Getting Started with FlooNoC¶

This guide covers how to set up the environment to simulate and verify the FlooNoC hardware IPs (SystemVerilog). If you are looking to generate a network configuration, please refer to the FlooGen documentation.

Prerequisites¶

1. Bender¶

FlooNoC uses Bender for hardware IP management and dependency handling. Bender is available as pre-compiled binaries for Linux, macOS, and Windows (or can be installed via Cargo).

curl --proto '=https' --tlsv1.2 https://pulp-platform.github.io/bender/init -sSf | sh

cargo install bender

Then you can check whether Bender is installed correctly by fetching the dependencies:

bender checkout

This is not strictly necessary since subsequent Make commands will perform this step automatically, but it is useful to verify that Bender is set up correctly.

2. Simulation Tools¶

The testbenches provided with FlooNoC are designed to be run with QuestaSim and VCS.

Installation¶

Clone the repository to get the hardware IPs and verification environment:

git clone https://github.com/pulp-platform/FlooNoC.git && cd FlooNoC

Running Simulations¶

We provide a Makefile to simplify compiling and running the testbenches.

1. Compile the Hardware¶

Compile the RTL and testbenches:

make compile-vsim

make compile-vcs TB_DUT=<testbench_name>

2. Run a Testbench¶

You can run specific testbenches by setting the TB_DUT variable:

make run-vsim TB_DUT=<testbench_name>

make run-vsim-batch TB_DUT=<testbench_name>

make run-vcs TB_DUT=<testbench_name>

Available Testbenches¶

You can substitute <testbench_name> with other testbenches found in hw/tb/:

Advanced mesh testbenches¶

There are additional testbenches for entire mesh networks:

Those testbenches require generated networks from FlooGen. Please refer to the FlooGen documentation for instructions on how to install FlooGen.

Generating Mesh Testbenches¶

Then, you can generate either of the testbenches with:

uv run floogen rtl -c floogen/examples/<mesh>_<route_algo>.yml -o generated

floogen rtl -c floogen/examples/<mesh>_<route_algo>.yml -o generated

Where <mesh> is either axi_mesh or nw_mesh, and <route_algo> is either xy, yx, id or src.

The generated RTL must be placed under generated, as referenced by Bender.yml.

Compiling Testbenches¶

Then, you can compile and run the generated testbenches as described above. Setting TB_DUT automatically adds the Bender flags needed to include the generated files:

make compile-vsim TB_DUT=tb_floo_<mesh>

# Currently not supported

Generating Traffic¶

The testbench endpoints are DMA models that accept job files to perform AXI4 transactions over the NoC. This is better documented in the DMA documentation here. Job files are generated via floogen from a traffic configuration file:

uv run floogen traffic -c floogen/examples/<floonoc_config>.yml --traffic-cfg floogen/examples/traffic/<traffic_config>.yml -o <outdir>

floogen traffic -c floogen/examples/<floonoc_config>.yml --traffic-cfg floogen/examples/traffic/<traffic_config>.yml -o <outdir>

Traffic Configuration File¶

A traffic configuration file contains a list of traffic flows, which describes the transfers issued by one initiator node towards one endpoint node, both identified by their XY coordinates in the NoC mesh:

traffic_flows:
  - name: "cl_0_0_to_mem_1_0"
    initiator: [0, 0]
    endpoint: [1, 0]
    rw: write
    narrow_burst:
      number: 4
      length: 8
    wide_burst:
      number: 32
      length: 256

Each traffic flow accepts the following fields:

Both narrow_burst and wide_burst take a burst descriptor with two fields:

Reference traffic configuration examples for the mesh testbenches can be found under floogen/examples/traffic/.

Built-in Mesh Traffic Patterns¶

Alternatively, floogen traffic also supports generating a handful of built-in, mesh-wide traffic patterns that onlyrequire a FlooNoC configuration file:

floogen traffic -c <floonoc_config>.yml --traffic-type <traffic_type> --traffic-rw <read_or_write> -o <outdir>

Currently supported traffic types are:

The number and length of the generated bursts can be tuned with the --num-narrow-bursts, --num-wide-bursts, --narrow-burst-length and --wide-burst-length options (see floogen traffic --help).

Running Mesh Testbenches¶

You can run the generated testbenches with:

make run-vsim TB_DUT=tb_floo_<mesh>

# Currently not supported