Two issues caught re-reviewing 7862f4d: 1. doppler_processor.v: at sub_frame = NUM_SUBFRAMES-1 (=2 in production), the read-ahead pointer was advanced one cycle past the last useful chirp, producing an out-of-range mem_read_addr (chirps 48/49 in a 48-chirp frame) on the BRAM read port. The result was never consumed — counter > CPS-1 blocks the multiply — so the OOB read had no functional effect, but it still drives mem_mem[OOB_idx] every frame and would trigger Vivado synth range warnings. Gate the read_doppler_index advance on fft_sample_counter <= CHIRPS_PER_SUBFRAME - 3 so the last NBA at counter = CPS-3 schedules the data needed at counter = CPS-1 and no more. For sub_frame < NUM_SUBFRAMES-1 this just replaces previously-wasted forward reads with redundant reads of the same address; outputs are bit-exact. 2. radar_system_top.v: cfar_detect_class, cfar_detect_threshold_soft, and cfar_detect_count_cand were declared and connected to cfar_inst but went nowhere downstream. They will be wired to USB / telemetry in PR-G; until then they show up as dangling wires that Vivado optimises away with noisy warnings. Drop the wire decls and leave the cfar_ca output ports unconnected. The soft-tier comparison is still synthesized because the 1-bit detect_flag (which IS wired) depends on noise_product_soft via the `else if (cur > thr_soft)` branch, so the candidate logic is preserved in the netlist — only the class / soft-thr / cand-count rails are gone. Tests (parity with the PR-F numbers in 7862f4d): - tb_chirp_controller: 43/43 PASS - tb_chirp_contract: 10/10 PASS - tb_cfar_ca: 24/0 PASS - tb_mti_canceller: 43/43 PASS - tb_doppler_realdata: 2056/2056 PASS - tb_doppler_frame_start_gate: 21/21 PASS - tb_system_e2e: 33/49 PASS (PR-F baseline parity)
570 lines
24 KiB
Verilog
570 lines
24 KiB
Verilog
`timescale 1ns / 1ps
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// ============================================================================
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// doppler_processor.v — Multi-subframe Doppler Processor (chirp-v2 PR-F)
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// ============================================================================
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//
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// ARCHITECTURE:
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// Processes NUM_SUBFRAMES = CHIRPS_PER_FRAME / CHIRPS_PER_SUBFRAME independent
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// 16-point FFTs per range bin. The chirp-v2 production build runs three
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// sub-frames (SHORT, MEDIUM, LONG) at 16 chirps each = 48 chirps per frame:
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//
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// Sub-frame 0: chirps 0..15 → 16-pt windowed FFT (SHORT in chirp-v2)
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// Sub-frame 1: chirps 16..31 → 16-pt windowed FFT (MEDIUM in chirp-v2)
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// Sub-frame 2: chirps 32..47 → 16-pt windowed FFT (LONG in chirp-v2)
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//
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// Each sub-frame produces 16 Doppler bins per range bin. Outputs are tagged
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// with the 2-bit sub_frame index and the 4-bit bin index is packed into the
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// 6-bit doppler_bin port as {sub_frame[1:0], bin[3:0]}.
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//
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// Legacy 2-subframe golden-vector tests (tb_doppler_realdata,
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// tb_fullchain_realdata) override CHIRPS_PER_FRAME=32 + CHIRPS_PER_SUBFRAME=16
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// to make NUM_SUBFRAMES=2; the FSM generalises cleanly. doppler_bin still
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// reports 6 bits there with the high bit always zero.
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//
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// Staggered-PRF ambiguity resolution downstream picks the matching Doppler
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// bin from the SHORT vs MEDIUM vs LONG sub-frame to resolve velocity.
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//
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// WINDOW:
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// 16-point Hamming window (Q15), symmetric. Computed as:
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// w[n] = 0.54 - 0.46 * cos(2*pi*n/15), n=0..15
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// ============================================================================
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`include "radar_params.vh"
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// ----------------------------------------------------------------------------
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// [RX-D FIX] RANGE_BINS and range_bin port now scale with `RP_MAX_OUTPUT_BINS
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// and `RP_RANGE_BIN_WIDTH_MAX (auto-conditional on SUPPORT_LONG_RANGE).
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// 50T (no SUPPORT_LONG_RANGE): 512 bins / 9-bit — 3 km only
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// 200T (SUPPORT_LONG_RANGE): 4096 bins / 12-bit — 3 km and 20 km
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// In 3 km mode the upstream produces 512 bins (uses bins 0..511 only on 200T).
