NetCrux — Netlist Driver Tracing

"What drives this?" is a question you ask with the cursor already on the signal.

Select an identifier in Verilog, SystemVerilog or VHDL, run one command, and NetCrux resolves that name through the design's stems index and highlights it in a running NetCrux schematic — so you can follow the cone of influence back from exactly where you were reading.

• Registries: Marketplace · Open VSX (Cursor, Windsurf, VSCodium, Theia)
• Licence: Apache-2.0 · Home: netcrux.app

What it does

One gesture: What Drives This? (NetCrux), on the editor context menu for Verilog, SystemVerilog and VHDL.

1. Takes your selection — or the word under the caret.
2. Resolves it to a hierarchical element path through the stems index, the same source-to-netlist mapping the rest of the suite uses. When a bare identifier matches more than one path, it asks rather than guessing.
3. Finds a running NetCrux desktop peer over CXP and sends it request_highlight.

Every branch is answered rather than left to fail silently: no selection, no netlist index in the workspace at all, a name the index does not contain, a peer that never acknowledges, a peer whose socket is unreachable, and a peer that declines all say what happened. If no NetCrux is running but it is installed, the extension offers to launch it. If it is not installed, you get one honest sentence and one link.

The netlist index

The command needs a *.stems file in the workspace folder. Without one it says so, and says how to make one: in WaveCrux Desktop, Tools > Generate RTL Stems, then save the file inside the folder you have open. Run the command again and it is picked up.

Language ids

The menu entry appears on files whose language is Verilog, SystemVerilog or VHDL. A fresh editor with no HDL language extension opens .v and .sv as Plain Text, so this extension registers those three language ids for .v .vh .sv .svh .vhd .vhdl (and nothing else: no grammar, no highlighting). An HDL language extension you install keeps providing the highlighting, and VSCode merges the registrations by id. If another extension also claims .v, for example a Coq one, choose with files.associations in your settings.

Why this reaches outside your editor

This is the part an in-editor extension API structurally cannot do. CXP is a cross-process peer protocol, so the target is a real NetCrux desktop application, on your machine, over loopback — with its full schematic canvas, its layout engine, and your netlist already loaded. The editor is where you ask the question; the schematic is where the answer is worth looking at.

Discovery is on demand. There is no background poller added by this extension: the manifest directory is scanned once, at the moment you invoke the command.

Your VSCode window is one CXP peer no matter how many of the four extensions you install — one identity, one manifest, one heartbeat, capabilities composed from whatever is installed.

Install the EDACrux Suite pack to get all four at once.

Settings

Commands

What this extension does not do — stated plainly

• It does not draw schematics in VSCode. There is no netlist canvas in this extension and no netlist loaded in this window. It is a sender: it turns a source selection into a question and routes it to a tool that can answer it. If you want the schematic, you want NetCrux Desktop — and this extension will offer to open it for you.
• It advertises no inbound capabilities, because a NetCrux-only VSCode window genuinely has nothing to highlight. It will not accept a request it cannot honour just to look well-connected.
• Restricted workspaces. It runs with limited support in a folder you have not trusted, and nothing is held back: it reads the source and stems files you open and sends selections to a NetCrux app already running on this machine. It never runs a program named by workspace content.

Telemetry

Off unless you have VSCode telemetry on. The extension checks vscode.env.isTelemetryEnabled at send time, not once at startup.

Localization

English, 简体中文, 日本語 and 한국어 — hand-translated, commands and settings included.

The rest of the suite

Built by Ferrite Engineering. Apache-2.0. edacrux.app