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Messages from 65900

Article: 65900
Subject: Re: iteration Vs LUT table entry vs accuracy in Cordic
From: Jerry Avins <jya@ieee.org>
Date: Mon, 09 Feb 2004 17:07:13 -0500
Links: << >>  << T >>  << A >>
praveen wrote:

> Hello,
> I wanted the relationship between the number of iteration vs LUT table
> entry.
> Because i wanted to estimate the arc tan to a accuracy of 1
> microradians.
> In my simulation i found that even if the iteration is around 25
> iteration i could not achieve the 1 microradian accuracy.
> 
> My LUT i have represented using 32 bit and the two number whos atan is
> to be obtained is also 32 bit(all fixed point).
> 
> Please suggest a solution
> with regards
> praveen

Go to my web site, http://users.erols.com/, look at my article
"Quadratic Interpolation in Forth", and even it the article itself
gives you no ideas, there's a link at the top that may.

Jerry
-- 
Engineering is the art of making what you want from things you can get.
ŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻŻ


Article: 65901
Subject: Re: FIR filter coefficient (with COE file)
From: bmhowe@yahoo.com (Ben Howe)
Date: 9 Feb 2004 14:24:05 -0800
Links: << >>  << T >>  << A >>
http://www.mathworks.com/access/helpdesk/help/toolbox/filterdesign/coewrite.shtml

If you can't use coewrite from Matlab, then use this format...

;
; XILINX CORE Generator(tm) Distributed Arithmetic FIR filter
; coefficient (.COE) File
; Generated by MATLAB(tm) and the Filter Design Toolbox.
;
; Generated on: 15-Mar-2002 13:47:15
;
Radix = 10; 
Coefficient_Width = 16; 
CoefData =   -41,
 -851,
 -366,
  308,
  651,
   22,
 -873,
 -658,
  749,
 1504,
   21,
-2367,
-2012,
 3014,
 9900,
....

"Yttrium" <Yttrium@pandora.be> wrote in message news:<DTPVb.4731$16.313447@phobos.telenet-ops.be>...
> hey,
> 
> I'm using the Xilinx CoreGenerator for the first time because i need a FIR
> filter and saw the DA FIR in the IPCore library and found it really usefull
> in this design. The only problem is dat i don't find how to generate a COE
> file?
> So i don't know how to turn a floating point coefficients (which i found
> through firdes or matlab) into a COE file?
> 
> thanx in advance,
> 
> kind regards,
> 
> Yttrium

Article: 65902
Subject: MAC FIR V3.0 POLYPAHSE DECIMATION
From: bonorato@yahoo.com (B)
Date: 9 Feb 2004 14:30:27 -0800
Links: << >>  << T >>  << A >>
Greetings DSP Guru's

Does anyone have experience with the Xilinx MAC FIR V3.0

I am interested in implementing a polyphase decimator.
The Xilinx data sheet is lacking in the timing department for the
polyphase decimator.
A simple simulation test seems to fail
    Input a impulse -> output should equal the FIR coeffs.
    The decimation is 4 and this is where the impulse is (@ sample 4)

The MAC FIR core works under this test without decimation.

Any insight would be appreciated.

Rgds
B.Onorato

Article: 65903
Subject: Re: Pricing, 101
From: Jan Panteltje <pNaonStpealmtje@yahoo.com>
Date: Mon, 09 Feb 2004 22:34:48 GMT
Links: << >>  << T >>  << A >>
On a sunny day (Mon, 09 Feb 2004 13:21:48 -0800) it happened Peter Alfke
<peter@xilinx.com> wrote in <4027F9ED.F7C82422@xilinx.com>:

>If you build something in small volume, everything is expensive: design
>effort, pc-boards, most components, testing, marketing, advertising,
>selling, servicing etc.  You must have a really good product to absorb
>all these high costs. That's life.
>Peter Alfke
Hey, of cause things are expensive.
Now log in to www.microchip.com
Find a PIC, you can enter a quantity and order right there.
Whats your problem?
Perfect for small business.
WYSIWYG

Article: 65904
Subject: Re: Stratix II NIOS sizes ?
From: kempaj@yahoo.com (Jesse Kempa)
Date: 9 Feb 2004 14:49:30 -0800
Links: << >>  << T >>  << A >>
> 
> Jesse,
>   Thanks for that. We would expect NIOS II to be more 'tuned'
> for Stratix II...
> 
>   Here's a question, (for when you can comment :)
>   Will NIOS II have a variant that fits/runs on MAX II devices ?
> 
> -jg

Hi Jim,

I'd love to address that right now but can't -- stay tuned for the MAX
II & Nios II launches. They will answer that question.

