EP1C12 or XC3S400?

Hi,

I've seen this prototype board from Altium that seems to have a very good 
price: http://www.altium.com/livedesign/
It comes in two flavours: one with an Altera Cyclone series EP1C12F324C8 and 
the other one with a Xilinx Spartand 3 XC3S400-4F456C. Both options have the 
same price of $99. Besides the FPGA, the both kits are exactly the same 
thing.
My question is which one to select? Personally, I'd rather select the BIGGER 
one but I don't know which one it is. I know it is very difficult to compare 
the SIZE of two FPGAs with very different architectures.
I used to compare the total number of the programmable flipflops in the 
FPGAs as my index. (it can be discussed if it is indeed a good index or not, 
but I think for syncronous and NORMAL designs this is much better than fuzzy 
things like system gates etc.). It seems that EP1C12 has much more FFs in 
the programable sections than XC3S400.
So what do you think? Do you think EP1C12 is bigger than XC3S400? For 
designs that would be more of DSP type which one is better? And what for 
designs with a small processor inside?
Well, one option is to buy both of them as you can easily cascade them an 
use them together in peace :)

Regards
Arash

Hi Arash,

> It comes in two flavours: one with an Altera Cyclone series EP1C12F324C8
and
> the other one with a Xilinx Spartand 3 XC3S400-4F456C. Both options have
the
> same price of $99. Besides the FPGA, the both kits are exactly the same
> thing.
> My question is which one to select? Personally, I'd rather select the
BIGGER
> one but I don't know which one it is. I know it is very difficult to
compare
> the SIZE of two FPGAs with very different architectures.

The Cyclone 1C12 (www.altera.com/cyclone) has 12060 logic elements (4-LUT +
FF + goo).  In addition, we believe our LE is more efficient than Xilinx's
logic element based on benchmarking results of how much we can pack into
ours; I can't find the stats right now by memory tells me we believe there
is a ~10% difference in packing density.  The XC3S400 has 8,064 "logic
cells", or in other words 7168 4-LUT + FF + different goo blocks (Xilinx
inflates by 12.5% for random marketing reasons).  So as you can see there is
a large difference in logic capacity.

The XC3S400 has embedded multipliers, which the 1C12 does not, so if you
require substantial multiplication then some of the logic difference will be
consumed for multiplication.  It also depends on how large the multipliers
are that you need, what speed you need to run them, and what latency you
require -- there are solutions involving "soft multipliers" that allow you
to use M4K RAM blocks as multipliers if need be.

Speed may also be a consideration.  In general, Cyclone is faster than
Spartan-3; see www.altera.com/switch for benchmarking results, and be sure
to search this newsgroup for Steve (from Xilinx)'s responses to these
claims.  Note that the two devices offered on the dev board in question are
both the slowest speed grade offered in the two respective families.

As far as processors go, both companies offer embedded soft processor
solutions.  Altera's Nios core was the first soft-processor solution
available and has a large user base and mature, robust development tools.
Nios II is the next-generation version of this core and offers improve
capabilities and performance.  Please see www.altera.com/nios for more
information.

You can try out both devices using the freely available software available
from both companies.  Our Quratus II Web Edition software
(http://www.altera.com/products/software/products/quartus2web/sof-quarwebmai
n.html) fully supports Cyclone.  If you have a design in mind, try it out on
both and see which software and which chip you like.

Regards,

Paul Leventis
Altera Corp.

"Paul Leventis (at home)" wrote:
> 
> Hi Arash,
> 
> > It comes in two flavours: one with an Altera Cyclone series EP1C12F324C8
> and
> > the other one with a Xilinx Spartand 3 XC3S400-4F456C. Both options have
> the
> > same price of $99. Besides the FPGA, the both kits are exactly the same
> > thing.
> > My question is which one to select? Personally, I'd rather select the
> BIGGER
> > one but I don't know which one it is. I know it is very difficult to
> compare
> > the SIZE of two FPGAs with very different architectures.

I looked at the Altium site and did not find the Spartan 3 modules you
describe.  Did you get this info directly from the sales people? 

But keep in mind that there are other issues than just size or even the
hardware.  You should download the free versions of the software from
each company and run them a bit to get a feel for them.  You can do a
*lot* of work with FPGAs without ever using hardware.  One significant
difference is that the Altera sofware does not include an HDL
simulator.  It has a gate level simulator, so you can't run a test bench
if I am not mistaken.  You have to generate a waveform stimulus file
instead which is much less flexible and portable. 


> The Cyclone 1C12 (www.altera.com/cyclone) has 12060 logic elements (4-LUT +
> FF + goo).  In addition, we believe our LE is more efficient than Xilinx's
> logic element based on benchmarking results of how much we can pack into
> ours; I can't find the stats right now by memory tells me we believe there
> is a ~10% difference in packing density.  The XC3S400 has 8,064 "logic
> cells", or in other words 7168 4-LUT + FF + different goo blocks (Xilinx
> inflates by 12.5% for random marketing reasons).  So as you can see there is
> a large difference in logic capacity.

