Review03082010
PCB review held on 3 August 2010
Present: P.Alvarez-Sanchez, M.Cattin, T.Wlostwski, E.van der Bij
Revision files can be found here:
https://www.ohwr.org/project/fmc-pci-carrier/tree/265/
1. VTT_QDR and VTT GN4124 planes. Consider unifying VTT_QDR and VTT
GN4124.
_ Now only a single VTT_QDR and VTT GN4124. The footprints of both VTT
driver have been left. In principle only one should be mounted._
2. FMC Stand-offs to ground.
Done
3. 12V routing (12V_FILTERED).
Done
4. Vref lines are too long, thin and have no decoupling capacitors.
Lines now are thicker and have decoubling capacitors at the arrival
5. Power tracks 4mil under BGAs should be thicker.
6. P1V5 plan (remove inductor for P1V5_DDR3 and join to P1V5)
Done. P1V5 is added in layer 5 close to P1V2
7. Remove text “Close to FPGA or DDR” on DDR3 schematic.
Done
8. Put 22uF capacitors a bit farther from FPGA.
Done, but their not really much further, moving them away did not
really improved the routing of other signals in this case.
9. Try remove GND on top and Bottom.
10. Do not adjust differential pair length under BGAs.
Done
11. 90 degrees corners on DDR3 lines should be 45 degrees.
Done
12. P3V3_PCIE layer 8 use polygon instead.
13. Replace 22uF 10V on 12V_FMC by a 16V capacitor.
Done
14. Place C72 and inductor a bit further from FMC connector (replace
inductor by something smaller).
Done. No replaced yet
15. Try to increase the distance between lines, especially on DDR3 area.
16. Add optional crystal oscillator for GN4124.
Finaly not done
17. DDR3 address lines should not be swapped.
Done
18. For clarity, swap the DDR3 data line on the memory side, not on the
FPGA side.
Done
19. GND planes must stop before the board edge under the PCIe
connector.
Done
20. Add 0Ohm serial resistor ENABLE_VADJ
Done
Added 31/08/2010 (pablo)
21. Swap differential lines to match length if needed (including PCIe
lines) Pablo
Done
22. Swap planes 1.2V and 1.8V (1.8V is cut just close to the 1.8V FPGA
VCC by the 1V5 plane)
Done
P.Alvarez, E. van der Bij, M. Cattin 4 August 2010
Comments added by P. Alvarez 2nd September 2010