The original repository is now located on my own git-server at https://git.goodcleanfun.de/tmeissner/cocotb_with_ghdl
It is mirrored to github with every push, so both should be in sync.
cocotb_with_ghdl
At the moment, this repo is in an early state and serves as a learning tool for me. So it contains a a lot of quirks and code which can be done much better by cocotb-professionals.
A collection of examples of using cocotb for functional verification of VHDL designs with GHDL.
This is a project with the purpose to learn using cocotb with GHDL. It is intended for my simple (and more complex in future) experiments with using the Python language instead of VHDL or SV to verify digital designs.
It is recommended to use an up-to-date version of GHDL as potential bugs are fixed very quickly. You can build GHDL from source or use one of the Docker images of the hdl containers project (recommended). For example the hdlc/sim:scipy docker image. This image contains a recent version of cocotb and a C++ compiler (needed to build some wheels during installing requirements with pip).
Have fun!
Quickstart guide
Change into docker container & install requirements
$ git clone https://git.goodcleanfun.de/tmeissner/cocotb_with_ghdl.git
$ cd cocotb_with_ghdl
$ git clone https://git.goodcleanfun.de/tmeissner/libvhdl.git
$ docker run --rm -ti --volume=$(pwd):/build -e DISPLAY=$DISPLAY \
--volume /tmp/.X11-unix:/tmp/.X11-unix hdlc/sim:scipy /bin/bash
$ ./docker-setup.sh
Collecting cocotb-bus
Downloading cocotb-bus-0.2.1.tar.gz (28 kB)
Installing build dependencies ... done
Getting requirements to build wheel ... done
Preparing wheel metadata ... done
...
Successfully built cocotb-bus wavedrom python-constraint
Installing collected packages: lxml, cocotb-bus, toposort, svgwrite, pyyaml, pyucis, python-constraint, pyboolector, cocotbext-axi, attrdict, wavedrom, pyvsc, pyuvm, cocotbext-uart, cocotbext-spi, cocotbext-pcie, cocotbext-eth, cocotb-coverage
Successfully installed attrdict-2.0.1 cocotb-bus-0.2.1 cocotb-coverage-1.1.0 cocotbext-axi-0.1.18 cocotbext-eth-0.1.18 cocotbext-pcie-0.1.20 cocotbext-spi-0.1.2 cocotbext-uart-0.1.2 lxml-4.7.1 pyboolector-3.2.2.20220125.14 python-constraint-1.4.0 pyucis-0.0.5.20211020.1 pyuvm-2.6.1 pyvsc-0.6.7.1792877175 pyyaml-6.0 svgwrite-1.4.1 toposort-1.7 wavedrom-2.0.3.post2
Run default test (UART TX)
root@6ee2bee145d4:~# cd /build/tests/
root@6ee2bee145d4:/build/tests# make
make -f Makefile results/uarttx.xml
make[1]: Entering directory '/build/tests'
mkdir -p results
mkdir -p work
/usr/local/bin/ghdl -i --std=08 --workdir=work --work=libvhdl ../libvhdl/common/UtilsP.vhd && \
/usr/local/bin/ghdl -i --std=08 --workdir=work --work=work ../libvhdl/syn/*.vhd && \
/usr/local/bin/ghdl -m --std=08 --workdir=work -Pwork --work=work uarttx
analyze ../libvhdl/common/UtilsP.vhd
analyze ../libvhdl/syn/UartTx.vhd
elaborate uarttx
MODULE=tb_uart TESTCASE=test_uarttx TOPLEVEL=uarttx TOPLEVEL_LANG=vhdl \
/usr/local/bin/ghdl -r --workdir=work -Pwork --work=work uarttx --vpi=/usr/local/lib/python3.9/dist-packages/cocotb/libs/libcocotbvpi_ghdl.so --wave=results/uarttx.ghw --psl-report=results/uarttx_psl.json --vpi-trace=results/uarttx_vpi.log
loading VPI module '/usr/local/lib/python3.9/dist-packages/cocotb/libs/libcocotbvpi_ghdl.so'
-.--ns INFO cocotb.gpi ..mbed/gpi_embed.cpp:76 in set_program_name_in_venv Did not detect Python virtual environment. Using system-wide Python interpreter
-.--ns INFO cocotb.gpi ../gpi/GpiCommon.cpp:99 in gpi_print_registered_impl VPI registered
VPI module loaded!
0.00ns INFO Running on GHDL version 2.0.0-dev (v1.0.0-974-g0e46300c) [Dunoon edition]
0.00ns INFO Running tests with cocotb v1.7.0.dev0 from /usr/local/lib/python3.9/dist-packages/cocotb
0.00ns INFO Seeding Python random module with 1644236947
/usr/local/lib/python3.9/dist-packages/attrdict/mapping.py:4: DeprecationWarning: Using or importing the ABCs from 'collections' instead of from 'collections.abc' is deprecated since Python 3.3, and in 3.10 it will stop working
from collections import Mapping
/usr/local/lib/python3.9/dist-packages/attrdict/mixins.py:5: DeprecationWarning: Using or importing the ABCs from 'collections' instead of from 'collections.abc' is deprecated since Python 3.3, and in 3.10 it will stop working
from collections import Mapping, MutableMapping, Sequence
0.00ns INFO Found test tb_uart.test_uarttx
0.00ns INFO running test_uarttx (1/1)
First simple test
0.00ns INFO Valid-accept driver
0.00ns INFO cocotbext-vai version 0.0.1
0.00ns INFO Copyright (c) 2022 Torsten Meissner
0.00ns INFO UART receiver
0.00ns INFO cocotbext-uart version 0.0.1
0.00ns INFO Copyright (c) 2022 Torsten Meissner
0.00ns INFO Hold reset
100.00ns INFO Released reset
110.00ns INFO Sending data: 0xaf
1170.00ns INFO Received data: 0xaf
1190.00ns INFO Sending data: 0x56
2280.00ns INFO Received data: 0x56
2300.00ns INFO Sending data: 0xb1
3390.00ns INFO Received data: 0xb1
3410.00ns INFO Sending data: 0x80
4500.00ns INFO Received data: 0x80
4520.00ns INFO Sending data: 0xc4
5610.00ns INFO Received data: 0xc4
5630.00ns INFO Sending data: 0x8
6720.00ns INFO Received data: 0x8
6740.00ns INFO Sending data: 0x68
7830.00ns INFO Received data: 0x68
7850.00ns INFO Sending data: 0x30
8940.00ns INFO Received data: 0x30
8960.00ns INFO Sending data: 0xa2
10050.00ns INFO Received data: 0xa2
10070.00ns INFO Sending data: 0x70
11160.00ns INFO Received data: 0x70
11160.00ns INFO test_uarttx passed
11160.00ns INFO **************************************************************************************
** TEST STATUS SIM TIME (ns) REAL TIME (s) RATIO (ns/s) **
**************************************************************************************
** tb_uart.test_uarttx PASS 11160.00 0.23 48943.29 **
**************************************************************************************
** TESTS=1 PASS=1 FAIL=0 SKIP=0 11160.00 0.31 35939.72 **
**************************************************************************************
make[1]: Leaving directory '/build/tests
Available Tests
UART
Simple tests of UART transmitter & receiver of the libvhdl project
