wafer.space Community - 🕰️-analog

Been dabbling with analog recently and was curiosu if any of the automated analog layout tools worked well. ALIGN (https://github.com/ALIGN-analoglayout/ALIGN-public) looked most promising and had a Sky130 PDK, so I threw Claude Code at it. Sorta have a working GF180 PDK now? Takes in a spice netlist, constraints (matching, symmetry, etc) and spits out GDS Found some pretty serious limitations though, namely that ALIGN was built with finfet nodes in mind so there are a lot of restrictive routing/placement constraints baked into the core. Had to modify the core to get even moderately compact layouts and it's still a lot of wasted space. DRC and LVS match, but haven't run simulations on the generated output yet... could be hot garbage

Still, neato tool. Kinda want to start working on something that's tailored for big legacy nodes that have less restrictive DRC. (screenshot is a CSA + Discriminator + Krummenacher feedback circuit that i've been playing around with)

GitHub - ALIGN-analoglayout/ALIGN-public

Contribute to ALIGN-analoglayout/ALIGN-public development by creating an account on GitHub.

Harald pretl also tested an automatic layout tool on tt05

1:20 p.m.

https://tinytapeout.com/chips/tt05/tt_um_tt05_analog_test

271 TT05 Analog Testmacro (Ringo, DAC) - Tiny Tapeout

For future analog enablement of TinyTapeout we designed a few simple analog blocks for testing the flow. The first block is a ca. 500kHz ring oscillator outputting a square-wave signal. The second block is a 3bit R-2R DAC outputting a programmable dc voltage. Both analog output signals can be gated or shorted using integrated transmission gates....

@BreakingTaps - Take a look at OpenFASoC from Mehdi

7:24 a.m.

@BreakingTaps - https://www.crowdsupply.com/wafer-space/gf180mcu-run-1/updates/openfasoc

Building Real Sensors with GF180MCU — See What's Possible!

Wonder what you can do with GF180MCU? Mehdi's OpenFASoC design creates a cool finger flex sensor, complete with an IEEE paper containing real silicon characteristics and analog blocks reusable for your own design!

Finally got the LVS working end-to-end from xschem to klayout without any manual conversion steps from a user point of view

Just need to wait for @Leo Moser (mole99) to upstream the improvements from wafer space now

And did you check you didn't break the xschem / magic / netgen flow ? (like if you changed anything in the xschem symbols for instance that could break the other flows ... )

tnt

And did you check you didn't break the xschem / magic / netgen flow ? (like if you changed anything in the xschem symbols for instance that could break the other flows ... )

The changes are fully contained in the klayout directory, so likelihood of breaking other flows is rather low (edited)

Clyde Laforge

Finally got the LVS working end-to-end from xschem to klayout without any manual conversion steps from a user point of view

Just need to wait for @Leo Moser (mole99) to upstream the improvements from wafer space now

Awesome Clyde

I'll start upstreaming the wafer.space changes to the FOSSi repos soon. However, you don't necessarily have to wait for that, since your LVS changes should be standalone?

Leo Moser (mole99)

Awesome Clyde

I'll start upstreaming the wafer.space changes to the FOSSi repos soon. However, you don't necessarily have to wait for that, since your LVS changes should be standalone?

It is slightly dependent, as it adds new GUI options, but let's discuss it when I open the MR, maybe they are not necessary

Tim 'mithro' Ansell

@BreakingTaps - https://www.crowdsupply.com/wafer-space/gf180mcu-run-1/updates/openfasoc

oh neat! Will give this a closer read tomorrow