Node Constraints - 2021.2 English

Versal ACAP AI Engine Programming Environment User Guide (UG1076)

Document ID
UG1076
ft:locale
English (United States)
Release Date
2021-12-17
Version
2021.2 English

The NodeConstraints section is used to constrain graph nodes. Constraints are grouped by node, such that one or more constraints can be specified per node.

Syntax

{
  "NodeConstraints": {
    "<node name>": {
      <constraint>,
      <constraint>,
      ...
    }
  }
}
<node name> ::= string
<constraint> ::= tile
               | shim
               | reserved_memory
               | colocated_nodes
               | not_colocated_nodes
               | colocated_reserved_memories
               | not_colocated_reserved_memories

Example

{
  "NodeConstraints": {
    "mygraph.k1": {
      "tile": {
        "column": 2,
        "row": 1
      },
      "reserved_memory": {
        "column": 2,
        "row": 1,
        "bankId": 3,
        "offset": 4128
      }
    },
    "mygraph.k2": {
      "tile": {
        "column": 2,
        "row": 2
      }
    }
  }
}

Node Names

Nodes must be specified by their fully qualified name, for example: <graph name>.<kernel name>.

In the following example, the graph name is myGraph and the kernel name is k1. The fully specified node name is myGraph.k1.

class graph : public adf::graph {
private:
  adf::kernel k1;
public:
  my_graph() { 
    k1 = kernel::create(kernel1);
    source(k1) = "src/kernels/kernel1.cc";
  }
};
graph myGraph;

Whenever this kernel is referenced in the constraints JSON file it must be named myGraph.k1, as shown in the various examples throughout this document.