The main window — module browser, trace list, and waveform canvas with cursors and Δt readouts.
Overview
Scansion 3 is a fresh rebuild of a long-running Mac waveform viewer, modernized for current macOS. The features you remember have been carried over from the original, along with many others to ensure you stay productive analyzing your designs. It reads quickly and stays responsive even on large files.
Showcase feature
Browse Mode
Select a module in the hierarchy and every signal under it renders at
once. Exploring an unfamiliar dump is immediate — not a chore of
adding signals one at a time. Carried over from the original Scansion
and rebuilt to scale to larger files.
Per tab, so you can browse in one and curate a hand-picked trace list
in another.
Pick a module → every trace under it draws. Click to zoom.
What's inside
Built for reading real-world VCD.
Browse Mode
Click a module and all of its traces draw instantly. No setup, no manual signal-picking just to see what's there. Per tab, and you can curate your own trace list too.
Fast on real-world VCD
Opens large files quickly, making sense of the messy shapes simulators emit: collapses per-bit dumps into vectors, infers multi-dimensional arrays and structs.
Multiple render modes
Digital, bus with value labels, analog, and real-valued traces with step or linear interpolation.
Cursors & measurement
Multiple cursors with time-delta (Δt) between them, value-under-cursor readouts, and cursor statistics — including min, max, duty cycle and average over a window.
Genuinely native Mac UI
Supports multiple files and tabs, a split trace view, module-browser and trace-list sidebars, a Property Inspector for per-trace color, radix, row height and display mode, search and filter, tags, and full keyboard navigation.
Profiles & Reload
Save and reapply a window and trace layout as a profile. After a new simulation run, Reload (⌘R) re-reads the file while preserving your layout and selection.
Who it's for
For people who live in their waveforms.
Simulator names are examples of tools that emit VCD — not
integrations or endorsements. If it writes VCD, Scansion reads it.
RTL and digital design engineers — FPGA and ASIC — working on macOS.
Anyone running simulators that emit VCD: Icarus Verilog, Verilator / SystemC, ModelSim / Questa, Vivado, Xcelium, and more.
Students learning Verilog and SystemVerilog who want a clean way to inspect testbench output.
People using GTKWave on a Mac who prefer something native.
Available on the Mac App Store.
Scansion is ready to download. Grab it from the Mac App Store — or get in
touch if you have a question.
