Replaces plfm_chirp_controller_enhanced (5-state FSM with hardcoded
LONG/SHORT timings + 60-entry inline short LUT) with plfm_chirp_controller_v2,
a pure DAC playback driver: IDLE -> CHIRP -> IDLE keyed off a 1-cycle
dst_chirp_valid pulse, with sample count selected by dst_wave_sel
(SHORT=120 / MEDIUM=600 / LONG=3600). Inter-chirp timing (LISTEN, GUARD,
frame boundaries) is now owned exclusively by chirp_scheduler.
Scheduler -> TX bridge: cdc_async_fifo (Cummings style #2, WIDTH=2 DEPTH=4)
crosses {wave_sel} from clk_100m to clk_120m_dac, with chirp_pulse as
src_valid. frame_pulse rides a separate toggle CDC for chirp_counter
clear and the new_chirp_frame status output. mixers_enable now also gates
the scheduler so it stays in S_IDLE while the radar is "off" — without
this gate the first chirp_pulse fires at reset and gets dropped before
mixers come up.
Files:
- NEW plfm_chirp_controller_v2.v DAC playback driver (3 LUTs, FSM)
- DEL plfm_chirp_controller.v legacy controller (382 lines)
- DEL long_chirp_lut.mem legacy LUT (3600 lines), replaced
by tx_long_lut.mem from PR-B
- chirp_scheduler.v + mixers_enable input (master quiesce)
- radar_receiver_final.v + sched_*_out output ports + mixers_enable_100m
- radar_system_top.v wire sched_*_out -> tx_inst.sched_*; pass
stm32_mixers_enable_100m to rx_inst
- radar_transmitter.v full rewrite: drop new_chirp edge detector +
toggle CDC, instantiate cdc_async_fifo for
{wave_sel}, toggle CDC for frame_pulse,
plfm_chirp_controller_v2 in place of _enhanced
- tb/tb_chirp_controller.v + tb/tb_chirp_contract.v rewritten for v2
contract (43/43 unit + 10/10 contract green)
- tb/tb_radar_receiver_final.v + .mixers_enable_100m(1'b1) pin
- run_regression.sh, scripts/200t/build_200t.tcl file-list bumped
Test summary:
- tb_chirp_controller_v2: 43/43 PASS
- tb_chirp_contract: 10/10 contracts upheld
- tb_rxb_fullchain: peak 24033 ~80x (parity with PR-D)
- tb_mti_canceller: 43/43 PASS
- tb_system_e2e: 33/49 (1 new vs 34/49 PR-D baseline: G2.2
new_chirp_frame, intentional v2 frame-pulse
semantics — fires once per Doppler frame
instead of once per stm32 chirp toggle.
TB needs widening in PR-H to wait the full
frame.)
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).
Jason