Preview - New RF-AMS chip design/simulation/layout flow, ConfirmaXL with Kicad - Page 1
Forum section: electronics / general

author: RFdesigner
author_rank: Newbie
timestamp: April 11, 2025, 07:14:19 pm
content: Greeting EE, RF/uW and IC design enthusiasts.I've been working on a Cadence/Mentor like chip design flow based on an assemblage of 3rd party point tools together with a lot of custom software. It is called ConfirmaXL. It uses the very popular Kicad PCB tool for front end design capture. Standard Kicad has been greatly extended to allow hierarchical design similar to Cadence virtuoso and as required for IC design. Multi-bit busses and sharable hierarchical symbols and libraries are supported.A variety of free and paid spice simulators (topspice, ngspice, xyce, smartspice, etc) may be plugged into the framework without changing the design flow. A variety of IC layout software of the users choosing (LASI, Ledit, Klayout, etc) may also be plugged in. The software is not quite ready for release but is getting very close now. Confirma is suitable for individual designers, multi engineer design teams and university research teams. Although in use for many years, this will be the first version released to the public. It is intended to be free or near free for personal use. It is currently undergoing extensive testing and code polishing to ensure high quality and ease of use. The distribution method is still TBD (suggestions about this are very welcome).This first video runs about 23 minutes and shows operation using a 180nm CMOS OTA and a behavioral ROMDAC as examples. Simulations with topspice, xyce and ngspice are shown with all being driven from the same set of schematics.Thanks for your interest, Kevin!https://youtu.be/1_a0Tpsoubs?si=xv_XnIJFN55fMVBO

author: Uky
author_rank: Regular Contributor
timestamp: April 12, 2025, 10:07:47 am
content: Watched the video.Impressed!

author: RFdesigner
author_rank: Newbie
timestamp: April 12, 2025, 04:53:30 pm
content: Thank you for your kind reply.I hope to be able to distribute Confirma very soon. A lot of attention is currently being paid to ease of use. At the moment I am working on a file manager that allows easy copying of test benches, schematics and symbols along with simulator settings across design folders & projects. Something similar as to what you might see in Cadence IC tools.Also running ever larger circuits and subsystems to see if I can break the flow. The hierarchical netlisting in kicad is the main focus of testing at this point... so far so good! Also working on documentation, always important.There are synthesis tools also coming. Things like pll/synthesizer design aids, filter design, logic & transistor level synthesis, all coming but likely in a 2nd wave.Seems I may have to set up a web page for people to gain access. It will be free or near free but is not technically open source. I am finding that not being "open source" locks me out of some free hosting options it appears.Thanks again!Kevin

author: Uky
author_rank: Regular Contributor
timestamp: April 13, 2025, 06:51:14 pm
content: University of Uppsala, Sweden is using free/open software(s) in MSCEE classesfor IC design. (*) Together with some free/open PDK, students can get aquaintedwith software for IC design. If ConformaXL has any place in this I do not knowbut at least you are not alone in trying to create/compile software that accomplishsimilar things.I myself is a RF guy. Not anymore enjoying free access to the (very) expenceive softwareslike Keysight ADS that my employer had the posibility to provide, I try to use Qucs (RF simulator) formy hobby needs.I have been using Cadence Allegro for 25+ years and as the number of customers are shrinkingI am seriously considering moving over to KiCAD. This software has been improving over the yearsnow with some features rivalling those of Cadence and Mentor (Siemens). IMO, there is no better free softwaretoday than KiCAD. Your efforts will have the potential to add to its popularity.(ETN magazine, Sept. 2024 pp 12-13)

author: djsb
author_rank: Super Contributor
timestamp: April 13, 2025, 08:44:05 pm
content: How much of your development efforts will be contributed back to the KiCad project to benefit everyone? Is EVERYTHING you are working on open source? Or just certain parts of your work? Thanks.

author: RFdesigner
author_rank: Newbie
timestamp: April 13, 2025, 11:16:39 pm
content: Hey, thanks for the tip. I will look at what's happening there. While I have access to some pdks, I need to port my examples to open pdks so people can run them without licensing concerns.I am same boat regarding to rf/uW tools. I still have MMICAD running on a XP virtual machine. It is great software but company, optotek, is no longer in existence. I also have a licensed copy of Keysite Golden Gate. It is also great software but my version is old now. I run that on a Linux VM. I run both from confirma by converting spice netlists (to mmicad & spectre for GG). All the old RF tool vendors have been acquired and have gone up-market making accessibility a big problem.Before getting into Si IC design I did GaAs MMIC's and distributed element RF design on pcb's. RF is also one of my targets in this project. Using standard spice simulators with Confirma & RF test benches you can do s-parameter based amplifier design. So s-params, K, Gmax, simultaneous match is all possible. I will attach an example of an RF amp using this methodology to this message, all created in Confirma/Kicad. Also, distributed element filters. I have assembled microstrip models to run in spice... mlin, mtee, mcross, mbend, etc. I use mmicad to validate the rf models I come up with in confirma. So yes, rf & uwave are also a priority.The kicad schematics works very well. I have not done any pcb layout work myself but many great examples are out there. The main limitation for me was no hierarchical symbols or hierarchical symbol libraries as you need for IC design and for multi-engineer project teams. Multipin buses and correct parameter passing through the hierarchy was also an issue. Plus I cant be locked into just NGspice as good as it is. BTW. the previous version of Confirma used Mentor Dx designer for capture. All the best! Kevin

author: RFdesigner
author_rank: Newbie
timestamp: April 13, 2025, 11:30:55 pm
content: Quote from: djsb on April 13, 2025, 08:44:05 pmWell, my plan at this point is to make Confirma available for free. If you are a kicad user interested in IC or RF design then that in itself would be considerable benefit I would think.Regarding open source, nothing I am working on is open source. I'm already pretty busy and don't think I have the energy or desire to manage an open source project. Kiddo's to those that do!