- Jesse

Article: 65905
Subject: [Altera/Quartus] Tools to regenerate block schematics from .vhd files
From: "Pszemol" <Pszemol@PolBox.com>
Date: Mon, 9 Feb 2004 17:05:22 -0600
Links: << >>  << T >>  << A >>
I am kind of new to FPGA design and I have to understand a circuit given
as a set of hierarchical .vhd files (top level and two-three lower levels),
but it would be kind of nice to see it layed out on a piece of paper...
Is there a tool to generate schematics from vhd files to visualize vhd?

Article: 65906
Subject: Re: How may I restrain the P&R to only a small area...
From: "Kelvin @ SG" <kelvin8157@hotmail.com>
Date: Tue, 10 Feb 2004 07:34:03 +0800
Links: << >>  << T >>  << A >>
Thank you Chris.

I have read the xapp290...
However I have defined AREA_GROUP on each modules of my design, now I need
to restrain the P&R of a particular module to be within a corner of the
module's AREA_GROUP instead...

Best Regards,
Kelvin




"Chris Ebeling" <christopher.ebeling@xilinx.com> wrote in message
news:4027E24B.10145AF8@xilinx.com...
> Apologies,
> I  didn't read your post very carefully  have you looked at this?
> http://www.xilinx.com/bvdocs/appnotes/xapp290.pdf
>
> Chris Ebeling wrote:
>
> > Xilinx Docs -> Constraint Guide -> AREA_GROUP
> > http://toolbox.xilinx.com/docsan/xilinx6/books/manuals.htm
> >
> > Tungsten-W wrote:
> >
> > > Hi, there:
> > >
> > > I am doing a design which only covers 10% of the slices...but after
P&R, it
> > > spreaded all over the FPGA.
> > > How may I constrain it into, say, one corner...
> > >
> > > How may I "nail down the logic into a known location"(Somebody told me
this
> > > trick)?
> > >
> > > BTW, I am doing reconfigurable design, so the AREA_GROUP constraints
can't
> > > be used...
> > >
> > > Kelvin
>



Article: 65907
Subject: VHDL:Dividing a real number by two??
From: "kwaj" <k.otengNOSPAM@student.unsw.edu.auNOSPAM>
Date: Tue, 10 Feb 2004 12:26:54 +1100
Links: << >>  << T >>  << A >>
I would have assumed that given a real variable, LAPP, to divide it by two
would simply be;

LAPP / 2

But I get as an error, "no feasible entries for /". How would one divide
through a real number??

- Kingsley





Article: 65908
Subject: Re: VHDL:Dividing a real number by two??
From: "Bevan Weiss" <kaizen__@NOSPAMhotmail.com>
Date: Tue, 10 Feb 2004 15:03:11 +1300
Links: << >>  << T >>  << A >>
I think that you're mistaking VHDL as some form of programming language.
VHDL is a hardware description language, and as such it has no real
knowledge of a divide.  The only thing that a divide would be used for would
be as an expression to form a constant.

If you're trying to divide some non-constant value by two, then you have to
ask yourself where this non-constant value is coming from, what kind of
operation would need to be performed on it to divide it by two, and where
you want the result to end up.  Then you must design the logic to go between
the input and the output of the divide operation (or alternatively use some
prebuilt libray which already has such a design).

I think that you should read an introductory book on VHDL, it should help
you understand where you're going wrong with your approach.

"kwaj" <k.otengNOSPAM@student.unsw.edu.auNOSPAM> wrote in message
news:c09bq7$r6t$1@tomahawk.unsw.edu.au...
> I would have assumed that given a real variable, LAPP, to divide it by two
> would simply be;
>
> LAPP / 2
>
> But I get as an error, "no feasible entries for /". How would one divide
> through a real number??
>
> - Kingsley
>
>
>
>



Article: 65909
Subject: Re: Quartus II taking forever to compile
From: "Paul Leventis \(at home\)" <paul.leventis@utoronto.ca>
Date: Tue, 10 Feb 2004 02:04:58 GMT
Links: << >>  << T >>  << A >>
Hi Kenneth,

> Is there any chance a 64bit version of Quartus will be released?

