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Messages from 85550

Article: 85550
Subject: Re: computer upgrade time.
From: John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com>
Date: Fri, 10 Jun 2005 12:46:51 -0700
Links: << >>  << T >>  << A >>
On 10 Jun 2005 11:11:57 -0700, Eric Smith <eric@brouhaha.com> wrote:

>Ray Andraka <ray@andraka.com> writes:
>> I'd like something that doesn't sound like a vacuum
>> cleaner and heat the room like a space heater this time around too,
>> perhaps I need to consider liquid cooling?
>
>I've been thinking about using a Zalman Reserator fanless watar
>cooling kit when I upgrade my machine to an Athlon 64 X2 4400+
>(dual core 2.2 GHz), but I haven't tried it yet so I can't personally
>confirm the claims.
>
>    http://www.zalman.co.kr/eng/product/view.asp?idx=63&code=021
>
>I've been happy with Zalman's other products, though.  I'm using their
>CNPS7000B-Cu heatsink/fan on a Athlon 64 3500+, and it does a great
>job of keeping the temperature down without much noise.
>
>    http://www.zalman.co.kr/eng/product/view.asp?idx=141&code=005
>
>But the X2 uses a lot more power (up to 105W, IIRC), and I suspect that
>the Reserator will be able to keep it cooler than the CNPS7000B-Cu
>would.
>
>Zalman recommends distilled water for the Reserator.  I wonder whether
>it's a good idea to add something to inhibit growth of microorganisms,
>like a tiny amount of bleach?  If the thing is working properly, the
>water won't get hot enough to kill all the critters.
>

Car anti-freeze?

John


Article: 85551
Subject: Re: How do I find out the connection of the LCD I took out from a digital camera?
From: Peter TB Brett <peter@peter-b.co.uk>
Date: Fri, 10 Jun 2005 19:59:08 GMT
Links: << >>  << T >>  << A >>
"Krist Neot" <Krist_Neot@hotmail.com> writes:

> For such LCDs, is the display RAM usually implemented in the LCD panel
> or the camera manufacturer implements that in his camera's circuit board?

Look at the panel's FPC (Flexible Plastic Connector).  There should be
a chip bonded to it -- that's the LCDC (Liquid Crystal Display
Controller).

Anyway, the LCDC generates panel voltages from incoming data.  Most
panels need something like the following:

- Parallel data (6 or 8 bit)
- Clock (anything from 500 kHz to 25 MHz)
- Supply voltages.  These are often suprisingly high, and if you
  connect them to the wrong pins you've got a dead panel.

I work with small LCD panels (actually, I'm busy writing HDL for a
LCDC at the moment) and I'll warn you: if you don't have a spec for
the device you're quite likely to fry it or break it in other ways
(for instance, most LC requires row-by-row voltage inversion to stop
it from sticking).

When we hook up competitors panels for testing we use a tool for
hooking into the FPC to probe the signals being sent to it.  It's
pretty ridiculously expensive though.

HTH,

Peter

-- 
E-mail:  peter@peter-b.co.uk
Website: http://www.peter-b.co.uk

v2sw6YShw7ln5pr6ck3ma8u7Lw3+2m0l7CFi6e4+8t4Eb8Aen4g6Pa2Xs5MSr5p4 hackerkey.com

Article: 85552
Subject: Re: pcb layers on BGAs Spartan-3
From: John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com>
Date: Fri, 10 Jun 2005 12:59:29 -0700
Links: << >>  << T >>  << A >>
On Thu, 09 Jun 2005 11:17:34 -0500,
calaf_calaf_calaf@yahoo-dot-es.no-spam.invalid (calaf) wrote:

>Hi all, I am new in this forum, and I have not found a question as the
>stated below. Sorry if it has already done.  I have been designing
>with Spartan-3 and as a consequence of the number of different power
>suply and the pinout distribution on the board it is impossible to me
>to have a very reduced number of pcb layers. Allowing for simetries
>between powers and gnd layers on the stack I almost can't decrease
>from ten. Is there any idea I am missing?  maybe as 2.5 V is only
>used in configuration I can create islands on the 3.3V layer and
>share the ground layer return between both power supply?
>I think there must be something else that allow me to work effitienly
>wilt fewer layers.
>Thanks in advance


I did an S2E in the FG456 package in 8 layers, 6 mil design rules in
places. The same arrangement would probably work for an S3 with three
supplies if you split one of the power planes. The trick of course is
to not go nuts with bypass caps.

