---
license: cc-by-4.0
pretty_name: WaveformQA VCD Traces
language:
- en
tags:
- vcd
- waveform
- risc-v
- hardware
- rtl-simulation
- temporal-reasoning
- benchmark
size_categories:
- n<1K
viewer: false
---

# WaveformQA VCD Traces

The 13 VCD traces used by [WaveformQA](https://github.com/tenstorrent/waveformqa), a benchmark for evaluating LLM temporal reasoning over digital signal traces (IEEE ICLAD 2026). The traces were produced by RTL simulation of five open-source RISC-V cores running firmware workloads (~3.3 GB total).

The questions, ground-truth answers, evaluation harness, and per-core generation instructions live in the GitHub repository; this dataset only holds the traces.

## Files

A single archive, `waveformqa_vcds.zip` (~364 MB; ~3.3 GB extracted), containing a `LICENSE` file (the CC-BY-4.0 terms and third-party attributions below) and one IEEE 1364 VCD file per trace:

| Core | Upstream license | Traces | Signal range |
|------|------------------|--------|--------------|
| [DarkRISCV](https://github.com/darklife/darkriscv) | BSD-3-Clause | `darkriscv_coremark.vcd`, `darkriscv_dhrystone.vcd`, `darkriscv_mandelbrot.vcd` | ~394 |
| [PicoRV32](https://github.com/YosysHQ/picorv32) | ISC | `picorv32_custom.vcd`, `picorv32_dhrystone.vcd` | ~338 |
| [biRISCV](https://github.com/ultraembedded/biriscv) | Apache-2.0 | `biriscv_custom.vcd`, `biriscv_tcm_soc.vcd`, `biriscv_tcm_soc_custom.vcd`, `biriscv_testbench.vcd` | 1,642-2,295 |
| [Ibex](https://github.com/lowRISC/ibex) | Apache-2.0 | `ibex_custom.vcd`, `ibex_dhrystone.vcd` | ~4,185 |
| [SERV](https://github.com/olofk/serv) | ISC | `serv_custom.vcd`, `serv_hello_world.vcd` | ~957 |

## Usage

Download the archive, extract it into `vcds/` in a clone of the repository, and point the benchmark runner at it:

```bash
hf download dcummingsTT/waveformqa waveformqa_vcds.zip --repo-type dataset --local-dir vcds
unzip -o vcds/waveformqa_vcds.zip -d vcds
rm vcds/waveformqa_vcds.zip   # optional: delete the archive once extracted
uv run python scripts/run_benchmark.py benchmark/t5000 --vcd-dir vcds --eval-only \
    -o output/t5000/evaluation_results.json
```

See the repository README (**Getting Started**) for the full set of runner flags.

## License

Copyright 2026 Tenstorrent USA, Inc.

The VCD traces are generated by simulating the third-party RISC-V cores listed above and are licensed under [CC-BY-4.0](https://creativecommons.org/licenses/by/4.0/legalcode). Signal names and design hierarchy in the traces derive from those cores, which remain under their own licenses.

The ibex_custom and ibex_dhrystone traces derive from the Ibex core. Its upstream NOTICE file reads:

```text
The Ibex Project
Copyright 2024 lowRISC contributors.

This product includes hardware and/or software developed as part of the
Ibex(R) (https://github.com/lowRISC/ibex) and OpenTitan(R) projects.

Ibex was originally developed by the PULP team at ETH Zurich and University of
Bologna under the name zero-riscy. Ibex verification, performance enhancement
and security hardening have been supported by the OpenTitan project
(https://www.opentitan.org).
```

The serv_hello_world trace was produced by running the Zephyr RTOS hello-world image shipped with SERV (Zephyr is Apache-2.0). See [NOTICE](https://github.com/tenstorrent/waveformqa/blob/main/NOTICE) in the repository for full third-party attributions.

## Citation

```bibtex
@misc{liu2026waveformqabenchmarkingllmtemporal,
      title={WaveformQA: Benchmarking LLM Temporal Reasoning on Digital Waveforms},
      author={Yichuan Liu and Daniel Cummings and Nick Vadlamudi},
      year={2026},
      eprint={2607.20638},
      archivePrefix={arXiv},
      primaryClass={cs.AI},
      url={https://arxiv.org/abs/2607.20638},
}
```