Hand-merged files modified on both fix/pre-bringup-audit-p0 and
feat/fft-2048-upgrade. Wave 1 (commit 60e49c7) took 20 files from fft
verbatim; this wave resolves the overlap.
- run_regression.sh: 3-way merge. Adopts fft's ${RECEIVER_RTL[@]} array
refactor and drops the self-blessing golden pair from p0. Skip count
bumped to 5.
- usb_data_interface.v (FT601/200T): p0 FSM + clock-loss watchdog kept
wholesale; widened stream_control 3 -> 6 bits to carry fft's extended
mode bits through the CDC sync chain and the 0xFF status word.
- mti_canceller.v: fft's BRAM-inferred 512-range-bin implementation as
the base, with p0's F-6.3 saturation counter grafted onto the d1
pipeline stage. Overflow detection uses the top-two-bits disagreement
on diff_{i,q}_full (DATA_WIDTH+1 signed).
- radar_receiver_final.v: fft's 2048-pt / 512-bin structure + p0
diagnostic plumbing (ADC overrange sticky+CDC, DDC diagnostics,
tx_frame_start edge detector replacing chirp_counter frame sync,
mti_saturation_count, range_decim_watchdog).
- radar_system_top.v: clean 3-way merge, orthogonal regions
(+38 / -27).
- usb_data_interface_ft2232h.v (FT2232H/50T): fft's per-frame bulk BRAM
rewrite kept wholesale. Ported two p0 items that are orthogonal to
the write FSM:
* ft_clk-loss watchdog (heartbeat + 2FF ASYNC_REG sync + 16-bit
timeout) ORed into a 2FF sync'd ft_effective_reset_n for the FSM.
* rd_cmd_complete flag so RD_DEASSERT can distinguish a legitimate
3-byte completion from an ft_rxf_n abort that also zeros
rd_byte_cnt.
Deliberately NOT taken from 2401f5f: cic_decimator_4x_enhanced.v and
ddc_400m.v reset-strategy changes. Those conflict with p0's shipped
registered-sync-reset + max_fanout=25 distribution, which is already
timing-clean on the production build.
Addresses findings from docs/DEVELOP_AUDIT_2026-04-19.md:
P0 source-level:
- F-4.3 ADAR1000_Manager::adarSetTxPhase now writes REG_LOAD_WORKING
with LD_WRK_REGS_LDTX_OVERRIDE (0x02) instead of 0x01. Previous value
toggled the LDRX latch on a TX-phase write, so host TX phase updates
never reached the working registers.
- F-6.1 DDC mixer_saturation / filter_overflow / diagnostics were deleted
at the receiver boundary. Now plumbed to new outputs on
radar_receiver_final (ddc_overflow_any, ddc_saturation_count) and
aggregated into gpio_dig5 in radar_system_top. Added mark_debug
attributes for ILA visibility. Test/debug inputs tied low explicitly.
- F-0.8 adc_clk_mmcm.xdc set_clock_uncertainty: removed invalid -add
flag (Vivado silently rejected it, applying zero guardband). Now uses
absolute 0.150 ns which covers 53 ps jitter + ~100 ps PVT margin.
P1:
- F-4.2 adarSetBit / adarResetBit reject broadcast=ON — the RMW sampled
a single device but wrote to all four, clobbering the other three's
state.
- F-4.4 initializeSingleDevice returns false and leaves initialized=false
when scratchpad verification fails; previously marked the device
initialized anyway so downstream PA enable could drive a dead bus.
- F-6.2 FIR I/Q filter_overflow ports, previously unconnected, now OR'd
into the module-level filter_overflow output.
- F-6.3 mti_canceller exposes 8-bit saturation counter. Saturation was
previously invisible and produces spurious Doppler harmonics.
Verification:
- 27/27 iverilog testbenches pass
- 228/228 pytest pass (cross-layer contract + cosim)
- MCU unit tests 51/51 + 24/24 pass
- Remote Vivado 2025.2 build: bitstream writes; 400 MHz mixer pipeline
now shows WNS -0.109 ns which MATCHES the audit's F-0.9 prediction
that the design only closed because F-0.8's guardband was silently
dropped. ft_clkout F-0.9 remains a show-stopper (requires MRCC pin
move), tracked separately.
Not addressed in this PR (larger scope, follow-up tickets):
F-0.4, F-0.5, F-0.6, F-0.7, F-0.9, F-1.1, F-1.2, F-2.2, F-3.2, F-4.1,
F-4.7, F-6.4, F-6.5.
MTI canceller (2-pulse, H(z)=1-z^{-1}) between range decimator and
Doppler processor. Subtracts previous chirp from current, nulling DC
Doppler (stationary clutter). Pass-through when host_mti_enable=0.
DC notch filter (post-Doppler, pre-CFAR) zeros bins within
+/-host_dc_notch_width of DC. Complements MTI for residual clutter.
New host registers: 0x26 (mti_enable), 0x27 (dc_notch_width).
Both default to 0 (disabled) - fully backward-compatible.
Verification: 23/23 regression, 29/29 MTI standalone, 3/3 real-data
co-sim (5137/5137 exact match) all PASS.
Jason