I could post some layer pics to alt.binaries.schematics.electronic if
there's demand.

John




Article: 85553
Subject: Re: pcb layers on BGAs Spartan-3
From: John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com>
Date: Fri, 10 Jun 2005 13:00:40 -0700
Links: << >>  << T >>  << A >>
On Fri, 10 Jun 2005 18:46:51 +0200, "Falk Brunner"
<Falk.Brunner@gmx.de> wrote:

>
>"calaf" <calaf_calaf_calaf@yahoo-dot-es.no-spam.invalid> schrieb im
>Newsbeitrag news:jYGdnT7auunXIDTfRVn_vg@giganews.com...
>
>> problem. Shouldn't a power plane be below or above all the pins of
>> the FPGA as it happens with ground planes?
>
>This is the better solution (if you have the layer available) but split
>power planes are OK too. Just be carefull, dont use these as reference
>planes for high speed lines, this can bite you.
>

Why? They're all at AC ground.

John


Article: 85554
Subject: Re: pcb layers on BGAs Spartan-3
From: "Falk Brunner" <Falk.Brunner@gmx.de>
Date: Fri, 10 Jun 2005 22:04:01 +0200
Links: << >>  << T >>  << A >>

"John Larkin" <jjlarkin@highNOTlandTHIStechnologyPART.com> schrieb im
Newsbeitrag news:6asja1deqev84jtunnakfmqunqls0k3e57@4ax.com...

> >This is the better solution (if you have the layer available) but split
> >power planes are OK too. Just be carefull, dont use these as reference
> >planes for high speed lines, this can bite you.
> >
>
> Why? They're all at AC ground.

Yes, but connected through vias + decoupling caps to "real" ground. It
works, but less good than a real ground plane.

Regards
Falk




Article: 85555
Subject: Re: computer upgrade time.
From: "Marc Randolph" <mrand@my-deja.com>
Date: 10 Jun 2005 13:08:17 -0700
Links: << >>  << T >>  << A >>


billh40@aol.com wrote:
> Ray Andraka wrote:
> > Time has come for a computer upgrade (I'm currently using a dual Athlon
> > 1.8GHz with 4GB memory and 15000RPM scsi raid array running Win2K,
> > matrox dual head video with a pair of 19" monitors), but I haven't kept
> > up at all with the computer market.  I'm wondering what people are using
> > these days for high end designs (for simulation and PAR especially).
> > I'd like something that doesn't sound like a vacuum cleaner and heat the
> > room like a space heater this time around too, perhaps I need to
> > consider liquid cooling?  ANy comments would be appreciated.  Yes, I
> > admit I am being lazy.
> >
> >     I am using a 2.6 GHZ P4 , XP PRO, DELL GX270, 2GB RAM, 7200 RPM IDE.
> > It takes 7 hours to  PAR for a V6000 at 83% utilization (28,400 slices).
> > Bill

Howdy Ray and Bill,

Config: 3.2 GHz P4, XP Pro, Dell PWS360, 2 GB RAM.  Files stored out on
a network drive.

Results: It takes 3 hours for timing driving MAP + PAR to spit out an
LX25 (10.8k slices) design at 91% LUT utilization, using 6.3.3i.  7.1i
takes noticably longer if global optimization is turned on.

According to http://www.polybus.com/linux_hardware/index.htm
and other things I've read, you want as much cache as you can afford.
The general agreement also seems to be that Athlon 64's tend to be the
fastest things out right now, to make a very sweeping generalization.

