E2E integration test + RTL fixes: mixer sequencing, USB data-pending, receiver wiring (0773001)
New end-to-end testbench (tb_system_e2e.v) with 46 checks across 12 groups covering reset, TX, safety, RX, USB R/W, CDC, beam scanning, reset recovery, stream control, latency budgets, and watchdog. RTL fixes discovered via E2E: chirp controller TX/RX mixer enables now mutually exclusive by FSM state; USB write FSM gains doppler/cfar data_pending sticky flags with stream-control reset default changed to range-only (3'b001); receiver gets STM32 toggle signal inputs and dynamic frame detection. USB unit tests 21/22/56 updated for data_pending architecture. Regression script PASS/FAIL parsing hardened. 19/19 FPGA, 20/20 MCU.
FFT engine optimizations: 4-cycle butterfly + barrel-shift twiddle (a3e1996)
Merged SHIFT state into WRITE stage for a 5→4 cycle butterfly pipeline (20% throughput improvement). Replaced multiplier-based twiddle factor index computation with variable left-shift (barrel shift), freeing one DSP48 multiplier. Both changes verified via FFT testbench.
Gap 2: GUI Settings — runtime chirp timing, stream control, status readback (7cdfa48)
Radar chirp timing parameters (long/short chirp, listen, guard cycles, chirps-per-elevation) are now runtime-configurable via 6 new USB opcodes (0x10-0x15). Stream control (opcode 0x04) gates the USB write FSM per-stream. CFAR threshold (opcode 0x03) is wired to actual comparison logic (was hardcoded). Status readback (opcode 0xFF) returns a 7-word packet with all current settings. CDC handled via per-bit 2-stage synchronizers (stream control) and toggle CDC (status request). 4 new testbench groups added. 18/18 FPGA, 20/20 MCU.
Gap 4: USB Read Path wired with toggle CDC (e5d1b3c)
FT601 read FSM cmd_* outputs connected through toggle CDC to clk_100m command decode registers in radar_system_top.v. Host can now set radar mode, trigger chirps, set CFAR threshold, and control data streaming via USB. 3 new testbench groups (55 total checks). 18/18 FPGA regression.
Build 20 tagged v0.1.3-build20 — new production baseline (c6103b3)
WNS improved 7x to +0.426 ns (from +0.062 ns in Build 18). Includes 400 MHz MMCM jitter cleaner, CIC comb DSP48E1 CREG pipeline, and XDC clock-name fix. All timing constraints met. 6,092 LUTs (4.5%), 9,024 FFs (3.4%), 16 BRAM (4.4%), 140 DSP48E1 (18.9%), 0.730 W.
Build 19 timing failure root-caused and fixed
Build 19 had WNS -0.011 ns due to conflicting XDC create_generated_clock preventing false-path application on CDC paths. Fixed by removing the conflicting constraint and using Vivado auto-generated clk_mmcm_out0.
Gap 3: Safety Architecture closed (f3bbf77)
Added IWDG watchdog configuration, Emergency_Stop PA rail cutoff, temperature max guard, periodic IDQ re-read, and emergency state ordering. 5 new MCU tests, 20/20 MCU regression pass.
Gap 5: BRAM async reset fixed (c87dce0)
Chirp memory loader BRAM async reset converted to synchronous reset pattern per Xilinx UG901 guidelines. Prevents BRAM inference failures on production target.
Build 18 tagged v0.1.2-build18 — prior production baseline
WNS +0.062 ns, WHS +0.059 ns. 6,088 LUTs, 8,946 FFs, 16 BRAM, 140 DSP48E1, 0.631 W. All timing met.
Firmware bug sweep closed with regression coverage
All 17 audited MCU firmware bugs were fixed, regression-tested, and pushed, including LO init ordering, SPI chip-select handling, PA calibration logic, TIM3 PWM bring-up, and stale diagnostic mismatches. 20/20 MCU tests pass.
FPGA timing/resource cleanup phase completed
Chirp BRAM migration, Doppler DSP48 pipelining, CIC pipeline staging, matched-filter regression repair, and full FPGA regression brought the active baseline to 18/18 passing tests.