Choice of FPGA device

"Paul Leventis (at home)" wrote:
> 
> The Quartus II Web Edition is almost fully-featured when it comes to
> push-button place & route.  Web Edition provides all synthesis & fitter
> options intended for optimizing design performance and/or area, with the
> exception of the physical synthesis options.  Physical synthesis can be a
> huge boost on many designs (10-15%?), so its ommision is a bit of a downside
> to using the Web Edition.  It may be included in a future edition of the
> product.

Is physical synthesis supported for the ACEX 1K devices?  I don't know
if it will improve the logic synthesis since I have done a lot of hand
optimization using specific 4 input equations and "keep" attributes to
control the mapping to LUTs.  But I find the routing is not very optimal
(likely from poor placement) and I expect it could shave some 10% off my
worst case paths (~20 nS) if that could be dealt with.  

Is physical synthesis available for the 1K50 part and will this help my
design?  

-- 

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

The next version of the Quartus II Web Edition will support physical 
synthesis for the Stratix, Cyclone, Stratix II, Cyclone II and Max II 
families.

Hope this helps.

- Subroto Datta
Altera Corp.


"rickman" <spamgoeshere4@yahoo.com> wrote in message 
news:41A8F514.E2E1C1BA@yahoo.com...
> "Paul Leventis (at home)" wrote:
>>
>> The Quartus II Web Edition is almost fully-featured when it comes to
>> push-button place & route.  Web Edition provides all synthesis & fitter
>> options intended for optimizing design performance and/or area, with the
>> exception of the physical synthesis options.  Physical synthesis can be a
>> huge boost on many designs (10-15%?), so its ommision is a bit of a 
>> downside
>> to using the Web Edition.  It may be included in a future edition of the
>> product.
>
> Is physical synthesis supported for the ACEX 1K devices?  I don't know
> if it will improve the logic synthesis since I have done a lot of hand
> optimization using specific 4 input equations and "keep" attributes to
> control the mapping to LUTs.  But I find the routing is not very optimal
> (likely from poor placement) and I expect it could shave some 10% off my
> worst case paths (~20 nS) if that could be dealt with.
>
> Is physical synthesis available for the 1K50 part and will this help my
> design?
>
> -- 
>
> 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 

"Hal Murray" <hmurray@suespammers.org> wrote in message
news:W6idnWZS49YksjXcRVn-jg@megapath.net...
> >So my advice to someone is write your code using no built in libraries..
> >then compile using free tools on both... look at the speeds, delays
etc...
> >is it what you want ? is it everything you need ?  Do both manufacturers
> >work ?
>
> Anybody have a rule-of-thumb on how much performance you give up if
> you don't tweak your code to take advantage of a vendor's
> features/quirks?  (both software and hardware)

I've never seen a performance difference... but we use synplify.  There is a
unit size penalty... the hard coded routines have better optimisation.  but
thats not important... Follow the software rule.  Don't use machine code
until you have too.  theres no point unless your running against the wire or
its a specific routine but thats what subroutines are for... even hardware
can have a 'hardware' ('vendor') abstraction layer.

> Are the free tools appropriate if we are discussing volumes big enough
> to be worth arguing about?
>

Free tools are just a place to start.. if you are considering big volume
then you will have simplify, mentor or something similar... in which case it
is the same code for both.

Simon Peacock wrote:

> I've never seen a performance difference... but we use synplify.

I agree. I use mentor leonardo and quartus.

> Free tools are just a place to start.. if you are considering big volume
> then you will have simplify, mentor or something similar... in which case it
> is the same code for both.

I run a test synthesis on all brand A code with quartus.
It works quite well in recent releases.
However simplify or mentor tools make it easier to
choose devices or verify code as portable.

      -- Mike Treseler