We'll release a 64-bit version of Quartus when one is needed in order to
address more memory.  Windows XP maxes out at 3 GB (with a command-line
flag), and Linux maxes out at ~3.7 GB.  In all our testing of Stratix II, I
don't think I've seen any compile (even on a 2S180) that required more than
2 GB of memory, and most compiles require much less than this -- and we get
some very stressful, pathological designs from our internal test/product
engineering groups.  Also, as memory needs keep increasing due to larger and
larger chips, we strive to beat down on the memory requirements of Quartus.
In addition, architectural changes in Stratix II result in reduced memory
consumption compared to the same design compiled in Stratix.

So there is still plenty of room left before we _have_ to go 64-bit -- and
we will be ready when the market needs a 64-bit version of Quartus.

> I got my 15+ min. builds down to 5+ by upgrading to the fastest available
> cpu, but I was thinking this process might benefit from the new 64 bit AMD
> and upcoming Intel procs.

Contrary to popular belief, the "bitness" of a processor does not
(necessarily) equate with speed.  The primary advantage of switching to
64-bit computing is the increase in (easily) addressable memory that you get
with 64-bit pointers.  You are limited in 32-bit machines to 4 GB of
addressable memory (minus the up to 2 GB of address space the OS reserves).
There are tricks to get this up higher, but aren't fun to program to.

From a processing speed perspective, switching to 64-bit code may help and
may hinder things.  It can help in those cases where you would have had to
break up something that wanted a > 32-bit representation across multiple
integers.  But most things fit fine in 32 bits, and promoting those
variables to 64 bits just pollutes your data cache, effectively reducing the
amount of cache memory available to the processor.  And 64-bit code can be
larger (because of larger pointers, instruction extensions, larger data
values, etc.) thus chewing up valuable instruction/trace cache room.
Luckily, recompiling C code to 64-bits does not change your integers to
64-bits -- just your pointers -- but this still has some impact on data and
instruction cache consumption.  I am glossing over many pros and cons of
32/64-bit code, but you get the idea.

Intel plans to ramp the Prescott (90 nm version of P4) core up to 4 Ghz+,
and AMD will be making Opteron/Athlon64 for years to come.  As they up the
speed, you will get more performance on your 32-bit applications.  And you
can bet future versions of the processors will support fast 32-bit
processing, since it will take a LONG time before many programs make the
switch to 64-bit.

If you are interested in some early benchmarks comparing 32-bit and 64-bit
x86 performance using a beta of Windows XP 64-bit, see
http://www.anandtech.com/.

Another bit of performance data:  http://www.speg.org/.  Do a search on
results from "AMD Athlon" and click through to find results that were on the
same machine, one running 32-bit windows, the other 64-bit SuSE Linux
w/64-bit gcc compilation.  On the few machines I looked at, the SPEC level
was ~5% better on 32-bit.  If you look at the "VPR" component of the SPECint
test, this is an academic FPGA place and route tool, and it too yields
something ~7-8% less speed on 64-bit x86.  Of course, there could be
immaturity of compilers, different OS efficiencies, etc. in here, but 64-bit
will be no silver bullet when it comes to performance.

Regards,

Paul Leventis
Altera Corp.



Article: 65910
Subject: Re: VHDL:Dividing a real number by two??
From: Allan Herriman <allan.herriman.hates.spam@ctam.com.au.invalid>
Date: Tue, 10 Feb 2004 13:18:04 +1100
Links: << >>  << T >>  << A >>
On Tue, 10 Feb 2004 15:03:11 +1300, "Bevan Weiss"
<kaizen__@NOSPAMhotmail.com> wrote:

>"kwaj" <k.otengNOSPAM@student.unsw.edu.auNOSPAM> wrote in message
>news:c09bq7$r6t$1@tomahawk.unsw.edu.au...
>> I would have assumed that given a real variable, LAPP, to divide it by two
>> would simply be;
>>
>> LAPP / 2
>>
>> But I get as an error, "no feasible entries for /". How would one divide
>> through a real number??
>>
>> - Kingsley

try 

LAPP / 2.0

'2.0' is a real, and '2' is an integer (and the compiler hasn't been
told to divide a real by an integer).

