6. Host Programming#
As discussed in Section 1.2.1, the PS, more specifically the ARM Cortex-A53 APU, serves as a host that controls the DSP kernels implemented in the PL. The ADC hardware component serves as a data source for the DSP kernels. In addition, the PS may also serves as a data source as well as a data (result) sink for the DSP kernels. Data transfer between the PS host and the DSP kernels occurs via the global memory as discussed in Section 5.1.
Under the VAAD flow, as discussed in Section 1.3, the XRT library provides APIs to let the PS host program control the DSP kernels as well as transfer data to and from the kernels via the global memory.
The Vitis and XRT library provide two different classes of APIs:
OpenCL APIs (Vitis and XRT support OpenCL 1.2 [Khronos OpenCL Working Group12])
We will discuss mainly the OpenCL APIs here. We will start with a very brief overview of OpenCL and then discuss how to employ the OpenCL APIs to set up, control, and execute DSP kernels in the PL as well as to perform data exchange with between the host and the DSP kernels.