>> Maybe it's overheating? Do you have a little fan right on the FPGA? >> We've found that is necessary, even in a "proper" case. We cut a hole >> in >> the lid and add a fan right over the chip. > > Interesting idea. I do have a small fan attached to the iBOB heat > sink. It was running at the time. The iBOB is mounted in a rack with > plenty of ventilation. > One other point that just occurred to me... the 8 small LEDs > accessible from the fabric were off, but the larger LED that indicates > that the fabric is programmed was ON. Not sure if that helps support a > diagnosis of the FPGA overheating. > >> That, or a power supply regulator is overheating and shutting down. >> might be able to diagnose that with your finger. (carefully, as they run >> somewhat hot anyway!) > > Hmm... Would a power supply regulator overheating cause the FPGA to > lose it's programming? When it comes back to life it returns to normal > with its software registers set correctly and everything. >
Could be, if the power supply that supplies the I/O is bad, but the other supplies on the board are OK. This is a bit of a pathological case! Maybe you can add some logic to see if the I/O power stays on and read it from the CPU. John > Laura > > >> >> John >> >>> Thanks, >>> Laura >>> >> >> >> >