The odd thing is that in the V2P data sheet they even *define* what a
logic cell is "Logic Cell = (1) 4-input LUT + (1)FF + Carry Logic" and
they *STILL* inflate the count by 12.5%.  I wonder why they bother to
define logic cells if they are not going to count them.  


-- 

Rick "rickman" Collins

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

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

"rickman" <spamgoeshere4@yahoo.com> wrote in message 
news:416CB979.EC57FD01@yahoo.com...
> I looked at the Altium site and did not find the Spartan 3 modules you
> describe.  Did you get this info directly from the sales people?
>
No, I found the information in the altium website. It seems they have just 
recently modified the evaluation package and now offer it with Spartan 3. 
Here is the online order form with the part number of the FPGAs on board. 
http://www.altium.com/evaluation/
It seems that the original offer included BOTH Xilinx and Altera's FPGAs (in 
the form of daugther boards) but the new one comes separately.

> But keep in mind that there are other issues than just size or even the
> hardware.  You should download the free versions of the software from
> each company and run them a bit to get a feel for them.  You can do a
> *lot* of work with FPGAs without ever using hardware.  One significant
> difference is that the Altera sofware does not include an HDL
> simulator.  It has a gate level simulator, so you can't run a test bench
> if I am not mistaken.  You have to generate a waveform stimulus file
> instead which is much less flexible and portable.
>

Thanks. Yes that's the way to go. The point is that it is now round 3 years 
that I have not done any new designs using FPGAs but before that (in the 
Altera's 10K and 20K age!) I used to work actively with both Altera and 
Xilinx. So basically I know the toolsets quite well but I have never used 
Cyclone or Spartan and that's why I was wondering.
Simulator in the Quartus or ISE is not that important for me. I have yet an 
older version (but a full version!) of ModelSim and I think even though it 
is old, yet it is much better of any offerings from Altera or Xilinx. At 
least I can use the full potentials of VHDL and also interface to C codes 
and much more. 

Arash Salarian wrote:
> Thanks. Yes that's the way to go. The point is that it is now round 3 years 
> that I have not done any new designs using FPGAs but before that (in the 
> Altera's 10K and 20K age!) I used to work actively with both Altera and 
> Xilinx. So basically I know the toolsets quite well but I have never used 
> Cyclone or Spartan and that's why I was wondering.
> Simulator in the Quartus or ISE is not that important for me. I have yet an 
> older version (but a full version!) of ModelSim and I think even though it 
> is old, yet it is much better of any offerings from Altera or Xilinx. At 
> least I can use the full potentials of VHDL and also interface to C codes 
> and much more. 

There are free options as well.  I'm very happy with Icarus Verilog, 
which suits my workstyle much better than a slow GUI.

Tommy

"Paul Leventis (at home)" <paulleventis-news@yahoo.ca> wrote in message 
news:5t2dnaO327O9DfHcRVn-jg@rogers.com...
>
> The Cyclone 1C12 (www.altera.com/cyclone) has 12060 logic elements (4-LUT 
> +
> FF + goo).  In addition, we believe our LE is more efficient than Xilinx's
> logic element based on benchmarking results of how much we can pack into
> ours; I can't find the stats right now by memory tells me we believe there
> is a ~10% difference in packing density.  The XC3S400 has 8,064 "logic
> cells", or in other words 7168 4-LUT + FF + different goo blocks (Xilinx
> inflates by 12.5% for random marketing reasons).  So as you can see there 
> is
> a large difference in logic capacity.
Thanks for the info Paul. As I see the Xilinx datasheet says 896 CLB. Each 
CLB is four slices and each slice has 2 FF so 896*4*2=7168. Hmmmm, it seems 
my logic of only counting the embedded flipflops works :) Well It seems that 
the EP1C12 is indeed much BIGGER than XC3S400. Your point about the 
multipliers in the Spartan is also interesting. But the fact is that I need 
a board for prototyping and only God knows what I will try on it so I can't 
predict how many times I'll need a multiplier or not (sometimes I do DSP 
designs but not all DSP designs need full multipliers) ant thats why having 
more LEs (or FFs or CLBs or anything) is more important to me.

Just one more question. I remember that in the 10K series (yes, I'm an old 
guy!) the block RAM (EAB?) could also work in a fully asyncronous mode while 
the Xilinx devices at that time did not have this feature (and I used it a 
lot!). Is it the same for Cyclone and Spartan? Does Cyclone supports fully 
async block RAM while Spartan does not?

