LiteX demo
~~~~~~~~~~
This example design features a LiteX+<CPU variant>-based SoC. It also includes DDR
controller. First, enter this example's directory:
.. code-block:: bash
:name: example-litex-dir
cd litex_demo
Install the litex dependencies with the following:
.. code-block:: bash
:name: example-litex-req
pip install -r requirements.txt
There are multiple CPU types supported, choose one from the below commands to generate the design and build it.
**Picorv32**
.. code-block:: bash
:name: example-litex_picorv32-a35t-group
./arty.py --toolchain=symbiflow --cpu-type=picorv32 --sys-clk-freq 80e6 --uart-baudrate=1000000 --output-dir build/picorv32/arty_35 --board-variant a7-35 --build
.. code-block:: bash
:name: example-litex_picorv32-a100t-group
./arty.py --toolchain=symbiflow --cpu-type=picorv32 --sys-clk-freq 80e6 --uart-baudrate=1000000 --output-dir build/picorv32/arty_100 --board-variant a7-100 --build
**VexRiscv**
.. code-block:: bash
:name: example-litex_vexriscv-a35t-group
./arty.py --toolchain=symbiflow --cpu-type=vexriscv --sys-clk-freq 80e6 --uart-baudrate=1000000 --output-dir build/vexriscv/arty_35 --board-variant a7-35 --build
.. code-block:: bash
:name: example-litex_vexriscv-a100t-group
./arty.py --toolchain=symbiflow --cpu-type=vexriscv --sys-clk-freq 80e6 --uart-baudrate=1000000 --output-dir build/vexriscv/arty_100 --board-variant a7-100 --build
Depending on which board and CPU-type you selected, the bitstream is loacted in:
.. code-block:: bash
cd build/<cpu-type>/<board>/gateware
Now you can upload the design with:
.. code-block:: bash
openocd -f ${INSTALL_DIR}/${FPGA_FAM}/conda/envs/${FPGA_FAM}/share/openocd/scripts/board/digilent_arty.cfg -c "init; pld load 0 top.bit; exit"
.. note::
This example uses baud rate of ``1000000`` by default.
You should observe the following line in the OpenOCD output
.. code-block:: bash
Info : JTAG tap: xc7.tap tap/device found: 0x0362d093 (mfg: 0x049 (Xilinx), part: 0x362d, ver: 0x0)
In the ``picocom`` terminal, you should observe the following output:
.. image:: ../../docs/images/litex-picorv32-console.gif
:align: center
:width: 80%
63d392b21c