Hey Jons, I responded on the usrp-users list (didn't see that you had cross-posted).
--M On Sat, Jul 26, 2025 at 10:18 AM Jons <[email protected]> wrote: > Hi all, > I am trying to add a custom RFNoC block and my block runs on different > clocks(not the default ones). So I followed the instructions from the FAQ > page in RFNoC wiki of deriving clocks from the available clocks - > https://kb.ettus.com/RFNoC_Frequently_Asked_Questions#How_do_I_add_a_clock_with_a_different_frequency.3F > But when I add the parameters in block YAML, it added new ports to my > *rfnoc_block_myblock* module, which is not what I expected. My intention > was to derive 2 clocks from the rfnoc_chdr_clk and use it inside my block. > For this I added the clock IP module (instantiated) in the > noc_shell_myblock, because this is where the CDC FIFOs are there. So, with > this method the generated clock just stays inside my block and won't be > available outside to it. Maybe the steps described in the FAQ might not be > the right way to go about with my requirement? I am not sure. > > Also, I tried not adding the YAML parameters of the clocks for my block. > This worked to the point where the implementation of the entire design > failed with WNS of -0.8ns on the new derived clock I added. I also got a > few Critical warnings for the clocks I added, not sure if it is related > somehow or if I can ignore it - > > > > *TIMING-4#1 Critical WarningInvalid primary clock redefinition on a clock > tree Invalid clock redefinition on a clock tree. The primary clock > x4xx_core_i/rfnoc_image_core_i/b_myblock_3/noc_shell_myblock_i/clk_wiz_chdr_200_125_inst/inst/clk_in_chdr > is defined downstream of clock clk200 and overrides its insertion delay > and/or waveform definition. * > > I followed this thread ( > https://www.mail-archive.com/usrp-users%40lists.ettus.com/msg14663.html) > to add IPs of my clock module that I generated with with Vivado IP catalog > and copied the *.xci, .v* and other generated files into the > path/to/module/rfnoc/fpga/myblock/ip/ and changed the Makefile and block > YAML definitions like the example given in the example Gain block. > > Any tips or leads in adding custom derived clocks to the design would be > super helpful and thank you all for maintaining such a nice community!! > -J > > >
