t180-ioring

AI Agent: Skip to Agent Setup Guide below for executable installation steps with concrete commands and ask/write tables.

A Claude Code skill for automated IO Ring generation on TSMC 180nm (T180) process nodes — from natural-language requirements to verified layout, including JSON construction, Cadence SKILL generation, Virtuoso execution, and DRC/LVS.

Overview

t180-ioring depends on virtuoso-bridge-lite for all Virtuoso communication (TCP + SSH). The project layout after setup:

<project-root>/
├── .venv/                          ← one shared Python env (bridge + all skills)
├── virtuoso-bridge-lite/           ← bridge source
└── .claude/skills/
    └── t180-ioring/
        ├── .env                    ← T180 skill config (CDS_LIB_PATH_180, VB_FS_MODE)
        └── calibre/
            └── site_local.csh      ← Calibre/PDK paths on the EDA server (you fill this in)

How the system works

Claude Code (your machine)
       │
       │  1. Generates JSON + SKILL scripts locally
       │
       ▼
virtuoso-bridge-lite
       │
       ├─ TCP socket ──────────────► Virtuoso daemon (EDA server)
       │                              loads .il, returns results
       │
       └─ SSH tunnel ──────────────► EDA server
              │
              ├─ uploads .il file → Virtuoso load()
              ├─ uploads calibre/ scripts → runs csh
              └─ downloads reports / screenshots

Filesystem mode controls how Calibre scripts and output files are exchanged:

Mode	When	Behavior
`remote`	Windows PC, or no NFS	Scripts uploaded to `/tmp/vb_t180_calibre_${USER}/` via SSH; results downloaded back
`shared`	Linux on same NFS as EDA server	Both machines see the same paths; Calibre reads/writes directly

Auto-detected: Windows path (C:\...) → remote; NFS probe → shared. Set VB_FS_MODE in .env to override.

Prerequisites

Requirement	Notes
Python 3.9+	Local machine
Git	For cloning repos
Cadence Virtuoso	On the EDA server — required for SKILL execution and screenshots
Calibre (Mentor/Siemens)	On the EDA server — required for DRC and LVS
TSMC 180nm PDK	On the EDA server — layer map, LVS include files, `cds.lib`, IO library `tpd018bcdnv5`
`csh`	On the EDA server — Calibre wrapper scripts are written in csh

Quick Setup (Human)

1. Clone and install:

# At your project root:
git clone https://github.com/chenzc24/virtuoso-bridge-lite.git
mkdir -p .claude/skills
git clone https://github.com/chenzc24/t180-ioring.git .claude/skills/t180-ioring

# Create venv and install (Linux/Mac/Git Bash):
python -m venv .venv && source .venv/bin/activate
# Windows PowerShell:  python -m venv .venv; .venv\Scripts\Activate.ps1

pip install -e virtuoso-bridge-lite
pip install -r .claude/skills/t180-ioring/requirements.txt

2. Configure bridge connection:

The bridge .env is created by virtuoso-bridge init. See virtuoso-bridge-lite/README.md for full details (jump hosts, multi-profile, local mode).

Make sure the .venv is activated before running any virtuoso-bridge commands.

virtuoso-bridge init <username>@<eda-server>    # creates ~/.virtuoso-bridge/.env
# With jump host:
# virtuoso-bridge init <username>@<eda-server> -J <username>@<jump-host>

3. Configure T180 skill .env:

Edit .claude/skills/t180-ioring/.env — the fields marked # <-- CHANGE:

Variable	Required	What to set
`CDS_LIB_PATH_180`	Yes	Remote Linux path to your T180 `cds.lib`
`VB_FS_MODE`	Optional	`remote` (Windows) or `shared` (NFS Linux). Auto-detected if blank.
`AMS_DRAFT_EDITOR`	Optional	`on` or `off` — open Draft Editor after Step 2 (default: `on`)
`AMS_LAYOUT_EDITOR`	Optional	`on` or `off` — open Confirmation Editor at Step 6 (default: `on`)

4. Configure site_local.csh (Calibre/PDK paths on the EDA server):

cd .claude/skills/t180-ioring/calibre
cp site_local.csh.example site_local.csh   # then edit with your site paths

Set MGC_HOME, PDK_LAYERMAP_180, incFILE_180, and source your site's Cadence/Mentor cshrc files. Do not edit env_common.csh — site_local.csh overrides it.

