Location and other constraints might be applied in the parent graph which instances the FFT graph class. To apply a constraint, you will need to know the name of the kernel, which will include the hierarchial path to that kernel. The simplest way to derive names, including the hierarchial part, is to compile a design and open it in AMD Vitis™ , using the graph view. The names of all kernels and memory buffers can be obtained from there. These names may then be back-annotated to the parent graph to apply the necessary constraint.