Site Home   Archive Home   FAQ Home   How to search the Archive   How to Navigate the Archive   
Compare FPGA features and resources   

Threads starting:
1994JulAugSepOctNovDec1994
1995JanFebMarAprMayJunJulAugSepOctNovDec1995
1996JanFebMarAprMayJunJulAugSepOctNovDec1996
1997JanFebMarAprMayJunJulAugSepOctNovDec1997
1998JanFebMarAprMayJunJulAugSepOctNovDec1998
1999JanFebMarAprMayJunJulAugSepOctNovDec1999
2000JanFebMarAprMayJunJulAugSepOctNovDec2000
2001JanFebMarAprMayJunJulAugSepOctNovDec2001
2002JanFebMarAprMayJunJulAugSepOctNovDec2002
2003JanFebMarAprMayJunJulAugSepOctNovDec2003
2004JanFebMarAprMayJunJulAugSepOctNovDec2004
2005JanFebMarAprMayJunJulAugSepOctNovDec2005
2006JanFebMarAprMayJunJulAugSepOctNovDec2006
2007JanFebMarAprMayJunJulAugSepOctNovDec2007
2008JanFebMarAprMayJunJulAugSepOctNovDec2008
2009JanFebMarAprMayJunJulAugSepOctNovDec2009
2010JanFebMarAprMayJunJulAugSepOctNovDec2010
2011JanFebMarAprMayJunJulAugSepOctNovDec2011
2012JanFebMarAprMayJunJulAugSepOctNovDec2012
2013JanFebMarAprMayJunJulAugSepOctNovDec2013
2014JanFebMarAprMayJunJulAugSepOctNovDec2014
2015JanFebMarAprMayJunJulAugSepOctNovDec2015
2016JanFebMarAprMayJunJulAugSepOctNovDec2016
2017JanFebMarApr2017

Authors:A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Custom Search

Messages from 23375

Article: 23375
Subject: Re: dual processor PC for PPR - are they worth the extra cost?
From: bobperl@best_no_spam_thanks.com (Bob Perlman)
Date: Fri, 23 Jun 2000 14:49:31 GMT
Links: << >>  << T >>  << A >>
Hi - 

>In article <01bfdc4a$feb79d00$c4f262d1@Dan.i-tech.com>,
>Dan Kuechle <dan_kuechle@i-tech.com> wrote:
>>Anyone out there using a dual processor PC for Xilinx?

A couple of comments on using dual processors:

1) If you're trying to get substantive work done while running place
and route, a dual processor is the way to go.  If, however, you want
to do things that place a relatively light load on the CPU, such as
web browsing or editing, you can change the priority of the place and
route run by using a UNIX-like utility such as "nice."  I scrounged a
free version of "nice" (from Cygnus, I think) and have used it when
invoking the route tool in batch mode (nice par ...).  This lowers the
priority of par sufficiently to let you run other things on the
machine; with the version of "nice" I have, par run time is increased
by only ~5%.  

2) I just bought a dual-processor motherboard, and can tell you that
this is a particularly treacherous time to buy one.  Intel has
recently produced not one but two chip sets--the i820 and i840--that
are unreliable when used with SDRAM.  (Extremely condensed history:
Intel produced these chip sets expressly for Rambus RDRAM, then
decided to create additional interface chips that would allow them to
talk to SDRAM: the MTH for the i820, and the MRH-S for the i840.  Both
the MTH and MRH-S are unreliable; Intel has recalled its i820/MTH
motherboards, and has (very quietly) announced that the MRH-S is
unreliable and will no longer be produced--see their PCN #996.)  Some
retailers are still happily selling i840/MRH-S boards such as the
SuperMicro P3DMx series; stay away from these.

If you do get a dual-processor motherboard, get one that's based on
the old-but-reliable 440BX chip set.  Or you can spend major bucks and
buy an RDRAM-based i820 or i840 system.

Take care,
Bob Perlman
  
-----------------------------------------------------
Bob Perlman
Cambrian Design Works
Digital Design, Signal Integrity
http://www.best.com/~bobperl/cdw.htm
Send e-mail replies to best<dot>com, username bobperl
-----------------------------------------------------
Article: 23376
Subject: lGen - Synthesis Library [Help manufacturer]
From: Sebastien Favard <Sebastien.Favard@utc.fr>
Date: Fri, 23 Jun 2000 16:51:40 +0200
Links: << >>  << T >>  << A >>
Hi,

I search informations about the software lGen from Mentor Graphics. It's
a software to generate new synthesis libraries.

In fact I try to use it but I have poor informations about the language
:( I search to define a LUT and I have not find informations about this.
I just find definition of simple gates :(( It's really poor...

Thanks a lot if anyone can help me,


Regards,

Sebastien


Article: 23377
Subject: Re: What tools do people use for Xilinx FPGAs?
From: "B. Joshua Rosen" <bjrosen@polybus.com>
Date: Fri, 23 Jun 2000 10:52:00 -0400
Links: << >>  << T >>  << A >>
Synplicity is the best choice for synthesis. I use both Finsim and VCS
for verilog simulation. VCS is expensive but a Finsim license thats good
enough for a medium size FPGA can be had for about $2.5K, a full blown
Finsim lincense is 10K. Also Cadence has brought out NC Verilog on Linux
and I think they are only asking $5K.

If you are just picking an HDL, go with Verilog. Verilog simulators are
much faster than VHDL, Verilog is much easier to read and write, and
it's much more concise. A couple of years ago it seemed like the world
was about evenly split between Verilog and VHDL, but these days I don't
see VHDL anywhere, everyone seems to be using Verilog. Admitedly my
sample is limited, and all the companies that I deal with are in the
networking industry.

