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Messages from 51625

Article: 51625
Subject: Re: Booting Spartan IIE from SPI
From: "Falk Brunner" <Falk.Brunner@gmx.de>
Date: Fri, 17 Jan 2003 18:32:29 +0100
Links: << >>  << T >>  << A >>
"Michael Wilspang" <michael@wilspang.dk> schrieb im Newsbeitrag
news:3e280bd9$0$71705$edfadb0f@dread11.news.tele.dk...
> Are it possible to boot Spartan IIE  in "Slave Serial Mode" directly
> from an microcontroller with SPI interface (master mode) ?

Yes, just connect PROGRAM and DONE to free IOs, CCLK and Din to the SPI IOs
and you have all you need.

--
MfG
Falk





Article: 51626
Subject: Re: SpartanII DLL lock issue
From: "Falk Brunner" <Falk.Brunner@gmx.de>
Date: Fri, 17 Jan 2003 18:38:56 +0100
Links: << >>  << T >>  << A >>
"Richard Coster" <richard.coster@4rf.com> schrieb im Newsbeitrag
news:732c59cc.0301161344.737576f5@posting.google.com...

> The DLL is fed a 49MHz clock from a Cypress CY22393 programmable
> clock, which itself is sourced from a crystal oscillator.  CLK0 is fed
> back via a BUFG to the CLKFB pin.  The DLL is configured to divide by

What is the jitter specification of the clock comming from the cypress?? The
Spartan-II demoboard from Insight comes with a programmable low cost
oscillator (some kindo of RC-type), it has a HELL lot of jitter. The DLL
cant lock reliable to a jittery signal. Is the clock present AND stable
before the FPGA is configured?

--
MfG
Falk





Article: 51627
Subject: Re: quality of software tools in general
From: Matt <matt@NOSPAMpeakfive.com>
Date: Fri, 17 Jan 2003 17:43:41 GMT
Links: << >>  << T >>  << A >>
john jakson wrote:
[a great description of working with ffts in hw, thanks]

> If you try to
> use HandelC to do real hw design at the level of detail hw guys would
> get into, I'd say you beating a dead horse.

I'll take your word for it, as that's kind of what I expected

> Seeing your web site, if you are familiar with Occam & its view of
> Processes, then you will know exactly where HandelC is coming from,
> since its is just the C version of Occam and Occam is basically a HDL
> simulator.

Occam isn't used in supercomputing.  It's all C and Fortran. The reason
is the people that write the codes do science first and software second.

> If you have a more interesting app than FFT, lets us know.

I've been staying away from the app because it's fuzzy but this is it:
Someone writes a fortran/C program for use on a single processor.  They
then add directives on how to parallelize it. It's important to realize
that the person that wrote this program barely wants to mess with
parallelism, not to mention hardware design. Now, the whole game with
parallel computing is to keep the alus busy. The alus are plenty fast
but getting data to and from them is difficult. It's worse when you tie
1000 processors together. Mostly, if people get 15% of peak speed
they're happy. What's worse is the contortions that people have to go
through to make use of the hardware. It's said that software lags
hardware but I believe that's because the hardware is such a pain to use
efficiently. It would be much easier for people to use parallel
computers if they weren't so difficult to squeeze work out of.

What I'm wondering is rather than use a one size fits all communication
interconnect it wouldn't be better to use an fpga fabric (with lots of
cpus embedded) that could be specialized for each program. So if a chunk
of code includes something along the lines of

    do j=1,n
	do i=1,n
	   a(i,j) = k1*b(i+1,j) + k2*b(i-1,j)
	enddo
    enddo

and this runs across 1000 processors then the fpga would contain
circuitry to handle communication and synchronization for elements not
on the local processor. There are lots of ways to handle this depending
on the context of the loop nest and a few other things. It would be best
if the values of B needed on different processors were sent as soon as
they were generated. So the cpu might write the value and address to a
port in the fpga, which would in turn send a message to the fpga on the
correct node, which would would hold it in some sort of cache like
memory until the local processor asked for it. If it could figure out
how to write it to main memory that would be better. But it could be
that this loop nest is rewritten to first send a fetch request of all
the neighbor's b values needed on this processor, execute the internal
loops, wait on the fetch request, and then do the edge elements. 

