View Single Post
  #5 (permalink)  
Old 02-19-2005, 06:54 AM
IgI
Guest
 
Posts: n/a
Default Re: Issues with a batch of Virtex-II chips

No, there isn't any reason, I simply forgot. We had to solve the problem the
fastest we could, because the customers are waiting for the products. And
the fastest way was to exchange the chips with the "good" ones. I still have
5 PCBs with problematic chips. We will analyze them further on Monday. If we
don't come up with some reasonable explanation, I will open a web-case.

Igor Bizjak

"Austin Lesea" <[email protected]> wrote in message
news:[email protected]
> Igor,
>
> Any reason why you haven't open a web-case? Or called the hotline?
>
> With your "lines down" situation, you should be moved to the head of the
> line, and be given the highest level of service.
>
> Let me know,
>
> Austin
>
>
>
> IgI wrote:
> > Hi!
> >
> > I'm using Virtex-II (XC2V1000-FF896-4C) in one of the product which we

have
> > been selling for over 3 years. Recently we got "new" batch of Virtex-II
> > chips and problems started to arise. So far I have isolated PCBs with

three
> > different batch of Virtex-II chips:
> >
> > Batch A:
> > XC2V1000
> > FF896AFT0301
> > F1247582A
> > 4C
> > Philippines
> >
> > Batch B:
> > XC2V1000
> > FF896AGT0409
> > D2169507A
> > 4C
> > Taiwan
> >
> > Batch C:
> > XC2V1000
> > FF896AFT0205
> > F1205613A
> > 4C
> > Philippines
> >
> > All the chips in batch A have the suffix AFT301, all the chips in batch

B
> > have the suffix AGT0409,...
> > PCBs with chips from batch B and C are working fine, on the other hand

none
> > of the 42 PCBs, where chips from batch A are used are working. PCBs are

the
> > same (same revision) for all the products, all other components

(ZBTRAMs,
> > DDR SDRAMS, passive components,....) are the same. All voltages are

within
> > the safe margins, all input clocks are clean. All the affected boards

pass
> > the JTAG test, in other words we didn't find any soldering errors, short
> > circuits, vias without metallization, wrong resistors or capacitors,
> > incorrectly oriented diodes or capacitors... or any other error we could
> > think of. We got all the chips in a sealed package. PCBs were tested at
> > different temperatures (from 8 degrees Celsius to 46). Only the PCBs

with
> > chips from batch A don't work. Let me explain what precisely is not

working.
> >
> > I'm using 6 DCMs to generate clocks for ZBTRAM, DDR, System,

ConfigBus,...
> > and two DCMs don't set the locked signal after I release them

sequentially
> > from reset. I don't know if other parts of the design (the parts which

don't
> > use ZBTRAM clock) don't work either, because the missing clock is a

fatal
> > error and I didn't have the time to investigate further in that

direction.
> > Working freq. of ZBTRAM is 120MHz, DDR is working at 166MHz, System at
> > 100MHz, ConfigBus at 10MHz,...
> >
> > We are currently using ISE 5.2 SP3 for this design. I have verified the

bit
> > stream by reading it back from the chip and it's ok.
> > Two coworkers, guys from the production and I are working on solving

this
> > problem for the last two days and we are almost out of ideas what else

we
> > could try, except replace the problematic chips with the

non-problematic. I
> > can't use ISE 6.1 or newer because the routing is not successful or ISE
> > simply doesn't meet the timing constraints (the chip is 99% full).
> >
> > Have you experienced anything similar in the past? How did you solve the
> > problem? Do you have any ideas/suggestions what else I could try? I

couldn't
> > find any document on the xilinx web site explaining the detailed chip
> > signatures. I would like to know, what AFT0301 stands for? Is this the
> > product date, production line, factory code...? I would like to know,

when
> > the chips have been manufactured (how old are they)?
> >
> > I guess we'll have a competition in the company next week. And the goal

will
> > be; who can throw virtex-II the farthest... Ok, I'm just joking, but I
> > needed to vent...argh...
> >
> >
> > Igor Bizjak
> >
> >



Reply With Quote