matched_filter_processing_chain declared `input wire [5:0] chirp_counter`
but never read it inside the module. matched_filter_multi_segment passed
its own chirp_counter through to that dead port.
Removed the port from the chain and the corresponding hookup at the
multi_segment instantiation site. Five testbenches also referenced the
port (tb_mf_cosim, tb_matched_filter_processing_chain, tb_rxb_latency
_measure plus the four MF cosim variants that share tb_mf_cosim) — the
reg/connection/init lines were dropped, and the now-stale "Test Group 8:
Chirp Counter Passthrough" was repurposed as a port-removal smoke test
that confirms the chain still produces FFT_SIZE outputs without that
input.
multi_segment.chirp_counter input remains on the port list (it could
plausibly be wired to per-chirp logic in the future); it is now formally
unused but iverilog/Vivado do not flag unused module inputs.
Quick regression: 28/29 PASS (same as baseline; the 1 fail is the known
iverilog/Xilinx-IP RX-NEW-3 gap unchanged by this commit).
Jason
0b8b933e27