Josh

James Kennedy wrote:
> 
> Hi everyone,
> 
> At risk of starting a religious war, I'd like to ask all you people out
> there who do _real_ designs with Xilinx FPGA's, what tools do you
> currently use, and/or recommend?
> 
> I'm currently in the process (and have been for some time) of trying to
> use Xilinx's foundation express but I think it has won the battle :)
> 
> So we're thinking of investing in a less buggy tools suite and I'm
> looking for any suggestions.
> 
> Cheers,
> James.
> 
> --
> James Kennedy
> Electronics/Computer Design Engineer
> IntelliDesign
> Brisbane, Australia
> 
> james (at) intellidesign dot com dot au
> 
> Tel: (07) 3366 6478
> Fax: (07) 3366 6471
Article: 23378
Subject: Re: Defining a reset concept for VirtexE
From: Rickman <spamgoeshere4@yahoo.com>
Date: Fri, 23 Jun 2000 11:29:29 -0400
Links: << >>  << T >>  << A >>
This question comes up periodically in this newsgroup. The limitation in
using the asynch reset is the slowness of the distribution. The problem
is trying to make sure that all FFs come out of reset at the same time.
Using a synch reset does not help the problem since the reset can still
happen on different clock edges for the different FFs. Further, you may
need to use an asynch reset since your clock may not be present or
running slowly and a synch reset will not work in that case. 

There are a couple of things a design can do to make the end of reset
work correctly. 

1) If you are running with a sufficiently slow clock, then you can
externally synch reset to the clock and you don't have a problem. This
is not practical for most designs and the speed of the GSR net is not
spec'ed. This also won't work if you have more than one clock domain. 

2) Use an additional, separate, synch reset signal that only runs to the
critical FFs in the design. By synch, I mean this comes from a FF which
is released after the asynch reset and has a two or three clock delay.
This should hold in reset any FFs which are in FSMs or other logic which
will start changing state as soon as the asynch reset is released. Not
all logic needs this signal. 

For example, only the first two levels of FFs in a one-hot encoded FSM
need the synch reset. The rest won't be enabled by the logic until the
FSM starts moving through the states. This works well for circuits with
mulitple clocks. You can have an independant synch reset for each clock
domain. 

3) Use the existing logic to hold the circuits in reset. If your circuit
depends on external signals to do anything once it is reset, you can
make sure that a few clock cycles go by after reset before you start
operating the circuit. 

For example, if the design interfaces to a processor and is idle until
the processor sends a command, then you need no additional reset
circuit. 

Anyone else have ideas on this?


derekwallace1@my-deja.com wrote:
> 
> Hi All,
> Ive started a design of a VirtexE1000. I am looking for advice on how i should
> control the taking of the device out of reset after a board reset to the FPGA.
> 
> Here is a summary of my system. 1. a microcontroller delivers an Asynchronous
> reset signal to the FPGA. 2. it will be active low for 1 us. 3. the purpose
> of the reset is to return the device to the same state as it was just after
> configuration.
> 
> Here are some of my questions. 1. it is my understanding that all FFs in
> Virtex can be directly Synchronously set or reset i.e. it does not utilise
> the LUT. Is this true? 2. should i use the reset signal to reset every FF in
> my design? (i think so) 3. should i perform a synchronous reset or an
> asynchronous reset of the FFs 4. should i mix it up so that some FFs are rest
> Synchronously and some asynchronusly? Is there any real
> advantage/disadvantage to this in Virtex if the FFs can be reset
> synchronously without using LUT resources. 5.  to re-synchronise the
> asynchronus input reset i plan to put it through 2 FFs for metastability
> purposes. In some case i have seen people only use a single FF. Is it best to
> use 1 FF or 2 FFs? 6. how should i drive the reset signal (whether it is
> async or sync). Should i use a Bufg (can a Bufg connect to Set reset pins of
> FF?) Or should i use the low skew lines?
> 
> Thank you for your time
> 
> Derek
> 
> Sent via Deja.com http://www.deja.com/
> Before you buy.

-- 

Rick 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

Arius
4 King Ave
Frederick, MD 21701-3110
301-682-7772 Voice
301-682-7666 FAX

Internet URL http://www.arius.com
Article: 23379
Subject: Re: What tools do people use for Xilinx FPGAs?
From: John Larkin <jjlarkin@highlandSnipSniptechnology.com>
Date: Fri, 23 Jun 2000 08:54:37 -0700
Links: << >>  << T >>  << A >>
On Fri, 23 Jun 2000 05:30:22 GMT, James Kennedy <spam@this.com> wrote:

|Hi everyone,
|
|At risk of starting a religious war, I'd like to ask all you people out
|there who do _real_ designs with Xilinx FPGA's, what tools do you
|currently use, and/or recommend?  
|
|I'm currently in the process (and have been for some time) of trying to
|use Xilinx's foundation express but I think it has won the battle :)
|
|So we're thinking of investing in a less buggy tools suite and I'm
|looking for any suggestions.
|
|Cheers,
|James.

James,

we use Xilinx Foundation right out of the box, schematic entry. Works
fine.

John

Article: 23380
Subject: Re: 500 million transistor FPGA's
From: Rickman <spamgoeshere4@yahoo.com>
Date: Fri, 23 Jun 2000 12:00:20 -0400
Links: << >>  << T >>  << A >>
Peter Alfke wrote:
> 
> Well, nobody is joking or pulling anybody's leg.
...snip...
> I don't want to parse Illan's syntax here, but I think he tried to challenge
> our assertion that ASIC designers will have more trouble with deep submicron
> than FPGA users will. But that is a fact. At the deep submicron level, things
> are not as clean and digital as they were in the olden days of Mead-Conway.
> Capacitive loading, fan-out issues, on-chip transmission-line effects,
> crosstalk, ground bounce, clock-tree balancing, Vcc and ground distribution
> etc. are getting really demanding, and every ASIC user will be confronted with
> these ugly issues.
...snip...
> Technological progress favors FPGAs more than ASICs, and it thus tilts the
> playing field.
> That's all we wanted to say. We preached this in our seminars more than a year
> ago.
> If you don't want to believe us now, let's talk again next year, when we're
> heading for a billion transistors on a chip. Moore's law has a few more years
> to go...
> 
> Peter Alfke, Xilinx Applications
> ==================================================

That sounds great, but you need to compare apples to apples. There is a
BIG difference in the number of gates on the two devices at a given
technology level. So if I am using an FPGA at .15 micron, I would only
need to use an ASIC at say, .5 micron to get the same number of useful
gates on the same size chip. The silicon and the tools at this level
have been around for a long time and are not a problem to use. 

