Data Flow Graph Construction

Once AIE kernels have been prepared, next step is to create a Data Flow Graph class which defines the top level ports, Run time parameters, connectivity, constraints etc. This consists of the following steps:

Create graph.h and include Adaptive Data Flow (ADF) header file (adf.h). Also include header file with kernel function prototypes (kernel.h)
```
#include <adf.h>
#include "kernels.h"
```

Define your graph class by using the objects which are defined in the adf name space. All user graphs are derived from the class graph.

include <adf.h>
#include "kernels.h"

using namespace adf;

class myGraph : public graph {
private:
    kernel k1;
};

Add top level ports to graph. These ports will be responsible to data transfers to / from the kernels.

#include <adf.h>
#include "kernels.h"

using namespace adf;

class simpleGraph : public graph {
private:
    kernel k1;

public:
    port<input> inptr;
    port<output> outptr;
    port<input> kernelCoefficients;
};

Specify connections of top level ports to kernels. Primary connections type are `Window`_, Stream, Run time parameters. Below is example code specifying connectivity.

class myGraph : public adf::graph {
private:
    kernel k1;
public:
    port<input> inptr;
    port<output> outptr;
    port<input> kernelCoefficients;

    myGraph() {
        k1 = kernel::create(filter2D);
        adf::connect(inptr, k1.in[0]);
        adf::connect<parameter>(kernelCoefficients, async(k1.in[1]));
        adf::connect(k1.out[0], outptr);
    }
};

Specify the source file location and other constraints for each kernel.

class myGraph : public adf::graph {
private:
    kernel k1;
public:
    port<input> inptr;
    port<output> outptr;
    port<input> kernelCoefficients;

    myGraph() {
        k1 = kernel::create(filter2D);
        adf::connect(inptr, k1.in[0]);
        adf::connect<parameter>(kernelCoefficients, async(k1.in[1]));
        adf::connect(k1.out[0], outptr);
        source(k1) = "xf_filter2d.cc";
        // Initial mapping
        runtime<ratio>(k1) = 0.5;
    }
};

Data Flow Graph Construction - 2024.1 English

Vitis Libraries