( ESNUG 426 Item 3 ) -------------------------------------------- [03/31/04]
Subject: Ten Letters On Mentor/Exemplar/Leonardo/Precision
> Scenario 1: Wally's Revenge
>
> Synplicity was founded by ex-Mentor synthesis gurus Ken McElvain and Andy
> Dauman. For Wally Rhines, the CEO of Mentor, it's a wee bit embarrassing
> to have his ex-employees best him in a market that Mentor used to own.
> If it turns out that Synplicity sales really did drop 31% while Mentor
> sales remained steady in FPGA synthesis, Wally gets to laugh as he watches
> Bernie Aronson, the CEO of Synplicity, do his best imitation of the
> Help-I've-Fallen-And-I-Can't-Get-Up lady. Sweet, sweet revenge....
>
> - from http://www.deepchip.com/gadfly/gad031204.html
From: Tom Dillon <tdillon=user domain=dilloneng spot balm>
Hello John,
We're an engineering firm specializing in DSP applications in large FPGAs,
mostly Xilinx Virtex II and Virtex II Pro. We use Precision RTL and
Precision Physical for all our designs.
We reuse our IP in many applications and maintain it in a very generic
format and force the synthesis tools to do all target specific
optimizations. Precision has always done a great job pulling out
memories, multipliers and so on from our source and properly mapping
them to the destination technology. This saves us a considerable amount
of time creating and maintaining our IP.
We can consistently get between 150 MHz and 200 MHz system level clock
rates from our multi-million gate designs without floor planning,
RLOCing and any other time consuming target specific optimizations.
Since we have many designs in process at the same time, ease of use is
very important to us. With Precision we simply add our source files, all
types, including VHDL, Verilog, EDIF and constraint files, select the
top level of the design, and let it run. After synthesis Precision
identifies the worst timing paths allowing us to modify our source to
add pipelines and fix the timing issues. Precision RTL has a retiming
feature that is very useful as it automatically balances logic level
around pipelines in your design.
Some of our designs require Precision Physical to get the last 15% or so
of performance. Again the ease of use is very important to us, our use
of Precision Physical is basically push button, it takes the post place
and route design and squeezes extra performance out of it.
About half of our clients use Synplicity and we find Precision always
outperforms it. We routinely send a post synthesis EDIF file for those
clients to include in their designs so they can get the same performance.
I am not surprised that Mentor has caught Synplicity in the last couple
of years, since Synplicity now has to compete against Precision. We have
always used Exemplar/Mentor synthesis tools but prior to Precision,
Synplicity did have an ease of use advantage which would have caused the
more casual user trouble.
- Tom Dillon
Dillon Engineering, Inc.
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From: Tim Davis <timdavis=user domain=aspenlogic spot balm>
Hi, John,
I've used Leonardo for years now and had great luck with it.
It doesn't crash on me and gives quality results. I have considered
evaluating Synplify now that Mentor is dumping Leonardo (ie not
providing any more feature upgrades) in favor of Precision. But, I paid
up another years worth of maintenance in December and will give it
another year. I may yet switch to Precision but Mentor marketing/sales
has not made a persuasive case for me yet. My past experience (a few
years ago) with Synplify showed that it provided comparable results to
Leonardo but required me to substantially modify my VHDL to get it to
parse. Consequently, I've not found a compelling reason to fork over a
lot of money to switch.
The one powerful capability that Leonardo has is the ability to let the
user traverse and modify the netlist using TCL. New cells, instances,
views and nets can be created using the "create" command. Unfortunately,
Mentor Graphics removed this capability in Precision. That now makes
Precision and Synplify identical in my view. All that is left to compare
is the companies, their level of passion, their support and their
documentation.
If Mentor Graphics put synthesis at the #1 forefront of its capital
spending and gave it the attention that it deserved then Synplicity
would certainly not exist. (Synopsys would have been a fraction of the
size too -- no guts no glory.) Synplicity certainly exists and succeeds
because synthesis is their baby and they take care of it. If Mentor
Graphics had kept Leonardo in the Exemplar division, gave it the
autonomy that Modeltech enjoys then it to would have risen to greatness,
Ken would have never left Mentor and Synplicity would not exist.
- Tim Davis
Aspen Logic, Inc.
---- ---- ---- ---- ---- ---- ----
From: [ An Anon Engineer ]
John,
Please keep me anon.
I don't think it happened in 2002 at my company, but instead in 2003, we
actually increased the number of Precision licenses while decreasing the
number of Synplify Pro licenses.
This isn't because we use Precision yet, only because we are locked into
a multi-year license agreement with Mentor. So we stopped maintenance on
most of our Synplify licenses and in the Mentor license re-mix, added some
Precision licenses. We have yet to use those Precision licenses.
- [ An Anon Engineer ]
---- ---- ---- ---- ---- ---- ----
From: Wilhelm Diesch <wilhelm.diesch=user domain=siemens spot balm>
Hello John,
Yes, we are using Mentor's Precision-RTL successfully. Almost one
and a half year now.