Different circuitry is needed to handle global reductions (sum, max,
etc), fetch requests where the processor isn't known until run-time,
support for indirect addressing (a[i] = k*b[x[i]]), and lots of other
scenarios. 

There are conferences on reconfigurable computing so I assume people are
working on this sort of thing. There's even a machine, the SRC-6, but I
haven't heard from them in awhile so I assume it's not so simple. But
I'd like to know what the problems are. 

The hardware sounds reasonable: Lots of fpgas around a cpu and memory
with some inbetween. The compiler that takes fortran and decides what
communication should be put in hardware doesn't sound too bad. That
communication has to be translated to verilog. If the scope of the
problem is limited to reading and writing memory, sending and receiving
packets, adding internal cache like objects, and synchronization, would
this be difficult?

Finally comes the rest of the compilation to fpga. Can this all be
easily handled by current tools? It sounds like people still get
involved with floor planning (I don't know about routing).

Hope this helps.

Matt

Article: 51628
Subject: Re: copy of a project
From: "Patrick Mullarky" <pat@nwce.com>
Date: Fri, 17 Jan 2003 10:06:35 -0800
Links: << >>  << T >>  << A >>
Assuming you are using ISE 4 or 5:   If you want to simply make a new
project using all the same source files, just do a "File -> Save Project
As..." and you'll create a new project with a new name...using all the same
files as your original project. The only thing different will be the project
name.

If you want to clone the whole project, files and all, simply use Explorer
to make a copy of the entire project directory, using a new name. Go into
the new directory and change the filename portion of the project ".npl"
filename to reflect your new directory's name. The first time you "Implement
Design" you'll get a blizzard of filename warnings...which you can
completely ignore.


"flora" <floreq10@hotmail.com> wrote in message
news:552bda4b.0301170324.4b3d26c7@posting.google.com...
> Hello,
> how can we rename  an implementation project within the Xilinx tool.
> I want to create a clone copy of a project by giving it another name
> Thanks



Article: 51629
Subject: Re: Booting Spartan IIE from SPI
From: "Patrick Mullarky" <pat@nwce.com>
Date: Fri, 17 Jan 2003 10:13:12 -0800
Links: << >>  << T >>  << A >>
Nope.

Xilinx's "Answer Record 9632" specifically says neither SPI nor I2C will
work for serial configuration on Xilinx devices.

I tried it myself...doesn't work...at least on Virtex and Spartan devices.

"Michael Wilspang" <michael@wilspang.dk> wrote in message
news:3e280bd9$0$71705$edfadb0f@dread11.news.tele.dk...
> Are it possible to boot Spartan IIE  in "Slave Serial Mode" directly
> from an microcontroller with SPI interface (master mode) ?
>
>
> /Michael Wilspang
>
>



Article: 51630
Subject: Re: Support for older Virtex
From: Steve Lass <lass@xilinx.com>
Date: Fri, 17 Jan 2003 11:17:26 -0700
Links: << >>  << T >>  << A >>
Kevin Brace wrote:

> Steve,
>
> Since Virtex-E up to 300K system gates is supported by ISE WebPACK, why
> not Xilinx support Virtex up to 300K system gates in ISE WebPACK?

The main reason is size.  The WebPACK is currently about 180Mb.  If we included
all Spartan and Virtex families, it would get to 300Mb.  So, we have decided to
support 2 Spartan families and 2 Virtex families (plus 1 device from a newer
family that we want to promote).  We are trying to keep the WebPACK simple by
keeping the size reasonable and the installation easy.

Steve

>
>
> Kevin Brace (If someone wants to respond to what I wrote, I prefer if
> you will do so within the newsgroup.)
>
> Steve Lass wrote:
> >
> > David,
> >
> > Virtex was never supported in WebPACK.  The first Virtex family supported
> > in the WebPACK was VirtexE.  You will  need to purchase ISE BaseX to do
> > a XCV50.
> >
> > Steve
> >


Article: 51631
Subject: Re: Modelsim crashes
From: "Patrick Mullarky" <pat@nwce.com>
Date: Fri, 17 Jan 2003 10:24:44 -0800
Links: << >>  << T >>  << A >>
A hacked license???  That's the usual cause. ModelSim detects a hacked
license in many different ways, but the Wave display code seems to be the
most thorough in checking. If you're crashing back to the desktop from the
Wave window, you most almost certainly have a bad license file.

