Milkymist One RC2 Known Issues

Here is the known issues found during debugging and testing RC2

Joerg's feedback

• insert fuse between powerjack and first capacitor (see above). Add a diode parallel to first capacitor, to short inverse polarity and make fuse trip
• cut connection from J11,pin1 to C142. Insert a 2A fuse slowblow

Major errors

• cannot boot after fast power cycling, need to ask Xilinx FAE.
• Production
  • parts swapped manually in wrong, must be R30 -- 4.7K ohm, R39 -- 330 ohm.
  • parts manually entered in wrong, must be R147/R148/R150 -- 4.7K ohm.
• BoM
  • change Y2 to other stronger package 49US(SMD) Crystal and place it at top side.

Minor errors and improvements

These errors do not alter the functionality of the board.

• Schematic
  • Add bigger test point for GND on top copper with circular mask to easily do some scopes.
• PCB design
  • Put one more via on U6 pin8 and U4/U5 Vcc pins.
  • Change Y2 to a different type like Y1.
  • Placement MK1 to be more precisely.
  • Let J11 DC Jack footprint tighten to its body for better mechanical match later.
• Materia
  • Incoming parts check: pins lifted? different mark?
• Production/SMT
  • Notice that even incoming parts are not good, try to use AOI and manually visual inspection to cover the poor, cool and crappy soldering.
• Testing
  • Use jtag-serial board for faster reflashing