On Fri, Aug 11, 2017 at 12:37 AM, Richard Wilbur richard.wilbur@gmail.com wrote:
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!
ooooOoo :)
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.
*deep breath*.... aaaaaaaa! :)
well.... that actually happens for the majority of the length in the middle (starting layer 6)
but.... if i simply *take out* the intermediary wiggles on layer 6....
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.
which has probably been truncated...
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">
whoops.... something melted there...