datasheet

name	datasheet
description	Draft, review, audit, and revise customer-facing IC / component datasheets — the spec-bearing document a customer designs against — using the standard anvil lifecycle with a mandatory spec source-of-truth audit.
domain	datasheet
type	skill
user-invocable	false

anvil:datasheet — Customer-facing IC / component datasheets

The datasheet skill produces customer-facing datasheets for ICs and components — the spec-bearing document a customer designs against. A datasheet is not a pitch and not a report: every number in it is a commitment a customer's board, firmware, and procurement decisions will rest on. The skill is distilled from hand-authoring two real preliminary datasheets at the studio canary (a dual-SKU edge-AI part family sharing one base die — issue #418); the failure modes hit there are what the rubric and the audit encode.

It runs the canonical anvil lifecycle with a mandatory audit pass: draft → review + audit (parallel, both REQUIRED) → revise → … → READY → AUDITED → figures, with revise looping to review + audit until the rubric threshold is met or the iteration cap is reached. The structure mirrors anvil:proposal (the sibling LaTeX-prose skill with mandatory audit) almost file-for-file; the audit-by-default discipline mirrors anvil:report; the lifecycle/rubric format follows anvil:memo. Like report, deck, and anvil:ip-uspto, datasheets sit in the customer-facing advance tier (≥39/44) — see CLAUDE.md's threshold tiers.

The six canary failure modes this skill exists to catch

1. Wrong numbers that read fine in isolation — die area, ISP resize, inference input size, bus index ranges that contradict the design model / RTL / quant config. → spec source-of-truth cross-check, audit-owned (datasheet-audit steps 5–6).
2. Pin-map violations — pins double-assigned (power AND a MIPI differential pair) while others sit unassigned; N-bit fields that cannot represent their claimed range (a 5-bit field claiming a 0–79 index). → deterministic pre-flight via lib/pinmap_check.py + lib/buswidth_check.py, run in BOTH datasheet-review and datasheet-audit.
3. Layout drift — datasheets that don't "look right" to a customer (no two-column first page, major sections splitting mid-page, inconsistent rev/footer). → baked into templates/anvil-datasheet.cls + datasheet.tex.j2, gated by the render-gate pre-flight.
4. Silent spec changes — a corrected number with no revision-history row. → READY-gate: spec-touching changes without a new revision-history entry block advance: true (see §"Revision-history discipline").
5. Pre-silicon numbers presented as final — simulated/estimated values with no "est." / "from system-model simulation" / "characterization pending" labeling. → rubric dim 4 + critical flag 4.
6. Shared-die SKU drift — sibling SKUs sharing one base die whose shared specs diverge across sheets. → rubric dim 5 + documented audit step reading the sibling thread (see §"Shared-die / family SKU coherence").

Artifact contract

A datasheet thread is a single datasheet for one part / SKU, authored across one or more revisions. A thread is identified by a slug (e.g., ax101-objdet). Each thread lives inside a project root that carries a project-level BRIEF.md (the post-#296 config locus — frontmatter documents: list naming every thread in the project). Sibling SKUs of one part family SHOULD share one project root so the auditor can cross-read them. Within the project root, each thread occupies a directory named for its slug; version dirs and critic siblings are nested under that thread directory per the issue #295 project-org model:

<project>/                   Project root (project-level BRIEF.md; issues #295/#296)
  BRIEF.md                   Project-level brief (frontmatter `documents:` list + prose)
  research/                  Optional shared evidence pool across documents
  <thread>/                  Thread root (named for the slug; one per SKU)
    BRIEF.md                 Optional thread-level brief (frontmatter + prose; carries
                             part_number / status / signature_color knobs)
    refs/                    Source-of-truth spec bundle (model/quant/RTL exports,
                             foundry quotes, package drawings) — see below
    <thread>.1/              First drafted version (immutable once written)
      datasheet.tex          Datasheet body (XeLaTeX; skill-fixed filename — see note below)
      anvil-datasheet.cls    Class file, copied alongside so the version dir compiles standalone
      figures/               Block diagram, package drawing, typical-application schematic
      _progress.json         Phase state for this version
      changelog.md           (revisions only) Maps prior critic notes to changes
    <thread>.1.review/       Reviewer output for version 1 (read-only)
      verdict.md             Top-level decision (advance / block) + total /44
      scoring.md             Per-dimension scores against the datasheet rubric
      comments.md            Line-level comments keyed to datasheet.tex
      _gate.json             Render-gate + pin-map/bus-width pre-flight results
      _meta.json             { critic, scorecard_kind: "human-verdict", rubric_id, ... }
      _progress.json         Phase state for the reviewer
    <thread>.1.audit/        Auditor output for version 1 (read-only, REQUIRED by default)
      verdict.md             Audit decision (pass / fail) + critical-flag list
      findings.md            Per-claim audit log (spec back-checks, pin-map, bus-width,
                             revision-history gate, SKU coherence)
      evidence.md            Source → dependent-claims traceability map
      _meta.json             { critic: "audit", scorecard_kind: "human-verdict", ... }
      _progress.json         Phase state for the auditor
    <thread>.2/              Revised version (after revise consumes v1 + ALL critic siblings)
    ...
    <thread>.{N}/            Terminal version, marked READY/AUDITED in its _progress.json