This is unlikely to be synthesisable (depending on context) as Bevan
suggested.

Regards,
Allan.

Article: 65911
Subject: Re: Is nobody using c++ and/or plugs-lib? was Re: nios c++ and ethernet [may by ot?]
From: "Paul Leventis \(at home\)" <paul.leventis@utoronto.ca>
Date: Tue, 10 Feb 2004 02:23:31 GMT
Links: << >>  << T >>  << A >>
> The one thing I remember that was special was includes were inside an
> "extern "C" { <includes here> } statement... like this:

And for those C++ "boneheads" wondering what this does:  It is equivalent to
putting an extern "C" modifier in front of all the function declarations in
the contained header file.  Why is this needed?  Because C++ uses
"name-mangling" to turn the user-friendly names you see in your code into
nearly unreadable function names that incorporate function name, type
information of the arguments, and likely some other stuff.  The reason it
does this is that you can have overloaded functions that have same name and
different argument types, but the compiler wants to generate object code
that any old linker can properly link (I think).  There are probably other
reasons (like, where else would it store the type info?) that I can't think
of.

Bottom line, by saying extern "C" you're telling the compiler that the
function will not have multiple variants and thus the compiler should use
the straight-forward name, which is just the function name with a _ in front
(assuming __cdecl calling convention) rather than the mangled name.  This is
needed because the library you are linking to (or C files) were compiled by
a C-compliant compiler that did not mangle the names.

Besides linking to C code, this can be handy when cutting down on the size
of the debug information in your executable.

And just in case you're a C/C++ coder and were confusing this with calling
conventions (as I was until recently), C & C++ have the same default calling
convention (__cdecl).  That is, there is no difference in the way they pass
function parameters and return values on the stack/registers -- they both
pass parameters on the stack with the caller responsible for stack clean-up.

Paul Leventis
Altera Corp.



Article: 65912
Subject: Partial reconfig flow
From: John Williams <jwilliams@itee.uq.edu.au>
Date: Tue, 10 Feb 2004 14:00:57 +1000
Links: << >>  << T >>  << A >>
Hi folks,

I'm trying to get the modular partial reconfig flow going (as per XAPP 
290).  Details below - if anyone has any suggestions I'm all ears!  I'm 
doing this all with ISE 6.1.02i (trying under both Linux and Windows XP, 
same behaviour/problems).

As a first test, I successfully modularised my design, and implemented 
it using the modular flow described in the ISE documentation (Chapter 4 
of the Development System Reference Guide).  This all worked as expected.

Next, I inserted the partial reconfig bus_macro between my two modules, 
and created a set of placement constraints that ngdbuild would be happy 
with.  My toplevel design complies with all of the guidelines and rules 
I can find in the various bits of documentation about the partial 
reconfig flow (my hard-copy of XAPP290 is very well worn!).

I can perform top level initial budgeting without errors or warnings 
(except the expected "assuming such-and-such is a module").

Doing active module implementation - I can MAP and PAR the individual 
modules, and export the PIMs.  PAR reports failure due to some signals 
being unrouted.  This concerned me, however I see that the same happens 
in the example distributed with XAPP290...

I can perform final assembly on the pims and my toplevel, and it MAPs 
and PARs succesfully (all signals routed in final assembly 
implementation).  There is one strange message in this final PAR during 
guide file processing:

WARNING:Guide:147 - Design contains an unroutable situation due to 
existing islands. This may be caused by having an invalid NCD as input. 
  Verify that the input NCD's were implemented correctly.

However eventually PAR completes without errors or more warnings.

Now here's the really wierd bit - if I try to load the placed and routed 
toplevel NCD file into either fpga_editor, or even bitgen, it causes 
that program to crash.  Doing it on Linux I get a segfault, and on 
windows I get the standard "error in this application".

So, somehow, the tools have build such a broken NCD file that it crashes 
the other tools.  The "progressive" NCDs produced during the various 
lead-up phases seem OK - I can load them into FPGA editor etc.

