1558f17d05
Convert async→sync reset on DSP/BRAM datapath registers for timing closure
...
P1-CRITICAL: doppler_processor.v — split FSM into control (async reset)
and BRAM/DSP datapath (sync reset) blocks. Fixes REQP-1839/1840 BRAM
address register corruption risk; enables DSP48 absorption of window
multipliers (mult_i/q).
P1-CRITICAL: frequency_matched_filter.v — convert all 4 pipeline stages
(input capture, multiply, add, saturate) from async to sync reset.
Enables DSP48E1 absorption of complex multiplier registers.
P1-HIGH: fir_lowpass.v — convert adder tree (L0-L4), output stage, and
valid pipeline from async to sync reset. Fixes 856 DPOR-1 warnings
(428 per FIR instance × 2 I/Q channels), enabling DSP48 absorption
of the entire pipelined adder tree.
Expected impact: eliminate ~1000 DRC warnings, improve WNS from +0.019ns
by enabling Vivado to absorb hundreds of registers into DSP48E1/BRAM
hard blocks. Full regression: 13/13 test suites pass (257+ assertions).
2026-03-17 20:11:13 +02:00
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
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
NawfalMotii79