Body filename convention — datasheet.tex (slug-echo deferred). Following the proposal skill's precedent (anvil/skills/proposal/SKILL.md §"Body filename convention"), the body filename is the skill-fixed datasheet.tex — it is the LaTeX source filename consumed by xelatex invocations and the class lookup across the command surface. The slug-echo rename is deferred until the proposal-side migration lands; the directory nesting is load-bearing today, the body filename is not.

Versioned dirs (<thread>.{N}/) and critic sibling dirs (<thread>.{N}.<critic>/) are immutable once their _progress.json records the phase as done. Revisions are produced as a new version dir, never by editing in place.

Source-of-truth materials (the spec bundle)

<thread>/refs/ is the canonical home for the spec bundle — the authoritative sources every numeric claim in the datasheet must trace to. This is the datasheet analog of the proposal skill's §"Source-of-truth materials" contract, and the audit's central input. Typical spec-bundle materials:

• model-<name>.md / model-export.json — design-model exports (die area, block sizes, memory map); load-bearing for physical and architectural claims (dim 1).
• quant-config.md / quant-<sku>.json — quantization / network configuration exports (input sizes, layer shapes, resize targets); load-bearing for inference-spec claims (dim 1). The canary's 300×300-vs-320×320 and 32×96-vs-48×192 errors are exactly this class.
• rtl-params.md / rtl-<block>.json — RTL parameter exports (bus widths, register fields, FIFO depths); load-bearing for register-map and interface claims (dims 1–2).
• foundry-quote-<vendor>.{pdf,md} — foundry / OSAT quotes; load-bearing for process, die-size, and package claims.
• package-<pkg>.{pdf,md} — package mechanical drawings and ballout references; load-bearing for pinout and mechanical claims (dim 2 + dim 3).
• characterization/<campaign>.md — silicon measurement campaigns when they exist; load-bearing for the measured-vs-projected split (dim 4).
• sibling-shared-specs.md — optionally, an explicit statement of which spec blocks are shared across the family's SKUs (dim 5).

The contract: "if a numeric claim's evidentiary basis lives in a file, that file goes in <thread>/refs/." Text-readable files (.md, .txt, .json) are read as authoritative; PDFs and images are presence-only in v0 (the auditor back-checks against a sibling .md companion or BRIEF.md-surfaced content; PDF text extraction is deferred per issue #167). When refs/ is empty or contains no spec-bundle materials, the back-check is inactive and the audit degrades to internal-consistency + pin-map/bus-width checks alone — but a customer-facing datasheet with no spec bundle SHOULD be flagged in the audit's verdict prose as un-back-checkable.

The back-check is audit-owned. datasheet-audit resolves every numeric claim against the spec bundle with the four-valued verdict schedule (VERIFIED / UNVERIFIED / CONTRADICTED / NOT-IN-REFS) inherited from the proposal skill's refs back-check. A CONTRADICTED claim raises critical flag 1. The reviewer notes the spec bundle's presence (dim 1 justification) but does not duplicate the per-claim walk — the same review-vs-audit boundary as anvil/lib/snippets/audit.md.

