Add the DATAFLOW Optimization - 2022.2 English

Select the dct.cpp tab to make the Code Editor active.

In the Directive view, select the top-level dct function, right-click and select Insert Directive.

This opens the Vitis HLS Directive Editor.

Make the following selections:

1. In the the Directive Field, select DATAFLOW.

2. In the Destination field, select Directive File.

3. Click OK to close the form, and apply the directive.

From the main menu select Solution > Run C Synthesis > All Solutions to rerun synthesis. This runs synthesis for all solutions, letting you compare the results.

After synthesis completes, the Synthesis Summary report is displayed for the active solution; in this case, the DATAFLOW solution. A Vitis HLS Report Comparison is also displayed for the synthesis results of all solutions that were synthesized as shown in the following figure.

You can see from the comparison results, the interval for the DATAFLOW solution is about 65% of first solution results. This is the primary advantage of the task-level parallelism provided by the DATAFLOW optimization. The other thing you can see is the increased utilization estimates for FF and LUTs in the design. These are just estimates, and you need to run Vivado synthesis and/or the implementation flow to get more accurate details on the resources used.

The following figure shows the Synthesis Summary report for the DATAFLOW solution.