Fast Versatile DMA

Copyright (c) 2019-2024 Antmicro

Overview

FastVDMA is a DMA controller designed with portability and customizability in mind.

Supported features

• Interrupts
• 2D transfers with configurable stride
• External frame synchronization inputs

Supported buses

• Data
  • AXI4
  • AXI-Stream
  • Wishbone
• Control
  • AXI4-Lite
  • Wishbone

Dependencies

Because the controller is written in Chisel, it requires sbt, scala and java to be installed; additionally the tests require imagemagick.

Simulation

FastVDMA can be simulated as a whole but certain components can be tested separately.

You can simulate the full memory to memory design by running:

make testM2M

And the full stream to memory test by:

make testS2M

Each test run generates a .vcd file which can be opened using GTKWave or any other .vcd viewer. Output files are located in a separate sub directories inside the test_run_dir directory.

The full test should generate an outM2M.png/outS2M.png file demonstrating a 2D transfer with configurable stride. The resulting image should look similar to:

Synthesis

To generate a synthesizable verilog file either proceed with the default configuration by running:

make verilog

Or provide a valid configuration file with:

make CONFIG_FILE=<path_to_json_file> verilog

The generated file will be named DMATop$(configuration).v where configuration is chosen configuration of buses in the DMA. Verilog module will be named in the same manner. See the documentation on how to provide custom configuration -- link here.

Source code structure

• src/main/scala/DMAController contains sources of the DMA controller
  • Bus contains definitions of various bus bundles
  • CSR contains code responsible for handling configuration registers
  • Frontend contains modules handling various bus types
  • Worker contains generic code supporting controlling the DMA behavior
• src/test/scala/DMAController contains tests
  • Bfm contains Bus models that are used in full configuration tests
  • Frontend contains tests used for generating timing diagrams for various bus types
  • Worker contains tests that generate timing diagrams for the generic part of the DMA