New Contributor
New ContributorHi,
I'm back on this problem again. Based on a previous reply I thought that I would look into why the Blaster (programmer) couldn't identify the chip and I captured the JTAG waveforms but the TDO pin is just outputting a constant low.
I have checked all the chips power pins and they all have correct voltages on them.
I have checked the GND pins and again they all seem to be soldered ok.
The only thing I can't check is, it would seem from the PCB layout drawing that there is a "heat spreader plate" on the underside of the chip we are using (10CL025YE144C8G). Our PCB design appears to allow for this to be soldered to the GND plane.
What would happen if this was not soldered to GND ? We have had some cases in the past (other designs) where our manufacturing sub-contractor makes a mistake and this pad is not solder pasted.
Does any of the internal circuitry connect through this pad instead of the normal GND pins ?
thanks
PhilipJ
ContributorI had a problem years ago with (as I recall) a Cyclone III part that wouldn't configure. In that family at least the thermal pad on the FPGA HAD to be grounded. After reworking the board to ground the pad, everything configured properly. I would search through the "pin connection guideline" document for your part and see if the thermal pad must be grounded.
New ContributorHi GLees,
thanks for your reply.
We have spoken with our sub-contractor and they have said we should send the batch of boards back to them and they will "re-flow" them.
I will let you know what happens after I get them back for re-testing.
PhilipJ
