FlooGen: The NoC Generation Framework

FlooGen is the Python-based configuration and generation framework bundled with FlooNoC. While FlooNoC provides the efficient hardware IP blocks (mainly routers and network interfaces), FlooGen acts as the system architect that assembles them into a functional Network-on-Chip.

It transforms a high-level, human-readable description of your network (topology, routing rules, protocols) into fully connected, verified, and synthesizable SystemVerilog RTL.

Why use a Generator?

Designing a Network-on-Chip manually is tedious and error-prone. Connecting hundreds of router ports, calculating deadlock-free routing tables, and maintaining consistent global address maps becomes unmanageable as system complexity grows.

FlooGen solves this by raising the abstraction level. Instead of writing Verilog wire connections, you define endpoints, routers and their connections. FlooGen handles the low-level implementation details, ensuring that:

• Protocol conversion: Network interfaces are automatically instantiated to bridge different endpoint protocols to the NoC link protocol.
• Routing is correct: Paths are calculated automatically based on the topology.
• Configuration is consistent: Address maps and endpoint IDs are allocated globally without overlaps.

Key Capabilities

• Topology Agnostic: Generate standard topologies (Mesh, Ring, Tree) or completely custom irregular graphs based on your system constraints.
• Automatic Routing: Built-in engines to calculate routing tables for different routing algorithms.
• Protocol Abstraction: Define endpoints using high-level protocols (e.g., AXI4). FlooGen automatically manages the conversion to the internal NoC link protocol.
• Network Visualization: Generate visual graphs of your network topology to inspect connections and routing paths before simulation.
• Validation: The internal graph model checks for errors such as overlapping address regions, isolated nodes, or invalid port assignments before a single line of RTL is generated.

The Generation Flow

FlooGen operates in four distinct stages to turn your configuration into hardware:

1. Parse & Elaborate: Reads the YAML configuration file to understand the requested nodes, links, and system parameters.
2. Graph Construction: Builds an internal Network Graph representation of the system.
3. Routing & Mapping:
   • Runs routing algorithms on the graph.
   • Allocates Endpoint IDs.
   • Computes the global system address map.
4. Render: Generates the final SystemVerilog code using validated templates.

Generated Artifacts

When you run FlooGen, it produces two primary outputs:

• The NoC Top-Level (floo_<name>_noc.sv): A structural SystemVerilog module that instantiates all routers and network interfaces and connects them according to the topology.
• The NoC Package (floo_<name>_noc_pkg.sv): A SystemVerilog package containing all the necessary metadata, including:
  • Typedefs for flits and links.
  • Routing tables and rules.
  • System address maps and endpoint ID enumerations.