AXI4-Stream Interfaces with Side-Channels - 2023.2 English - UG1399

The following example shows how the side-channels can be used directly in the C/C++ code and implemented on the interface. The code uses #include "ap_axi_sdata.h" to provide an API to handle the side-channels of the AXI4-Stream interface. In the following example a signed 32-bit data type is used:

#include "ap_axi_sdata.h"
#include "ap_int.h"
#include "hls_stream.h"

#define DWIDTH 32

typedef ap_axiu<DWIDTH, 1, 1, 1> trans_pkt;

extern "C"{
    void krnl_stream_vmult(hls::stream<trans_pkt> &A, 
						   hls::stream<trans_pkt> &B) {
#pragma HLS INTERFACE mode=axis port=A
#pragma HLS INTERFACE mode=axis port=B
#pragma HLS INTERFACE mode=s_axilite port=return bundle=control
        bool eos = false;
        
        vmult: do {
#pragma HLS PIPELINE II=1
            trans_pkt t2 = A.read();
            
            // Packet for Output
            trans_pkt t_out;
            
            // Reading data from input packet
            ap_uint<DWIDTH> in2 = t2.data;
            ap_uint<DWIDTH> tmpOut = in2 * 5;

            // Setting data and configuration to output packet
            t_out.data = tmpOut;
            t_out.last = t2.last;
            t_out.keep = -1; //Enabling all bytes
            // Writing packet to output stream
            B.write(t_out);
            if (t2.last) {
               eos = true;
            }
        } while (eos == false);
    }
}

After synthesis, both the A and B arguments are implemented with data ports, the standard AXI4-Stream protocol ports, TVALID and TREADY and all of the optional ports described in the struct.