RTL fixes discovered via new end-to-end testbench:
- plfm_chirp_controller: TX/RX mixer enables now mutually exclusive
by FSM state (Fix#4), preventing simultaneous TX+RX activation
- usb_data_interface: stream control reset default 3'b001 (range-only),
added doppler/cfar data_pending sticky flags, write FSM triggers on
range_valid only — eliminates startup deadlock (Fix#5)
- radar_receiver_final: STM32 toggle signals wired through for mode-00
pass-through, dynamic frame detection via host_chirps_per_elev
- radar_system_top: STM32 toggle signal wiring to receiver instance
- chirp_memory_loader_param: explicit readmemh range for short chirp
Test infrastructure:
- New tb_system_e2e.v: 46 checks across 12 groups (reset, TX, safety,
RX, USB R/W, CDC, beam scanning, reset recovery, stream control,
latency budgets, watchdog)
- tb_usb_data_interface: Tests 21/22/56 updated for data_pending
architecture (preload flags, verify consumption instead of state)
- tb_chirp_controller: mixer tests T7.1/T7.2 updated for Fix#4
- run_regression.sh: PASS/FAIL regex fixed to match only [PASS]/[FAIL]
markers, added E2E test entry
- Updated rx_final_doppler_out.csv golden data
Adds two-layer lint pass (iverilog -Wall + custom static checks) that
catches part-select OOB errors and case-without-default warnings before
pushing to remote Vivado. Catches the exact Synth 8-524 class error that
broke Build 18 initial attempt. Lint errors abort regression; warnings
are advisory. Regenerated golden data for BRAM-migrated matched filter.
CDC fixes across 6 RTL files based on post-implementation report_cdc analysis:
- P0: sync stm32_mixers_enable and new_chirp_pulse to clk_120m via toggle CDC
in radar_transmitter, add ft601 reset synchronizer and USB holding
registers with proper edge detection in usb_data_interface
- P1: add ASYNC_REG to edge_detector, convert new_chirp_frame to toggle CDC,
fix USB valid edge detect to use fully-synced signal
- P2: register Gray encoding in cdc_adc_to_processing source domain, sync
ft601_txe and stm32_mixers_enable for status_reg in radar_system_top
- Safety: add in_bin_count overflow guard in range_bin_decimator to prevent
downstream BRAM corruption
All 13 regression test suites pass (159 individual tests).
New testbenches:
- tb_latency_buffer.v: 13/13 tests for BRAM delay line (P1-3)
- tb_cdc_modules.v: 27/27 tests for all 3 CDC primitives (P1-4)
- tb_ad9484_xsim.v: XSim testbench for AD9484 with Xilinx BUFIO/IDDR
- tb_nco_xsim.v: XSim testbench for NCO DSP48E1 path verification
Fixes:
- tb_usb_data_interface.v: updated test 33 from divide-by-2 check to
ODDR-style clock forwarding verification (39/39 pass)
- rx_final_doppler_out.csv: updated golden reference after bug fixes
RTL fix: matched_filter_multi_segment.v ST_WAIT_FFT now waits for
processing chain to complete ALL 1024 outputs and return to IDLE
before advancing to next segment. Previously, it transitioned on the
first fft_pc_valid edge, causing the chain to still be outputting
while multi-seg started collecting data for the next segment. This
broke the handshake and caused permanent deadlock after segment 0.
Also fixes forward reference of sample_addr_from_chain in
radar_receiver_final.v (declaration moved before first use).
New files:
- tb/tb_radar_receiver_final.v: P0 integration test for full RX
pipeline (ADC->DDC->MF->range_bin_decimator->doppler), 10 checks
- tb/ad9484_interface_400m_stub.v: behavioral ADC stub for iverilog
All existing tests still pass: multi-seg 32/32, MF co-sim 3/3,
Doppler co-sim 14/14.
Bit-accurate Python model (fpga_model.py) mirrors full DDC RTL chain:
NCO -> mixer -> CIC -> FIR with exact fixed-point arithmetic matching
RTL DSP48E1 pipeline behavior including CREG=1 delay on CIC int_0.
Synthetic radar scene generator (radar_scene.py) produces ADC test
vectors for 5 scenarios: DC, single target (500m), multi-target (5),
noise-only, and 1 MHz sine wave.
DDC co-sim testbench (tb_ddc_cosim.v) feeds hex vectors through RTL
DDC and exports baseband I/Q to CSV. All 5 scenarios compile and run
with Icarus Verilog (iverilog -g2001 -DSIMULATION).
Comparison framework (compare.py) validates Python vs RTL using
statistical metrics (RMS ratio, DC offset, peak ratio) rather than
exact sample match due to RTL LFSR phase dithering. Results: 5/5 PASS.
Jason