Dear Kicad friends and IC design enthusiasts,
As some may know, I have been working towards an IC RF/analog/ mixed-signal design flow that uses Kicad as the design capture front end. The flow emulates that of commercial tools like Cadence Virtuoso.
I have made an introductory video demonstrating kicad/confirmaXL interaction through the simulation of both a transistor level OTA circuit and a behavioral level mixed signal ROMDAC sinewave generator. Both designs make use of hierarchical symbols & symbol libraries made possible through ConfirmaXL. Three different user selectable spice simulators (topspice, xyce & ngspice) are used, all driven by the same Kicad schematics.
There is still work to do but it is getting closer to public release. It is intended to be free for individual users. The distribution method is still to be determined.
Here is the link to the youtube video (now updated with 25% faster audio as I talk too slow, ha!).
ConfirmaXL IC design with Kicad design capture
Cheers,
Kevin
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Hello @kgfaison i’m in the process of learning ASIC design. Do you have a mailing list I could subscribe to? I did see your latest video update .
How can I get a copy of ConfirmaXL?
Is there anything I could do to help?
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Hi Billy,
Thanks for your interest in ConfirmaXL. I am currently finishing up various details related to the port to the kicad front end. This includes a file manager that handles all the IC related files in addition to the schematic and symbol “views” of the design cells. Also, a generator for auto creation of the hierarchical kicad symbols.
ConfirmaXL utilizes a custom spice hierarchical netlister to enable an IC type design flow with unmodified kicad. That has undergone a lot of testing and is working well.
I am planning to release with simulatable behavioral libraries and perhaps transistor level library examples for multiple spice simulators. If I do this, I need to target a representative foundry process. This could be anything from 22nm to 180nm. Any preference?
I also just put up a web page but the links to download are not setup yet. My thinking is Ill release a 0.8v version. I expect it to be usable as shown in the videos but with some unfinished features disabled.
The web site is www.ucosm.net . Ill put some status updates on there from time to time.
All this take a bit of time of course. BTW, the original version of confirma has been in use for a long time but with a mentor graphics schematic capture. Having kicad available is what makes it possible to release to the public. The flow is very Cadence Virtuoso like if that is what you are used to. The nice thing is you will always have access to your portfolio of designs as no licenses to contend with.
Id be interested in what layout software you prefer. We often used Ledit in addition to what is shown in the video.
As an aside, I enjoyed watching the kicad 2025 expo and the Qspice presentation. Qspice is one of the plugins in ConfirmaXL with Kicad. I was simulating with it just last night!
Definitely stay tuned!
All the best, Kevin
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Thanks Kevin,
I will be watching for updates and releases.
The past six years I was working on digital PCBs and am reading and learning everything I can about Analog / mixed signal IC design. I’m not the best person to weigh in on the foundry process / layout software since I’m just getting into this field.
How do you like Qspice? I’ll have to check it out. So far I’ve used PSPICE and NGSPICE.
That’s great you are interested in AMS IC design. It is an exciting career and pays well also I may add. Your digital PCB experience will be valuable, dont worry. PCB knowhow is important in chip design.
I would definitely encourage you to establish a personal tool flow where you can simulate designs as you learn about them. You will be surprised at the amount of IP you can amass over time. Word of caution, keep reference notes on your schematics to show techniques you are applying are in public domain rather than something that belongs to an employer.
Regarding QSPICE. It seems to offer speed advantages over other spices. Sometimes the syntax does not agree with other simulators I use. This caused problems when I tried to benchmark it on existing designs. I worked through a lot of this about a year ago. And also believe there have been improvements since I last tried it so taking another look.
Another issue is while it has bsim3/4 foundry models it does not read the Hspice style foundry models as they come from tsmc (with the corner model & monte-Carlo) as verified by Mike about a year ago. That may have changed. Topspice, NGspice, Xyce, Smartspice, Golden Gate, Spectre all do.
Qspice does not have smith charts either but my guess it will eventually as Qorvo is an RF company. The topview viewer has smithchart so a work around may be to plot data intended for smithchart from the qspice plotter and then read it into topview. I think that would work.
Anyway, below is a QPSK behavioral RF transceiver captured in KiCad. Random bits are applied to the transmitter and upconverted to RF. The RF then goes into the receiver where downconvertion and carrier recovery take place to enable demodulation of the original bits from the transmitter. The 2nd & 3rd plots from top show the TXI & RXI bits and the TXQ & RXQ bit streams. You want to see the RX match the Tx bits and they do. It is like doing a matlab simulation in the QSPICE simulator. It this was all transistor level this sim would take a long time. Qspice speed improvements would be of great interest in that case.
Regarding PSPICE, we stopped using that after Cadence acquired it and switched the schematics to ocad. I more recently started using NGspice, very encouraged too. I use the topview plot tool to plot the NGspice data. That makes it much easier for me. Even the Topview demo will read it, smith chart and all.
All this spice tools have pro’s and con’s it seems. It is nice to be able to switch between them according to the task at hand. Confirma allowed us to do that at one of my old companies.
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