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// In 20 km mode the upstream produces 4096 bins, which the BRAMs and counters
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// can now represent without aliasing.
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// ----------------------------------------------------------------------------
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module doppler_processor_optimized #(
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parameter DOPPLER_FFT_SIZE = `RP_DOPPLER_FFT_SIZE, // 16
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parameter RANGE_BINS = `RP_MAX_OUTPUT_BINS, // 512 (50T) / 4096 (200T)
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parameter CHIRPS_PER_FRAME = `RP_CHIRPS_PER_FRAME, // 48 (PR-F); legacy TBs override to 32
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parameter CHIRPS_PER_SUBFRAME = `RP_CHIRPS_PER_SUBFRAME, // 16
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parameter WINDOW_TYPE = 0, // 0=Hamming, 1=Rectangular
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parameter DATA_WIDTH = `RP_DATA_WIDTH // 16
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)(
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input wire clk,
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input wire reset_n,
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input wire [31:0] range_data,
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input wire data_valid,
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input wire new_chirp_frame,
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output reg [31:0] doppler_output,
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output reg doppler_valid,
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output reg [`RP_DOPPLER_BIN_WIDTH-1:0] doppler_bin, // 6-bit {sub_frame[1:0], bin[3:0]}
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output reg [`RP_RANGE_BIN_WIDTH_MAX-1:0] range_bin, // 9-bit (50T) / 12-bit (200T)
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output reg [`RP_SUBFRAME_ID_WIDTH-1:0] sub_frame, // 2-bit subframe index
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output wire processing_active,
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output wire frame_complete,
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output reg [3:0] status
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`ifdef FORMAL
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,
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output wire [2:0] fv_state,
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output wire [`RP_DOPPLER_MEM_ADDR_W-1:0] fv_mem_write_addr,
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output wire [`RP_DOPPLER_MEM_ADDR_W-1:0] fv_mem_read_addr,
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output wire [`RP_RANGE_BIN_WIDTH_MAX-1:0] fv_write_range_bin,
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output wire [5:0] fv_write_chirp_index,
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output wire [`RP_RANGE_BIN_WIDTH_MAX-1:0] fv_read_range_bin,
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output wire [5:0] fv_read_doppler_index,
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output wire [9:0] fv_processing_timeout,
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output wire fv_frame_buffer_full,
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output wire fv_mem_we,
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output wire [`RP_DOPPLER_MEM_ADDR_W-1:0] fv_mem_waddr_r
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`endif
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);
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// Derived: number of sub-frames in the current configuration. Production
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// build = 3 (SHORT/MEDIUM/LONG @ 16 chirps each = 48 frame). Legacy TBs
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// override CHIRPS_PER_FRAME=32 to get NUM_SUBFRAMES=2 for golden compat.
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localparam NUM_SUBFRAMES = CHIRPS_PER_FRAME / CHIRPS_PER_SUBFRAME;
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// ==============================================
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// Window Coefficients — 16-point Hamming (Q15)
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// ==============================================
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// w[n] = 0.54 - 0.46 * cos(2*pi*n/15), n=0..15
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// Symmetric: w[n] = w[15-n]
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reg [DATA_WIDTH-1:0] window_coeff [0:15];
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integer w;
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initial begin
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if (WINDOW_TYPE == 0) begin
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// 16-point Hamming window, Q15 format
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// Computed: round(32767 * (0.54 - 0.46*cos(2*pi*n/15)))
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window_coeff[0] = 16'h0A3D; // 0.0800 * 32767 = 2621
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window_coeff[1] = 16'h0E5C; // 0.1116 * 32767 = 3676
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window_coeff[2] = 16'h1B6D; // 0.2138 * 32767 = 7021
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window_coeff[3] = 16'h3088; // 0.3790 * 32767 = 12424
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window_coeff[4] = 16'h4B33; // 0.5868 * 32767 = 19251
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window_coeff[5] = 16'h6573; // 0.7930 * 32767 = 25971
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window_coeff[6] = 16'h7642; // 0.9245 * 32767 = 30274
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window_coeff[7] = 16'h7F62; // 0.9932 * 32767 = 32610
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window_coeff[8] = 16'h7F62; // symmetric
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window_coeff[9] = 16'h7642;
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window_coeff[10] = 16'h6573;
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window_coeff[11] = 16'h4B33;
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window_coeff[12] = 16'h3088;
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window_coeff[13] = 16'h1B6D;
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window_coeff[14] = 16'h0E5C;
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window_coeff[15] = 16'h0A3D;
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end else begin
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for (w = 0; w < 16; w = w + 1) begin
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window_coeff[w] = 16'h7FFF;
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end
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end
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end
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// ==============================================
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// Memory Declaration - FIXED SIZE
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// ==============================================
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localparam MEM_DEPTH = RANGE_BINS * CHIRPS_PER_FRAME;
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(* ram_style = "block" *) reg [DATA_WIDTH-1:0] doppler_i_mem [0:MEM_DEPTH-1];
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(* ram_style = "block" *) reg [DATA_WIDTH-1:0] doppler_q_mem [0:MEM_DEPTH-1];
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// ==============================================
