From: JoSa on
Me and my college are first time users of programming a FPGAs. We have
bought the already assembled card Xylo-L from knjn. It has a Spartan-3E
FPGA among other parts. Somewhere during the process of handling this card
something has gone wrong and now when we connect power to the card it gets
really hot fast. We can still put in some simple functions into the FPGA,
e.g. we can make a couple of LED glow and blink. This must mean that the
FPGA is not totally crashed. We have tested to reset the card with the USB
cable that's connected to the card.
When be put 3,3V to the card there is a current of about 900mA to the card,
which is plenty when we expect at most 300mA.

We would be very happy if anyone can give us some idea of what's wrong
and/or how we can test our card to find the problem, or maybe how to reset
the card completely.




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Posted through http://www.FPGARelated.com
From: Jon Elson on
JoSa wrote:
> Me and my college are first time users of programming a FPGAs. We have
> bought the already assembled card Xylo-L from knjn. It has a Spartan-3E
> FPGA among other parts. Somewhere during the process of handling this card
> something has gone wrong and now when we connect power to the card it gets
> really hot fast. We can still put in some simple functions into the FPGA,
> e.g. we can make a couple of LED glow and blink. This must mean that the
> FPGA is not totally crashed. We have tested to reset the card with the USB
> cable that's connected to the card.
> When be put 3,3V to the card there is a current of about 900mA to the card,
> which is plenty when we expect at most 300mA.
>
> We would be very happy if anyone can give us some idea of what's wrong
> and/or how we can test our card to find the problem, or maybe how to reset
> the card completely.
You have probably had an ESD event and damaged one or several I/O pads
on the FPGA. The rest of the FPGA may contin ue to work for a while.
If this board has an EPROM to load the FPGA configuration, try to
disable it or hold the PROG pin on the FPGA in the active state,
preventing it from loading any config. If it still gets hot, it is most
likely ESD damage. If it runs at normal current and doesn't get hot,
then your program may be clocking at excessive rates or causing
contention within the chip or on I/O pins.

Jon