( DAC 02 Item 24 ) ---------------------------------------------- [ 9/10/02 ]
Subject: Barcelona, Antrim, Analog DA, NeoLinear, Saber
ANALOG SYNTHESIS: This is a niche within a niche. I overheard an analog
designer at DAC say that he'd never trust anything crafted by an analog
synthesis tool. (He claimed they were just too stupid and he'd be spending
more time cleaning up & fixing these machine generated designs than it was
worth.) This could be an engineer feeling his skill were threatened or a
realistic user gripe. Not being an analog designer, I couldn't tell.
"NeoLinear, ADA, and Antrim essentially share the same pie on analog
synthesis. On the other hand, Barcelona is different by selling their
IP with fixed circuit topology. Although this will find its
application for standard analog blocks, the other three’s real netlist
sizing and simulation based synthesis will provide more value for
analog designs where analog circuit design itself is the major core
competence."
- Weikai Sun of Volterra
"The only two real players in this space are Analog Design Automation
(ADA) and Neolinear who have competing transistor sizing tools. Antrim
and Barcelona's offerings are not in the same biz. Barcelona is
selling IP built with their tools and Antrim provides a design
environment and simulator.
ADA's 'Genius' products seem to be far ahead of Neolinear's NeoCircuit.
The Neolinear products are stuck with just the Cadence simulator, and
ADA can use multiple 3rd party simulators; so you can plug in different
engines like Silvaco/Mentor/etc in addition to Cadence. The Neolinear
tool can not handle as many variables and process corneers as ADA's so
their transistor sizer is a bit limited for trying to do design
re-targeting to 130 nm and 90 nm flows with a lot of process options.
ADA's tradeoff analyzer, I think it is called "IP Explorer" (do not
quite remember) is a lot more robust and easier to use than the one in
NeoCircuit -- since you can light up the tool and get around in it
faster -- it is also faster to pick a good result from faster. I
think the new API that will allow high capacity simulators and other
private branded device simulator engines that ADA is rolling out is
going to make it very hard for NeoLinear as they are betting the farm
on the world of device level being done with Spectra - and I see
people using HPSPICE/ELDO/SmartSPICE/HSIM/StarSim/NanoSim in a lot more
accounts than those still on Cadence - especially in Networking and
wireless markets."
- Pallab Chatterjee of SiliconMap
"The MIT Technical Review did an article on the top 100 young technical
researchers to watch, and I was surprised to see the researcher from
Barcelona in this list. The little bit I've heard about Barcelona
sounds interesting, but I couldn't find out much about it. They don't
have a web site yet."
- John Filion of Theseus
"Last year Barcelona showed some promising things on analog synthesis,
especially the PLL synthesizer. However, I don't have comparison data
with other tools."
- [ An Anon Engineer ]
"We plan to check out Barcelona this year."
- Jay Abel of Shera International
"Now Barcelona, Antrim, Analog DA are tools to watch. Very useful."
- Jai Durgam of SiImage
"32.0 Analog Tools
Tools from Antrim Design and ComCAD take a netlist and produces a sized
netlist. Antrim's tool can take multiple test benches for measuring
your desired specs.
Neolinear takes an input schematic, SPICE models, test benches and
functions to compute an evaluation of each design alternative. One of
their tools sizes the netlist and another actually does layout as well
(it's integrated into Cadence's tool set). The one that does layout is
sold by Cadence. They say STMicro has done 6 designs with their tools
and has noted big gains I efficiency.
Intusoft sells software for automatic test generation for analog and
mixed signal parts. I'm not even sure exactly what that means, but
their literature looks very good."
- John Weiland of Intrinsix
"For example, starting from a fully unsized schematic with about a
hundred of devices, Neolinear's Neocircuit can do the correct sizing
taking into account simultaneous specifications (transient, small
signal, power, noise, corners, or whatever you need.) Moreover, while
Neocircuit is running you can have a look at the variables changes.
You really have the feeling that instead of a mathematical behaviour of
conventional optimisation tool, it has a real physical behaviour that
is much more similar to an analog designer behaviour.
I have personally used Neocircuit for optimisation and sizing of high
speed switched capacitor blocks. The results of the optimisation are
excellent if you CAREFULLY constrain Neocircuit. The main limitation
of Neocircuit is not in the tool itself, but in the ability of the
designer to express pertinent criteria. The other drawback is that the
tool requires high level of workstation power.
In my opinion, Neocircuit is not just an other analog optimisation
tool, it is the first one of a new generation of optimisation tool."
- Stephane Dugalleix of STMicroelectronics
"Neocircuit is a young tool and it needs to be more stable but it
addresses important points: you can size an analog circuit
using the simulator on which your used to using. There are no
particular constraints on the architecture, but it forces you to
adopt a clear methodology that often is lack in the analog design
flow. Neocircuit supports the circuit synthesis in a trasparent way,
leaving the control to the designer and it's easy to collect a lot
of information about the architecture he is working on. Their next
step should be to add a capability to work on hierarchical designs."
- Monia Chiavacci of YogiTech Italy
"For mixed signal designs, Cadence seems to keep their domination and
momentum by introducing more mature Automated Custom Physical Design
flow. With the help from NeoCell by NeoLinear, it clearly stands out
compared to other similar tools like those in Mentor and Avanti."
- Weikai Sun of Volterra
"Our systems designers use Saber to verify designs since our automotive
customers demand it. Models exist for many automotive components so
driving realistic loads is very easy to do in Saber. The simulation
sizes are quite small by IC design standards, but the models usually
take temperature and other environmental factors into account.
Our IC design people also use Saber. We are unique in this regard as
everyone else seems to use Spectre, HSPICE or Mentor-based simulators.
We create our own models (we have our fab with a handful of bipolar,
CMOS and mixed-signal processes). We do a lot of DC, and transient
simulations, with a lot of component altering to perform design
optimization. We do not use any optimization features of Saber.
Our main reasons for Saber:
1. Support of mixed analog and digital simulations using Saber
with Verilog-xl. Although this has worked for some time,
netlisting is difficult and convergence and runtimes are
always an issue.
2. MAST language for modeling allows us to create custom models of
components. At the time (1989), there was no Verilog-A, or
VHDL-AMS, so MAST was great. It is of course proprietary, so
obtaining models is more difficult.
The support for Saber under Analogy was pretty good. They had a good
group of FAEs available to help out. When Avanti bought the company,
lots of FAEs were let go, and support suffered. It is too soon to
tell how Synopsys will support this tool set.
Saber issues:
Although there is some overlap between Saber, HSPICE and now Nanosim,
Saber is different enough IMO to be kept around. The Verias tool has
some grand plans, but so far, it is a VHDL-AMS tool only. It SHOULD
support MAST models to offer a way for Saber customers to use other
model IP, but that seems to be going slowly. In addition, it should
support Verilog-A and/or Verilog-AMS, but who knows when (if) this
will happen."
- [ An Anon Engineer ]
"Our analog groups are using Saber now and seem pretty happy with it.
We don't yet use it much for mixed-mode, analog & digital sims, but
we've demonstrated for ourselves that it works. No analog synthesis
tool use planned AFAIK. For awhile our focus has been to make the
analog as simple and rock solid as we can, and do as much of the
filtering and etc. in the digital side as possible."
- Mark Wroblewski of Cirrus Logic
|
|
