5 – A simple multiplication example

To explore these methods of passing data around, let’s use our template to write a very simple program to pass one integer to the FPGA from the host and tell the FPGA to multiply this integer by 2 and pass it back to the host. As we’re passing a single integer, the host can pass this straight to the FPGA’s control register but the route back from the FPGA to the CPU is always via the shared memory. As we have done in previous tutorials, lets first look at a flow diagram for this example:

../_images/StructureDiagram1.svg

We can use our template to write the code to perform this multiplication.