Loom

What Loom is

Loom (by Broccoli) compiles circuit descriptions down to hardware. A project is a folder with lm.mod and its sources in src/: Weaver (.wv), whose functions (func) describe behaviour with channels (send, recv, probe) and compile to Verilog, and whose protocols (proto) give the handshake wire by wire and compile to production rules, a transistor netlist and a layout in SkyWater's 130 nm process. Loom also reads handshaking expansions (.cogw), production rules (.prs) and SPICE. It is pre-alpha: its own README lists what works.

Commands

The console runs lm commands on the project (the lm in front is optional):

build: Compile the project into build/; the Layout window shows project.gds
build src/file.wv: Compile one file
show: Draw each process as a Petri net (build/dbg/, in the Graph window)
sim build/src/<cell>.prs: Simulate production rules; also .cogw, .chp, .hse, .astg
mod init name · mod show: Start a module; list its processes
help · help build: Loom's own help
clear: Clear the console

While a simulator runs, the console takes its commands (help, e enabled transitions, f0 fire one, s 10 step, t tokens, q quit); quitting writes a .vcd that the Waves window draws. Stop ends any command.

Windows

Files shows and edits the project's files. Layout draws GDS files by layer (sky130's names): drag to pan, wheel or pinch to zoom, untick layers to hide them. Graph draws lm show's graphs with Graphviz. Waves draws simulations.

Projects

Project > New project, Open files or Open folder, or drop a folder or a .zip / .tar.gz on the page. To keep your work, work in a folder on disk (Chrome, Edge and other Chromium browsers) or keep the project in browser storage (any browser): what lm writes and your edits are saved there.

In the browser

Each command runs in a fresh copy of lm, as in a terminal. Loom's technology files are built in (/usr/local/share/tech/sky130). Without Python, the technology file is read by a small reader of the plain calls it is made of; the placer's one OpenCL kernel runs on the CPU; graphs are drawn by Graphviz in its own worker.