Burst Inference 1 - 2020.2 English

Vitis HLS Messaging (UG1448)

Document ID
UG1448
Release Date
2020-11-24
Version
2020.2 English

Description

The tool is informing the user of incorrect usage of the interface pragma.

Explanation

For mapping to a single bundle there are certain rules and the current code is violation one such rule mentioned below.

All the arguments mapped to the same interface bundle should have the same interface width else automatic burst interface is disabled.

Solution

This example shows an incorrect use of the bitwidth:

  • Incorrect bitwidth:
    void cnn( long *pixel, // Input pixel
      int *weights, // Input Weight Matrix
      int *out, // Output pixel
      ... // Other input or Output ports
                
    #pragma HLS INTERFACE m_axi port=pixel offset=slave bundle=gmem
    #pragma HLS INTERFACE m_axi port=weights offset=slave bundle=gmem1
    #pragma HLS INTERFACE m_axi port=out offset=slave bundle=gmem
  • Correct bitwidth:
    void cnn( long *pixel, // Input pixel
      int *weights, // Input Weight Matrix
      long *out, // Output pixel
      ... // Other input or Output ports
                
    #pragma HLS INTERFACE m_axi port=pixel offset=slave bundle=gmem
    #pragma HLS INTERFACE m_axi port=weights offset=slave bundle=gmem1
    #pragma HLS INTERFACE m_axi port=out offset=slave bundle=gmem