Industrial Tech Note – Calibre DFM PVR Automation

1. Industry Background

In advanced semiconductor nodes, power integrity and reliability verification are mandatory signoff requirements. Calibre DFM / PVR tools detect:

IR-drop hotspots
Power grid weaknesses
Single via reliability risks
Potential electromigration concerns

Detection alone is not sufficient.  
Large SoC designs generate thousands of violations.  
Manual review and fixing are inefficient and non-scalable.

2. Real Calibre Signoff Flow

Layout (GDS / OA) ↓ Calibre DRC / PEX / PERC ↓ PVR / Power Analysis ↓ RDB / SVDB Output ↓ RVE Review ↓ Manual Layout Fix ↓ Re-run Verification

The bottleneck exists between RDB output and Layout Fix. This automation addresses that gap.

3. Automation Architecture

Input (JSON / Converted RDB) ↓ Data Validation ↓ Rule Engine ↓ Fix Plan Generation ↓ Export: - JSON Report - TCL Script

This mirrors industrial automation structure:

Data Ingestion
Rule Evaluation
Corrective Recommendation
EDA Tool Integration

4. Python Automation Core (Key Concept)

The script performs:

Threshold-based IR-drop filtering
Single-via reliability detection
Fix action generation
Export to JSON and TCL

Example Input (analysis.json)

[
  {
    "id": 1,
    "coordinate": [120.5, 450.2],
    "drop_mv": 45,
    "type": "IR_DROP",
    "net": "VDD"
  },
  {
    "id": 4,
    "coordinate": [150.2, 300.5],
    "drop_mv": 0,
    "type": "SINGLE_VIA",
    "net": "SIGNAL_A"
  }
]

Core Logic Concept

if entry["type"] == "IR_DROP" and entry["drop_mv"] > threshold:
    → Generate WIDEN_METAL action

if entry["type"] == "SINGLE_VIA":
    → Generate ADD_REDUNDANT_VIA action

Example Output (dfm_pvr_fix_report.json)

[
  {
    "action": "WIDEN_METAL",
    "target_net": "VDD",
    "coord": [120.5, 450.2]
  },
  {
    "action": "ADD_REDUNDANT_VIA",
    "target_net": "SIGNAL_A",
    "coord": [150.2, 300.5]
  }
]

Generated TCL Script Example

# IR drop 45mV > 40mV
db_enhance_metal -net VDD -coord 120.5 450.2 -add_width 0.2

# IR drop 85mV > 40mV
db_enhance_metal -net VDD -coord 500.0 500.0 -add_width 0.2

# Single Via Reliability
db_insert_via -net SIGNAL_A -coord 150.2 300.5 -type DOUBLE

This transforms analysis output into actionable layout correction commands.

5. Industrial Value

✔ Scalable Fix Planning

Reduces manual review workload in large SoC environments.

✔ Structured & Extendable

Future rules can include EM, density, CMP, or advanced power grid optimization.

✔ Interview & Portfolio Value

Demonstrates understanding of Calibre flow
Shows automation mindset
Bridges verification and layout correction

6. Future Realistic Enhancements

ASCII RDB parsing
Calibre batch execution integration
Closed-loop re-verification
OpenAccess direct layout modification
Multi-rule configuration file support

Current version is a structured prototype.
It models industrial DFM automation logic
while remaining tool-agnostic.

Calibre DFM PVR Automation Framework