Even when the state of the art is .05 microns, a comparable ASIC will
only need to be at .15 microns and the tools will be very mature by that
time. 

I agree that FPGAs will keep eating into ASIC territory. But it is not
because deep submicron design is getting tougher. It is because FPGAs
will reach price and density points that satisfy more and more designs. 

It is probably comparable to what is happening in the microprocessor
world. The 8 bit chips get faster and have more memory on board. But
they have not taken over from the 16 and 32 bit chips. The applications
get bigger with the chips and there will always be separate markets for
each. But the 8 bit chips do grow faster and eat a bigger share every
year. 


-- 

Rick 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

Arius
4 King Ave
Frederick, MD 21701-3110
301-682-7772 Voice
301-682-7666 FAX

Internet URL http://www.arius.com
Article: 23381
Subject: Looking for old Altera Application Brief Designs ab 84?
From: sierratech@my-deja.com
Date: Fri, 23 Jun 2000 16:32:35 GMT
Links: << >>  << T >>  << A >>
Anyone ever download the old Application Briefs from ALTERA BBS back in
the early 90's?

I have all my old application books and was looking specifically for AB
84 design files.  Some of it is on ftp.altera.com but not the original
GDF.

I know someone must have downloaded these old files, finding them is a
pain.  Altera will not release them because they want to sell megacores.

--Bob


Sent via Deja.com http://www.deja.com/
Before you buy.
Article: 23382
Subject: Re: Error: Clock skew plus hold time of destination register exceeds register-to-register delay
From: iglasner@my-deja.com
Date: Fri, 23 Jun 2000 16:44:01 GMT
Links: << >>  << T >>  << A >>
Hi,

   While I belive all FPGA vendor will work properly when you connect
directly FF to FF inspite of this warning, when it come to asic we
simple add buffer between the two FF's.

So you might want to do this, as it will not effect the design and will
remove this msg. (of course you might need two buffers or on the other
hand use a smaller buffer, just choose a one that his time (min) delay
is a bit more than what the msg complain).

have a nice day

   Illan


In article <39483ea7.0@news.cyberway.com.sg>,
  "MK Yap" <mkyap@REMOVE.ieee.org> wrote:
> Hi!!
>
> "  Error: Delay path from '|bsp_in:73|bytedata_2_.Q' to
> '|bsp_in:73|intdata_2_.Q' is 4.2ns, but Clock skew is 2.9ns and hold
time
> required for '|bsp_in:73|intdata_2_.Q'  is 1.4ns - circuit cannot
operate
> because Clock skew plus hold time of destination register exceeds
> register-to-register delay "
>
> I encounter this problem when i've finished compiling the project &
doing
> the timing analysis. Most of the time, my design did not give me this
error
> mesg but it happened ocassionally. I changed other part of the
circuit but
> did not make any changes on the bsp_in portion. What can I do to
ensure this
> won't happen again? How can i put any constraint and where i should
put it?
> Thanks.
>
> I'm using Maxplus2 9.3 & Synplify 5.3.1 for my VHDL codes, running on
PC,
> targetted at flex10k30e.
> Pls advice
>
> MK
>
>


Sent via Deja.com http://www.deja.com/
Before you buy.
Article: 23383
Subject: Re: Atmel bidirectional pins problem
From: "Andy Peters" <apeters.Nospam@nospam.noao.edu.nospam>
Date: Fri, 23 Jun 2000 09:47:45 -0700
Links: << >>  << T >>  << A >>
gordon.haddow@eev.com wrote in message <8iv9lr$l47$1@nnrp1.deja.com>...
>Hi everyone,
>I've been using the Atmel FPGA integrated development system for some
>months, including the Everest VHDL synthesiser. Unfortunately it seems
>to have a bug in the way bidirectional pins are handled. If you look at
>the .edf netlist the input line does not come from the pin, but from
>the output line prior to the output tristate.
>Atmel don't have a fix. Has anyone else come across this? Does anyone
>have a way of working round this in VHDL - perhaps coding at very low
>level? Anyway, here's the code that fails:
>


> gen_data_ram : process(pixel_clock)
> begin
> if pixel_clock = '1'
> then data_ram <= data_in;
> else data_ram <= "ZZZZZZZZZZ";
> end if;
> end process gen_data_ram;

problem!!! your sensitivity list needs to include data_in.  This is a
combinatorial process.  Or, more succintly, do the following:

data_ram <= data_in when pixel_clock = '1' else (others => 'Z');

> gen_data_out : process(pixel_clock, data_ram)
> begin
> if pixel_clock'event and pixel_clock='1' then
> data_out <= data_ram;
> end if;
> end process gen_data_out;
>
>end behave;

problem!!! If you want to generate flip-flops, the ONLY things that should
be in the sensitivity list are the clock and an async reset.  In other
words,

    gen_data_out : process (pixel_clock) is
    begin
        if rising_edge(pixel_clock) then
            data_out <= data_ram;
        end if;
    end process gen_dat_out;


Now, there's another, more subtle issue here: you're using pixel_clock as
both the clock to a bunch of flops, and as an output enable.  Depending on
your chip's architecture, you may not be able to do this.  Usually, clocks
get put onto global low-skew routing resources which only drive clock
inputs, and if you try to do anything else with it (like drive an output
enable, or use it as an input to a function) the tools will not use the
low-skew resource, which could lead to big trouble.

