rtl-p7-exploration-policy

Phase 7 Exploration Policy

Why Phase 7 Exists

Phases 1-6 enforce strict pipeline gates for production quality. Phase 7 provides a safe sandbox for investigating alternatives without production risk:

• Algorithm alternatives that may improve area/performance/power
• Optimization experiments on existing modules
• Technology evaluation (new tools, methodologies, IP blocks)
• "What-if" scenarios from Phase 6 design review findings

Exemptions

Phase 7 is exempt from all pipeline rules (Rule 9):

• No Phase 5 PASS requirement
• No Phase 6 completion requirement
• No verification gate enforcement
• No cascading quality enforcement

Guard Rails

Despite exemptions, guard rails prevent accidental production impact:

Rule	Rationale
Existing rtl/ files must NOT be directly modified	Protect production RTL
Use exploration branch for any code experiments	Isolation from main branch
Results stored in docs/phase-7-exploration/	Separate from production docs
No verification bypass for production code	Exploration cannot weaken existing quality
No feature additions without spec change proposal	Changes must flow through pipeline

Scope

Allowed:

• Algorithm alternatives analysis and comparison
• Optimization experiments (area, power, timing trade-offs)
• Technology evaluation (new EDA tools, IP blocks, methodologies)
• Prototype implementations in exploration branch
• Performance modeling and estimation

Prohibited:

• Direct modification of production RTL files
• Verification bypass for production modules
• Feature additions without formal spec change
• Modifying pipeline state or phase gate artifacts

ADR Workflow

Successful exploration produces an Architecture Decision Record:

• Location: docs/decisions/ADR-{NNN}.md
• Content: Context, Decision, Alternatives, Consequences
• Integration proposal: How to formally bring exploration results into the pipeline
• Required phase: Which pipeline phase must be re-entered for formal integration

Structured Re-entry Metadata (MANDATORY in ADR)

Every ADR from Phase 7 must include a YAML frontmatter block for pipeline re-entry:

---
adr_id: ADR-{NNN}
status: accepted | proposed | superseded
affected_phases: [P1, P2]        # Which phases need re-work if this ADR is adopted
stale_artifacts:                  # Specific docs that become stale
  - docs/phase-1-research/requirements.json
  - docs/phase-2-architecture/architecture.md
re_entry_point: P1               # Recommended phase to re-enter
re_entry_skill: p1-spec-research # Skill to invoke for re-entry
impact_summary: "New algorithm requires spec update + architecture re-partition"
---

How this integrates with existing pipeline:

• Orchestrators already check upstream artifact mtimes in Step 0 (E1 entry gate)
• When an ADR is adopted and upstream docs are updated, downstream orchestrators will detect mtime staleness and flag affected sections for targeted re-design
• No rat-setup modification needed — existing staleness detection handles re-entry naturally

Output Artifacts

Artifact	Location	Content
Exploration notes	docs/phase-7-exploration/exploration-notes.md	Detailed findings, data, analysis
Exploration review	reviews/phase-7-exploration/exploration-review.md	Summary, conclusions, recommendations
ADR (if successful)	docs/decisions/ADR-{NNN}.md	Formal decision record with integration proposal

Escalation

• Exploration reveals production RTL bug → file via rtl-p4s-bugfix, do NOT fix in exploration branch
• Exploration requires spec change → propose via p1-spec-research, do NOT modify spec directly
• Exploration scope exceeds single session → document partial results, resume later