Microblaze Soft Processor

Table of Contents

The following procedure gives detailed steps for how to program a Nexys 4 DDR board with a microblaze soft processor and run code on that same processor. It assumes that the board file for the Nexys 4 DDR board is already downloaded and added to vivado.

Create a New Vivado Project

  • Run Vivado (vivado) from terminal
  • Create Project
  • Click Next
  • Choose a project name and location and click next
  • Choose RTL Project and check “Do not specify sources at this time” and click next
  • At the top of the window select Boards
  • From the list of boards highlight the Nexys4 DDR and click next
  • If the board is not shown in the list, you need to download and add the board file to vivado.
  • Follow the steps towards the bottom of this tutorial for instructions on how to obtain and add the board file
  • Click Finish

    Create Block Design

  • On the left in the Flow Navigator, under IP INTEGRATOR, select “Create Block Design”
  • Choose a design name and click OK
  • Select the board tab

  • Right click on the Push Buttons entry
  • Select Connect Board Component
  • In the popup, select Create new IP -> AXI GPIO -> GPIO and click OK

  • In the board tab, right click on the LEDs
  • Select Connect Board Component
  • In the popup, select existing IP -> axi_gpio_0 -> GPIO2 and click OK
  • In the board tab, right click on System Clock
  • Select Connect Board Component
  • Check the box next to “clock_CLK_IN1” and click OK
  • Double click on the clk_wiz_0 block in the block diagram
  • On the Board Tab, make sure that CLK_IN1 has sys clock selected
  • For EXT_RESET_IN select reset

  • Select Output Clocks tab
  • Make sure that the clk_out1 box is checked and that the Requested Frequency is 100 MHz
  • Select Active Low for the Reset Type

  • Click OK
  • Click “Run Connection Automation”
  • Make sure the resetn box is checked

  • Click OK
  • In the Board tab, right click on USB UART
  • Select Connect Board Component
  • Select AXI Uartlite -> UART
  • Click OK
  • You can double click the new UART Block to check the UART settings
  • Click the “Add IP” (Plus sign at the top of the block diagram)
  • Search Microblaze
  • Double click microblaze
  • Click Run Block Automation
  • Set Local Memory to 32 KB
  • Click OK
  • Click Run Connection Automation
  • Check the box next to All Automation
  • Click OK

    Generate Bitstream

  • Click the Validate design button
  • Click OK
  • On the sources tab, right click your block design and select Create HDL Wrapper
  • Check Let Vivado manage wrapper and auto-update
  • Click OK
  • Under the Flow Navigator select “Generate Bitstream”
  • Click Yes
  • Click OK
  • Wait
  • On the next pop up click Cancel
  • In the File drop-down select Export, then Export Hardware,
  • Click Next
  • Check Include bitstream and click Next
  • Choose a name for your XSA filename and click Next
  • I named mine dh_microblaze and saved it to /home/danh444/microblaze_tutorial/microblaze
  • Click Finish

    Program Board

  • Click Open Hardware Manager -> Open Target -> Auto Connect
  • Click Program Device -> xc7a100t_0
  • Click Program

    Launch Vitis

  • Run Vitis (vitis) in terminal window
  • Choose a Workspace and click Launch

    Create the Platform Project

  • Click File -> New -> Platform Project
  • Choose a name for the platform project
  • Click Next
  • Under Hardware Specification, Browse to the XSA file you created
  • Click Finish

    Create the Application Project

  • Click File -> New -> Application Project
  • Click Next
  • Select the platform you created
  • Choose an application project name
  • Click Next
  • Choose Empty Application C++
  • Click Finish
  • Under your new application project, right click on src and click add file.

  • Name it main.cpp and click Finish
  • Add the following simple program 
    #include <stdio.h>  
int main() {
  printf("Hello World\n");
}
  • Save the file
  • Right-click on your application project and select build project

    Connect to UART

  • In order to see the program output you need to connect to the board UART
  • Open a separate terminal
  • Enter the following command
  • python3 -m serial.tools.miniterm /dev/ttyUSB1 9600

    Application

  • Right-click on your application project and select run as -> Launch on Hardware (Single application debug)
  • You should see the message Hello World in the UART terminal

    Sources

  • This was done following this tutorial
  • https://digilent.com/reference/vivado/getting-started-with-ipi/2018.2