Otherwise, there was a ModelSim version, I think it was 4.1-something, that
did something like this under WinXP when WinXP first came out. Upgrading
ModelSim is the only cure.


<scepan@serbiancafe.com> wrote in message
news:17d2d0ec.0301170614.441d72be@posting.google.com...
> My friend and myself have bought laptops and tried to run Modelsim on
> them. Everything works fine till we try to see some signals in the
> waveform. The waveform itself opens normaly, but when some signals are
> tried to be added into it, Modelsim crashes. The same problem occures
> on both of our computers. Does anybody know the reason?



Article: 51632
Subject: Re: Multiple FPGA-boards integration issues
From: spam_hater_7@email.com (Spam Hater 7)
Date: 17 Jan 2003 10:37:36 -0800
Links: << >>  << T >>  << A >>
Prashant,

What everyone is trying to tell you: Yes, everything you want to do is
possible, BUT...

You are going to need to treat the devices like they all have
different clocks.

The fact that they all run at 40MHz is irrevelant.  The internal
differences can not be ignored.

Do a web search on transferring data between different clock domains. 
(Xilinx has a couple of app notes on their web site.  IIRC, Peter
wrote them, and they're good.)

It's a common problem that everyone has to face.

SH

prashantj@usa.net (Prashant) wrote in message news:<ea62e09.0301170743.1b3a638e@posting.google.com>...
> > You get rid of long-term differences, yes.  But you still have to employ
> > interface protocols to transfer data from one FPGA to the other.
> > 
> > Marc
> 
> I think it is these interface protocols that I'm trying to get an idea
> about (And I still dont have a lot). I also realized that my FPGA
> board does not have a clk out (unlike my mention of it in the 1st
> posting). Which means that while the board can accept external clocks,
> I dont see a way to send a clock out from the board. Any ideas how
> that can be achieved.
> 
> Thanks,
> Prashant

Article: 51633
Subject: Lecroy Research Systems - what happened?
From: Mu Young Lee <muyoung@umich.edu>
Date: Fri, 17 Jan 2003 13:41:53 -0500
Links: << >>  << T >>  << A >>
Is there a company out there that makes anything close to what LeCroy
Research Systems used to make?  Anyone know of people who used design the
boards at LRS?

Mu Young Lee
Thousand Oaks, CA


Article: 51634
Subject: Re: quality of software tools in general
From: Ray Andraka <ray@andraka.com>
Date: Fri, 17 Jan 2003 18:56:10 GMT
Links: << >>  << T >>  << A >>
The FPGA gains its advantage by creating a circuit optimized to the
particular task, not by replicating CPUs.  For example, in DNA pattern
matching, hardware is built specifically to search patterns in a parallel
hardware circuit rather than doing a linear search through the space one
pattern at a time.  The hardware for these optimized tasks is almost never
the structure that would be inferred by unrolling software code.  The costs
and goals are entirely different, therefore an efficient solution in one
domain is quite different than an efficient solution in the other.

One common stumbling block is floating point.  General purpose processors
with floating point need to be able to cover an extremely wide dynamic
range, and usually have fairly large mantissas to maintain precision in
accumulations.  Most single applications only use a small portion of that
dynamic range, and many times a fixed point realization is as good or even
better and costs less to implement.  For applications that require the
dynamic range offered by floating point, there are things that can be done
to reduce the hardware, from reduced word sizes, to renormalizing less
frequently...in the case of the FFT, one can separate out a common exponent
before the FFT kernel, operate the kernel in fixed point on just the
denormalized mantissa, and then renormalize afterwards to get back into
floating point format and marry the passed around common exponent back with
the data.  This results in considerably less hardware than a full floating
point implementation, and you don't give up anything in accuracy.

Regarding the FFT, Cooley Tukey is more or less a software algorithm.  There
are other factorizations that significantly reduce the number of
multiplies.  For example, a radix 16 Winograd FFT only requires 14
multiplies using only 6 unique (including unity) multiplicands.  The trade
is a significantly more complex data reordering, but for 16 points that is
not onerous.  Our 8 and 16 point FFT kernel cores, which are much smaller
and faster than the xilinx cores are based on the Winograd factorization.