5. Start bridge and verify:

virtuoso-bridge start
virtuoso-bridge status                  # tunnel ✓  daemon ✓

In Virtuoso CIW, load the daemon SKILL file once per session (path printed by start):

load("/tmp/virtuoso_bridge_<user>/virtuoso_bridge/virtuoso_setup.il")

# Run from project root:
.venv/bin/python .claude/skills/t180-ioring/scripts/check_virtuoso_connection.py
# Windows: .venv\Scripts\python.exe .claude\skills\t180-ioring\scripts\check_virtuoso_connection.py

Auto-activate .venv: Set VS Code to use .venv as the interpreter, or add echo 'source .venv/bin/activate' > .envrc && direnv allow (Linux/Mac). Claude Code finds .venv automatically — no manual activation needed for skill runs.

Workflow

The skill runs a 12-step pipeline automatically:

 1.  Parse input → create timestamped output directory
 2.  Build draft intent graph JSON (structure only)
 2b. [Optional] Draft Editor — visual pad placement (skip if AMS_DRAFT_EDITOR=off)
 3.  Enrich draft → final intent graph (devices, pins, corners, voltage domains)
 4.  Reference-guided gate check (continuity, provider count, pin families)
 5.  Validate JSON (validate_intent.py)
 6.  Build confirmed config — optionally open Layout Editor (see below)
 7.  Generate schematic SKILL (.il)
 8.  Generate layout SKILL (.il)
 9.  Check Virtuoso connection
10.  Execute SKILL in Virtuoso + capture screenshots
11.  Run Calibre DRC
12.  Run Calibre LVS   [optional: PEX after LVS]

Output files land in ${AMS_OUTPUT_ROOT}/generated/<YYYYMMDD_HHMMSS>/: io_ring_intent_graph.json, io_ring_confirmed.json, io_ring_schematic.il, io_ring_layout.il, schematic_screenshot.png, layout_screenshot.png, drc_report.txt, lvs_report.txt.

Draft Editor (Step 2b)

When AMS_DRAFT_EDITOR=on (default), a browser editor opens after Step 2 for visual pad placement. Users can drag pads between sides, add/remove pads, set device type, set domain (digital/analog), and confirm structural layout before enrichment (Step 3).

Skip when: AMS_DRAFT_EDITOR=off AND user did not request the editor. Users can still request the editor by saying "I want to use the editor" — the .env setting is a default, not a hard gate.

Layout Editor / Confirmation Editor (Step 6)

When AMS_LAYOUT_EDITOR=on (default), the skill asks at Step 6:

"The layout is ready for confirmation. Open the visual Layout Editor?" (no response within ~15 s → skip automatically)

If opened: a browser launches on localhost showing the IO ring as an interactive SVG. Every pad, corner, and filler is draggable and editable. Click "Confirm & Continue" when done — edits are merged back into the confirmed config and the pipeline resumes.

Component colors:

Category	Color	Examples
Analog IO	Blue	`PVDD1ANA`, `PVSS1ANA`
Digital devices (all)	Green	`PDDW0412SCDG`, `PVDD1CDG`, `PVSS1CDG`, `PVDD2CDG`, `PVSS2CDG`
Corners	Red	`PCORNER`
Fillers / Blank	Gray / Red	`PFILLER10`, `PFILLER20`, `blank`

Key operations: drag to move · click Inspector to edit properties · Ctrl+Z undo · toolbar Add/Delete · Import/Export JSON · Confirm & Continue to proceed.

