FIFO Constraint - 2024.1 English

AI Engine-ML Kernel and Graph Programming Guide (UG1603)

Document ID
Release Date
2024.1 English

This constrains a FIFO to a specific tile located at a specified column and row within the array. The tile can be an AI Engine-ML tile, or interface tile.

The following code block shows the syntax.

"PortConstraints": [<fifo list>]
<fifo list> ::= <fifo type>[, <fifo type>...]
<fifo type> ::= <stream_fifos>

<stream_fifos> ::= {
  "fifo_id": string,
  "tile_type": "shim",
  "column": integer,
  "row": integer,
  "channel": integer

The following code shows an example.

  "PortConstraints": {
    "fifo_locations_records": {
      "stream_fifos": {
        "r3": {
          "tile_type": "shim",
          "row": 1,
          "column": 3,
          "channel": 1
    "[0]": {
      "not_colocated_nodes": ["mygraph.k1"],
      "fifo_locations": ["r3"]
Note: The AI Engine-ML does not support DMA FIFO.