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The topic of this short video is How to Get the Models You Need From Your IC Vendors.
My name is Colin Warwick, signal integrity product manager for Agilent EEsof EDA. The
agenda is the IC vendors’ dilemma: how to share information with you, and yet protect
the IP. I’ll go over the pros and cons of various tools to do this. I’ll demonstrate
the software for model creators and the model users. And we’ll do some summary and resources.
So, the IC vendors’ dilemma is: how do they share a simulatable model with you, the prospective
OEM customer, to show how the IC will work in your design? And yet, they also want to
protect their IP. The solution, of course, is encrypted models. You, the OEM, can run
the black box, but not see inside the box.
For this presentation, I’m going to assume the IC vendor’s design is in the form of
a textual net list in the HSPICE dialective space. This is the most common case. ADS can
actually encrypt other dialects and languages too, and most of the steps are the same. Tech
support can walk you through any differences, if the design is in some other form.
So, assuming your vendor’s model is an HSPICE net list, you have three options to get hold
of it, as shown in this table. Unencrypted HSPICE is our HSPICE compatibility flow. You
can run that in the ADS Transient Convolution license. This is faster and more flexible
than co-simulation. Unfortunately, the IC vendor is probably unwilling to expose the
IP in this format.
So, the second option is the HSPICE encrypted with Agilent Encryption Key. I just wanted
to demonstrate today. Again, this is our HSPICE compatibility flow – same license and the
same advantages. The con here is you may have to dodge the IC vendor to encrypt the HSPICE
net list with the Agilent Encryption Key. That’s the purpose of today’s video.
There is actually a third option, which is to run the HSPICE net list encrypted with
Synopsys’s encryption key. This is our so-called encrypted SPICE flow. You’ll need the ADS
Transient Convolution license and also a Synopsys HSPICE license; because we’re going to do
co-simulation, in this case. The models are widely available already. But you do have
the co-simulation overhead, and there are some restrictions in co-simulating with HSPICE
and ADS. For example, Ptolemy is not available.
So, I strongly recommend this second option, which is what I’ll demonstrate today. So,
these are the steps the IC vendor will go through to get you the models you need. First
of all, go to our website: Agilent.com. Find EEsof Support and go to the Knowledge Center.
There, you’ll find the download section for ADS. On the download page, you’ll need
three things: the binaries for ADS for your platform, the binaries for RFIP Encoder for
your platform, and this trial license.
The IP encoder’s got kind of a strange name. It’s actually much more general than RF
circuitry. It encodes any kind of ADS project. The name’s kind of a legacy name. The reason
why the binaries are separate is because of export restrictions. So, you download those
two binaries.
Then you fill out this form to get the evaluation license. The ADS Installer walks you through
the installation procedure. And you have to put the license in the license folder. And
then you can fire up ADS and create a new project. I’ll give it a name.
I’m going to call this one “Staging,” just because it’s the staging area for our
encryption project. I don’t need any help for this particular project. So, this opens
a design window. Just expand that a little bit. Now, I’ll go into this Tools menu here
and pick the HSPICE Compatibility Component Wizard. I’ll browse through my HSPICE file,
wherever it is on the network.
I can view the HSPICE space – make sure I’ve got the right file here. Give it a
name. I’ll just call it Flipflop, in this case.
Now we need to expose some of the nodes in the symbol. And these have to be in numerical
order, so I’m going to put these in the correct order – PIN1, PIN2, and so on. Actually,
I need to make – the VSS is actually PIN3. We’ll move it up. You can reorder them,
if you need to. It’ll give you some information about the symbol. You can take the default
symbol or generate a custom symbol, if you want to do some branding. You can put a bitmap
on the symbol. I’ll just take the default.
You’re also passing parameters in the ADS design into the HSPICE net list. For example,
if you have poles and zeroes for equalizer settings or something like that. In my case,
I don’t have any parameters, so I can just leave that blank. And then I’m done. I’ll
just click Finish and drop the symbol into my blank design. Now normally, you could use
this symbol as is.
But in my case, I want to encrypt it, so I have to put ports on the design. And I have
to put them on in the order of the PINs. So, just bear in mind you always start top left
and work your way around counterclockwise. Just put the PINs on and tie these up later.
I’m going to rotate these PINs – make them neat. So, after neatening up the PINs,
we’re going to save this. Give it a name – maybe the name of the chip part number
or something like that would be meaningful.
Now we’re going to run another tool – the Encode Design tool. This will close all
the windows, so make sure you’ve saved everything. It opens up this dialog box. We want to encode
this design. You can put a bitmap on top of it, if you want to do some branding. You can
make the DC nodes visible, if you like. That’s optional. You can do it on a case-by-case
basis or globally.
Give it a meaningful name, because this will appear in a customer’s browser window, and
so you don’t want it to conflict with other libraries. And also, you want it to be easily
identifiable. So, just put your company name or something like that. Put some description
here. You want to encrypt it as a ZIP file. Provide your name, so they’ll know where
the library has come from, and encode it.
The encoding process may take a few seconds; if it’s a very large file, it may take several
minutes. But we have encoded some very large designs, including the Altera Stratix II transceiver.
So, that’s actually it. As mentioned in that log file, the design kit’s written
to this ZIP file here, and you could distribute that encrypted file to the customers. But
I recommend that you do some verification before distribution. I’ll show you how to
do that now.