T180 Device Reference

T180 uses the tpd018bcdnv5 IO library with a unified pad architecture (same power pins for analog and digital, distinguished by voltage-domain label routing).

Signal type	Device	Notes
Analog IO (V-type)	`PVDD1ANA`	Analog signal pad with AVDD pin; "V" in name → V-type
Analog IO (G-type)	`PVSS1ANA`	Analog signal pad with AVSS pin; "G" in name → G-type
Voltage-domain power provider	`PVDD2CDG`	VDDPST provider; exactly ONE per voltage domain
Voltage-domain ground provider	`PVSS2CDG`	VSSPST provider; multiple with same name allowed per domain
Power consumer	`PVDD1CDG`	Regular VDD pad; VDD → Self Name
Ground consumer	`PVSS1CDG`	Regular VSS pad; VSS → Self Name
Digital IO	`PDDW0412SCDG`	Bidirectional digital pad; requires `direction` field
Corner	`PCORNER`	Single corner type for all pad adjacencies
Filler	`PFILLER10` / `PFILLER20`	Inserted between different voltage domains

Pad Dimensions (defaults)

Parameter	Value
`pad_width`	80 µm
`pad_height`	120 µm
`pad_spacing`	90 µm
`corner_size`	130 µm

Pin Architecture

All power pads share a common pin set: VDD, VSS, VDDPST, VSSPST. Analog IO adds AVDD/AVSS as signal pins. Digital IO adds PAD, I, OEN, DS, IE, PE, C pins.

Pin connections are voltage-domain-based: VDDPST/VSSPST connect to the provider's signal name within the same voltage domain block; VDD/VSS connect to the consumer pair in the same block.

Multi-Voltage Domain Support

T180 supports multiple voltage domains within both analog and digital sections. Each voltage domain block MUST have:

Exactly ONE PVDD2CDG (VDDPST provider)
One or more PVSS2CDG (VSSPST provider, same signal name)
A consumer pair: PVDD1CDG + PVSS1CDG

Different VDDPST/VSSPST label pairs define different voltage domains. Filler pads (PFILLER10) are automatically inserted between adjacent pads belonging to different voltage domains.

Usage

Via Claude Code (natural language):

Generate T180 IO ring with signals: MCLK, VIOLA, GIOLA, VIOHA, GIOHA, FGCAL, DITM.
4 pads per side, clockwise placement.
Library: LLM_Layout_Design, Cell: IO_RING_test.

Or explicitly: Use t180-ioring to generate an IO ring with...

Writing Effective Prompts

The skill classifies signals by name pattern and voltage domain assignment. For non-standard names, always specify explicitly — it overrides all inference.

Required in every prompt:

Signal list (in placement order)
Pads per side (e.g. 4 pads per side or top=4, bottom=4, left=2, right=2)
Placement order: clockwise or counterclockwise
Library and cell name

Signal classification (how the skill decides device type):

Signal type	Auto-detected when	Device
Analog IO	Name matches analog patterns (MCLK, VDCK, AVSC…) or user-specified	`PVDD1ANA` / `PVSS1ANA`
Voltage-domain provider	Name matches `VIOH`/`GIOH`/`VPST`/`GPST` or user-specified	`PVDD2CDG` / `PVSS2CDG`
Power/ground consumer	Other VDD/VSS signals in the domain	`PVDD1CDG` / `PVSS1CDG`
Digital IO	Name matches digital patterns (FGCAL, DA*, CKTM…) or user-specified	`PDDW0412SCDG`
Corner	Inferred at side transitions	`PCORNER`

Full recommended prompt:

Task: Generate IO ring schematic and layout for Cadence Virtuoso.
4 pads per side. Clockwise placement.

