An update on Teho labs Procyon ARM development board that we’re been following in the forum:
We are pleased to announce the Revision 2 of Procyon is free of PCB problems and is ready for production.
Via the forum.
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An update on Teho labs Procyon ARM development board that we’re been following in the forum:
We are pleased to announce the Revision 2 of Procyon is free of PCB problems and is ready for production.
Via the forum.
Thanks for the post Ian. I likely will make these the week after Maker Faire.
Hmm, I wonder why the SDRAM is at 45 degrees but the ARM is not. Seems many of the traces come in towards the ARM package at 45 degrees anyway, so the board might have routed easier. Then again, I had trouble in Eagle when rotating chips in 45 degree increments because the tiny TSSOP pins don’t line up with a normal grid as easily, and finer grids take so much longer with the autorouter (which, yes, I do use).
The chips are like that to give the SDRAM better access to 2 sides of the ARM chip. I could have had the ARM at 45 degrees and the SDRAM at 90 equally well. The USB and Ethernet traces would have been nice. The XTALs would then have been at 45 deg also. I think it would be minimally different the the angle of the SDRAM and ARM swapped.
The EPI pins for the SDRAM are on all 4 sides, but the two sides facing the SDRAM on the ARM have something like 80% of the needed pins. You can see there are many vias on the JTAG side, those all go to the SDRAM on the back side.
A picture is worth 1000 words? http://teholabs.com/docs/_detail/procyon:procyonpcb.png?id=procyon%3Aoverview