the tiniest bit of delay (TI recommendations iirc).
Very nicely done! 57.134mm - 56.413mm = 721um => T(delay) = 721um / 150um/ps = 4.8ps
That is a very tiny delay! Now that we have achieved such close synchronization, I'm suggesting we go for the next goal where we design a certain amount of inter-pair skew into the layout for purposes of lowering the strength of our synchronized pulsing data lines to a more diffuse chatter.
no - not even enough space to do 5.1mil / 5.0 clearance... just... too much.
I understand. We might end up with more room--see discussion below.
the other images show the via'd portions, they're all either symmetrical or perfectly length-matched to 0.001mm.
Again, they look nice.<div id="DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2"><br /> <table style="border-top: 1px solid #D3D4DE;"> <tr> <td style="width: 55px; padding-top: 13px;"><a href="http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail" target="_blank"><img src="https://ipmcdn.avast.com/images/icons/icon-envelope-tick-green-avg-v1.png" alt="" width="46" height="29" style="width: 46px; height: 29px;" /></a></td> <td style="width: 470px; padding-top: 12px; color: #41424e; font-size: 13px; font-family: Arial, Helvetica, sans-serif; line-height: 18px;">Virus-free. <a href="http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail" target="_blank" style="color: #4453ea;">www.avg.com</a> </td> </tr> </table><a href="#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2" width="1" height="1"></a></div>