-andy

--
-----------------------------------------
Andy Peters
Sr Electrical Engineer
National Optical Astronomy Observatories
950 N Cherry Ave
Tucson, AZ 85719
apeters (at) noao \dot\ edu

"A sufficiently advanced technology is indistinguishable from magic"
     --Arthur C. Clarke



Article: 23384
Subject: Xilinx xc4000
From: eefox@uxmail.ust.hk ( WU Chi Hang FOX )
Date: 23 Jun 2000 16:56:10 GMT
Links: << >>  << T >>  << A >>
an XC4000 CLB got 2 4-input-LUTs and 1 3-input-LUT
it said it can implements some functions up to 9 variables.
I want to ask who knows exactly how many functions up to 9 variables 
can be implemented....
-- 
*************************************************************************
*       /\ /\     Name : Wu Chi Hang J  ( FOX )  **  W **       *
*       ^  ^      Job  : ELEC/CPEG Demonstrator (Rm. 2466, Ext. x7037 ) * 
*       .  .      Email: eefox@uxmail.ust.hk  /  eefox@ee.ust.hk        *
*     =o =               chwu@usa.net / 97Cwch@alumni.ee.ust.hk         *
*       u         Hpage: http://www.ee.ust.hk/~eefox/index.html 4294435 *
*************************************************************************
Article: 23385
Subject: Re: dual processor PC for PPR - are they worth the extra cost?
From: "Andy Peters" <apeters.Nospam@nospam.noao.edu.nospam>
Date: Fri, 23 Jun 2000 09:56:53 -0700
Links: << >>  << T >>  << A >>
Dan Kuechle wrote in message <01bfdc4a$feb79d00$c4f262d1@Dan.i-tech.com>...
>Anyone out there using a dual processor PC for Xilinx?
>
>My last project takes about 1.5 hours to complie the single
>Xilinx chip if I do nothing else,  and upwards of 3 hours if I
>try and do some work while the Xilinx s/w is running.  Since
>my PC is only 350mhz (windows 95) its probably time for
>an upgrade.  I'm wondering about dual processors, thinking
>one could run Xilinx while I use the other to get some real
>work done while the Xilinx s/w is running.   Anyone got
>any insights or recomendations?


Others have tried dual processors and reported their results.  Here's what I
did:  I told the boss that the old PII/233 wasn't cutting it, so I got a
PIII/550.  I pleaded my case: let me use the new machine for design only and
keep the old one for MS Office and crap like that, and he bought the
argument.  The new machine only has the FPGA development tools, and some
other stuff, like WinSpice and MathCAD.  No MS Office, no mail client, no
extraneous BS.  So I do P+R on the new machine and read Usenet on the old
one.

Here's the moral of the story: the new machine is more expensive if you're
buying a dual CPU system.  And I'll bet the old one isn't going to just
vanish in a puff of smoke.  Dig?

>Dual processors will force me into windows 2000 or NT.
>Any problems with that?

NT is better than 98.  No question.  In fact, you should probably be doing
the real work on NT.  I don't know about Win2K.  I think I'll wait until
Service Pack 4 comes out.


-- a
-----------------------------------------
Andy Peters
Sr Electrical Engineer
National Optical Astronomy Observatories
950 N Cherry Ave
Tucson, AZ 85719
apeters (at) noao \dot\ edu

"A sufficiently advanced technology is indistinguishable from magic"
     --Arthur C. Clarke



Article: 23386
Subject: Re: 500 million transistor FPGA's
From: iglasner@my-deja.com
Date: Fri, 23 Jun 2000 18:12:51 GMT
Links: << >>  << T >>  << A >>
Hi,

   You can't be serius,

This remind all those places who ask you to bring name of people that
will be your referance and obviusly you will give only name of people
who think you are at the very least the newxt Einstein.

the same here the point of showing a site with success story is nothing.

who says there design was done quicker than if it was done in asic, who
says that they are not poor designer who don't know how to design
Asic's, who says that they didn't had a bad experiance in the past and
using it now and so on and so on ...

I wonder if TSMC will show a site with success story of people who
desing Asic's and pass them in the first time and did it very quickly
and wrote it so will this mean that Asic are faster easier better can
be done on first and so on ?

I would expect some thing more concret in which you explain why you
said what you said and why you belive it to be right.

Of course as one mention you should compare how a certain design whould
have been done in FPGA Vs Asic and not that in FPGA it took 500M gate
and in Asic same thing will cost ... since in Asic we don't need so
many gates.
also as one mention we will not need in asic the same technology even
tho' I think he gave a bit bigger technology than I would but still his
point is right.

once you take a "imagenary design" and do the comparision than you are
standing on equal ground, and you can claim what ever you claim base on
it.

I belive in my previus msg I put all the phases needed to get a chip I
even put timing you might disagree with so I would love to see a table
in which you compare the time etc of each stage asic vs fpga and than
the total sum and conclution. I wonder if once you get this table done
you will still hold your belive so strongly.

Lastly about the clock tree that someone else mention, I must say that
while a clock tree is not "fun", it is sometime a GREAT advantage to be
able to control, and "play with", and no need to tell me it is risky or
dangerous etc etc as thing are risky and dangerous when you do thing
you don't understand but if you do understand you can get thing done
that in other way you might not been able and had to compremise, or use
an extra pll etc.

and to give a small exmaple assume a chip with 20 clock domain, one is
the "master" which most of the chip work with it and 19 other are only
use in small part/logic.

to use 20 PLL will be ... the power/noise etc are ... so you will most
likely want to use one PLL for the main clock and the other clock will
have clock tree but without PLL.

now the output signal from those 19 clock domain in the best case will
take several ns since there is the clock tree than the clk->Q of the FF
and than if you have Jtag there is additional mux and than there is the
Output pad itself.

now assume you work in 125M clock so the period is 8n, and assume this
signal need to go to another chip which is not yours and the trace on
the board plus setup is let say 4n than you need to have your signal
out in 4n and it is a problem as the clock tree can be (of course
depend on the load) let say 3n and the rest is also 3n so you are 2n to
much.

now if you can "play" with the clock tree and to this particular signal
FF give the clock from the root of the tree than you are in good shape.

of course this mean that the signal which come to the FF have less time
than a whole period as the clock to this FF come sooner but this can be
solved in the design or even by adding another FF (or even two as
syncronizer and treat it as going from one clock domain to another even
tho it is only phase issue). this way you can get it work.

