All, The rfnoc-radio-redo branch now supports Xilinx's free XSIM HDL simulator which is included with Vivado. To test out XSIM, there are several example test benches in usrp3/lib/rfnoc. For example, run 'make xsim' while in usrp3/lib/rfnoc/noc_block_fft_tb to run the FFT RFNoC block test bench. If you want to see the simulation waveforms using Vivado's GUI, use 'make GUI=1 xsim'. Also, the test bench API has had some improvements. There will be a knowledge base article on this topic in the future. For now, refer to the example RFNoC block "Skeleton" (noc_block_skeleton.v) and associated test bench. Please let me know if you run into any issues or have any suggestions! Jonathon