PDKs, Standard-Cell Libraries and Design Formats
Understand the process design kit and the logical, physical, timing, parasitic and mask-data views exchanged across the flow.
Overview
A process design kit is the controlled interface between a manufacturing process and design tools. It includes technology layers, device models, design rules, extraction decks, reliability limits and supported libraries.
Each design view answers a different question. RTL/netlist describe logic; Liberty describes timing/power; LEF/DEF describe abstract physical implementation; SPEF describes parasitics; SDC describes constraints; GDSII/OASIS describe final geometry. Version consistency is essential.
Learning objectives
Identify core PDK components
Match file formats to flow stages
Qualify standard-cell and macro releases
Prevent mixed-version collateral errors
Core concepts
PDK
Foundry-qualified technology data, models, rules and decks consumed by design tools.
Liberty (.lib)
Cell function, timing arcs, constraints, power and operating-condition characterization.
LEF/DEF
Technology/cell abstracts and placed-routed design exchange formats.
GDSII/OASIS
Hierarchical polygon formats used for mask-data handoff and physical verification.
SPEF
Standard parasitic exchange format for extracted resistance and capacitance.
SDF
Standard delay format used for timing annotation into simulation.
Engineering workflow
Select technology release
Choose process option, metal stack, voltage and supported flow.
• Product needs
• Foundry agreement
• PDK baseline
Qualify libraries/IP
Check cells, corners, models, abstracts and provenance.
• Library releases
• Approved collateral
Map flow views
Define which version and format each tool consumes and produces.
• Flow definition
• View manifest
Control updates
Regression-test PDK/library changes and preserve release evidence.
• New release
• Compatibility report
• Approval
Metrics and interpretation
Corner coverage
Required process, voltage and temperature conditions with complete models.
View consistency
Logical, timing and physical views represent the same cell or macro release.
Deck version
Immutable identifier for DRC, LVS, extraction and reliability rule content.
Signoff checklist and pitfalls
Evidence checklist
- PDK and libraries are approved for the target flow
- All views have aligned version/checksum
- Layer maps are correct across tools
- Required corners and models are complete
- Release notes and known limitations are reviewed
Common pitfalls
•
Mixing LEF and Liberty from different releases•
Treating an open PDK as foundry support•
Using typ-only characterization•
Changing layer maps without full verification