Have fun,

   Marc


Article: 85556
Subject: Re: ISE7.1 PAR Warinng: excessive skew because 1 NON-CLK pins...
From: "Vladislav Muravin" <muravinv@advantech.ca>
Date: Fri, 10 Jun 2005 16:25:50 -0400
Links: << >>  << T >>  << A >>
Michael,

I had a warning like this on the clock signal which is originally routed 
through the clock pin,
but not directly to BUFG, i.e. there was some muxes on the way.

I think the explanation is that BUFGP is IBUFG + BUFG, and if there is logic 
in between,
then the placer fails using a template (i.e. BUFGP). May be your design / 
core has some gated clocks or
any other logic associated with clock muxing.

Hope this helps.

Vladislav.

"MM" <mbmsv@yahoo.com> wrote in message 
news:3gtpr1Feefu1U1@individual.net...
>I am getting the following warning on a Virtex-II design:
>
> WARNING:Route - CLK Net:clk50_BUFGP may have excessive skew because 1
> NON-CLK pins failed to route using a CLK template.
>
> My question is how can I find the problematic pin?
>
> A similar question was asked here in the past, but the discussion slipped
> into design practices. My design is pretty big and the biggest part of it 
> is
> third party core, for which I don't have source code. So, I need to figure
> out what exactly causes this warning...
>
> Thanks,
> /Mikhail
>
> 



Article: 85557
Subject: Re: computer upgrade time.
From: "Daniel Lang" <invalid@invalid.caltech.edu>
Date: Fri, 10 Jun 2005 13:35:19 -0700
Links: << >>  << T >>  << A >>
"Ray Andraka" <ray@andraka.com> wrote in message 
news:HFiqe.559$FP2.71@lakeread03...
> Time has come for a computer upgrade (I'm currently using a dual Athlon 
> 1.8GHz with 4GB memory and 15000RPM scsi raid array running Win2K, matrox 
> dual head video with a pair of 19" monitors), but I haven't kept up at all 
> with the computer market.  I'm wondering what people are using these days 
> for high end designs (for simulation and PAR especially).  I'd like 
> something that doesn't sound like a vacuum cleaner and heat the room like 
> a space heater this time around too, perhaps I need to consider liquid 
> cooling?  ANy comments would be appreciated.  Yes, I admit I am being 
> lazy.
>

The new Opterons actually have relatively low power dissipation
requirements.  You may want to consider 2 of the Opteron 252s
(single core 90nm devices) as they have fastest clock speed and
lowest power consumption requirements.

Here are some benchmarks of the new Opterons:

http://www.gamepc.com/labs/view_content.asp?id=opteron275&page=1

Daniel Lang



Article: 85558
Subject: Re: pcb layers on BGAs Spartan-3
From: Sylvain Munaut <com.246tNt@tnt>
Date: Fri, 10 Jun 2005 22:53:21 +0200
Links: << >>  << T >>  << A >>
Falk Brunner wrote:

>>IIRC the "official" escape pattern for FT256 is 6/6 and uses top &
>>botton layer only.
> 
> 
> I doubt it. For a BGA fanout, you need n/2-1 signal layers, where n is the
> number of rows/columns (assuming you have a complete ball grid without space
> in the center. So for a 16x16 (FG256) you need 7 signal layers. To our
> advantage, the inner balls are just VCC/GND, so you get away with 4 signal
> layers.

Take a look at
http://www.xilinx.com/bvdocs/appnotes/xapp157.pdf
For the FG256 they only show two signal layers.


