Drop the chirp-v1 1-bit use_long_chirp memory loader and its 6 .mem files;
introduce chirp_reference_rom — wave_sel-native, single 8192x16 BRAM array
per Q15 lane, 4-region init (SHORT, MEDIUM, LONG seg0/seg1) loaded from the
PR-B mem files. Same 1-clk read latency as the legacy module so the RX-B
autocorrelation alignment fix carries through unchanged.
Receiver-side wave_sel shim added in radar_receiver_final.v:
wire [1:0] wave_sel = use_long_chirp ? RP_WAVE_LONG : RP_WAVE_SHORT;
This is a 1-line transitional bridge while radar_mode_controller still
emits 1-bit use_long_chirp; PR-D deletes the shim and wires chirp_scheduler
straight through. MEDIUM is loaded into the ROM but unreachable through
the production path until PR-D.
BRAM cost: 8 RAMB18 (was 6 in chirp-v1). +2 BRAM is the cost of adding
MEDIUM to the waveform set; not avoidable.
Files added:
- chirp_reference_rom.v
Files removed:
- chirp_memory_loader_param.v
- long_chirp_seg{0,1}_{i,q}.mem (4 files)
- short_chirp_{i,q}.mem (2 files)
- tb/cosim/validate_mem_files.py (legacy file-set validator; replaced by
gen_chirp_mem.py's internal verify_phase_match)
- tb/cosim/analyze_short_chirp_mismatch.py (one-shot tool from the
chirp-v1 TX-I investigation; finding incorporated, references the
deleted short_chirp_*.mem files)
Files updated for module rename:
- radar_receiver_final.v — instance, comments, wave_sel shim
- radar_mode_controller.v — header comment
- matched_filter_processing_chain.v — header comment
- scripts/200t/build_200t.tcl — explicit RTL list
- run_regression.sh — 5 spots
- tb/tb_rxb_fullchain_latency.v — instance, wave_sel shim, mem filenames,
SHORT_LEN 50 → 100 (1 µs at 100 MHz)
- tb/tb_system_e2e.v — header comment
Verification:
- chirp_reference_rom standalone iverilog compile: clean
- Full receiver chain compile (21 RTL files): clean
- tb_rxb_fullchain_latency runs end-to-end with new ROM + new mem files
+ 100-sample SHORT chirp; autocorrelation peak at bin 0, peak |I|+|Q|
= 15115. Confirms 1-clk ROM read latency is preserved and the RX-B
direct-wire-with-1-FF alignment still holds.
- 50T build script (scripts/50t/build_50t.tcl) uses glob *.v — no edit
needed; it picks up the new file automatically.
