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Fix all 10 CDC bugs from report_cdc audit, add overflow guard in range_bin_decimator

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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).
This commit is contained in:
Jason
2026-03-17 13:48:47 +02:00
parent fb59e98737
commit 5fd632bc47
9 changed files with 2299 additions and 2098 deletions
Download Patch File Download Diff File Expand all files Collapse all files
9_Firmware/9_2_FPGA/radar_transmitter.v
+61 -16
View File
@@ -79,16 +79,61 @@ module radar_transmitter(
);
// Edge Detection Signals
wire new_chirp_pulse;
wire new_elevation_pulse;
// Edge Detection Signals
wire new_chirp_pulse;
wire new_elevation_pulse;
wire new_azimuth_pulse;
// Chirp Control Signals
wire [7:0] chirp_data;
wire chirp_valid;
// CDC: Synchronized versions of signals crossing clk_100m -> clk_120m_dac
wire mixers_enable_120m; // stm32_mixers_enable sync'd to clk_120m_dac
wire new_chirp_pulse_120m; // new_chirp_pulse (toggle CDC) in clk_120m_dac domain
// Chirp Control Signals
wire [7:0] chirp_data;
wire chirp_valid;
wire chirp_sequence_done;
// Toggle CDC for new_chirp_pulse: clk_100m -> clk_120m_dac
// Edge detector produces a 1-cycle pulse on clk_100m. A level synchronizer
// would miss it (120/100 MHz ratio). Toggle CDC converts pulse to level toggle,
// syncs the toggle, then detects edges on the destination side.
reg chirp_toggle_100m;
always @(posedge clk_100m or negedge reset_n) begin
if (!reset_n)
chirp_toggle_100m <= 1'b0;
else if (new_chirp_pulse)
chirp_toggle_100m <= ~chirp_toggle_100m;
end
// Sync the toggle to clk_120m_dac domain
wire chirp_toggle_120m;
cdc_single_bit #(.STAGES(3)) cdc_chirp_toggle (
.src_clk(clk_100m),
.dst_clk(clk_120m_dac),
.reset_n(reset_n),
.src_signal(chirp_toggle_100m),
.dst_signal(chirp_toggle_120m)
);
// Detect edges on synchronized toggle to recover pulse in clk_120m domain
reg chirp_toggle_120m_prev;
always @(posedge clk_120m_dac or negedge reset_n) begin
if (!reset_n)
chirp_toggle_120m_prev <= 1'b0;
else
chirp_toggle_120m_prev <= chirp_toggle_120m;
end
assign new_chirp_pulse_120m = chirp_toggle_120m ^ chirp_toggle_120m_prev;
// Sync stm32_mixers_enable (async GPIO level) to clk_120m_dac domain
cdc_single_bit #(.STAGES(3)) cdc_mixers_en_120m (
.src_clk(clk_100m), // Treat as pseudo-source (GPIO is async)
.dst_clk(clk_120m_dac),
.reset_n(reset_n),
.src_signal(stm32_mixers_enable),
.dst_signal(mixers_enable_120m)
);
// Enhanced STM32 Input Edge Detection with Debouncing
edge_detector_enhanced chirp_edge (
.clk(clk_100m),
@@ -111,16 +156,16 @@ edge_detector_enhanced azimuth_edge (
.rising_falling_edge(new_azimuth_pulse)
);
// Enhanced PLFM Chirp Generation
plfm_chirp_controller_enhanced plfm_chirp_inst (
.clk_120m(clk_120m_dac),
.clk_100m(clk_100m),
.reset_n(reset_n),
.new_chirp(new_chirp_pulse),
.new_elevation(new_elevation_pulse),
.new_azimuth(new_azimuth_pulse),
.new_chirp_frame(new_chirp_frame),
.mixers_enable(stm32_mixers_enable),
// Enhanced PLFM Chirp Generation
plfm_chirp_controller_enhanced plfm_chirp_inst (
.clk_120m(clk_120m_dac),
.clk_100m(clk_100m),
.reset_n(reset_n),
.new_chirp(new_chirp_pulse_120m), // CDC-synchronized pulse in clk_120m domain
.new_elevation(new_elevation_pulse),
.new_azimuth(new_azimuth_pulse),
.new_chirp_frame(new_chirp_frame),
.mixers_enable(mixers_enable_120m), // CDC-synchronized level in clk_120m domain
.chirp_data(chirp_data),
.chirp_valid(chirp_valid),
.chirp_done(chirp_sequence_done),