Area Location Constraints - 2022.1 English

Area location constraints direct the compiler to contain nodes to a custom location in the array. Properties to specify on an area group are described in the following table.

The following examples show how an area location constraint can be applied in a graph file.

using namespace adf;

class testGraph1: public adf::graph {

    private:
        kernel first;
        kernel second;
    public:
        testGraph1()  {
            first = kernel::create(simple1);
            second = kernel::create(simple2);
            connect< window<128> > net1 (first.out[0], second.in[0]);
            source(first) = "src/kernels/kernels.cc";
            source(second) = "src/kernels/kernels.cc";
            runtime<ratio>(first) = 0.1;
            runtime<ratio>(second) = 0.1;

            // Create area group with some valid ranges.
            location<graph>(*this) = area_group({{aie_tile, 0, 0, 1, 7}, {shim_tile, 0, 0, 1, 0}});
        }

};

using namespace adf;

class testGraph2: public adf::graph {

    private:
        kernel first;
        kernel second;
    public:
        testGraph2()  {
            first = kernel::create(simple1);
            second = kernel::create(simple2);
            connect< window<128> > net1 (first.out[0], second.in[0]);
            source(first) = "src/kernels/kernels.cc";
            source(second) = "src/kernels/kernels.cc";
            runtime<ratio>(first) = 0.1;
            runtime<ratio>(second) = 0.1;

            // Explicitly specify contain_routing, exclusive_routing, exclusive_placement.
            location<graph>(*this) = area_group({{aie_tile, 0, 0, 1, 7}, {shim_tile, 0, 0, 1, 0}}, true, false, true);
        }

};

The following table clarifies whether the nodes and nets can access the resources of the area group given various combinations of the flags. The use cases presented in the table as columns are illustrated in the figure that follows. Two important things to consider when applying the rules from the following table.

• Broadcast nets that are driven from one node to several destination nodes, are considered as individual point-to-point nets
• Any FIFOs on a net (stream switch or DMA) adhere to the same conditions as the net. For example, if a net is fully contained in an area group (both driver and receiver are contained in the area group) and the contain_routing flag is used, then the following table indicates that the net routing must be fully contained in the area group. Similarly, any FIFOs on that net, must also be placed within the boundary of the area group.

An illustration of the use cases is shown in the following figure.