- Wilhelm Diesch
Siemens AG Munich, Germany
---- ---- ---- ---- ---- ---- ----
From: Nikolaus Demharter <nikolaus.demharter=user domain=siemens spot balm>
Yes, I am using Precision RTL and Precision Physical successfully since
Summer 2003 even if the software needed some fixes back then.
- Nikolaus Demahrter
Siemens Medical Erlangen, Germany
---- ---- ---- ---- ---- ---- ----
From: [ An Anon Engineer ]
John,
Our company location has been using Exemplar FPGA synthesis since the
mid-90's. We bought it as a stand alone tool, not part of a suite. We
have been very satisfied with its performance when used to synthesize
VHDL RTL to Xilinx target devices. The devices most commonly used have
been the Virtex, Virtex-E, Virtex2, and Virtex2-PRO devices.
We have conducted evaluations using Synplicity, but have not found a
compelling reason to change from Exemplar.
- [ An Anon Engineer ]
---- ---- ---- ---- ---- ---- ----
From: Thomas Zerrer <thomas.zerrer=user domain=pe-gmbh spot balm>
Hi John,
We are on Mentor since 2001. For synthesis we use Leonardo Spectrum 2002
Level 3 ASIC and FPGA with great success. We are not under maintenance
anymore to save this money for a new tool in 2005/2006. In 2002 we made
several comparisons with Synplify (V7.2) and found out the following:
a) Synplify is faster in optimization, no doubt, I guess 50%
b) Memory inference works for both tools. We tried dual port and single
port. Leonardo 2002 had major improvements here, so there shouldn't
be a great difference. Both Tools struggle when you need a true
DPRAM where both ports can write. Instantiation is needed.
c) In my opinion Leonardo has 4 advantages:
1. Better TCL Scripting support
2. Better for Retargeting of designs
3. One tool for FPGAs and ASICs
4. schematic viewing was better at this time
5. Broader VHDL language support (try a shifter with the shiftcount
determined by a signal!)
For Precision we have no experience, but we think the following 2 drawbacks
are eliminated:
1. Register Retiming supported
2. Better Timing reports due to new timing analyzer, support for several
clock domains (related and unrelated)
3. timing driven synthesis
Best Regards,
- Thomas Zerrer
PE-GmbH Herrenberg, Germany
---- ---- ---- ---- ---- ---- ----
From: [ An Anon Engineer ]
Hi John,
Please keep me anonymous.
We use Mentor FPGA tools. Historically we have always used Leonardo, and are
currently in the process of upgrading to Precision.
I believe we have the tools as part of a ModelTech package deal, making them
attractive from a cost point of view. We do use the tools extensively and we
are able to do everything we need to (in Leonardo anyway - Precision is
another story).
We haven't done any kind of in depth comparison against other tools, as
Mentors tools are satisfactory from a cost against performance perspective.
- [ An Anon Engineer ]
---- ---- ---- ---- ---- ---- ----
From: Bob Collins <rac=user domain=appsig spot balm>
John,
We are currently using Leonardo levels 2 and 3 and are looking at Precision.
We've been using, and buying more seats of the Exemplar tools for about 10
years and they have met our needs. We have not done a recent comparision
with Synplicity, but our last comparision showed that the differences were
not enough to change our process.
- Bob Collins
---- ---- ---- ---- ---- ---- ----
From: [ An Anon Engineer ]
John,
Per your request, the following Exemplar/Leonardo Spectrum tool thoughts
are offered. Please keep my opinion anonymous.
We've used the Exemplar synthesis tool virtually from its inception
(remember Exemplar CORE in the early 90's?) through all its various
incarnations (now Mentor's Leonardo Spectrum). The original switch to
Exemplar was made due to less-than-optimal FPGA synthesis results being
obtained with the Synopsys alternative, not to mention, what was then, an
enormous sale and maintenance price delta between these two legacy synthesis
tools. Our FPGA design complexities have spanned virtually the entire
spectrum ranging from quite simple CPLD designs to multi-million gate
modulator/demodulator designs. That being said, on average, these designs
tend to incorporate more "straight-forward" control logic sporting
low-to-modest speed interfaces, e.g. 1 MHz to 125 MHz data rates. A brief
sampling of targeted FPGA families would include Xilinx Virtex-II, Virtex-E,
Spartan-II, CoolRunner, Actel ProASIC Plus and various Altera CPLD families.
Synthesis of such control-centric FPGA designs typically does not represent
a major hurdle to present day synthesis tool algorithms.
Leonardo Spectrum has met our FPGA synthesis demands quite well and the tool
has been relatively easy to use. Still, all indications I've received from
various demos, trade magazines, benchmark data and designers at DAC would
drive me to take a very close look at Synplicity's offerings and definitely
benchmark these two tools should a synthesis tool purchase opportunity
arise.
- [ An Anon Engineer ]
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