Stream Memory Map Mixed
=======================

This is a simple streaming Vector Addition C Kernel design with 1 Stream
input, 1 memory mapped input to the kernel, and 1 stream output that
demonstrates on how to process a stream of data along with memory mapped
interface.

**KEY CONCEPTS:** Read/Write Stream, Create/Release Stream

**KEYWORDS:** cl_stream, CL_STREAM_EOT

This example demonstrate how to process an input stream of data from
host for computation along with memory mapped OpenCL buffer inputs.
``krnl_stream_vadd`` has 1 stream input, one memory mapped buffer input
and 1 stream output.

Following is the kernel definition along with Interface pragma:

.. code:: cpp

   typedef qdma_axis<DWIDTH, 0, 0, 0> pkt;
   void krnl_stream_vadd(hls::stream<pkt> &out, // Write-Only output Stream
                         hls::stream<pkt> &in1, // Input Stream 1
                         int *in2,              // Memory mapped Input Vector 2
                         int size               // Size in integer
   ) {
   #pragma HLS INTERFACE axis port = out
   #pragma HLS INTERFACE axis port = in1
   #pragma HLS INTERFACE m_axi port = in2 offset = slave bundle = gmem
   #pragma HLS INTERFACE s_axilite port = in2 bundle = control
   #pragma HLS INTERFACE s_axilite port = size bundle = control
   #pragma HLS INTERFACE s_axilite port = return bundle = control
   ...
   }

Here kernel has two input argument in1 and in2. in1 is axis (AXI
Streaming) type and in2 is m_axi (memory Master AXI) Interface type.

Inside host code, user has to set argument only for non-streaming
interface as shown below:

.. code:: cpp

   cl::Kernel krnl_vadd = cl::Kernel(program, "krnl_stream_vadd", &err));
   krnl_vadd.setArg(2, buffer_in2);
   krnl_vadd.setArg(3, size);

For ``axis`` streaming interface type argument, host needs to creates
streaming objects as below:

.. code:: cpp

   cl_int ret;
   cl_mem_ext_ptr_t ext;
   ext.param = krnl_vadd.get(); //specifying the kernel object on which stream connection will be established
   ext.obj = NULL;

   ext.flags = 0; //Create read stream for argument 0 of kernel
   cl_stream read_stream xcl::Stream::createStream(device.get(), CL_STREAM_READ_ONLY, CL_STREAM, &ext, &ret));
   ext.flags = 1; //Create write stream for argument 1 
   cl_stream write_stream_a = xcl::Stream::createStream(device.get(), CL_STREAM_WRITE_ONLY, CL_STREAM, &ext, &ret));

Please refer ``streaming_simple`` example to more about Streaming kernel
usage.

EXCLUDED PLATFORMS
------------------

Platforms containing following strings in their names are not supported
for this example :

::

   zc
   xdma
   xilinx_u250_qep
   aws
   samsung

DESIGN FILES
------------

Application code is located in the src directory. Accelerator binary
files will be compiled to the xclbin directory. The xclbin directory is
required by the Makefile and its contents will be filled during
compilation. A listing of all the files in this example is shown below

::

   src/host.cpp
   src/krnl_stream_vadd.cpp

COMMAND LINE ARGUMENTS
----------------------

Once the environment has been configured, the application can be
executed by

::

   ./vadd_stream <krnl_stream_vadd XCLBIN>