This is only one example and even here I could extrem it by taking the
frequancy even higher.

one small additional point since someone mention that you don't need to
do in FPGA clock tree etc, while I don't see it as advantage mostly it
is the same in asic as your vendor will do it so for you as a user in
mnay cases it is only the desing part and than synthesis place and
route etc etc are done not by you.

FPGA are great components and my belive is that if you have a new
design and you can do it in FPGA than do so, but many design simple
can't be done in FPGA and can only be done in Asic, and just as FPGA
vendor are keeping moving forward with technology the same is for Asic
vendors. and just as FPGA vendor work to make there fpga look digital
for the user as we users don't want to take care of the analog effect
of sub-micron the same is with Asic's Vendor and Fabs, so I wouldn't
jump and say that Asic designer will have to either move to fpga or
have to deal with analog problems.

have a nice day

   Illan



In article <395277DA.24784027@xilinx.com>,
  Austin Lesea <austin.lesea@xilinx.com> wrote:
> Well,
>
> Look at our customers' success stories.
>
>  http://www.xilinx.com/company/success/index.htm
>
> Austin
>
> iglasner@my-deja.com wrote:
>
> > Hi,
> >
> >   I might missed something but it seem to me as you belive this huge
> > chip when target to FPGA take less time than when target to ASIC.
and
> > more over they have "have inferior tools"
> >
> > I wonder how did you come to this conclutions ?
> >
> > I would think the design might take even longer in FPGA as I might
need
> > to re-code or write is a bit more messy to get the FPAG work in
high-
> > performance.
> > than the simulation I would think are just about the same (as while
you
> > might want to save sometime in the FPAG as you can always re-code it
> > for a big design if you don't simulate properly you will simple go
> > forth and back between the lab and your computer)
> > than come the synthesis which is again about the same as well as the
> > simulation for the post synthesis gate level
> > and than come the place and route and the clock tree which about the
> > same with it's simulation of post place and route with the netlist
and
> > sdf files. (the clock tree might take few extra days)
> > and than come some saving which are the vectors which you don't need
> > and maybe also bist check and scan insertion that might make timing
> > problem if was not taken for the start into considuration
> > so I would think that for a design that take let say 10 month (after
> > all we do speak about large design so it might be even longer) you
> > might save about 2-3 weeks or even a month which is something but I
> > wouldn't say it is enough to say "takes too long"
> >
> > and to the tools what exactly is inferior ? there are very good
tools
> > for synthesis and place and route as well as scan insertion clock
tree
> > etc for asic (e.g you might heard about Synopsys) ?
> >
> > I can undertsand the risk as in many cases a metal fix can take
between
> > a 1-2 month and a complete spin will take even take a more (depend
of
> > course on how bad are the bugs).
> >
> > I will even agree with the more expensive as the NRE for 0.25 or
less
> > are something to consider. (the price for NRE for 0.35 as well as
the
> > price for metal spin etc in the overall are not "too expensive" but
you
> > might want to add them as well)
> >
> > have a nice day
> >
> >    Illan
> >
> > In article <3952285C.3DFA8EE7@xilinx.com>,
> >   Austin Lesea <austin.lesea@xilinx.com> wrote:
> > > Wake up & smell the silicon,
> > >
> > > I couldn't resist responding to this.
> > >
> > > Steve is in the cube across from me, and we teased him on how
> > conservative he
> > > was.
> > >
> > > Like Peter says, we have the time to do what is needed to make
this
> > scale of
> > > technology work:  the ASIC/ASSP model is probably limited to less
> > than 50
> > > million devices.  It is too expensive, too risky, takes too long,
> > have inferior
> > > tools, and is unable to claim the advantages it once did.
> > >
> > >  http://www.support.xilinx.com/xcell/xl30/xl30_10.pdf was written
two
> > years
> > > ago.  It is so satisfying to see the team's vision realized.
Thank
> > you to all
> > > of our customers, and we will continue to provide you with the
> > solutions you
> > > need to succeed.
> > >
> > > Austin Lesea, ICDES Group, Xilinx
> > >
> > > EKC wrote:
> > >
> > > > I got this quote from eetimes.com. Is this technically feasible?
> > > >
> > > > <<START QUOTE>>
> > > > Panelist Steve Young, an architect of the Virtex FPGA family of
> > Xilinx (San
> > > > Jose, Calif.), advocated FPGAs in his presentation. But he
> > surprised many
> > > > when he said he expects the number of transistors on a single
FPGA
> > to hit
> > > > 500 million in 2001, with the Xilinx Virtex-II family.
> > > >
> > > > Engineers designing FPGA silicon for companies such as Xilinx
are
> > coping
> > > > with some of the most difficult deep-sub-micron devices around,
> > Young said.
> > > > "We face a number of problems so you don't have to," he said.
These
> > include
> > > > simultaneous switching, deep-submicron parasitics, fault
coverage,
> > and clock
> > > > skew management.
> > > >
> > > > "Like all chip designers, we are customers of EDA tools," said
> > Young. "And
> > > > we are challenging them." He said commercial EDA tools just
aren't
> > designed
> > > > for the size of devices Xilinx engineers are building.
> > > >
> > > > Panel presentations will be available at the DAC Web site
> > (www.dac.com) in a
> > > > few weeks.
> > > >
> > > > http://www.eetimes.com/
> > > >
> > > > Copyright c 2000 CMP Media Inc.
> > > > <<END QUOTE>>
> > >
> > >
> >
> > Sent via Deja.com http://www.deja.com/
> > Before you buy.
>
>


Sent via Deja.com http://www.deja.com/
Before you buy.
Article: 23387
Subject: Re: Xilinx xc4000
From: Peter Alfke <peter@xilinx.com>
Date: Fri, 23 Jun 2000 11:24:10 -0700
Links: << >>  << T >>  << A >>
Let's take the original XC4000 CLB and only look at the basic structure with
two 4-input LUTs each feeding the third LUT, with an extra input to that 3rd
LUT.
Now you have 9 inputs driving 16+16+8=24 bits of ROM inside the LUTs.
So it seems to me that you can implement 2exp24 = 16.7 million functions of
the 9 variables.
Mathematically, there are 2exp512 functions of 9 variables, so the CLB can
only implement a tiny subset of that enormous number.
But parity check over 9 bits is one interesting application that can be
done. And there are many more.
Peter Alfke

