RTLDesignSherpa: Skill for Claude Code

.claude/skills/uart-harness/SKILL.md

uart-harness is a skill for Claude Code from sean-galloway/RTLDesignSherpa. It costs 55 tokens per session (178 once invoked), scanned A, original, MIT.

A method for testing and characterizing hardware through one host program that works both with a cocotb simulation and with an FPGA board. It accesses registers by name and documents serial-connection details.

In plain words
What is it for?
Bringing up FPGA boards, reading and writing registers by name, running the same characterization flow in simulation and on hardware, and handling JTAG and serial-port setup.
Why use it?
It keeps simulated and physical-board checks aligned and avoids errors caused by different host programs or fragile register addresses.

Skill for Claude Code

Written for Claude Code: installed under .claude/.

This is sean-galloway/RTLDesignSherpa's own configuration. It tells Claude Code how to work on RTLDesignSherpa itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything RTLDesignSherpa configures →

Reuse

Borrowing it

Nothing to install: this file belongs to sean-galloway/RTLDesignSherpa. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/sean-galloway/RTLDesignSherpa/main/.claude/skills/uart-harness/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/sean-galloway/RTLDesignSherpa

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for uart-harness

README.md
[![agentmods](https://agentmods.dev/badge/skills/sean-galloway/rtldesignsherpa/uart-harness/github.svg)](https://agentmods.dev/skills/sean-galloway/rtldesignsherpa/uart-harness)
Your own site
<a href="https://agentmods.dev/skills/sean-galloway/rtldesignsherpa/uart-harness"><img src="https://agentmods.dev/badge/skills/sean-galloway/rtldesignsherpa/uart-harness/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for uart-harness

Your own site · 80×15
<a href="https://agentmods.dev/skills/sean-galloway/rtldesignsherpa/uart-harness"><img src="https://agentmods.dev/badge/skills/sean-galloway/rtldesignsherpa/uart-harness.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 55 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 178 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00055 $0.00178
Opus 5 $0.00028 $0.00089
Sonnet 5 $0.00011 $0.00036
Haiku 4.5 $0.00006 $0.00018

Measured 9d ago against content hash 5847d400f39f, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

uart-harness scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/skills/uart-harness/SKILL.md · 14 lines

What it actually says

uart-harness

READ FIRST: vault/handbook/fpga/uart-harness.md (the handbook is the repo's memory; this skill is the signpost). One host program, sim + silicon; registers by name only. Board mechanics: vault/handbook/fpga/boards.md.

The handbook root is vault/handbook/INDEX.md - design/, dv/, fpga/ areas, atomic notes, wikilinked. When you learn a durable lesson in this domain, ADD IT TO THE HANDBOOK NOTE, not to this skill.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 9d ago First seen · 14 lines · 55 tokens per session scan A 5847d400f39f

Subscribe to this mod's changes

uart-harness is a skill published in the GitHub repository sean-galloway/RTLDesignSherpa (23 stars, last pushed today), licensed MIT. It adds 55 tokens to every session and 178 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.