Implementation Guide

This guide is intended for developers who want to extend FINN by adding new operators, transformation passes, or analysis passes.

If you’re new to FINN development, we recommend:

1. Reading the Concepts documentation to understand FINN’s core concepts (IR, ModelWrapper, transformations)

2. Reviewing the Developer documentation guide for contribution workflow

3. Consulting the PYTHON_STYLE_GUIDE.md and HDL_STYLE_GUIDE.md for coding standards

• CustomOp Class Hierarchy
  • Typical Pattern
  • Base Layer (Backend-Agnostic)
  • HLS Backend Variant
  • RTL Backend Variant
  • Alternative Patterns
  • Specialization: Choosing HLS vs RTL
  • Adding a New CustomOp
  • See Also
• SpecializeLayers: HLS vs RTL Selection
  • Overview
  • Selection Logic
  • RTL Constraint Table
  • Example: LayerNorm Specialization
  • Adding Specialization for New Layers
  • See Also
• Implementing HLS Variants
  • Overview
  • Code Generation Dictionary
  • Required Methods
  • Optional Methods
  • HLS-Specific Node Attributes
  • Generated Code Structure
  • Adding to FINN
  • See Also
• Implementing RTL Variants
  • Overview
  • Verilog Wrapper Requirement
  • Example: LayerNorm_rtl
  • Required Methods
  • RTL Simulation
  • Adding a New RTL Layer
  • See Also

Getting Started

Adding a new hardware layer:

1. Start with CustomOp Class Hierarchy to understand the CustomOp class hierarchy

2. See Implementing HLS Variants for HLS code generation or Implementing RTL Variants for RTL code generation

3. See SpecializeLayers: HLS vs RTL Selection to add selection logic for HLS vs RTL

Adding transformation or analysis passes:

• Custom transformation pass notebook

• Custom analysis pass notebook