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// Control Registers
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// ==============================================
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reg [`RP_RANGE_BIN_WIDTH_MAX-1:0] write_range_bin;
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reg [5:0] write_chirp_index; // 6-bit: 0..47 (PR-F)
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reg [`RP_RANGE_BIN_WIDTH_MAX-1:0] read_range_bin;
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reg [5:0] read_doppler_index; // 6-bit (PR-F)
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reg frame_buffer_full;
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reg [9:0] chirps_received;
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reg [1:0] chirp_state;
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// AUDIT-S3 fix: arm-on-frame-start gating. Set when frame_start_pulse arrives
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// in S_IDLE; cleared when the FSM transitions to S_ACCUMULATE. Prevents stale
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// data_valid from prior MF pipeline residue from advancing S_IDLE → S_ACCUMULATE
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// before the new frame is officially started, which would write the first
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// sample(s) into addr 0 of the previous frame's buffer if write_chirp_index
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// happened to be non-zero. The pointer-reset invariant (line 287-288 always
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// zeros pointers at end of S_ACCUMULATE) makes this race benign in current
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// operation, but the gate makes the FSM robust against future code paths
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// that might leave pointers stale on entry to S_IDLE.
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reg frame_armed;
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// Sub-frame tracking
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reg [`RP_SUBFRAME_ID_WIDTH-1:0] current_sub_frame; // 2-bit (PR-F): 0..NUM_SUBFRAMES-1
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// ==============================================
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// FFT Interface
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// ==============================================
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reg fft_start;
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wire fft_ready;
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reg [DATA_WIDTH-1:0] fft_input_i;
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reg [DATA_WIDTH-1:0] fft_input_q;
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reg signed [31:0] mult_i, mult_q;
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reg signed [DATA_WIDTH-1:0] window_val_reg;
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reg signed [31:0] mult_i_raw, mult_q_raw;
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reg fft_input_valid;
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reg fft_input_last;
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wire [DATA_WIDTH-1:0] fft_output_i;
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wire [DATA_WIDTH-1:0] fft_output_q;
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wire fft_output_valid;
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wire fft_output_last;
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// ==============================================
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// Addressing
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// ==============================================
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wire [`RP_DOPPLER_MEM_ADDR_W-1:0] mem_write_addr;
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wire [`RP_DOPPLER_MEM_ADDR_W-1:0] mem_read_addr;
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assign mem_write_addr = (write_chirp_index * RANGE_BINS) + write_range_bin;
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assign mem_read_addr = (read_doppler_index * RANGE_BINS) + read_range_bin;
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// ==============================================
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// State Machine
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// ==============================================
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reg [2:0] state;
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localparam S_IDLE = 3'b000;
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localparam S_ACCUMULATE = 3'b001;
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localparam S_PRE_READ = 3'b101;
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localparam S_LOAD_FFT = 3'b010;
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localparam S_FFT_WAIT = 3'b011;
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localparam S_OUTPUT = 3'b100;
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// Frame sync detection
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reg new_chirp_frame_d1;
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always @(posedge clk or negedge reset_n) begin
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if (!reset_n) new_chirp_frame_d1 <= 0;
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else new_chirp_frame_d1 <= new_chirp_frame;
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end
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wire frame_start_pulse = new_chirp_frame & ~new_chirp_frame_d1;
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// ==============================================
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// Main State Machine
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// ==============================================
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reg [4:0] fft_sample_counter; // Reduced: only need 0..17 for 16-pt FFT
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reg [9:0] processing_timeout;
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// Memory write enable and data signals
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reg mem_we;
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reg [`RP_DOPPLER_MEM_ADDR_W-1:0] mem_waddr_r;
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reg [DATA_WIDTH-1:0] mem_wdata_i, mem_wdata_q;
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// Memory read data
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reg [DATA_WIDTH-1:0] mem_rdata_i, mem_rdata_q;
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`ifdef FORMAL
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assign fv_state = state;
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assign fv_mem_write_addr = mem_write_addr;
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assign fv_mem_read_addr = mem_read_addr;
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assign fv_write_range_bin = write_range_bin;
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assign fv_write_chirp_index = write_chirp_index;
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assign fv_read_range_bin = read_range_bin;
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assign fv_read_doppler_index = read_doppler_index;
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assign fv_processing_timeout = processing_timeout;
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assign fv_frame_buffer_full = frame_buffer_full;
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assign fv_mem_we = mem_we;