WU Chi Hang FOX wrote:

> an XC4000 CLB got 2 4-input-LUTs and 1 3-input-LUT
> it said it can implements some functions up to 9 variables.
> I want to ask who knows exactly how many functions up to 9 variables
> can be implemented....
> --
> *************************************************************************
> *       /\ /\     Name : Wu Chi Hang ?J  ( FOX )  **  W **       *
> *       ^  ^      Job  : ELEC/CPEG Demonstrator (Rm. 2466, Ext. x7037 ) *
> *       .  .      Email: eefox@uxmail.ust.hk  /  eefox@ee.ust.hk        *
> *     =o =               chwu@usa.net / 97Cwch@alumni.ee.ust.hk         *
> *       u         Hpage: http://www.ee.ust.hk/~eefox/index.html 4294435 *
> *************************************************************************

Article: 23388
Subject: Re: What tools do people use for Xilinx FPGAs?
From: Muzaffer Kal <muzaffer@kal.st>
Date: 23 Jun 2000 14:41:31 EDT
Links: << >>  << T >>  << A >>
I'd definitely suggest Synplify from Synplicity. I have tried
fpgaexpress and leonardo and bought Synplify. Really fast synthesis,
really good output.

James Kennedy <spam@this.com> wrote:

>Hi everyone,
>
>At risk of starting a religious war, I'd like to ask all you people out
>there who do _real_ designs with Xilinx FPGA's, what tools do you
>currently use, and/or recommend?  
>
>I'm currently in the process (and have been for some time) of trying to
>use Xilinx's foundation express but I think it has won the battle :)
>
>So we're thinking of investing in a less buggy tools suite and I'm
>looking for any suggestions.
>
>Cheers,
>James.

Article: 23389
Subject: Re: Xilinx xc4000
From: Rickman <spamgoeshere4@yahoo.com>
Date: Fri, 23 Jun 2000 14:52:43 -0400
Links: << >>  << T >>  << A >>
The XC4000 can do any function of 4 variables in the 4 input LUTs. It
can do any function of 3 variables in the 3 input LUT. The combination
connected in the default manner does 3_func(4_func(a,b,c,d),
4_func(e,f,g,h), j). 

A logical combination of N inputs gives 2^(2^N) boolean functions. So a
3 input function can do 256 functions and a 4 input function can do
65536 functions. The above combination is 65536 * 65536 * 256 =
1099511627776 or 2^40. Compare to 9 input functions which are too large
to calculate on an 18 digit scientific calculator!!!



WU Chi Hang FOX wrote:
> 
> an XC4000 CLB got 2 4-input-LUTs and 1 3-input-LUT
> it said it can implements some functions up to 9 variables.
> I want to ask who knows exactly how many functions up to 9 variables
> can be implemented....
> --
> *************************************************************************
> *       /\ /\     Name : Wu Chi Hang J  ( FOX )  **  W **       *
> *       ^  ^      Job  : ELEC/CPEG Demonstrator (Rm. 2466, Ext. x7037 ) *
> *       .  .      Email: eefox@uxmail.ust.hk  /  eefox@ee.ust.hk        *
> *     =o =               chwu@usa.net / 97Cwch@alumni.ee.ust.hk         *
> *       u         Hpage: http://www.ee.ust.hk/~eefox/index.html 4294435 *
> *************************************************************************

-- 

Rick 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

Arius
4 King Ave
Frederick, MD 21701-3110
301-682-7772 Voice
301-682-7666 FAX

Internet URL http://www.arius.com
Article: 23390
Subject: Re: Xilinx xc4000
From: Peter Alfke <peter@xilinx.com>
Date: Fri, 23 Jun 2000 13:20:32 -0700
Links: << >>  << T >>  << A >>
Sorry, I said 16+16+8 = 24, not very smart!
Rickman is right, it's 40 ,and thus over a thousand billion functions.
So we both agree.
Peter



Rickman wrote:

> The XC4000 can do any function of 4 variables in the 4 input LUTs. It
> can do any function of 3 variables in the 3 input LUT. The combination
> connected in the default manner does 3_func(4_func(a,b,c,d),
> 4_func(e,f,g,h), j).
>
> A logical combination of N inputs gives 2^(2^N) boolean functions. So a
> 3 input function can do 256 functions and a 4 input function can do
> 65536 functions. The above combination is 65536 * 65536 * 256 =
> 1099511627776 or 2^40. Compare to 9 input functions which are too large
> to calculate on an 18 digit scientific calculator!!!
>
> WU Chi Hang FOX wrote:
> >
> > an XC4000 CLB got 2 4-input-LUTs and 1 3-input-LUT
> > it said it can implements some functions up to 9 variables.
> > I want to ask who knows exactly how many functions up to 9 variables
> > can be implemented....
> > --
> > *************************************************************************
> > *       /\ /\     Name : Wu Chi Hang ?J  ( FOX )  **  W **       *
> > *       ^  ^      Job  : ELEC/CPEG Demonstrator (Rm. 2466, Ext. x7037 ) *
> > *       .  .      Email: eefox@uxmail.ust.hk  /  eefox@ee.ust.hk        *
> > *     =o =               chwu@usa.net / 97Cwch@alumni.ee.ust.hk         *
> > *       u         Hpage: http://www.ee.ust.hk/~eefox/index.html 4294435 *
> > *************************************************************************
>
> --
>
> Rick 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
>
> Arius
> 4 King Ave
> Frederick, MD 21701-3110
> 301-682-7772 Voice
> 301-682-7666 FAX
>
> Internet URL http://www.arius.com

Article: 23391
Subject: Re: Xilinx xc4000
From: bobperl@best_no_spam_thanks.com (Bob Perlman)
Date: Fri, 23 Jun 2000 20:20:55 GMT
Links: << >>  << T >>  << A >>
On 23 Jun 2000 16:56:10 GMT, eefox@uxmail.ust.hk ( WU Chi Hang FOX )
wrote:

>an XC4000 CLB got 2 4-input-LUTs and 1 3-input-LUT
>it said it can implements some functions up to 9 variables.
>I want to ask who knows exactly how many functions up to 9 variables 
>can be implemented....

