FlintyLemming/PLFM_RADAR
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8 Commits

Author SHA1 Message Date
Jason d0b3a4c969 fix(fpga): registered reset fan-out at 400 MHz; default USB to FT2232H 
Replace direct !reset_n async sense with a registered active-high reset_h
(max_fanout=50) in nco_400m_enhanced, cic_decimator_4x_enhanced, and
ddc_400m.  The prior single-LUT1 / 700+ load net was the root cause of
WNS=-0.626 ns in the 400 MHz clock domain on the xc7a50t build.  Vivado
replicates the constrained register into ≈14 regional copies, each driving
≤50 loads, closing timing at 2.5 ns.

Change radar_system_top default USB_MODE from 0 (FT601) to 1 (FT2232H).
FT601 remains available for the 200T premium board via explicit parameter
override; the 50T production wrapper already hard-codes USB_MODE=1.

Regression: add usb_data_interface_ft2232h.v to PROD_RTL lint list and
both system-top TB compile commands; fix legacy radar_system_tb hierarchical
probe from gen_ft601.usb_inst to gen_ft2232h.usb_inst.

Golden reference files (rtl_bb_dc.csv, rx_final_doppler_out.csv,
golden_doppler.mem) regenerated to reflect the +1-cycle registered-reset
boundary behaviour; Receiver golden-compare passes 18/18 checks.

All 25 regression tests pass (0 failures, 0 skipped).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
 2026-04-18 20:34:52 +05:45
Jason 254c0e6f03 Improve timing margins with targeted datapath register tuning 
Reduce routing pressure on CIC/NCO critical paths and move Doppler BRAM read-address registers to sync-reset datapath logic so Build 13 closes with stronger setup/hold slack while preserving functional behavior.
 2026-03-17 23:51:04 +02:00
Jason fd6094ee9e Fix P0/P1 RTL bugs found during pre-hardware audit 
P0-1: nco_400m_enhanced.v — DSP48E1 OPMODE corrected from PCIN to P
      feedback (was routing stale cascade data into accumulator)
P0-2: radar_receiver_final.v — removed same-clock CDC that corrupted
      ADC data path between ad9484_interface and DDC
P1-5: fir_lowpass.v — fixed zero replication count in coefficient
      symmetric extension ({0{1'b0}} is empty, now uses explicit 0)

Also updates .gitignore to exclude debug/scratch artifacts.

All 30+ testbenches pass (unit, co-sim, integration).
 2026-03-16 22:24:06 +02:00
Jason 00fbab6c9d Achieve full timing closure on xc7a100tcsg324-1 at 400 MHz (0 violations) 
Complete FPGA timing closure across all clock domains after 9 iterative
Vivado builds. WNS improved from -48.325ns to +0.018ns (107,886 endpoints).

RTL fixes for 400 MHz timing:
- NCO: 6-stage pipeline with DSP48E1 phase accumulator, registered LUT
  index (Fix D splits address decode from ROM read), distributed RAM
- CIC: explicit DSP48E1 PCOUT->PCIN cascade for 5 integrator stages,
  CREG=1 on integrator_0 to eliminate fabric->DSP setup violation
- DDC: 400 MHz reset synchronizer (async-assert/sync-deassert),
  active-high reset register for DSP48E1 RST ports, posedge output stage
- FIR: 5-stage binary adder tree pipeline (7-cycle latency)
- FFT: 5-cycle butterfly pipeline with registered twiddle index,
  XPM_MEMORY_TDPRAM for data storage
- XDC: CDC false paths, async reset false paths, CIC comb multicycle paths

Final Build 9 timing (all MET):
  adc_dco_p (400 MHz): WNS = +0.278ns
  clk_100m  (100 MHz): WNS = +0.018ns
  clk_120m_dac (120 MHz): WNS = +0.992ns
  ft601_clk_in (100 MHz): WNS = +5.229ns
  Cross-domain (adc_dco_p->clk_100m): WNS = +7.105ns
 2026-03-16 15:02:35 +02:00
Jason c983a3c705 Achieve timing closure: DSP48E1 pipelines, 4-stage NCO, 28-bit CIC, ASYNC_REG 
Phase 0+ timing optimization (attempts #13-22 + implementation):

NCO (nco_400m_enhanced.v):
- 4-stage pipeline: DSP48E1 accumulate -> LUT read -> negate -> quadrant MUX
- DSP48E1 phase accumulator in P=P+C mode (eliminates 8-stage CARRY4 chain)
- Registered phase_inc_dithered to break cascaded 32-bit add path

DDC (ddc_400m.v):
- Direct DSP48E1 instantiation for I/Q mixers (AREG=1, BREG=1, MREG=1, PREG=1)
- CEP=1, RSTP=!reset_n for proper pipeline control
- 3-stage dsp_valid_pipe for PREG=1 latency
- Behavioral sim model under ifdef SIMULATION for Icarus compatibility

CIC (cic_decimator_4x_enhanced.v):
- 28-bit accumulators (was 36) per CIC width formula: 18 + 5*log2(4) = 28
- Removed integrator/comb saturation (CIC uses wrapping arithmetic by design)
- Pipelined output saturation comparison

CDC/ASYNC_REG:
- ASYNC_REG attribute on all CDC synchronizer registers (cdc_modules.v,
  radar_system_top.v, usb_data_interface.v)
- Sync reset in generate blocks (cdc_modules.v)

Results: Vivado post-implementation WNS=+1.196ns, 0 failing endpoints,
850 LUTs (1.34%), 466 FFs (0.37%), 2 DSP48E1 (0.83%) on xc7a100t.
All testbenches pass: 241/244 (3 known stub failures).
 2026-03-16 01:02:07 +02:00
Jason c871281f1e Fix synthesis blockers in 9 RTL files for Vivado compatibility 
Guard all $display/$error/$time calls with ifdef SIMULATION in:
- chirp_memory_loader_param.v (initial + always block debug prints)
- cic_decimator_4x_enhanced.v (5 saturation/overflow displays + monitor block)
- ddc_400m.v (FIR/baseband debug monitor block)
- fft_1024_inverse.v (IFFT config debug block)
- matched_filter_multi_segment.v (16 state machine displays + monitor)
- nco_400m_enhanced.v (initial block debug print)
- radar_receiver_final.v (frame/chirp counter displays)

Replace SystemVerilog constructs with Verilog-2001:
- usb_data_interface.v (typedef enum -> localparam + reg)
- usb_packet_analyzer.v (typedef enum -> localparam, output reg -> wire)
 2026-03-15 14:53:35 +02:00
Jason 76183e2e95 Fix 6 RTL bugs in FPGA signal processing chain 
- nco_400m_enhanced.v: Correct sine LUT values (3.7x quadrature error)
- ddc_400m.v: Fix wire forward-declaration (Verilog-2001 compliance)
- plfm_chirp_controller.v: Remove multi-driven chirp_counter (critical)
- radar_system_top.v: Fix CFAR wire-as-reg, connect chirp_counter to receiver
- radar_receiver_final.v: Promote chirp_counter to input port

All fixes verified with Icarus Verilog 13.0 testbenches (144/144 tests pass).
 2026-03-15 06:14:04 +02:00
NawfalMotii79 5fbe97fa5f Add files via upload 2026-03-09 00:17:39 +00:00