Creating the Vitis IP

In the previous unit on loop optimization, we built and optimized a simple vector multiplier IP core. Before starting, we need to select a set of parameters and package the IP and run the Implementation. You can build the IP manually with the Vitis GUI or via an included script.

Building the Vitis IP with a script

• Navigate to hwdesign/vector_mult/vmult_vitis.
• The script is located in scripts/build_ip.tcl. If you want you can change the unroll factor for the IP you want to build by modifying the line:

    # Set the desired unroll factor
    set uf 4
    set sol_name "sol_uf$uf"
  

  By default, it is set to 4.

• Run the script:

  vitis-run --mode hls --tcl scripts/build_ip.tcl
  

• Running the script will take about 1 to 2 minutes.
• The IP should be located in a directory such as /hwdesign/vector_mult/vmult_vitis/sol_uf4/ depending on what unroll factor you used.

Building the IP with the Vitis GUI

• Follow the instructions loop optimization to build the Vitis IP project
• In include/vmult.h set the parameters:

  #define PIPELINE_EN 1  // Enables pipelining
  #define UNROLL_FACTOR 4  // Unrolls loops when > 1
  #define MAX_SIZE 1024  // Array size to test
  #define DATA_FLOAT 1   // Data type:  1= float, 0=int
  

  This will use loop unrolling. But, you can use any parameters you like.

• In the FLOW panel, run the C simulation to make sure it works
  • You should see Test passed!
• Run the C synthesis:
  • Still in the FLOW panel, select C synthesis->Settings (the gear box icon). Set the clock to be 300 MHz.
  • Run the C synthesis
• Next in the FLOW panel, run the Package step.
  • Note that you do not need to run Implementation since we are not creating a standalone bitstream for the IP – just a IP that can be imported into Vivado.
• The IP should be located in /hwdesign/vector_mult/vmult_vitis/vmult_hls/

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