Hi,
I've got a really strange problem with a XC95144XL. It's a simple design, all schematic based, and the device is not behaving -- but only sort of. Pins that are unused are turning into weak outputs, some outputs work, and other don't (they may be high or low). I have data buses with 6 out of 8 pins working. Change something and recompile, reload and the results will be different eg. same data bus but now 5 pins work correctly and 3 are high or low. Most of the internal logic seems to be working OK -- this only seems to affect IO pins.
I've checked:
All pins (this is a TQ100 if that matters), including VCC/GND. A few pins ar "fast", most are not, and the 3.3 V supply looks fine. The download from a Parallel IV cable is verifyable, and repeated downloads work (or fail to work) the same. All the Fitter / Placer warnings make sense. The equations in the reports are all correct.
If I add some unneeded logic ie. add a counter, clock it and feed one output to an unused pin then the symptoms change.
Yes -- I do have it setup for the correct device.
Any bright ideas (or even some really silly ones)
While I hopefully wait for those I'm downloading 8.2 again.....