Matt wrote:

> john jakson wrote:
> [a great description of working with ffts in hw, thanks]
>
> > If you try to
> > use HandelC to do real hw design at the level of detail hw guys would
> > get into, I'd say you beating a dead horse.
>
> I'll take your word for it, as that's kind of what I expected
>
> > Seeing your web site, if you are familiar with Occam & its view of
> > Processes, then you will know exactly where HandelC is coming from,
> > since its is just the C version of Occam and Occam is basically a HDL
> > simulator.
>
> Occam isn't used in supercomputing.  It's all C and Fortran. The reason
> is the people that write the codes do science first and software second.
>
> > If you have a more interesting app than FFT, lets us know.
>
> I've been staying away from the app because it's fuzzy but this is it:
> Someone writes a fortran/C program for use on a single processor.  They
> then add directives on how to parallelize it. It's important to realize
> that the person that wrote this program barely wants to mess with
> parallelism, not to mention hardware design. Now, the whole game with
> parallel computing is to keep the alus busy. The alus are plenty fast
> but getting data to and from them is difficult. It's worse when you tie
> 1000 processors together. Mostly, if people get 15% of peak speed
> they're happy. What's worse is the contortions that people have to go
> through to make use of the hardware. It's said that software lags
> hardware but I believe that's because the hardware is such a pain to use
> efficiently. It would be much easier for people to use parallel
> computers if they weren't so difficult to squeeze work out of.
>
> What I'm wondering is rather than use a one size fits all communication
> interconnect it wouldn't be better to use an fpga fabric (with lots of
> cpus embedded) that could be specialized for each program. So if a chunk
> of code includes something along the lines of
>
>     do j=1,n
>         do i=1,n
>            a(i,j) = k1*b(i+1,j) + k2*b(i-1,j)
>         enddo
>     enddo
>
> and this runs across 1000 processors then the fpga would contain
> circuitry to handle communication and synchronization for elements not
> on the local processor. There are lots of ways to handle this depending
> on the context of the loop nest and a few other things. It would be best
> if the values of B needed on different processors were sent as soon as
> they were generated. So the cpu might write the value and address to a
> port in the fpga, which would in turn send a message to the fpga on the
> correct node, which would would hold it in some sort of cache like
> memory until the local processor asked for it. If it could figure out
> how to write it to main memory that would be better. But it could be
> that this loop nest is rewritten to first send a fetch request of all
> the neighbor's b values needed on this processor, execute the internal
> loops, wait on the fetch request, and then do the edge elements.
>
> Different circuitry is needed to handle global reductions (sum, max,
> etc), fetch requests where the processor isn't known until run-time,
> support for indirect addressing (a[i] = k*b[x[i]]), and lots of other
> scenarios.
>
> There are conferences on reconfigurable computing so I assume people are
> working on this sort of thing. There's even a machine, the SRC-6, but I
> haven't heard from them in awhile so I assume it's not so simple. But
> I'd like to know what the problems are.
>
> The hardware sounds reasonable: Lots of fpgas around a cpu and memory
> with some inbetween. The compiler that takes fortran and decides what
> communication should be put in hardware doesn't sound too bad. That
> communication has to be translated to verilog. If the scope of the
> problem is limited to reading and writing memory, sending and receiving
> packets, adding internal cache like objects, and synchronization, would
> this be difficult?
>
> Finally comes the rest of the compilation to fpga. Can this all be
> easily handled by current tools? It sounds like people still get
> involved with floor planning (I don't know about routing).
>
> Hope this helps.
>
> Matt

--
--Ray Andraka, P.E.
President, the Andraka Consulting Group, Inc.
401/884-7930     Fax 401/884-7950
email ray@andraka.com
http://www.andraka.com

 "They that give up essential liberty to obtain a little
  temporary safety deserve neither liberty nor safety."
                                          -Benjamin Franklin, 1759



Article: 51635
Subject: Re: Support for older Virtex
From: "Langmann" <dlang89@hotmail.com>
Date: Fri, 17 Jan 2003 14:08:18 -0500
Links: << >>  << T >>  << A >>
Are you sure? I may be wrong about this (my PC with the Webpack installation
is not available to me right now) but I think I  remember seeing directories
of Virtex (and possibly some other non-supported families) configuration
data included in the installation.
David

