Adding the Dataflow Directive - 2023.1 English - XD098

1. Add the Dataflow directive to the top-function of the design. In the Config File editor, select the Dataflow directive and add dct, or edit the hls_config.cfg file and add the following line: syn.directive.dataflow=dct

2. Rerun synthesis and review the reports.

You should notice the addition of the Dataflow Viewer report as a result of adding the Dataflow directive. However, you need to run C/RTL Co-simulation in order to get greater information from the dataflow design. Examine the Dataflow Viewer report prior to running Co-simulation, and then again after. First you should configure the Co-simulation to perform as you want.

1. Open the Config File editor, an select the C/RTL Co-Simulation category on the left side. The options for Co-simulation are displayed on the right.

2. Select enable_dataflow_profiling to turn on the feature.

3. Select enable_fifo_sizing to turn on this feature.

4. Select Run under C/RTL Co-Simulation in the Flow Navigator.

The DATAFLOW optimization is a dynamic optimization that can only really be understood after C/RTL co-simulation which provides needed performance data. After co-simulation the columns of the Process table are populated with values from the simulation results.