🚀 go-pugleaf

In article <scott.726798144@labtam> scott@labtam.labtam.oz.au (Scott Colwell) writes:
>luoni@jasper.mlb.semi.harris.com (Perry Luoni) writes:
>
>>In article <1993Jan11.142553.5103@ips.cs.tu-bs.de> koch@eis.cs.tu-bs.de (Andreas Koch) writes:
>>>Is it possible to physically destroy a Xilinx 3000 series LCA
>>>by programming only (meaning: outside electrical parameters
>>>are within valid bounds)? Since we are in the process of
>>>establishing FPGA design labs, we would like to know if
>>>we have to watch out for critical design flaws which would
>>>endanger our LCAs. Any hints are appreciated!
>>>
>>>Andreas Koch
>>>-- 
>>>Andreas Koch                                Email  : koch@eis.cs.tu-bs.de
>>>Institut f"ur theoretische Informatik       Phone  : x49-531-391-2384
>>>Abteilung Entwurf Integrierter Schaltungen  Phax   : x49-531-391-5840
>>>Gaussstr. 11                                Telex  : 95 25 26
>
>>Yes, it is possible to short a lot of nodes together with the wrong data programmed into
>>the LCA.  If you are using the Xilinx design software you don't have to worry about
>>it though.  The software will prevent you from programming it wrong.  
>
>
>We are worried about this too.  We have been told that as long as the
>configuration only causes internal drivers to clash with each other, the
>device will survive, but if you cause pin drivers to clash with other
>devices on your board, the device can be permanently damaged.
>
>We are not totally convinced that this is good advice.  We have seen a device
>get _very_ hot with only internal contention.
>
>
>By the way, the problem is not doing this at the design stage.  If you are
>building 200 units a week using an LCA in a pqfp package, you are going to
>get a percentage of boards that will not correctly load the LCA config
>from the prom.  (this is most likely when you use the parallel prom mode)
>We see our prototype get very hot when it can't read the prom correctly
>and we are worried that we will have the LCA destroyed on each board that
>has a fault that stops the config prom from loading correctly.
>
One solution would be to current limit the supplies when you are testing the part.
There really isn't any way to eliminate the problem.  If you look at the schematics
to the 3000 series you will see you can pretty much connect anything with anything
or short damn near every node in the chip together.  If you want to try to burn one
out just for fun try programming every memory location to a one, I'm pretty sure
you will have a near worst case condition.   If you guys want to buy some radiation hardened
parts (3090) we will be selling them next year for about $3500.00 a piece.