A couple of questions:

(1) should the active module implementation phase "fail" with unrouted 
signals?  I thought the purpose of the bus_macro was to lock all of them 
down, but seeing this behaviour in XAPP290 makes me wonder.

(2) Has anyone ever seen bitgen or fpga_editor choke on an NCD produced 
by the implementation tools?

(3) Is there some other step I need to take to get this going?

If anyone has any ideas, please let me know.

Thanks,

John


Article: 65913
Subject: Re: Artificial Intelligence/FPGA
From: msm30@yahoo.com (William Wallace)
Date: 9 Feb 2004 20:52:15 -0800
Links: << >>  << T >>  << A >>
If you can, use Synplify for synthesis.  Get the HDL Analist option.

Otherwise, just use the bundles that come from the manufacturer.

"Invisible One" <Invisible_1@sympatico.ca> wrote in message news:<hfuUb.8985$bp1.563899@news20.bellglobal.com>...
> I am doing my thesis in artificial intelligence, and wish to create a "proof
> of concept".  It has been a long time since I have been working with FPGAs
> directly and wish to know the following:
> 
> 1 - What software and hardware tools are available that operate well under
> Windows (compilation, etc...)?
> 2 - Has anyone had any experience with programming AI's on FPGAa?  Are there
> tools available for FPGA development?
> 3 - Are there any programmable logic devices out there that have a ADC built
> in?
> 4 - Are there any "tricks" that I would be able to use in order to generate
> uniform, gaussian or Cauchy noise with a minimal of external hardware?
> 
> Thank you in advance, I have posed many questions for a single posting!
> 
> John.

Article: 65914
Subject: Re: Artificial Intelligence/FPGA
From: "Invisible One" <Invisible_1@sympatico.ca>
Date: Tue, 10 Feb 2004 00:13:58 -0500
Links: << >>  << T >>  << A >>
Thank you all for the information.  I will look into it immediately.  If you
have anything else to say, I will be surely monitoring this thread.

John.
"Invisible One" <Invisible_1@sympatico.ca> wrote in message
news:hfuUb.8985$bp1.563899@news20.bellglobal.com...
> I am doing my thesis in artificial intelligence, and wish to create a
"proof
> of concept".  It has been a long time since I have been working with FPGAs
> directly and wish to know the following:
>
> 1 - What software and hardware tools are available that operate well under
> Windows (compilation, etc...)?
> 2 - Has anyone had any experience with programming AI's on FPGAa?  Are
there
> tools available for FPGA development?
> 3 - Are there any programmable logic devices out there that have a ADC
built
> in?
> 4 - Are there any "tricks" that I would be able to use in order to
generate
> uniform, gaussian or Cauchy noise with a minimal of external hardware?
>
> Thank you in advance, I have posed many questions for a single posting!
>
> John.
>
>



Article: 65915
Subject: Re: Pricing, 101
From: rickman <spamgoeshere4@yahoo.com>
Date: Tue, 10 Feb 2004 00:24:44 -0500
Links: << >>  << T >>  << A >>
Jan Panteltje wrote:
> 
> On a sunny day (Mon, 09 Feb 2004 13:21:48 -0800) it happened Peter Alfke
> <peter@xilinx.com> wrote in <4027F9ED.F7C82422@xilinx.com>:
> 
> >If you build something in small volume, everything is expensive: design
> >effort, pc-boards, most components, testing, marketing, advertising,
> >selling, servicing etc.  You must have a really good product to absorb
> >all these high costs. That's life.
> >Peter Alfke
> Hey, of cause things are expensive.
> Now log in to www.microchip.com
> Find a PIC, you can enter a quantity and order right there.
> Whats your problem?
> Perfect for small business.

And you will pay some 3 or 4 times what you would pay if you were buying
1000's.  I know, I have looked.  

-- 

Rick "rickman" Collins

rick.collins@XYarius.com
Ignore the reply address. To email me use the above address with the XY
removed.

Arius - A Signal Processing Solutions Company
Specializing in DSP and FPGA design      URL http://www.arius.com
4 King Ave                               301-682-7772 Voice
Frederick, MD 21701-3110                 301-682-7666 FAX

Article: 65916
Subject: power calculation in fpga
From: inaganti_suni@yahoo.com (sunil)
Date: 9 Feb 2004 21:33:33 -0800
Links: << >>  << T >>  << A >>
hi,
    i designed decoder in vhdl and i am going to map that on vertex-II
xilinx FPGA. Can any body have the idea how to calculate the power
consumption in that design.
                     thanking u all.

