Host Code with OpenCL - 2023.2 English

Host code is compiled for the host machine that runs on the host and provides the data and control signals to the attached hardware with the FPGA. The host code is written using OpenCL constructs and provides capabilities for setting up, and running a kernel on the FPGA. The following functions are executed using the host code:

1. Loading the kernel binary on the FPGA – xcl::import_binary_file() loads the bitstream and programs the FPGA to enable required processing of data.
2. Setting up memory buffers for data transfer – Data needs to be sent and read from the DDR memory on the hardware. cl::Buffers are created to allocate required memory for transferring data to and from the hardware.
3. Transfer data to and from the hardware –enqueueWriteBuffer() and enqueueReadBuffer() are used to transfer the data to and from the hardware at the required time.
4. Execute kernel on the FPGA – There are functions to execute kernels on the FPGA. There can be single kernel execution or multiple kernel execution that could be asynchronous or synchronous with each other. Commonly used command is enqueueTask().
5. Profiling the performance of kernel execution – The host code in OpenCL also enables measurement of the execution time of a kernel on the FPGA. The function used in our examples for profiling is getProfilingInfo().