	Sylvain

Article: 85559
Subject: Re: pcb layers on BGAs Spartan-3
From: "dlharmon" <harmon.darrell@gmail.com>
Date: 10 Jun 2005 13:56:57 -0700
Links: << >>  << T >>  << A >>


Falk Brunner wrote:
> "dlharmon" <harmon.darrell@gmail.com> schrieb im Newsbeitrag
> news:1118373181.586925.297720@f14g2000cwb.googlegroups.com...
>
> > I have laid out my first board using the FT256. I have not had it
> > fabricated yet. It is 4 layers 6/6mil track/space.  The real killer was
> > the size of the vias.  I used 1 solid groundplane and planelets for
>
> ??? How is it possible to fanout the balls on just 2 signal layers (1 layer
> is "lost" for Ground, the other for VCC)? Or do you mean a 6 layer board
> (which leaves 4 layers for signals)?
>
> Regards
> Falk

It isn't.  I just used about 120 of the 171 IO.  I used a solid ground
plane and another plane for power.  The first 2 rows were brought out
on top and a few IO were brought out on the bottom.

Darrell Harmon


Article: 85560
Subject: Re: re:pcb layers on BGAs Spartan-3
From: "dlharmon" <harmon.darrell@gmail.com>
Date: 10 Jun 2005 14:06:04 -0700
Links: << >>  << T >>  << A >>


calaf wrote:
>
> As far I can gather I find some issues: There are some disposition of
> vias on the 2.5V planelet that reduce significatively the path's
> width for currents (and therefore it raises the impedance. I have
> found quite interesting the method used to take the 3.3V to the VCCO
> pins but I wonder whether a trace (instead of a plane is not a
> problem. Shouldn't a power plane be below or above all the pins of
> the FPGA as it happens with ground planes?

Thanks for the tip.  I took out a few vias and enlarged the 2.5V
planelet.  It is fairly solid now.  Unfortunately the clearance around
the via is the minimum allowed by the PCB maker (PCBTrain).  The 3.3V
IO does not really have a plane, but has an 0402 cap between the ground
plane at each via.  All of the IO are 3.3V LVCMOS.  I am going to go
ahead and build it.  It has to be better than the alternative (PQ208).

Darrell Harmon


Article: 85561
Subject: Re: re:pcb layers on BGAs Spartan-3
From: "Symon" <symon_brewer@hotmail.com>
Date: Fri, 10 Jun 2005 14:30:01 -0700
Links: << >>  << T >>  << A >>
"Symon" <symon_brewer@hotmail.com> wrote in message
news:42a9de59_3@x-privat.org...
> "calaf" <calaf_calaf_calaf@yahoo-dot-es.no-spam.invalid> wrote in message
> news:jYGdnT7auunXIDTfRVn_vg@giganews.com...
>
> > As far I can gather I find some issues: There are some disposition of
> > vias on the 2.5V planelet that reduce significatively the path's
> > width for currents (and therefore it raises the impedance.
> >
> The vias are plated through. With metal. Like Khan, you're thinking too
two
> dimensionally. Think like Mr. Spock.
>
Doh, I was looking at the wrong bit. Shouldn't've gone drinking on a school
night yesterday!
Syms.



Article: 85562
Subject: Re: computer upgrade time.
From: Ben Twijnstra <btwijnstra@gmail.com>
Date: Fri, 10 Jun 2005 23:30:59 +0200
Links: << >>  << T >>  << A >>
Hi Ray,

> Time has come for a computer upgrade (I'm currently using a dual Athlon
> 1.8GHz with 4GB memory and 15000RPM scsi raid array running Win2K,
> matrox dual head video with a pair of 19" monitors), but I haven't kept
> up at all with the computer market.  I'm wondering what people are using
> these days for high end designs (for simulation and PAR especially).
> I'd like something that doesn't sound like a vacuum cleaner and heat the
> room like a space heater this time around too, perhaps I need to
> consider liquid cooling?  ANy comments would be appreciated. 

I personally use an Athlon XP 3200 with 2GB and plain old parallel IDE disks
- I don't think that RAID performance helps me with P&R that much. Mind
you, so far I've worked on designs up to the 20K1500E and the 2S60 - I
guess I'd need a bit more when designing for something bigger.