State machine

Per-thread state, derived from on-disk evidence (not flags):

EMPTY → DRAFTED → REVIEWED+AUDITED → REVISED → … → READY → AUDITED → figures
             ↘ (either critic alone is insufficient — both required to leave DRAFTED) ↗

State	Evidence
EMPTY	No <thread>.{N}/ directories exist
DRAFTED	Latest <thread>.{N}/ exists with datasheet.tex and _progress.json.draft == done; no critic sibling at the same N
REVIEWED	<thread>.{N}.review/verdict.md exists for the latest N (without .audit/) — transient; not advance-eligible
AUDITED-PARTIAL	<thread>.{N}.audit/verdict.md exists for the latest N (without .review/) — transient; not advance-eligible
REVIEWED+AUDITED	BOTH <thread>.{N}.review/verdict.md AND <thread>.{N}.audit/verdict.md exist for the latest N
REVISED	A <thread>.{N+1}/ exists after a prior REVIEWED+AUDITED state at N
READY	Latest review records advance: true (≥39) AND latest audit records pass: true AND no unresolved critical flag in either sibling AND the revision-history gate holds (see below)
AUDITED	Same as READY for this skill — the standard anvil terminal state. There is no further CUSTOMER-READY/promote stage (that is report-specific); a preliminary datasheet's release posture is carried by the status knob, not by an extra state.

Thresholds: ≥39/44 advances — the customer-facing tier shared with report, deck, and ip-uspto (CLAUDE.md threshold tiers). A datasheet is the purest customer-facing artifact anvil ships: a wrong number costs the customer a board spin. Any critical flag in EITHER .review/ or .audit/ short-circuits regardless of total.

Iteration cap: default max_iterations: 4. The per-document override carrier is the project-level BRIEF.md documents: entry (max_iterations + iteration_cap_rationale), per the paired-override schema in anvil/lib/project_brief.py. Exceeding the cap marks the thread BLOCKED and requires human review.

Revision-history discipline (the READY-gate)

Any spec-touching revision MUST bump the datasheet's rev and add a row to the Revision History table (the template's final section). The canary went 0.3 → 0.4 for four corrected numbers; a datasheet that silently changes a spec breaks the customer's ability to diff revisions.

The gate, enforced by datasheet-audit (step 8):

• When a prior version dir <thread>.{N-1}/datasheet.tex exists, the auditor diffs the spec-bearing content (numeric values in spec tables, pinout rows, ordering info) between N-1 and N.
• If spec-bearing content changed AND the Revision History table carries no new row relative to N-1 (or the rev value did not change), the auditor raises critical flag 3 (spec change without revision-history entry) — which blocks advance: true / pass: true regardless of total score.
• Prose-only edits (wording, layout, figure captions) do NOT require a rev bump; the gate is about numbers a customer might have designed against.

v1 implements this as a documented audit step (auditor judgment over a real diff); a mechanical spec-diff checker is a natural Phase-2 follow-on (the pin-map/bus-width checkers in lib/ establish the pattern).

Measured-vs-projected provenance

A datasheet must cleanly separate silicon-measured values from simulated / estimated / pre-silicon values. The template ships provenance macros — \est{...} ("(est.)"), \simval{...} ("(sim.)"), \meas{...} (bare; silicon-measured) — and a Notes/provenance column convention in the electrical-characteristics tables. The status: preliminary knob (default) drives a PRELIMINARY banner + standing "characterization pending" notice. Rubric dim 4 rewards explicit labeling; a bare pre-silicon number presented as measured/final is critical flag 4.

Shared-die / family SKU coherence

When sibling SKUs share a base die (the canary's object-detection + OCR pair), the shared spec blocks (process, die, package, abs-max, DC characteristics) must agree across the family's sheets, and per-SKU specs (network, performance) must be clearly differentiated. Sibling SKU threads share one project root, so the auditor can read the sibling thread's latest version (resolve via anvil/lib/latest_resolution.py's tolerant helper — walk-to-highest-N fallback; shipped commands never create or maintain the consumer-side .latest symlinks it tolerates; see also anvil/lib/cross_thread_refs.py).

datasheet-audit step 9 (documented step, v1): enumerate sibling datasheet threads named in the project-level BRIEF.md documents: list, read each sibling's latest datasheet.tex, and compare the shared spec blocks. A divergence on a shared-die spec is critical flag 5. An automated byte-diff of marked shared blocks is a Phase-3 follow-up (out of scope for v1 — documented audit judgment only). Single-SKU projects: the step is inactive, and rubric dim 5 scores on the family/ordering table's internal coherence alone (no deduction for having no siblings).

