fa23-si/talk.md

- [The State of Open Silicon](#the-state-of-open-silicon)
- [Talk Outline](#talk-outline)
- [About Me](#about-me)
- [What does it mean for silicon to be "Open"?](#what-does-it-mean-for-silicon-to-be-open)
  - [Levels of "open"](#levels-of-open)
  - [Parts of chip design](#parts-of-chip-design)
  - [Process Design Kit](#process-design-kit)
  - [Intellectual Property / Libraries](#intellectual-property--libraries)
  - [Digital design (In The Beginning)](#digital-design-in-the-beginning)
  - [Digital logic overview (Today)](#digital-logic-overview-today)
  - [How can we use standard cells?](#how-can-we-use-standard-cells)
  - [Tooling](#tooling)
  - [End-to-end runs take weeks or months](#end-to-end-runs-take-weeks-or-months)
  - [Method to tape out](#method-to-tape-out)
- [Where are we now (in open source)?](#where-are-we-now-in-open-source)
  - [Things are looking pretty good](#things-are-looking-pretty-good)
  - [End-to-end tool flow possible](#end-to-end-tool-flow-possible)
  - [Open PDKs](#open-pdks)
  - [Available IP](#available-ip)
  - [Standard cells](#standard-cells)
  - [What about tooling?](#what-about-tooling)
  - [Hardware synthesis](#hardware-synthesis)
  - [High level languages](#high-level-languages)
  - [Floorplanning, Placement, Routing](#floorplanning-placement-routing)
  - [Power and Clock generation](#power-and-clock-generation)
  - [Verification](#verification)
  - [What about taping out chips?](#what-about-taping-out-chips)
- [What can't we do today?](#what-cant-we-do-today)
  - [Memories are still hard](#memories-are-still-hard)
  - [Nonvolatile storage is still hard](#nonvolatile-storage-is-still-hard)
  - [Analogue IP is still difficult](#analogue-ip-is-still-difficult)
- [Where are we going from here?](#where-are-we-going-from-here)
  - [Improved languages](#improved-languages)
  - [Improved memories](#improved-memories)
  - [Better inference](#better-inference)
  - [More analogue IP](#more-analogue-ip)
- [Getting involved!](#getting-involved)

# The State of Open Silicon

# Talk Outline

- What does it mean to be "open"?
- What can we do today?
- What can't we do today?
- Where can we go from here?

# About Me

# What does it mean for silicon to be "Open"?

## Levels of "open"

1. Manuals available
2. Source available
3. GDSII available

## Parts of chip design

1. PDKs
2. IP
3. Tooling
4. Method to tape out

## Process Design Kit

- <https://skywater-pdk.readthedocs.io/en/main/_images/metal_stack.svg>
- Process design kits (PDKs) are closed and under NDA
- Mostly just a blank canvas

## Intellectual Property / Libraries

- Memories
- IO blocks
- Standard cells

## Digital design (In The Beginning)

- [Picture of Z80 or 6502]
- Magic
- [Picture of Siliwiz]

## Digital logic overview (Today)

- Standard cells
- Basic boolean logic

## How can we use standard cells?

- Manual synthesis
- Automated synthesis

Almost all code is automatically synthesized from source code!

[Example of live generation of cells]

## Tooling

- Synthesis
- Power generation
- Clock tree
- Place and route
- Verification
- **Industry tools cost $1mm plus per seat**

## End-to-end runs take weeks or months

- Specialized tooling requires specialized engineers
- Large separation between digital designers and tapeout

## Method to tape out

- Shuttle runs
- Full wafer
- Turnaround time is in months

# Where are we now (in open source)?

## Things are looking pretty good

## End-to-end tool flow possible

- Open tooling, open PDK
- Chips have been produced using this flow
- Digital logic is very doable

## Open PDKs

- Real PDKs
  - SKY130
  - SKY90FD
  - GF180MCU
- "Fake" PDKs
  - FreePDK45
  - ASAP5

## Available IP

- OpenMPW projects
- ADC, LDO, Bandgap, DAC, and more

## Standard cells

- SKY130
- GF180MCU
- OSU
- LibreSilicon

## What about tooling?

## Hardware synthesis

- Yosys (Verilog)
  - VHDL
  - SystemVerilog

## High level languages

- LiteX [Python]
- SpinalHDL [Scala]
- Clash

These all generate Verilog, and are fully open!

## Floorplanning, Placement, Routing

- OpenROAD is the current gold-standard
- Competitive with closed tools

## Power and Clock generation

- Setup and hold timing validation
- Basic power nets supported
- Straps are generated as expected

## Verification

- Parasitic extraction works
- Layout-versus-Schematics
- Simulation of extracted netlist
- Design Rule Checking

## What about taping out chips?

- Google OpenMPW shuttles
- MPW shuttle runs

# What can't we do today?

## Memories are still hard

- Density is constantly improving
- Expect kilobytes of RAM on a chip
  - Compare to megabytes of cache
- A ~4x increase is possible

## Nonvolatile storage is still hard

- No EEPROM or flash
- ReRAM is experimental on SKY130

## Analogue IP is still difficult

- Some tapeouts exist, but documentation is scarce
- Need more integration examples

# Where are we going from here?

## Improved languages

- Type-checking for timing?
- Bus integration
- Documentation generation

## Improved memories

- OpenRAM coming to more processes

## Better inference

## More analogue IP

# Getting involved!

- Siliwiz for raw tapeout
- TinyTapeout
- Write more blogposts
- Give it a try

Thank you!