Signals: MCLK VDCK GDCK VPID VNID IPPI IPNI VNSC AVSF AGSF CKAZ CKTM CONV RSTM DOFG CLKO DOTM GIOHD DA14 DA13

Signal classification:
- Analog IO: MCLK, VDCK, GDCK, VPID, VNID, IPPI, IPNI, VNSC, AVSF, AGSF
- Digital IO: CKAZ, CKTM, CONV, RSTM, DOFG, CLKO, DOTM, DA14, DA13

Voltage domains:
- Analog: VIOHA/GIOHA → consumers VIOLA/GIOLA
- Digital: VIOHD/GIOHD → consumers VIOLD/GIOLD

Technology: 180nm  |  Library: LLM_Layout_Design  |  Cell: IO_RING_mixed

Configuration Reference

Bridge `.env` variables

Bridge connection is configured via virtuoso-bridge init. See virtuoso-bridge-lite/README.md for the full reference (VB_REMOTE_HOST, VB_REMOTE_USER, jump hosts, multi-profile, etc.).

T180 skill `.env` variables

Variable	Description	Required
`CDS_LIB_PATH_180`	Remote path to T180 `cds.lib`	Yes
`VB_FS_MODE`	`shared` or `remote` (auto-detect if blank)	No
`AMS_DRAFT_EDITOR`	`on` or `off` — Draft Editor at Step 2b (default: `on`)	No
`AMS_LAYOUT_EDITOR`	`on` or `off` — Confirmation Editor at Step 6 (default: `on`)	No
`AMS_OUTPUT_ROOT`	Output root (default: `./output`)	No

These live in .claude/skills/t180-ioring/.env.

`site_local.csh` variables

Variable	Description
`MGC_HOME`	Calibre installation root on EDA server
`PDK_LAYERMAP_180`	T180 PDK layer map file
`incFILE_180`	T180 LVS include file (`source.added`)

env_common.csh defaults are applied only if the variable is not set by site_local.csh or the shell — all setenv calls are guarded by if ( ! $?VAR ).

Troubleshooting

Problem	Fix
Virtuoso connection fails	`virtuoso-bridge status` → `restart`; confirm daemon `.il` loaded in CIW
DRC/LVS path errors	Check `CDS_LIB_PATH_180` in `.env`; check `MGC_HOME` / `PDK_LAYERMAP_180` / `incFILE_180` in `site_local.csh`
Wrong output location	Set `AMS_OUTPUT_ROOT` in `.env`
Skill not triggering	Say `Use t180-ioring to...`; verify `SKILL.md` exists in `.claude/skills/`
`import virtuoso_bridge` fails	Run `pip install -e virtuoso-bridge-lite` inside the project `.venv`
Draft Editor not opening	Check `AMS_DRAFT_EDITOR` in `.env`; ensure port is not blocked
Voltage domain continuity fails	Check VDDPST/VSSPST labels — different labels mean different domains

🤖 Agent Setup Guide

Human readers: This section is written for AI agents performing automated setup. You can read it as a detailed reference, but the Human Guide above covers everything you need more concisely.

Steps marked 🤖 can be executed with the exact commands shown. Steps marked ❓ → 🤖 require collecting values from the user first, then writing them into the specified file. Every repo URL and command is concrete.

Step 0 — Clone repositories 🤖

# Run from the project root directory:
git clone https://github.com/chenzc24/virtuoso-bridge-lite.git
mkdir -p .claude/skills
git clone https://github.com/chenzc24/t180-ioring.git .claude/skills/t180-ioring

The skill lands in .claude/skills/t180-ioring/ — Claude Code discovers skills in .claude/skills/ automatically. Bridge repo stays at project root.

Step 1 — Create project `.venv` and install packages 🤖

python -m venv .venv

# Activate (choose by OS):
source .venv/bin/activate          # Linux / Mac / Git Bash
# .venv\Scripts\Activate.ps1       # Windows PowerShell
# .venv\Scripts\activate.bat       # Windows CMD

pip install -e virtuoso-bridge-lite
pip install -r .claude/skills/t180-ioring/requirements.txt

# Verify:
python -c "import virtuoso_bridge; print('ok:', virtuoso_bridge.__version__)"
virtuoso-bridge --version          # expect: 0.6.x

One .venv serves all skills. To add a second skill later: pip install -r .claude/skills/<other-skill>/requirements.txt.