Deterministic pre-flight (pin-map + bus-width)

The "deterministic pre-flight before judgment" pattern, instantiated for datasheets with machine-readable marker comments in datasheet.tex and skill-local checkers in anvil/skills/datasheet/lib/ (skill-local first per the lib-promotion rule):

• Pin-map markers — the template wraps the pinout table rows in % anvil-pinmap-begin package=<pkg> pins=<N> … % anvil-pinmap-end. lib/pinmap_check.py::check_pinmap(tex_source) parses the rows between the markers and asserts (a) every pin designator is assigned exactly once (a double-assigned pin is a violation), and (b) when pins=<N> is declared, every expected designator is assigned (an unassigned pin is a violation).
• Bus-width markers — every N-bit field whose value range the prose claims gets a % anvil-bus: name=<field> width=<W> max=<M> (or range=<lo>-<hi> / values=<count>) marker. lib/buswidth_check.py::check_buswidths(tex_source) asserts 2^W covers the claimed set (the canary's 5-bit field claiming 0–79 fails: capacity 32).
• Both checkers degrade gracefully: absent markers mean the mechanical check is inactive (found=False, passing) and the human critic reviews the pinout/bus claims manually. The drafter is REQUIRED to emit the markers (datasheet-draft step 6) so the checks are active on skill-authored sheets.
• The checkers run in both datasheet-review (pre-flight, before scoring — results recorded in _gate.json) and datasheet-audit (findings entries). A violation is critical flag 2 (pin-map / bus-width violation) in either sibling.

Command dispatch

Command	Role	Reads	Writes
datasheet	portfolio orchestrator	all <thread>.* dirs under cwd	(none; reports state per thread + recommends next command)
datasheet-draft <thread>	drafter	<thread>/BRIEF.md, <thread>/refs/** (spec bundle), templates	<thread>.1/ (or <thread>.{N+1}/)
datasheet-review <thread>	reviewer	latest <thread>.{N}/	<thread>.{N}.review/
datasheet-audit <thread>	auditor (REQUIRED by default)	latest <thread>.{N}/, <thread>/refs/**, prior <thread>.{N-1}/ (rev-history gate), sibling threads' latest (SKU coherence)	<thread>.{N}.audit/
datasheet-revise <thread>	reviser	latest <thread>.{N}/ + ALL <thread>.{N}.*/ critic siblings (both .review/ and .audit/ required)	<thread>.{N+1}/ with changelog.md
datasheet-figures <thread>	figurer	latest <thread>.{N}/datasheet.tex	renders/stubs under <thread>.{N}/figures/

datasheet-review and datasheet-audit run in parallel after datasheet-draft; both must complete before datasheet-revise and before the thread can reach READY/AUDITED. No synthesize/perspective specialists ship in v1 (the proposal skill's synthesizer is a natural follow-on once a datasheet canary surfaces the "3 findings, 1 gap" pattern).

Renderer

LaTeX via the shipped templates/anvil-datasheet.cls class, compiled with XeLaTeX (xelatex datasheet.tex) — the class uses fontspec (Helvetica Neue with a documented Latin Modern Sans fallback so it compiles on a stock TeX Live install). The accent is navy (#1F4E7A — ANVIL_NAVY from the shared figure palette, anvil/lib/figures/palette.py), overridable per-brief via signature_color. Customer-facing layout conventions are baked into the class + template:

• Two-column first page: Key Features | Applications side-by-side (via multicol), followed by General Description — the layout a customer expects from a part-vendor datasheet.
• Fresh-page major sections: Performance Characteristics and Pin Configuration start on a new page (\clearpage pre-wired in the template).
• Consistent rev/footer: every page footer carries part number · rev · date · page X/Y; the title block carries the PRELIMINARY/PRODUCTION status line.

datasheet-review runs the render-gate pre-flight via anvil/lib/render_gate.py::compile_and_gate(...) (compile success, overfull boxes >5.0pt, placeholder scan; page_cap=None — datasheet length is part-complexity-dependent). On engine-unavailable, the gate degrades gracefully and the review proceeds.