What happened to the good old days, when students copied their
homework answers from fellow classmates?

Bob Perlman


-----------------------------------------------------
Bob Perlman
Cambrian Design Works
Digital Design, Signal Integrity
http://www.best.com/~bobperl/cdw.htm
Send e-mail replies to best<dot>com, username bobperl
-----------------------------------------------------
Article: 23392
Subject: Re: Xilinx xc4000
From: fliptron@netcom.com (Philip Freidin)
Date: 23 Jun 2000 20:29:30 GMT
Links: << >>  << T >>  << A >>
In article <3953AB4A.CA452839@xilinx.com>,
Peter Alfke  <peter.alfke@xilinx.com> wrote:
>Now you have 9 inputs driving 16+16+8=24 bits of ROM inside the LUTs.
>Peter Alfke

 Nice one Peter!   New math is hard :-)

An answer to the original question is 2^40 possible functions, many of 
which are not interesting, or are synonyms.

Philip

Article: 23393
Subject: a lot of basic questions - where's the FAQ?
From: lamb_baa@hotmail.com (Eric L)
Date: 23 Jun 2000 20:30:26 GMT
Links: << >>  << T >>  << A >>
I have a lot of questions which I'm sure are asked constantly so let me just go 
ahead and ask where the FAQ is located or if someone would repost it?

Here are the questions anyway if someone doesn't mind answering them.

1) Where do you find FPGA programmers? Are there schematics to build your own? 
If I wanted to make a system say using a microcontroller with a PLD or FPGA to 
configure, how would I do it? I know xilinx sells their test boards but those 
are for one chip use and soldering and desolering would be a pain.

2) PLDs and FPGAs - When you remove them do they keep their data? For instance, 
I program them with say a simple register and remove it from the programmer 
would it still be usable on another system?

3) Off-Topic (sorry, no PLD newsgroup or is there?) - In digikey's catalog the 
Xilinx XC9500 CPLDs have registers but no mention of flip-flops. What's the 
difference? I know the difference as far as any digital design book will tell 
me but what does that mean when programming it?

4) What's a good site to learn more about PLDs and/or PGAs? 

Thanks,
Eric

Article: 23394
Subject: Re: a lot of basic questions - where's the FAQ?
From: Peter Alfke <peter@xilinx.com>
Date: Fri, 23 Jun 2000 14:40:38 -0700
Links: << >>  << T >>  << A >>


Eric L wrote:

> I have a lot of questions which I'm sure are asked constantly so let me just go
> ahead and ask where the FAQ is located or if someone would repost it?
>
> Here are the questions anyway if someone doesn't mind answering them.
>
> 1) Where do you find FPGA programmers? Are there schematics to build your own?

Don't. You really don't need a separate programmer since all "modern" CPLDs can be
programmed in the system, and SRAM-based FPGAs never needed a programmer. That
leaves only the antifuse parts in need of a programmer. But since they are not
even reprogrammable, you might as well let the distributor program them for you.

>
> If I wanted to make a system say using a microcontroller with a PLD or FPGA to
> configure, how would I do it? I know xilinx sells their test boards but those
> are for one chip use and soldering and desolering would be a pain.

I don't understand what you mean.

>
>
> 2) PLDs and FPGAs - When you remove them do they keep their data? For instance,
> I program them with say a simple register and remove it from the programmer
> would it still be usable on another system?

All CPLDs and all antifuse FPGAs keep their configuration, since they are
non-volatile.
All other FPGAs lose it, since it is stored in latches.

>
>
> 3) Off-Topic (sorry, no PLD newsgroup or is there?) - In digikey's catalog the
> Xilinx XC9500 CPLDs have registers but no mention of flip-flops. What's the
> difference? I know the difference as far as any digital design book will tell
> me but what does that mean when programming it?

"register" and "flip-flop' are synonymous, unless you specifically talk about
"byte-wide" register etc.

Peter Alfke


Article: 23395
Subject: Re: What tools do people use for Xilinx FPGAs?
From: fliptron@netcom.com (Philip Freidin)
Date: 23 Jun 2000 22:14:00 GMT
Links: << >>  << T >>  << A >>

Dual P-II/400, 512MB SDRAM, 24GB SCSI Disk, DAT tape backup, NT4.0 + SP5

Xilinx Alliance M2.1i / M3.1i + latest SP

Viewlogic (Inoveda) Viewdraw Schematic capture
Fliptronics FlibGen/Flibtime Automatic schematic module generator
Viewlogic (Inoveda) ViewSim gate level simulation
Viewlogic (Inoveda) VCS/Fusion Verilog simulation
Fliptronics ChipView for post place and route analysis of utilization, 
   placement, timing, worst case paths.
Synopsys FPGA Express Verilog and VHDL Synthesis
Synplicity Synplify Verilog and VHDL Synthesis

All use of Xilinx tools is from the command line. My experience is that 
all the  Automated flow engines (which is the core of the Foundation 
package) are too restrictive, make assumptions that are incorrect, do not 
allow flows that the underlying tools are capable of, and create a 
project directory tree that is crazy.

Philip Freidin


In article <3952F531.69095D19@this.com>, James Kennedy  <spam@this.com> wrote:
>At risk of starting a religious war, I'd like to ask all you people out
>there who do _real_ designs with Xilinx FPGA's, what tools do you
>currently use, and/or recommend?  
>I'm currently in the process (and have been for some time) of trying to
>use Xilinx's foundation express but I think it has won the battle :)
>So we're thinking of investing in a less buggy tools suite and I'm
>looking for any suggestions.
>James.
Article: 23396
Subject: F2.1i
From: erika_uk@my-deja.com
Date: Fri, 23 Jun 2000 22:37:58 GMT
Links: << >>  << T >>  << A >>
hey all,

I want to install the F2.1i at home. Unfortunately, i can't have
internet connection. Will the F2.1i be fully functionnal if i use just
a schematic entry

Thanks.