Take a look at http:// www.alienware.com and look up the Aurora ALX. Dress
it up as you go, but do use the Athlon 64 X2 4800+ CPU, 2G of memory, and
even though it's liquid-cooled, it may be a good idea to add the noise
dampener stuff as well.

Alienware PCs are fast and reliable, and even though they're designed for
gamers, they should do a good job running Modelsim and PAR as well. Also, I
must say that they have sublime taste in casing - which after all does
matter since you'll be seeing that thing under your desk for the next few
years.

As to the OS - it's completely up to you. I'm a Linux fan, and the whole
Altera kit runs at the same speed under Linux as under W2K, with Modelsim
running around 10% faster than under Windows. SOPC Builder is faster by a
(subjective) factor 2 under Linux.

I haven't tried webpack under Linux yet - so much to do, so little time...

Just my $.02

Best regards,


Ben

Article: 85563
Subject: Re: I2C clock stretching(XILINX reference design)
From: "Kryten" <kryten_droid_obfusticator@ntlworld.com>
Date: Fri, 10 Jun 2005 22:03:25 GMT
Links: << >>  << T >>  << A >>

"Gabor" <gabor@alacron.com> wrote in message 
news:1118417613.834535.32380@g43g2000cwa.googlegroups.com...

>> A master has to support clock stretching to be I2C compliant.

Yes.

>> Clock stretching is used by slaves that need time to process data.
>> If a slave doesn't need the extra time, it doesn't need to stretch the
>> clock and can maintain I2C compliance without clock stretching.

True.

The key point is that clock stretching allows any master to work with any 
slave.

Omitting it inserts an Achilles heel in the design.

It is really irritating when people publish interfaces with such flaws.
Even more so when the authors acknowledge the flaw and then waffle their 
excuses for not doing it the way it ought to work.


> A lot of IC's with I2C slaves show the SCL pin as
> an input-only.  The Xilinx app assumes you're getting data from
> inside the FPGA which should never require stretching even at
> the fastest bit rates.

If the slave runs fast enough it never needs to stretch the clock.

But the master always have to cope with clock stretching.

> A clock stretcher usually only asserts SCL during the ACK cycle of
> the access requiring more time.  This is not a requirement, but it
> keeps a slave from stretching SCL cycles that are not intended for
> that slave, as might happen if the address is still being sent.

IIRC any slave should be able to stretch the clock at any bit.
For example, and extremely slow slave might need to slow do the address bit 
rate in order to read all the bits. It doesn't matter if the address is for 
it or not, it still needs its own time to read it.

> Also make sure that the decision to stretch or not stretch does not
> come more than Tlow (min) after the falling edge of SCL or you may
> have a race condition allowing the SCL to "double pulse".  It's
> probably best to synchronize the start of the stretch pulse to the
> falling edge of SCL.

I thought a good way to clock stretch is to have a gated 3s buffer with the 
in and out both wired to SCL. Like a 74LS125 (IIRC). With the enable 
negated, it acts as if it were not there. With the enable asserted, it is 
'armed': when the SCL line goes low, the gate locks it low (for the slave to 
take its own sweet time to note it). The slave then negates the enable to 
allow SCL to float.




Article: 85564
Subject: Re: xmodem/kermit for edk/ppc
From: Paul Hartke <phartke@Stanford.EDU>
Date: Fri, 10 Jun 2005 15:48:45 -0700
Links: << >>  << T >>  << A >>
http://www.menie.org/georges/embedded/#xmodem

Petter Gustad wrote:
> 
> I want do download some date into my FPGA over a serial line. It would
> be great to do so using xmodem or kermit. However, the source code
> I've found (Omen and Columbia U) seem to be based upon a file system
> or assume a POSIX OS.
> 
> Are there any simple public domain xmodem or kermit implementations
> which will simply store the received data in a buffer out there?
> 
> Petter
> --
> A: Because it messes up the order in which people normally read text.
> Q: Why is top-posting such a bad thing?
> A: Top-posting.
> Q: What is the most annoying thing on usenet and in e-mail?

