With the various domain application projects added to the top-level system project, only the connections between the AI Engine graph and the PL kernels need to be defined using the hw_link project. This project is automatically generated during the creation of the AI Engine graph project.
- Open the hw_link
project by double-clicking on the project in the Explorer view. Right-click on the binary_container in the Hardware Functions window, and select the Edit V++ Options command.
- Edit the V++
Options field. It is important to add the correct path
to the config file because the
v++command needs it for the Vitis IDE workspace.
- Import the specified config file into
the hw_link project folder.
Tip: The system configuration file is added to the hw_link project folder and not to a src folder.
As explained in Linking the System, for AI Engine graph applications the Vitis compiler needs some instruction on how to connect PL kernels to the graph. The number of kernels to be instantiated is already configured in the IDE. However the definition of the connections between the PL kernels and the graph must be specified.
For the Vitis IDE the following is an example configuration file:
[connectivity] stream_connect=mm2s_1.s:ai_engine_0.DataIn1 stream_connect=ai_engine_0.clip_in:polar_clip_1.in_sample stream_connect=polar_clip_1.out_sample:ai_engine_0.clip_out stream_connect=ai_engine_0.DataOut1:s2mm_1.s
sc option defines
connections between the ports of the AI Engine
graph and streaming ports of PL kernels. Connections can be defined as the streaming
output of one kernel connecting to the streaming input of a second kernel, or to a
streaming input port on an IP implemented in the target platform.
The system.cfg file has some
differences between the Vitis IDE and the
command-line flow as described in Linking the System. The primary difference is that the IDE provides the connectivity
nk options of the config file, instantiating a specified number of compute units (CUs)
per kernels, as specified in the build settings. In addition, the IDE uses a naming
convention for CUs in the form
# indicates the CU instance. In the case where there is only
one CU instance, it has the
_1 extension. This
means that for the Vitis IDE, the system.cfg should not specify the
nk option, and the
sc option should use the CU instance name from the IDE.