--Erika


Sent via Deja.com http://www.deja.com/
Before you buy.
Article: 23397
Subject: Re: CHES 2000 accepted papers
From: phr@netcom.com (Paul Rubin)
Date: 24 Jun 2000 01:13:02 GMT
Links: << >>  << T >>  << A >>
In article <Pine.OSF.4.21.0006230159320.20030-100000@ece.wpi.edu>,
Christof Paar  <christof@ece.wpi.edu> wrote:
>H. Wu. 
>Montgomery multiplier and squarer in GF(2^m).

What does it mean to do Montgomery multiplication in GF(2^m)!?

Also, is the author H.-H. Wu of the University of California, Berkeley?
Or a different H. Wu?

Thanks.
Article: 23398
Subject: Re: a lot of basic questions - where's the FAQ?
From: lamb_baa@hotmail.com (Eric L)
Date: 24 Jun 2000 01:46:18 GMT
Links: << >>  << T >>  << A >>

>Don't. You really don't need a separate programmer since all "modern" CPLDs 
can 
>be
>programmed in the system, and SRAM-based FPGAs never needed a programmer. That
>leaves only the antifuse parts in need of a programmer. But since they are not
>even reprogrammable, you might as well let the distributor program them for 
you.
>
>>

So how would I do it if I bought a Xilinx XC9500?


>> If I wanted to make a system say using a microcontroller with a PLD or FPGA 
to
>> configure, how would I do it? I know xilinx sells their test boards but 
those
>> are for one chip use and soldering and desolering would be a pain.
>
>I don't understand what you mean.
>
>>
>>


well let's say I have a robot that has a xilinx FPGA in it and I program it to 
be an AND-gate (for discussion purposes) and then I suddenly need it to act as 
an OR-gate. How would I do something like that? Perhaps the previous question 
and this question are the same..

Thanks
eric

Article: 23399
Subject: Re: dual processor PC for PPR - are they worth the extra cost?
From: steve (Steve Rencontre)
Date: Sat, 24 Jun 2000 03:00 +0100 (BST)
Links: << >>  << T >>  << A >>
In article <01bfdc4a$feb79d00$c4f262d1@Dan.i-tech.com>, 
dan_kuechle@i-tech.com (Dan Kuechle) wrote:

> Anyone out there using a dual processor PC for Xilinx?
> 
> My last project takes about 1.5 hours to complie the single
> Xilinx chip if I do nothing else,  and upwards of 3 hours if I 
> try and do some work while the Xilinx s/w is running.  Since
> my PC is only 350mhz (windows 95) its probably time for
> an upgrade.  I'm wondering about dual processors, thinking
> one could run Xilinx while I use the other to get some real
> work done while the Xilinx s/w is running.   Anyone got
> any insights or recomendations?
> 
> Dual processors will force me into windows 2000 or NT.
> Any problems with that?
> 
> Others where I work are interested from an Altera point of 
> view also.

I've been using dual-processor systems for years, and would be very 
reluctant to have a uniprocessor as my main work machine. 2 x XXX MHz is 
slower on benchmarks than 1 x 2XXX, but subjectively /feels/ a lot faster 
because it doesn't bog down on CPU-intensive tasks. A machine that I can't 
use for 1.5 hours is costing me more than a machine that lets me get on 
with other stuff in the meantime.

There's a bit of a shortage of decent dual motherboards ATM. After Intel's 
cockup with the 820/840 chipsets, the only good one around that isn't a 
fairly ancient design seems to be the Tyan Thunder 2500. It's expensive, 
but includes a lot of good stuff on-board which you'd probably have to buy 
anyway.

I confess I don't know any specifics wrt Xilinx, but the Altera stuff 
works without problems. Ditto for ViewLogic, Cypress Warp and everything 
else I've actually used for CAE. It /is/ sometimes the case that things 
fail on a dual system because the developer hasn't done their homework 
properly, but it's getting rarer.
--
Steve Rencontre		http://www.rsn-tech.demon.co.uk
//#include <disclaimer.h>



Site Home   Archive Home   FAQ Home   How to search the Archive   How to Navigate the Archive   
Compare FPGA features and resources   

Threads starting:
1994JulAugSepOctNovDec1994
1995JanFebMarAprMayJunJulAugSepOctNovDec1995
1996JanFebMarAprMayJunJulAugSepOctNovDec1996
1997JanFebMarAprMayJunJulAugSepOctNovDec1997
1998JanFebMarAprMayJunJulAugSepOctNovDec1998
1999JanFebMarAprMayJunJulAugSepOctNovDec1999
2000JanFebMarAprMayJunJulAugSepOctNovDec2000
2001JanFebMarAprMayJunJulAugSepOctNovDec2001
2002JanFebMarAprMayJunJulAugSepOctNovDec2002
2003JanFebMarAprMayJunJulAugSepOctNovDec2003
2004JanFebMarAprMayJunJulAugSepOctNovDec2004
2005JanFebMarAprMayJunJulAugSepOctNovDec2005
2006JanFebMarAprMayJunJulAugSepOctNovDec2006
2007JanFebMarAprMayJunJulAugSepOctNovDec2007
2008JanFebMarAprMayJunJulAugSepOctNovDec2008
2009JanFebMarAprMayJunJulAugSepOctNovDec2009
2010JanFebMarAprMayJunJulAugSepOctNovDec2010
2011JanFebMarAprMayJunJulAugSepOctNovDec2011
2012JanFebMarAprMayJunJulAugSepOctNovDec2012
2013JanFebMarAprMayJunJulAugSepOctNovDec2013
2014JanFebMarAprMayJunJulAugSepOctNovDec2014
2015JanFebMarAprMayJunJulAugSepOctNovDec2015
2016JanFebMarAprMayJunJulAugSepOctNovDec2016
2017JanFebMarApr2017

Authors:A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Custom Search