"Steve Lass" <lass@xilinx.com> wrote in message
news:3E2848B6.D3BDFADE@xilinx.com...
> Kevin Brace wrote:
>
> > Steve,
> >
> > Since Virtex-E up to 300K system gates is supported by ISE WebPACK, why
> > not Xilinx support Virtex up to 300K system gates in ISE WebPACK?
>
> The main reason is size.  The WebPACK is currently about 180Mb.  If we
included
> all Spartan and Virtex families, it would get to 300Mb.  So, we have
decided to
> support 2 Spartan families and 2 Virtex families (plus 1 device from a
newer
> family that we want to promote).  We are trying to keep the WebPACK simple
by
> keeping the size reasonable and the installation easy.
>
> Steve
>
> >
> >
> > Kevin Brace (If someone wants to respond to what I wrote, I prefer if
> > you will do so within the newsgroup.)
> >
> > Steve Lass wrote:
> > >
> > > David,
> > >
> > > Virtex was never supported in WebPACK.  The first Virtex family
supported
> > > in the WebPACK was VirtexE.  You will  need to purchase ISE BaseX to
do
> > > a XCV50.
> > >
> > > Steve
> > >
>



Article: 51636
(removed)


Article: 51637
Subject: Synopsys tools for Linux
From: "DanyXP" <danyxpNOSPAM@terra.es>
Date: Fri, 17 Jan 2003 20:26:31 +0100
Links: << >>  << T >>  << A >>
I need to evaluate Synopsys Design Compiler synthesis tool to port an FPGA
design to ASIC.
I know that Synopsys Solvet can be only accessed by IDentified members
directly registered with Synopsys, itīs no valid a secundary user like a
user of Xilinx or Altera design flow with comes with Synopsys FPGA Compiler.
Is there a way to access Solvnet for download Design Compiler?
Thanks.



Article: 51638
Subject: Re: How can I use DCM to 1/24 freq-division?
From: mrand@my-deja.com (Marc Randolph)
Date: 17 Jan 2003 11:33:21 -0800
Links: << >>  << T >>  << A >>
Austin Lesea <austin.lesea@xilinx.com> wrote in message news:<3E258425.7C2ED314@xilinx.com>...
>
> Cisa wrote:
> 
> > Now I have a clk whose frequency is 30.72,and I want to use DCM
> > to generate another clk whose frequency is 1.28MHz.
> > How can I get it?I failed in reality.Pls give me some advance.
>
> Cisa,
> 
> The DCM outputs (all execpt for the CLKDV and CLK2X) have a minimum
> output frequency of 24 MHz.
> 
> CLK2X is 48 MHx min, and CLKDV is 24/16 MHz (1.5) min.
> 
> I suggest to use a simple synchronous counter to simply divide by 24
> (synchronously).  At these low frequencies, you do not need the 100 ps
> alignment offered by the DCM.

Or perhaps use the DCM to divide by 12, then use a single flop to do
the final divide by two...

   Marc

Article: 51639
(removed)


Article: 51640
Subject: Re: Booting Spartan IIE from SPI
From: "Michael Wilspang" <michael@wilspang.dk>
Date: Fri, 17 Jan 2003 20:47:48 +0100
Links: << >>  << T >>  << A >>
Hi Falk and Patrick

Falk; have you tried this interface solution ?

But Patricks experience  says something else !!!

I'm confused!
--

/Michael Wilspang



Article: 51641
Subject: newbie questions
From: cvmnk@yahoo.com (naveen)
Date: 17 Jan 2003 12:51:11 -0800
Links: << >>  << T >>  << A >>
hi, 
  iam a newbie to the field of fpga and iam very much interested in
this field.
 im workin with virtex 2 fpga board(xilinx). iam a graduate student.
  ive been goin through soo many materials. iam interested in the
practical aspect of fpga implementaion. i mean application side.
  iam not sure which part of the fpga i should concentrate to make use
of the fpga board( xc2v1000 ).
   ive been goin through the following topics. can you pleae lemme
know other important aspects i have to cover to bcom a good fpga
designer.

