A brief look at silicon
Through the recent announcement that GlobalFoundaries joined Google's open source silicon initiative, that Google had an open source silicon initiative. It turns out that Google wants to be what GNU was for FOSS, except for silicon. Furthermore they are funding some people to make chips of their own.
Coming at this in a somewhat backwards way we're going to look at the tooling that is used for silicon design, and hopefully work backwards from there.
Google maintains a handful of process design kits (PDKs). A PDK is a set of files used within the industry ^1. A typical PDK has a primitive device library, verification decks, technology data, rule files, simulation models of primitive device, and design rule manual.
The SkyWater Open Source PDK is a PDK that targets the SKY130 process node at the moment. Though, they are saying if this goes well then more advanced nodes will be developed. They currently have an experimental preview. Currently they have documentation, electronic design automation(EDA) tool with multiple files supported, primitive cell libraries and models for analog designs, multiple digital cell libraries, and they also have multiple examples.^2
Similarly the GlobalFoundries GF180MCU is an open source PDK that enable designs to be manufactured for their GF180MCU process node. They currently have an experimental preview. Briefly looking at the docs, it seems like they have some analog, digital, and physical verification.^3
