[sdiy] FPGA Synth Music

[Eric Brombaugh]

On Mar 2, 2010, at 7:51 AM, Jason Tribbeck wrote:

>> The configuration issue you
>> may be thinking of is that there's a little parameter you need to insert
>> into the .UCF file to let the part know that it's being given 3.3V for
>> VCCaux. That's just so that the internal references know where to set the
>> thresholds on some of the I/O standards. Otherwise it works transparently
>> with only two supplies (3.3V & 1.2V).
> 
> That was the issue - I wasn't sure what kind of damage would occur if you'd accidentally forgotten that setting ;)
> 
> Which knowing my luck I would've done for the first board, and then wondered if it was the schematic, layout or soldering that I'd got wrong somehow because it had caused irreparable damage to the chip, which would've put me off making any more boards. But that's worst case scenario :)

Given that it's just controlling an I/O threshold setting I'd assumed it wouldn't cause any damage. You might see some unreliable signaling after configuration, but nothing irreparable. And since we've pummeled this deceased equine I doubt you'll forget that setting now. :)

Eric