Article: 65917
Subject: sdram controller problems
From: "Antti" <antti1000@yahoo.com>
Date: Tue, 10 Feb 2004 07:03:23 GMT
Links: << >>  << T >>  << A >>
Hi,

I've implemented an sdram controller on an fpga (to micron 128 MB memory)
and tested it with a sequence of write and subsequent read bursts. In around
1 in 5 attempts, the correct read data appears on the dq[31..0] data bus,
otherwise the memory read just returns 0xFFFFFFF. Could someone please give
pointers to why might this be?

Thanks,
Antti



Article: 65918
Subject: Re: Is nobody using c++ and/or plugs-lib? was Re: nios c++ and ethernet [may by ot?]
From: "g.k." <replay@newsgroup>
Date: Tue, 10 Feb 2004 08:05:17 +0100
Links: << >>  << T >>  << A >>
Many thanx for that great insight!

Regards
g.k.



Article: 65919
Subject: Acquiring a Pilchard or TKDM board
From: Adam Megacz <adam@megacz.com>
Date: Tue, 10 Feb 2004 01:26:03 -0600
Links: << >>  << T >>  << A >>

Does anybody know where I can purchase a Pilchard or TKDM board?  I'd
like to use one in a research project at UC Berkeley.

  http://www.tik.ee.ethz.ch/~plessl/publications/fpt03/fpt03.ppt
  http://www.cse.cuhk.edu.hk/~phwl/papers/pilchard_fccm01.pdf

  - a

-- 
  "Keep your thoughts positive because your thoughts become your words.
   Keep your words positive because your words become your behaviors.
   Keep your behaviors positive because your behaviors become your habits.
   Keep your habits positive because your habits become your values.
   Keep your values positive because your values become your destiny."
                                                             - Gandhi Ji


Article: 65920
Subject: Re: power calculation in fpga
From: "Benjamin Todd" <Benjamin.Todd@cern.ch>
Date: Tue, 10 Feb 2004 08:49:44 +0100
Links: << >>  << T >>  << A >>
if you look on the Xilinx web-site they have power calculation tools, you
need to know the resources used and the clock frequency, as far as I can
remember.
Ben

"sunil" <inaganti_suni@yahoo.com> wrote in message
news:9f28d282.0402092133.2190279@posting.google.com...
> hi,
>     i designed decoder in vhdl and i am going to map that on vertex-II
> xilinx FPGA. Can any body have the idea how to calculate the power
> consumption in that design.
>                      thanking u all.



Article: 65921
Subject: Re: FIR filter coefficient (with COE file)
From: Vladislav Vasilenko <vlad@comsys.ntu-kpi.kiev.ua>
Date: Tue, 10 Feb 2004 10:24:56 +0200
Links: << >>  << T >>  << A >>


Yttrium wrote:

> hey,
>
> I'm using the Xilinx CoreGenerator for the first time because i need a FIR
> filter and saw the DA FIR in the IPCore library and found it really usefull
> in this design. The only problem is dat i don't find how to generate a COE
> file?
> So i don't know how to turn a floating point coefficients (which i found
> through firdes or matlab) into a COE file?
>
> thanx in advance,
>
> kind regards,
>
> Yttrium

The Active-HDL simulator has the similar built-in FIR core generator
which accepts the floating point coefficients.

Regards,
A.Ser.


Article: 65922
Subject: Re: Partial reconfig flow
From: Sean Durkin <23@iis.42.de>
Date: Tue, 10 Feb 2004 09:26:18 +0100
Links: << >>  << T >>  << A >>
John Williams wrote:
> A couple of questions:
> (1) should the active module implementation phase "fail" with unrouted 
> signals?  I thought the purpose of the bus_macro was to lock all of them 
> down, but seeing this behaviour in XAPP290 makes me wonder.
This is normal. When you implement a single module with the routing 
restricted to module boundaries by the "MODE = RECONFIG"-constraint, you 
can't route signals that belong to other modules or to the toplevel. 
E.g., if you have bus macro communication from lets say the left module 
to the right, and try to implement the left module, you can't route the 
signals coming out of the bus macro on the right side, hence these are 
reported as unrouted. Same applies to open signals (like not connected 
busmacro pins) and top-level-logic signals, if any. So at least that is 
nothing to worry about.