Article: 85565
Subject: Re: computer upgrade time.
From: "Austin Franklin" <austin@dark99room.com>
Date: Fri, 10 Jun 2005 18:51:45 -0400
Links: << >>  << T >>  << A >>
Hi Ray,

I use the following heatsinks:

http://www.sidewindercomputers.com/swmcforinxe.html

I use this on a 3.x GHz P4 dual system, and they work great.  I got a super
quiet $5 fan with it, and no problems.

I use this case:

http://www.antec.com/us/productDetails.php?ProdID=15001

and it comes with two very very quiet fans.  The biggest feature of it is
the way the disk drives mount and are easily removeable.  It comes with a
four carrier drive bay that allows access out the side.  You may not like
the neon blue lights, or the clear sides, but ignore them...it's a really
nice case.  Has front USB ports as well.

I also use this power supply:

http://www.antec.com/us/productDetails.php?ProdID=20551

which is sufficiently quiet.

As far as motherboard and memory goes, well, they really don't make much
noise, so I believe any of your liking that fit this case will do, and I'd
also recommend one that has at least a PCI-Express 16x video slot, if not
also a 4x and a few PCI slots.

Regards,

Austin


"Ray Andraka" <ray@andraka.com> wrote in message
news:HFiqe.559$FP2.71@lakeread03...
> Time has come for a computer upgrade (I'm currently using a dual Athlon
> 1.8GHz with 4GB memory and 15000RPM scsi raid array running Win2K,
> matrox dual head video with a pair of 19" monitors), but I haven't kept
> up at all with the computer market.  I'm wondering what people are using
> these days for high end designs (for simulation and PAR especially).
> I'd like something that doesn't sound like a vacuum cleaner and heat the
> room like a space heater this time around too, perhaps I need to
> consider liquid cooling?  ANy comments would be appreciated.  Yes, I
> admit I am being lazy.
>
> -- 
> --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: 85566
Subject: Re: Fast/low area Sorting hardware.
From: "Weng Tianxiang" <wtx@umem.com>
Date: 10 Jun 2005 16:06:53 -0700
Links: << >>  << T >>  << A >>
Hi,
Here you are for 'carry adder' key word in all patents title field:

 PAT. NO.  Title
1 5,045,681  Optoelectric ripple carry adder
2 4,931,981  Multi-place ripple-carry adder
3 4,899,305  Manchester carry adder circuit
4 4,839,849  Ripple-carry adder
5 4,704,701  Conditional carry adder for a multibit digital computer
6 4,675,838  Conditional-carry adder for multibit digital computer
7 4,660,165  Pyramid carry adder circuit


Article: 85567
Subject: FPGAFLASH
From: edick@hotmail.com
Date: 10 Jun 2005 16:09:51 -0700
Links: << >>  << T >>  << A >>
Some years ago, a XILINX project was "Designed by Jens Hildebrandt,
University of Rostock/Germany, 2002", as it says.  The purpose of this
piece of work was to enable one, by means of a CPLD, to program a FLASH
memory via an ASYNC serial link, and, after changing the state of RTS,
to use that FLASH memory to provide the bitstream and controls to
program a XILINX FPGA.

Unfortunately, the portion of this that I received did not specify
anything about the external interface.

Has anyone had experience with this project, to the extent that it's
been implemented?  If so, can you advise me as to how this scheme can
be implemented in hardware?

thanks in advance


Article: 85568
Subject: Re: computer upgrade time.
From: "John Adair" <loseitintheblackhole@blackholesextreme.co.uk>
Date: Sat, 11 Jun 2005 00:14:02 +0100
Links: << >>  << T >>  << A >>
I am well impressed with the Athlons we run. I am looking at the new X2s 
when they really become available in a couple of weeks. For a single thread 
type application like most of the current tools the Athlon FX55 would 
probably do slightly better but having something in reserve on a dual is 
great to have. The Intel equivalents in the main run hotter and need louder, 
or more sophisticated, cooling. In a couple of years I expect software to 
make better use of dual processors given the number of single chip dual 
cores coming into the mainstream market.