Knobs (thread-level BRIEF frontmatter)

• part_number — the part / SKU designator (title block + footer).
• status: preliminary | production (default preliminary) — drives the title-block status line ("PRELIMINARY --- SPECIFICATIONS SUBJECT TO CHANGE" vs "PRODUCTION") and whether the standing characterization-pending notice is expected. The reviewer reads dim 4 (measured-vs-projected) and dim 8 (provenance & legal) through this knob: a preliminary sheet MUST carry the preliminary notice; a production sheet MUST NOT carry unlabeled estimated values.
• signature_color (hex, no #; default 1F4E7A) — accent override.
• family — the part-family name; siblings sharing the same family value in the project BRIEF are the dim 5 coherence set.

Project BRIEF artifact type

datasheet is registered as a skill-identity artifact_type value in the shared project-BRIEF registry (anvil/lib/project_brief.py::REGISTERED_ARTIFACT_TYPES / SKILL_IDENTITY_ARTIFACT_TYPES; issue #486, following the #386/#408/#432/#440/#460 pattern). In a shared project BRIEF, a documents: entry with artifact_type: datasheet declares that this skill owns the thread. It is NOT a memo subtype: it selects no memo rubric overlay, and memo commands fail loudly when pointed at a thread declaring it. Registering the value lets a validated BRIEF carry it through strict load_project_brief_strict validation, which is what anvil:rubric-rebackport's BRIEF-route inference (#484) relies on to resolve an unstamped datasheet review to the ("datasheet", 44) rubric row. The body filename is datasheet.tex, but inference is BRIEF-artifact_type-driven (BRIEF-route-only), matching the ip-uspto-provisional (spec.tex) precedent — datasheet.tex is deliberately NOT added to rubric-rebackport's _BODY_FILENAME_TO_SKILL rule-2 table.

Progress tracking

Each <thread>.{N}/ directory contains _progress.json recording phase state per the canonical schema in anvil/lib/snippets/progress.md (read-merge-write, crash recovery, for_version on critic siblings). Validation is by file existence, not by flag.

Critic siblings follow the human-verdict scorecard kind documented in anvil/lib/snippets/scorecard_kind.md and carry the per-review rubric version stamping fields required since v0.4.0: rubric_id: "anvil-datasheet-v1", rubric_total: 44, advance_threshold: 39 in _meta.json. All critic-sibling writes go through the staged-sidecar atomicity primitive (anvil/lib/sidecar.py::staged_sidecar) per the convention every shipped critic-writing command follows. No anvil/lib/ schema changes are introduced by this skill.

Rubric

See rubric.md for the 9-dimension /44 scoring schema, the ≥39 advance threshold, and the five critical-flag short-circuit conditions. The dimensions are tuned for spec-bearing customer documents (spec accuracy / source-traceability, internal consistency incl. pin-map + bus-width, completeness, measured-vs-projected provenance, family/SKU coherence, usability / application guidance, customer-facing layout & typography, provenance & legal, rhetorical economy).

Defaults and overrides

Consumers override via .anvil/skills/datasheet/ in their own repo:

• voice.md (optional) — house editorial voice for descriptive prose.
• rubric.overrides.md (optional) — domain-specific critical-flag examples; never reduces the base rubric.
• templates/anvil-datasheet.cls (optional) — replacement class (company house style, logo, different accent).
• BRIEF.md.example — reference brief shape; freeform prose with optional YAML frontmatter (see templates/BRIEF.md.example).

Git sync hook (opt-in, off by default)

Consumers running anvil under an external orchestrator (a sphere channel-agent, a Loom-style daemon) can opt in to a per-phase git commit hook so every lifecycle phase leaves the working tree clean: a repo-level .anvil/config.json with git.commit_per_phase: true (and optionally git.push: true) has each write-bearing datasheet command end its phase by staging only the dirs it wrote and committing as anvil(datasheet/<phase>): <thread>.{N} [<state>]. The full contract — knob shape, defaults-off rule, commit-message format, staging scope, warn-and-continue failure semantics, and ordering after the _progress.json done write and the #350 sidecar atomic rename — lives in anvil/lib/snippets/git_sync.md (.anvil/lib/snippets/git_sync.md in an installed consumer repo). All 5 write-bearing datasheet commands adopt it; the read-only datasheet portfolio orchestrator is exempt by definition. When .anvil/config.json is absent or the knob is false, behavior is byte-identical to a pre-#426 install — the hook is default off.