You can open the corresponding .NCD in FPGA Editor and let it list the 
unrouted nets. You'll find that all these signals are either not 
connected, or belong to another module in some way.

> (2) Has anyone ever seen bitgen or fpga_editor choke on an NCD produced 
> by the implementation tools?
Yes, this happens to me regularly... the entire design flow runs through 
without any error messages or unusual warnings, but in the end I get an 
.NCD that can neither be opened in FPGA Editor nor be converted to a 
bitfile. The main problem is that I cannot reproduce this behaviour, so 
I haven't opened a webcase for this yet. I think that even though the 
Xilinx support guys are without a doubt very competent, it's best if you 
can give them a simple as possible test design to reproduce the problem 
reliably. That way, they can get into it more easily.

> (3) Is there some other step I need to take to get this going?
Yes: Pray to the gods of Virtex, and a human sacrifice every now and 
then has been known to help was well... :)

I've been working on partial reconfiguration for some months now, and 
run into new problems on a daily basis. I've seen so many "FATAL_ERROR" 
and "INTERNAL ERROR"-messages, that I could probably keep all of Xilinx 
support busy for a decade. The biggest problem is that there is no 
pattern behind this. Sometimes it works, most of the time it doesn't. If 
I find a combination of modules and cores inside the modules that works, 
it stops working as the moon shifts phases or I change the tiniest of 
things.

Let's just face it: Partial reconfiguration is a market niche, purely 
academical, and the support in the tools just plain sucks. It works for 
simple designs with few modules, but as soon as it gets a little 
interesting the tools simply can't cope. It gets a tiny little bit 
better from ISE to ISE, but unfortunately new bugs are introduced as 
well. Just found one in ISE6.1 that sometimes causes top level logic to 
be placed incorrectly und makes par fail in the final assembly stage. No 
workaround available, no general rules as to what you can do to avoid 
it. Will probably be fixed in one of the first service packs for ISE6.2, 
which isn't even released yet. Bugger...

But enough rambling and let's get back to your problem: The error 
message you get occured to me once. Basically it suggests that some 
components of a module have been placed outside of module boundaries 
somehow. I think this happened to me when I changed the area constraints 
of my modules causing the bus macros to be completely inside one of the 
modules. If that's not the problem in your case, I suggest you check the 
.NCD-files for each of the modules in PACE or Floorplanner and see if 
any components may have been misplaced.

Other than that, it might help to just start over. If you do exactly the 
same thing twice with the same settings, results will vary considerably.

-- 
Sean Durkin
Fraunhofer Institute for Integrated Circuits (IIS)
Am Wolfsmantel 33, 91058 Erlangen, Germany
http://www.iis.fraunhofer.de

mailto:23@iis.42.de
([23 , 42] <=> [durkinsn , fraunhofer])

Article: 65923
Subject: Re: Quartus II taking forever to compile
From: "David Brown" <david@no.westcontrol.spam.com>
Date: Tue, 10 Feb 2004 09:43:04 +0100
Links: << >>  << T >>  << A >>