Step 2 — Initialize bridge config ❓ → 🤖

All subsequent steps require the .venv to be active. If in a new terminal, run: source .venv/bin/activate (Linux/Mac) or .venv\Scripts\Activate.ps1 (Windows).

Ask user — required:

Question to ask user
"Hostname or IP of your EDA server?"
"SSH username on that server?"

Then run virtuoso-bridge init to create the bridge .env with correct format and defaults:

virtuoso-bridge init <username>@<eda-server>
# With jump host:
# virtuoso-bridge init <username>@<eda-server> -J <username>@<jump-host>

This writes ~/.virtuoso-bridge/.env with all bridge variables (VB_REMOTE_HOST, VB_REMOTE_USER, ports, jump host, etc.) in the correct format. Do not write the bridge .env manually — always use virtuoso-bridge init.

For advanced options (multi-profile, local mode, custom ports), see virtuoso-bridge-lite/README.md.

Step 3 — Configure T180 skill `.env` ❓ → 🤖

Ask user — required:

Variable	Question to ask user
`CDS_LIB_PATH_180`	"Remote Linux path to your T180 `cds.lib`? (e.g. `/home/youruser/TSMC180/cds.lib`)"

Write the value into .claude/skills/t180-ioring/.env. The file ships pre-filled with defaults — use the Edit tool to update only the CDS_LIB_PATH_180 line (the one marked # <-- CHANGE path), replacing the example path with the user's actual path.

Optional — ask user if they want to customize:

Variable	Question	Default
`AMS_DRAFT_EDITOR`	"Enable Draft Editor (visual pad placement before enrichment)?"	`on`
`AMS_LAYOUT_EDITOR`	"Enable Confirmation Editor (visual layout review at Step 6)?"	`on`

Step 4 — Write `site_local.csh` ❓ → 🤖

cp .claude/skills/t180-ioring/calibre/site_local.csh.example \
   .claude/skills/t180-ioring/calibre/site_local.csh

Note: If site_local.csh.example does not exist, create site_local.csh from scratch (see template below).

Ask user — required:

What	Question to ask user
Cadence cshrc path	"Path to site's Cadence setup script on EDA server? (e.g. `/home/cshrc/.cshrc.cadence.IC618SP201`)"
Mentor cshrc path	"Path to site's Mentor setup script? (e.g. `/home/cshrc/.cshrc.mentor`)"
`MGC_HOME`	"Calibre install root on EDA server? (e.g. `/home/mentor/calibre/calibre2022/aoj_cal_2022.1_36.16`)"
`PDK_LAYERMAP_180`	"T180 PDK layer map path on EDA server? (e.g. `/home/process/tsmc180bcd_gen2_2022/PDK/TSMC180BCD/tsmc18/tsmc18.layermap`)"
`incFILE_180`	"T180 LVS `source.added` path on EDA server?"

Write values directly into site_local.csh. Example of a complete filled-in file:

source /home/cshrc/.cshrc.cadence.IC618SP201
source /home/cshrc/.cshrc.mentor
setenv MGC_HOME /home/mentor/calibre/calibre2022/aoj_cal_2022.1_36.16
setenv PDK_LAYERMAP_180 /home/process/tsmc180bcd_gen2_2022/PDK/TSMC180BCD/tsmc18/tsmc18.layermap
setenv incFILE_180 /home/dmanager/shared_lib/TSMC180MS/calibre_rule/lvs/source.added

Step 5 — Start bridge and verify 🤖

virtuoso-bridge start         # opens SSH tunnel + deploys daemon on EDA server
virtuoso-bridge status        # expect: tunnel ✓  daemon ✓

Instruct user to load the daemon SKILL file in Virtuoso CIW once per Virtuoso session. virtuoso-bridge start prints the exact path to load:

load("/tmp/virtuoso_bridge_<user>/virtuoso_bridge/virtuoso_setup.il")

