Vyges Loom
Standard-cell characterization — generate Liberty (.lib) timing & power models from SPICE, in parallel, from one declarative job.
Used by: PDK teams, standard-cell library developers, and platform teams validating reusable IP.
vyges-char takes SPICE models and a cell list and produces a Liberty library — the timing and power model every downstream sign-off step (STA, power) depends on. It orchestrates the underlying SPICE runs in parallel, which is the piece the open-source flow has historically lacked; it is validated against reference Liberty for the open PDKs. The emitted Liberty is standard Liberty that downstream sign-off tools consume directly, and supports multi-corner, multi-voltage characterization.
A .char / .charlib job file declares the corner(s), the cells, and the collateral — no imperative scripting. Standard CLI: --json, --quiet, --verbose, -h / -V. The .lib it emits is read directly by vyges-sta-si, and its per-switch energy seam feeds vyges-em-ir.
One declarative job in; one standard sign-off artifact out. Exits non-zero on violations — designed to gate CI, not generate PDFs.
Characterization's cost is the SPICE sweep — one simulation per slew × load point, per arc, per corner. But delay and transition are smooth functions of slew and load, so vyges-char can simulate a coarse subset and predict the rest: export a tidy dataset, fit a small model, and fill the dense library — --sparse for a fixed coarse grid, or --auto to self-tune to a target accuracy. All in pure Rust — experiment with GPUs too via rust-gpu — and it runs locally: nothing leaves your machine.
A study in sample-efficiency and surrogate modeling on open PDKs — how few simulations for a given accuracy, which models, which cells and corners. Publish and share.
Evaluate the payoff on your PDK — across mature and advanced node PDKs. Characterize a few representative cells and measure how much characterization time --sparse / --auto saves at an accuracy your flow accepts — all on your confidential models, locally.
Try it and tell us what you find — the experiment guide is on GitHub; share results or talk through your flow at vyges.com/contact.
Open and runnable today, and inside VyBox Sley. The per-foundry calibration plugins (NDA) stay private — the engine is open, the fab-specific accuracy is gated. See all the engines & the data spine →