I would suspect your disk drives are a good part of your noise. Our RAID 
arrays make a reasonable racket. If you move to IDE arrays your will 
probably suffer some performance drop but you should be able to find some 
less noisy disk drives to take your noise down.

If your monitors are CRT then go LCD. CRTs would probably contribute a 
several hundred watts to your room heating our CRT pairs certainly do. We 
are also run LCD pairs and these are very impressive and all new monitors we 
buy will be LCD.

If you run XP and are really desperate consider running a remote desktop. 
Put the noise powerful machine in a suitably remote place and use a second 
low power, low noise, machine as your display machine. You can do similar 
things with Linux etc too but I am no expect on their implementations and 
limitations of running remote shells. Other practical things we do is to use 
full tower cases and put them under desks or behind noise baffles. Does not 
get rid of the heat but the perceived noise goes down.

John Adair
Enterpoint Ltd. - Home of Broaddown2. The Ultimate Spartan3 Development 
Board.
http://www.enterpoint.co.uk

"Ray Andraka" <ray@andraka.com> wrote in message 
news:HFiqe.559$FP2.71@lakeread03...
> Time has come for a computer upgrade (I'm currently using a dual Athlon 
> 1.8GHz with 4GB memory and 15000RPM scsi raid array running Win2K, matrox 
> dual head video with a pair of 19" monitors), but I haven't kept up at all 
> with the computer market.  I'm wondering what people are using these days 
> for high end designs (for simulation and PAR especially).  I'd like 
> something that doesn't sound like a vacuum cleaner and heat the room like 
> a space heater this time around too, perhaps I need to consider liquid 
> cooling?  ANy comments would be appreciated.  Yes, I admit I am being 
> lazy.
>
> -- 
> --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: 85569
Subject: Re: pcb layers on BGAs Spartan-3
From: John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com>
Date: Fri, 10 Jun 2005 17:26:19 -0700
Links: << >>  << T >>  << A >>
On Fri, 10 Jun 2005 22:04:01 +0200, "Falk Brunner"
<Falk.Brunner@gmx.de> wrote:

>
>"John Larkin" <jjlarkin@highNOTlandTHIStechnologyPART.com> schrieb im
>Newsbeitrag news:6asja1deqev84jtunnakfmqunqls0k3e57@4ax.com...
>
>> >This is the better solution (if you have the layer available) but split
>> >power planes are OK too. Just be carefull, dont use these as reference
>> >planes for high speed lines, this can bite you.
>> >
>>
>> Why? They're all at AC ground.
>
>Yes, but connected through vias + decoupling caps to "real" ground. It
>works, but less good than a real ground plane.
>

They're also connected by the parallel plane capacitance, which is
typically pretty hefty when the dielectrics are properly thin. If you
don't trust power planes for the "return current" you'll need a lot
more ground planes, hence more layers. I do stuff with jitters in the
low single digits of ps, and use microstrip traces referenced to power
planes all the time.

I blame Johnson for all this obsession with "return currents."

John



Article: 85570
Subject: Re: computer upgrade time.
From: Ray Andraka <ray@andraka.com>
Date: Fri, 10 Jun 2005 20:27:02 -0400
Links: << >>  << T >>  << A >>
Bob Perlman wrote:

>I've just upgraded to a 3GHz Prescott Pentium 4 system.  Prior to this
>I'd used dual-processor systems, but the hyperthreading feature seems
>to let me run small stuff painlessly while a simulation or route is
>running.  And speed is good, too.
>
>Sad to say, it doesn't meet your "no space heater" criterion.  The
>Prescott CPUs run very, very hot.
>
>Bob Perlman
>Cambrian Design Works
>
>  
>
Hmm, water cooling might let me put a radiator in another room. 