   1) vhdl coding( we have to use vhdl)
   2) schematic 
   3) architecture of fpga board.
   4) fucntional part of fpga board.

regards
 naveen

Article: 51642
Subject: Re: Support for older Virtex
From: Steve Lass <lass@xilinx.com>
Date: Fri, 17 Jan 2003 14:14:52 -0700
Links: << >>  << T >>  << A >>
Langmann wrote:

> Are you sure? I may be wrong about this (my PC with the Webpack installation
> is not available to me right now) but I think I  remember seeing directories
> of Virtex (and possibly some other non-supported families) configuration
> data included in the installation.

We include these directories for a variety of reasons, like:
 - VirtexE has a lot of common elements with Virtex, so the VirtexE tools get data from the Virtex directories.
 - The programming daisy chain may contain other devices, so we include programming info for all devices.

Steve

>
> David
>
> "Steve Lass" <lass@xilinx.com> wrote in message
> news:3E2848B6.D3BDFADE@xilinx.com...
> > Kevin Brace wrote:
> >
> > > Steve,
> > >
> > > Since Virtex-E up to 300K system gates is supported by ISE WebPACK, why
> > > not Xilinx support Virtex up to 300K system gates in ISE WebPACK?
> >
> > The main reason is size.  The WebPACK is currently about 180Mb.  If we
> included
> > all Spartan and Virtex families, it would get to 300Mb.  So, we have
> decided to
> > support 2 Spartan families and 2 Virtex families (plus 1 device from a
> newer
> > family that we want to promote).  We are trying to keep the WebPACK simple
> by
> > keeping the size reasonable and the installation easy.
> >
> > Steve
> >
> > >
> > >
> > > Kevin Brace (If someone wants to respond to what I wrote, I prefer if
> > > you will do so within the newsgroup.)
> > >
> > > Steve Lass wrote:
> > > >
> > > > David,
> > > >
> > > > Virtex was never supported in WebPACK.  The first Virtex family
> supported
> > > > in the WebPACK was VirtexE.  You will  need to purchase ISE BaseX to
> do
> > > > a XCV50.
> > > >
> > > > Steve
> > > >
> >


Article: 51643
Subject: Re: How can I use DCM to 1/24 freq-division?
From: Austin Lesea <austin.lesea@xilinx.com>
Date: Fri, 17 Jan 2003 13:16:16 -0800
Links: << >>  << T >>  << A >>
Marc,

Gosh, too easy!

Austin

Marc Randolph wrote:

> Austin Lesea <austin.lesea@xilinx.com> wrote in message news:<3E258425.7C2ED314@xilinx.com>...
> >
> > Cisa wrote:
> >
> > > Now I have a clk whose frequency is 30.72,and I want to use DCM
> > > to generate another clk whose frequency is 1.28MHz.
> > > How can I get it?I failed in reality.Pls give me some advance.
> >
> > Cisa,
> >
> > The DCM outputs (all execpt for the CLKDV and CLK2X) have a minimum
> > output frequency of 24 MHz.
> >
> > CLK2X is 48 MHx min, and CLKDV is 24/16 MHz (1.5) min.
> >
> > I suggest to use a simple synchronous counter to simply divide by 24
> > (synchronously).  At these low frequencies, you do not need the 100 ps
> > alignment offered by the DCM.
>
> Or perhaps use the DCM to divide by 12, then use a single flop to do
> the final divide by two...
>
>    Marc


Article: 51644
Subject: Re: Schematic design approach compared to VHDL entry approach
From: Eric Smith <eric-no-spam-for-me@brouhaha.com>
Date: 17 Jan 2003 13:20:32 -0800
Links: << >>  << T >>  << A >>
I wrote:
> Have you seen such a manual for a C compiler?

"Austin Franklin" <austin@da98rkroom.com> wrote:
> Er, yes.

I wrote:
> Where?

"Austin Franklin" <austin@da98rkroom.com> wrote:
> On my book shelf.

Well, don't keep us in suspense.  Tell us what manual it is.  I'd like
to see for myself this manual that allows one to predict what code will
be generated from an arbitrary C function.