Verify end-to-end:

# Linux/Mac/Git Bash:
.venv/bin/python .claude/skills/t180-ioring/scripts/check_virtuoso_connection.py
# Windows PowerShell:
# .venv\Scripts\python.exe .claude\skills\t180-ioring\scripts\check_virtuoso_connection.py
# Success: ✅ Virtuoso Connection: OK
# Failure: follow printed instructions; run `virtuoso-bridge restart` if tunnel is down

Setup complete ✅

<project-root>/
├── .venv/                                         ← shared env (bridge + all skills)
├── virtuoso-bridge-lite/                          ← bridge source (editable install)
└── .claude/skills/t180-ioring/
    ├── .env                                       ← T180 skill config (CDS_LIB_PATH_180, VB_FS_MODE, editors)
    └── calibre/
        └── site_local.csh                         ← written in Step 4

Bridge config lives in ~/.virtuoso-bridge/.env (created by virtuoso-bridge init in Step 2). AMS_PYTHON in SKILL.md Step 0 finds .venv at project root automatically — no manual activation needed when Claude Code runs scripts.

Document	Description
`SKILL.md`	Full workflow contract — Steps 0–12, repair loops, troubleshooting
`references/draft_builder_T180.md`	Structural draft JSON generation rules
`references/enrichment_rules_T180.md`	Signal classification, device selection, pin connection rules
`references/T180_Technology.md`	DRC rules and process details
`virtuoso-bridge-lite/README.md`	Bridge CLI, SSH tunnel, daemon, multi-profile setup

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Repository files navigation

t180-ioring

Overview

How the system works

Prerequisites

Quick Setup (Human)

Workflow

Draft Editor (Step 2b)

Layout Editor / Confirmation Editor (Step 6)

T180 Device Reference

Pad Dimensions (defaults)

Pin Architecture

Multi-Voltage Domain Support

Usage

Writing Effective Prompts

Configuration Reference

Bridge `.env` variables

T180 skill `.env` variables

`site_local.csh` variables

Troubleshooting

Related Documentation

🤖 Agent Setup Guide

Step 0 — Clone repositories 🤖

Step 1 — Create project `.venv` and install packages 🤖

Step 2 — Initialize bridge config ❓ → 🤖

Step 3 — Configure T180 skill `.env` ❓ → 🤖

Step 4 — Write `site_local.csh` ❓ → 🤖

Step 5 — Start bridge and verify 🤖

Setup complete ✅

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Name		Name	Last commit message	Last commit date
Latest commit History 21 Commits
calibre		calibre
io_ring		io_ring
references		references
scripts		scripts
skill_code		skill_code
.gitignore		.gitignore
README.md		README.md
SKILL.md		SKILL.md
requirements.txt		requirements.txt

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Repository files navigation

t180-ioring

Overview

How the system works

Prerequisites

Quick Setup (Human)

Workflow

Draft Editor (Step 2b)

Layout Editor / Confirmation Editor (Step 6)

T180 Device Reference

Pad Dimensions (defaults)

Pin Architecture

Multi-Voltage Domain Support

Usage

Writing Effective Prompts

Configuration Reference

Bridge .env variables

T180 skill .env variables

site_local.csh variables

Troubleshooting

Related Documentation

🤖 Agent Setup Guide

Step 0 — Clone repositories 🤖

Step 1 — Create project .venv and install packages 🤖

Step 2 — Initialize bridge config ❓ → 🤖

Step 3 — Configure T180 skill .env ❓ → 🤖

Step 4 — Write site_local.csh ❓ → 🤖

Step 5 — Start bridge and verify 🤖

Setup complete ✅

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Bridge `.env` variables

T180 skill `.env` variables

`site_local.csh` variables

Step 1 — Create project `.venv` and install packages 🤖

Step 3 — Configure T180 skill `.env` ❓ → 🤖

Step 4 — Write `site_local.csh` ❓ → 🤖

Packages