Regards
Arash 

"Tommy Thorn" <foobar@nowhere.void> wrote in message 
news:AD4bd.17169$54.287148@typhoon.sonic.net...
> Arash Salarian wrote:
>> Thanks. Yes that's the way to go. The point is that it is now round 3 
>> years that I have not done any new designs using FPGAs but before that 
>> (in the Altera's 10K and 20K age!) I used to work actively with both 
>> Altera and Xilinx. So basically I know the toolsets quite well but I have 
>> never used Cyclone or Spartan and that's why I was wondering.
>> Simulator in the Quartus or ISE is not that important for me. I have yet 
>> an older version (but a full version!) of ModelSim and I think even 
>> though it is old, yet it is much better of any offerings from Altera or 
>> Xilinx. At least I can use the full potentials of VHDL and also interface 
>> to C codes and much more.
>
> There are free options as well.  I'm very happy with Icarus Verilog, which 
> suits my workstyle much better than a slow GUI.
>
Well, I've never used Icarus before (maybe because I design most of the time 
in VHDL not in Verilog). But as I see Icarus does not have a waveform view 
(which can be very useful when dealing with complex timings) and also I 
won't call ModelSim a "slow GUI". As far as I know ModelSim is yet one of 
the fastest simulators in the industry and if you don't like GUI, you can 
use almost all of it from command line. In fact you need to do it as 
ModelSim's GUI is just a very thin layer of TCL over the command line tools 
so for any serious job you should write you own scripts. Also I use the code 
coverage tool and the debug mode of the ModelSim quite a lot and I don't 
know if Icarus has the same features or not (I could not find much info in 
the Icarus website). 

A word of caution here:

Altium or Protel as it was called is a PCB software company... Nextar is
their FPGA development tools and both of these boards are designed to use
Altium's software.  As such support outside this simple parameter will be
non existent.

Simon


"Arash Salarian" <arash.salarian@epfl.ch> wrote in message
news:416bf9fb$1@epflnews.epfl.ch...
> Hi,
>
> I've seen this prototype board from Altium that seems to have a very good
> price: http://www.altium.com/livedesign/
> It comes in two flavours: one with an Altera Cyclone series EP1C12F324C8
and
> the other one with a Xilinx Spartand 3 XC3S400-4F456C. Both options have
the
> same price of $99. Besides the FPGA, the both kits are exactly the same
> thing.
> My question is which one to select? Personally, I'd rather select the
BIGGER
> one but I don't know which one it is. I know it is very difficult to
compare
> the SIZE of two FPGAs with very different architectures.
> I used to compare the total number of the programmable flipflops in the
> FPGAs as my index. (it can be discussed if it is indeed a good index or
not,
> but I think for syncronous and NORMAL designs this is much better than
fuzzy
> things like system gates etc.). It seems that EP1C12 has much more FFs in
> the programable sections than XC3S400.
> So what do you think? Do you think EP1C12 is bigger than XC3S400? For
> designs that would be more of DSP type which one is better? And what for
> designs with a small processor inside?
> Well, one option is to buy both of them as you can easily cascade them an
> use them together in peace :)
>
> Regards
> Arash
>
>

Arash Salarian <arash.salarian@epfl.ch> wrote:
: Well, I've never used Icarus before (maybe because I design most of the time 
: in VHDL not in Verilog). But as I see Icarus does not have a waveform view 
: (which can be very useful when dealing with complex timings) and also I 
Icarus is a simulator. For waveform viewing there are other options, like
gtkview or dinotrace. 

Bye

-- 
Uwe Bonnes                bon@elektron.ikp.physik.tu-darmstadt.de

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

"Simon Peacock" <nowhere@to.be.found> wrote in message 
news:416ce1d3@news.actrix.gen.nz...
>A word of caution here:
>
> Altium or Protel as it was called is a PCB software company... Nextar is
> their FPGA development tools and both of these boards are designed to use
> Altium's software.  As such support outside this simple parameter will be
> non existent.

Actually they are now gearing towards more integrated solutions and from 
Protel 99, they used to have a Schematics/PLD/Spice/PCB solution in one 
package so FPGAs are the next logical step.
About the limitations of the evaluation board, as you can see from the 
specs, it supports a normal JTAG interface (using the PC's parallel 
port)that can be used with both Quartus and ISE so there is no problem with 
it if you don't want to use the Altium products for the development. So to 
me, it's just another FPGA prototype board as the others but with a bit 
better price/(density*features).

I myself, used to do my PCBs with Protel (and do the autorouting with 
SPECCTRA) so for me the new FPGA support in the Protel (or Nextar) is 
interesting and I may switch back to Protel in near future again. I don't 
think I'll use Protel/Nextar to actually design/simulate my FPGA based 
designs, but the changes in Schematics/PCB design programs to support FPGA 
based designs are attractive (like handling the pin-assignments based on the 
constrains of the PCB. Try to assign the pins manually for a 700+ pin BGA 
and see what I mean). Also they have a mixed signal simulator which can be 
sometimes useful if you need to mix analog/digital in the same board though 
I'm sure for pure digital simulation, my old trusty ModelSim is much better.