Article: 51645
Subject: XST vs Synplify observations
From: "Roger Green" <rgreen@bfsystems.com>
Date: Fri, 17 Jan 2003 14:30:31 -0700
Links: << >>  << T >>  << A >>
I have recently been driven to switch to Synplify synthesis, from XST, for a
fairly complex PCI core VHDL design targeting a Virtex 300 in order to work
around various ISE tool bugs (which is another story all together).  After a
fairly painful conversion of constraints (for both timespecs and previous
floorplannning) and getting the design to actually compile again, I have
noted that the logic paths now failing to meet my timespecs are in logic
that previously was not a problem with XST synthesis, although there were
problems paths then also.   At first glance, my "gut" says that there are
more logic levels (LUTs) being used in the problematic paths, but I don't
have a direct proof of that, since I never actually looked at these specific
paths with the XST runs.  I am using the identical "max" effort settings for
PAR settings as before the synthesis tool switch.

I was wondering if any of the experts here have had any similar or different
experiences regarding the "performance" of these two tools on the same
source design.  Or perhaps someone could point me to some links to any
"objective" comparison of these tools and/or information regarding what
types of logic each is better/worse at optimizing?

--
Roger Green
B F Systems - Electronic Design Consultants
www.bfsystems.com



Article: 51646
Subject: Re: quality of software tools in general
From: Matt <matt@NOSPAMpeakfive.com>
Date: Fri, 17 Jan 2003 21:47:18 GMT
Links: << >>  << T >>  << A >>
Ray Andraka wrote:
> 
> The FPGA gains its advantage by creating a circuit optimized to the
> particular task, not by replicating CPUs.  For example, in DNA pattern

Maybe it wasn't clear but I'm not interested in replacing CPUs, only the
hardware used for inter-processor communication.  The only way I could
see replacing the CPU is if something like a vector unit could be built
that would be substantially faster than a CPU. A 64 bit wide floating
point vector unit sounds beyond current capabilities. Maybe if a 1 bit
wide floating point alu could be built then 50 of these could be put on
a chip. Tie that to dual ported  memory so the reconfigurable part could
read and write vector registers  while the vector unit operates and that
would be interesting.  A nearby cpu could do scalar ops, set up the
communications part of the fpga, and issue vector instructions.

Matt

Article: 51647
Subject: Re: Lecroy Research Systems - what happened?
From: John Larkin <jjlarkin@highSNIPlandTHIStechPLEASEnology.com>
Date: Fri, 17 Jan 2003 14:13:06 -0800
Links: << >>  << T >>  << A >>
On Fri, 17 Jan 2003 13:41:53 -0500, Mu Young  Lee <muyoung@umich.edu>
wrote:

>Is there a company out there that makes anything close to what LeCroy
>Research Systems used to make?  Anyone know of people who used design the
>boards at LRS?
>
>Mu Young Lee
>Thousand Oaks, CA


My company makes some VME and CAMAC modules that do some of the
high-speed timing stuff that LeCroy used to do. We don't do high
voltage or FastBus, though.

http://www.highlandtechnology.com/

Also check out Phillips Scientific, Jorger, and Jorway. See vita.org
if you're interested in VME.

What sort of stuff are you working on?

John


Article: 51648
Subject: Re: XST vs Synplify observations
From: Mike Treseler <mike.treseler@flukenetworks.com>
Date: Fri, 17 Jan 2003 14:27:26 -0800
Links: << >>  << T >>  << A >>
Roger Green wrote:


> I was wondering if any of the experts here have had any similar or different
> experiences regarding the "performance" of these two tools on the same
> source design.  Or perhaps someone could point me to some links to any
> "objective" comparison of these tools and/or information regarding what
> types of logic each is better/worse at optimizing?


Maybe you are comparing XST post-route results to
Synplify pre-route timing estimates. Place and route
your Synplify netlist before making timing comparisons.

Synthesis is optimized for synchronous inputs
and registered outputs. The closer you can
be to this standard template the better.

  -- Mike Treseler


Article: 51649
Subject: Re: Booting Spartan IIE from SPI
From: Peter Wallace <pcw@karpy.com>
Date: Fri, 17 Jan 2003 14:29:54 -0800
Links: << >>  << T >>  << A >>
On Fri, 17 Jan 2003 11:47:48 -0800, Michael Wilspang wrote:

> Hi Falk and Patrick
> 
> Falk; have you tried this interface solution ?
> 
> But Patricks experience  says something else !!!
> 
> I'm confused!
> --
> 
> /Michael Wilspang
 
We've done it with a PIC and it works fine.

The configuration interface is not SPI, but it is a simple synchronous
serial interface, the PIC has no trouble configuring (at least SpartanII
chips)...

Peter Wallace



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