-- 
--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: 85571
Subject: Re: Fast/low area Sorting hardware.
From: "Weng Tianxiang" <wtx@umem.com>
Date: 10 Jun 2005 17:51:54 -0700
Links: << >>  << T >>  << A >>
Stephane,
Can you give a digital example on the median value algorithm or any
references to its original paper.

Thank you.

Weng


Article: 85572
Subject: Re: computer upgrade time.
From: "Marc Randolph" <mrand@my-deja.com>
Date: 10 Jun 2005 20:14:18 -0700
Links: << >>  << T >>  << A >>

John Adair wrote:
>
> If you run XP and are really desperate consider running a remote desktop.

I'll second that.  In fact, I neglected to mention in my other post
that the system that I described is nowhere near me.  It's in the
server room and I control it via XP's Remote Desktop.  In fact, I have
three Remote Desktop sessions open to different Windows XP boxes doing
FPGA builds this very moment.  Screen refresh is as if you were sitting
in front of the machine - good enough to use Model Sim.  Standard VNC
doesn't even come close, especially when connecting from home via VPN.

> Put the noise powerful machine in a suitably remote place and use a second
> low power, low noise, machine as your display machine. You can do similar
> things with Linux etc too but I am no expect on their implementations and
> limitations of running remote shells. Other practical things we do is to use
> full tower cases and put them under desks or behind noise baffles. Does not
> get rid of the heat but the perceived noise goes down.

Has anyone done any ISE runtime comparisons between Linux and Windows
on similar or identical machines?

   Marc


Article: 85573
Subject: Re: computer upgrade time.
From: nweaver@soda.csua.berkeley.edu (Nicholas Weaver)
Date: Sat, 11 Jun 2005 03:38:12 +0000 (UTC)
Links: << >>  << T >>  << A >>
In article <HFiqe.559$FP2.71@lakeread03>, Ray Andraka  <ray@andraka.com> wrote:
>Time has come for a computer upgrade (I'm currently using a dual Athlon 
>1.8GHz with 4GB memory and 15000RPM scsi raid array running Win2K, 
>matrox dual head video with a pair of 19" monitors), but I haven't kept 
>up at all with the computer market.  I'm wondering what people are using 
>these days for high end designs (for simulation and PAR especially).  
>I'd like something that doesn't sound like a vacuum cleaner and heat the 
>room like a space heater this time around too, perhaps I need to 
>consider liquid cooling?  ANy comments would be appreciated.  Yes, I 
>admit I am being lazy.

Performance and not sounding like a vaccume cleaner are going to be
exclusive, you can't do both.

However, a suggestion:  Make sure the computer has DVI output, run a
12' DVI cable, and a long USB cable, and put the space heater in a
closet on the OTHER side of your office, or down in the basement, etc.

The other option, as mentioned, is remote desktop.  But (big but),
putting graphics through the net frankly, uhh, blows.

In terms of architecture, a dual processor Athlon 64 would probably be
better than the dual processor P4: The AMDs have lower memory latency,
and the dual processor system will have 2x the memory bandwidth of a
1 processor system (thanks to the NUMA-ish architecture).

One other option would be a small form factor Shuttle system.  It
won't be as good on P&R as its only single processor, but it will be
quite WHEN you aren't doing P&R.
-- 
Nicholas C. Weaver.  to reply email to "nweaver" at the domain
icsi.berkeley.edu

Article: 85574
Subject: Re: computer upgrade time.
From: nweaver@soda.csua.berkeley.edu (Nicholas Weaver)
Date: Sat, 11 Jun 2005 03:41:24 +0000 (UTC)
Links: << >>  << T >>  << A >>
In article <ngrja1ll0gd4e0f2cmlgcenhvgjrdb4jn8@4ax.com>,
John  Larkin  <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
>Car anti-freeze?

Nah.  Use water-wetter.

It's an anticorrosion agent without the ethylene glycol:
http://www.redlineoil.com/products_coolant.asp
-- 
Nicholas C. Weaver.  to reply email to "nweaver" at the domain
icsi.berkeley.edu



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