Vivado Block Design Tutorial

Table of Contents

Setup

Installing Boards

If you are using a Digilent board, such as the Zedboard, you need to setup the board files in Vivado. See https://github.com/Digilent/vivado-boards/.

Running Vivado

Before you can run the Vivado tools you should first run the configuration script:

source /tools/Xilinx/Vivado/2020.2/settings64.sh

This will add the tools to your PATH.

To run Vivado, simply run vivado.

Creating a Simple Hardware Project

Creating the Project

After launching Vivado, follow these steps to create a hardware project:

  1. Create Project…, and choose a project name and location. You can name your project whatever you want, but make sure you place the project in it’s own directory. For example, my project was named 625_lab5 and located at lab_vitis/hw/vivado_proj. (Note that I chose to add a hw subdirectory and then created a project directory within this. You will see why this is useful when you get to the section on Committing to Git). Click Next. Choose an RTL project. Click Next.
  2. You don’t need to add any sources or constraints yet, just click Next.
  3. On the next you will be asked to choose an FPGA part. Click Boards at the top, and choose your board (ie. Zedboard). Click Finish to create your project.

Creating a Base Design

In these steps we will create a basic system, containing only the Zynq processing system (PS).

  1. Click Create Block Design, and click OK on the popup.
  2. Add the ZYNQ7 Processing System IP to the design (right-click, Add IP).
  3. A green banner should appear with a link to Run Block Automation. Run this. This will configure the ZYNQ for your board.
  4. The FCLK_CLK0 output of the Zynq Processing System will serve as your system clock. It is set to 100MHz by default. Connect it to the M_AXI_GP0_ACLK input.
  5. Generate a top-level module: In the Sources window, expand Design Sources and right-click on your block design (design_1.bd) and select Create HDL Wrapper. Use the option to Let Vivado manager wrapper and auto-update.

Committing to Git

Want to commit your project to Git? Don’t try and commit your actual project files, as this won’t work. Instead, we will instruct Vivado to create a single Tcl script that can be used to re-create our project from scratch:

  • Select File->Project->Write Tcl.
  • Make sure to check the box Recreate Block Designs using Tcl.
  • Those choose a file location. This should be outside your project directory, since your project directory is temporary and not committed to Git. My script is located at lab_vitis/hw/create_hw_proj.tcl. Commit this Tcl script to Git.
  • Now, feel free to delete your Vivado project folder, and then you can simply recreate it using vivado -source create_hw_proj.tcl. I typically create a simple Makefile such as this:
proj:
	vivado -source create_hw_proj.tcl

clean:
	rm -rf 625_lab5

Synthesizing the hardware

  1. Run Generate Bitstream.
  2. Once the bitstream generation is complete, export the hardware:
    • File->Export Hardware.
    • Chose the Include Bitstream option, and choose a location to store the Xilinx Shell Archive (.xsa). Mine is placed at lab_vitis/hw/625_lab5_hw.xsa. This file will be provided to the software tools in the next section to tell the software tools all about our hardware system configuration.
  3. You should commit this .xsa file to Git.