home *** CD-ROM | disk | FTP | other *** search
- Xref: sparky comp.lsi.cad:1286 sci.electronics:22488
- Newsgroups: comp.lsi.cad,sci.electronics
- Path: sparky!uunet!zaphod.mps.ohio-state.edu!howland.reston.ans.net!spool.mu.edu!darwin.sura.net!mlb.semi.harris.com!jasper.mlb.semi.harris.com!luoni
- From: luoni@jasper.mlb.semi.harris.com (Perry Luoni)
- Subject: Re: Destroying Xilinx FPGAs by improper configuration?
- References: <1993Jan11.142553.5103@ips.cs.tu-bs.de> <1993Jan11.201525.26608@mlb.semi.harris.com> <scott.726798144@labtam>
- Date: Tue, 12 Jan 1993 15:25:38 GMT
- Nntp-Posting-Host: jasper.mlb.semi.harris.com
- Organization: Harris Semiconductor, Melbourne FL
- Sender: news@mlb.semi.harris.com
- Message-ID: <1993Jan12.152538.10700@mlb.semi.harris.com>
- Lines: 49
-
- 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.
-
-
-