DJ - On Thu, Sep 21, 2006 at 12:18:46PM -0400, DJ Delorie wrote: > Double sided, 0.062.
How quaint. ;-) The board I'm in the middle of bringing up is 6-layer, 0.045. I've probably linked to it before: http://recycle.lbl.gov/llrf4/ So the distance between a trace and its ground plane is an order of magnitude smaller than what you have. And yes, it's laid out with Gnu/PCB. > I figured that; they're going on the SRAM side of the DIN connector, > about in the middle of the run. On the board above, I have some 100-ohm series resistors [*] on digital traces. Signalling rate could be as high as 105 MS/s, and the longest traces are about 4.5 cm. > I have a 32 Ms/s scope and a 500MHz logic analyzer, neither of which > is great for this kind of test, but might be close enough. Only if you work with slow parts. Edge speeds faster than 1ns are fairly common these days. - Larry [*] On the board photo, look in the center of the board, to the left of the "big" FPGA. There is a vertical line of eight resistor packs, in series with the data pins from the four high speed ADCs just to their left. _______________________________________________ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user