"Paul Leventis (at home)" <paul.leventis@utoronto.ca> wrote in message
news:e%WVb.28093$R6H.7213@twister01.bloor.is.net.cable.rogers.com...
> Hi Kenneth,
>
> > Is there any chance a 64bit version of Quartus will be released?
>
> We'll release a 64-bit version of Quartus when one is needed in order to
> address more memory.  Windows XP maxes out at 3 GB (with a command-line
> flag), and Linux maxes out at ~3.7 GB.  In all our testing of Stratix II,
I
> don't think I've seen any compile (even on a 2S180) that required more
than
> 2 GB of memory, and most compiles require much less than this -- and we
get
> some very stressful, pathological designs from our internal test/product
> engineering groups.  Also, as memory needs keep increasing due to larger
and
> larger chips, we strive to beat down on the memory requirements of
Quartus.
> In addition, architectural changes in Stratix II result in reduced memory
> consumption compared to the same design compiled in Stratix.
>
> So there is still plenty of room left before we _have_ to go 64-bit -- and
> we will be ready when the market needs a 64-bit version of Quartus.
>
> > I got my 15+ min. builds down to 5+ by upgrading to the fastest
available
> > cpu, but I was thinking this process might benefit from the new 64 bit
AMD
> > and upcoming Intel procs.
>
> Contrary to popular belief, the "bitness" of a processor does not
> (necessarily) equate with speed.  The primary advantage of switching to
> 64-bit computing is the increase in (easily) addressable memory that you
get
> with 64-bit pointers.  You are limited in 32-bit machines to 4 GB of
> addressable memory (minus the up to 2 GB of address space the OS
reserves).
> There are tricks to get this up higher, but aren't fun to program to.
>
> From a processing speed perspective, switching to 64-bit code may help and
> may hinder things.  It can help in those cases where you would have had to
> break up something that wanted a > 32-bit representation across multiple
> integers.  But most things fit fine in 32 bits, and promoting those
> variables to 64 bits just pollutes your data cache, effectively reducing
the
> amount of cache memory available to the processor.  And 64-bit code can be
> larger (because of larger pointers, instruction extensions, larger data
> values, etc.) thus chewing up valuable instruction/trace cache room.
> Luckily, recompiling C code to 64-bits does not change your integers to
> 64-bits -- just your pointers -- but this still has some impact on data
and
> instruction cache consumption.  I am glossing over many pros and cons of
> 32/64-bit code, but you get the idea.
>
> Intel plans to ramp the Prescott (90 nm version of P4) core up to 4 Ghz+,
> and AMD will be making Opteron/Athlon64 for years to come.  As they up the
> speed, you will get more performance on your 32-bit applications.  And you
> can bet future versions of the processors will support fast 32-bit
> processing, since it will take a LONG time before many programs make the
> switch to 64-bit.
>
> If you are interested in some early benchmarks comparing 32-bit and 64-bit
> x86 performance using a beta of Windows XP 64-bit, see
> http://www.anandtech.com/.
>
> Another bit of performance data:  http://www.speg.org/.  Do a search on
> results from "AMD Athlon" and click through to find results that were on
the
> same machine, one running 32-bit windows, the other 64-bit SuSE Linux
> w/64-bit gcc compilation.  On the few machines I looked at, the SPEC level
> was ~5% better on 32-bit.  If you look at the "VPR" component of the
SPECint
> test, this is an academic FPGA place and route tool, and it too yields
> something ~7-8% less speed on 64-bit x86.  Of course, there could be
> immaturity of compilers, different OS efficiencies, etc. in here, but
64-bit
> will be no silver bullet when it comes to performance.
>
> Regards,
>
> Paul Leventis
> Altera Corp.
>

There are a few benifits of the AMD-64 architecture beyond the 64-bit width
(in general I agree with most of what you've written here - it's a good
explanation).  In particular, the larger number of registers is a help in
many types of application.  Also, for some types of application, convenient
64-bit data items can lead to other benifits - for example, povray runs
slightly faster in 64-bit mode than 32-bit mode on an Athlon-64, but more
importantly it runs more accurately, giving finer detail.  I don't know
whether this could apply to tools like Quartus (povray deals with
approximations to reality rather than absolute logic), but perhaps it might
have benifits for simulation.

Of course, for a real break-through in compilation speeds the key would be
effective multi-threading, but I understand that that's a bit difficult for
current algorithms.





Article: 65924
Subject: Re: VHDL:Dividing a real number by two??
From: Uwe Bonnes <bon@elektron.ikp.physik.tu-darmstadt.de>
Date: Tue, 10 Feb 2004 08:55:53 +0000 (UTC)
Links: << >>  << T >>  << A >>
Allan Herriman <allan.herriman.hates.spam@ctam.com.au.invalid> wrote:

: try 

: LAPP / 2.0

: '2.0' is a real, and '2' is an integer (and the compiler hasn't been
: told to divide a real by an integer).

What about substracting -1 from the exponent?
-- 
Uwe Bonnes                bon@elektron.ikp.physik.tu-darmstadt.de

Institut fuer Kernphysik  Schlossgartenstrasse 9  64289 Darmstadt
--------- Tel. 06151 162516 -------- Fax. 06151 164321 ----------



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