This is a collection of Clash designs, build scripts and Haskell programs that you can use to synthesise a bitstream, program it on to an FPGA and interact with it.
Much of the designs are FPGA/board agnostic, but there are a few ECP5 specific primitives, and the top entities/synthesis annotations and Makefile are specific to the ULX3S board.
You will need the following system dependencies:
- GHC with a suitable version of the
baselibrary. You can use GHCup to install specific GHC versions. The project has been tested with GHC 8.10. - Yosys tools. These can be installed all together with the
OSS CAD suite.
- Yosys for
yosys. - Nextpnr with ECP5 support for
nextpnr-ecp5. - Project Trellis for
ecppack.
- Yosys for
- SDL, e.g.
libsdl2-devin Ubuntu, for simulatingsnake.
Depending on your version of SDL, you might need to configure the project to
use a specific version of the Haskell sdl2 library, e.g. the version of
libsdl2-dev is too old for the most recent Haskell sdl2 library, so run:
$ cabal configure --constraint="sdl2 <2.5.5.0 && >=2.5.0.0"
before any of the build commands.
The bitstream for each example can be built with make <example name>.
A counter displayed on the on board LEDs.
A block RAM that you can interact with (read and write) over a USB connection
using a REPL. Run the REPL with cabal run ram-repl.
A simple stack machine processor that you can interact with (evaluate arithmetic
expressions) over a USB connection using a REPL. Run the REPL with cabal run stack-machine-repl.
Uses a DVI transmitter to display test pattern on a monitor connected via the GPDI port.
A game of Snake using the directional buttons as input and GPDI output for the
display. Run an SDL based simulation with cabal run snake-sim.