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assign fv_mem_waddr_r = mem_waddr_r;
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`endif
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// ----------------------------------------------------------
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// Separate always block for memory writes — NO async reset
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// ----------------------------------------------------------
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always @(posedge clk) begin
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if (mem_we) begin
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doppler_i_mem[mem_waddr_r] <= mem_wdata_i;
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doppler_q_mem[mem_waddr_r] <= mem_wdata_q;
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end
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mem_rdata_i <= doppler_i_mem[mem_read_addr];
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mem_rdata_q <= doppler_q_mem[mem_read_addr];
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end
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// ----------------------------------------------------------
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// Block 1: FSM / Control — async reset
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// ----------------------------------------------------------
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always @(posedge clk or negedge reset_n) begin
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if (!reset_n) begin
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state <= S_IDLE;
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write_range_bin <= 0;
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write_chirp_index <= 0;
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frame_buffer_full <= 0;
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doppler_valid <= 0;
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fft_start <= 0;
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fft_input_valid <= 0;
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fft_input_last <= 0;
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fft_sample_counter <= 0;
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processing_timeout <= 0;
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status <= 0;
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chirps_received <= 0;
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chirp_state <= 0;
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doppler_output <= 0;
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doppler_bin <= 0;
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range_bin <= 0;
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sub_frame <= 0;
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current_sub_frame <= 0;
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frame_armed <= 0;
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end else begin
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doppler_valid <= 0;
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fft_input_valid <= 0;
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fft_input_last <= 0;
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if (processing_timeout > 0) begin
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processing_timeout <= processing_timeout - 1;
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end
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case (state)
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S_IDLE: begin
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if (frame_start_pulse) begin
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write_chirp_index <= 0;
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write_range_bin <= 0;
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frame_buffer_full <= 0;
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chirps_received <= 0;
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frame_armed <= 1; // AUDIT-S3: arm on frame_start_pulse
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end
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// AUDIT-S3 fix: only transition to S_ACCUMULATE when armed,
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// i.e., when this frame has been officially started by a
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// frame_start_pulse. Pre-fix code accepted any data_valid in
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// S_IDLE and could race with a missing/late frame_start_pulse.
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// (frame_start_pulse || frame_armed) admits the same-cycle case
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// where both pulse and data_valid arrive together — write to
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// addr 0 still resolves correctly because the BRAM write block
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// uses the same gate.
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if ((frame_start_pulse || frame_armed) && data_valid && !frame_buffer_full) begin
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state <= S_ACCUMULATE;
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write_range_bin <= 1;
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frame_armed <= 0; // disarm; S_ACCUMULATE handles its own pointers
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end
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end
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S_ACCUMULATE: begin
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if (data_valid) begin
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if (write_range_bin < RANGE_BINS - 1) begin
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write_range_bin <= write_range_bin + 1;
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end else begin
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write_range_bin <= 0;
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write_chirp_index <= write_chirp_index + 1;
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chirps_received <= chirps_received + 1;
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if (write_chirp_index >= CHIRPS_PER_FRAME - 1) begin
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frame_buffer_full <= 1;
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chirp_state <= 0;
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state <= S_PRE_READ;
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fft_sample_counter <= 0;
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write_chirp_index <= 0;
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write_range_bin <= 0;
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// Start with sub-frame 0 (long PRI chirps 0..15)
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current_sub_frame <= 0;
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end
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end
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end
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end
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S_PRE_READ: begin
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// Prime BRAM pipeline for current sub-frame
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// read_doppler_index already set in Block 2 to sub-frame base
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fft_start <= 1;
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state <= S_LOAD_FFT;
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end
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S_LOAD_FFT: begin
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fft_start <= 0;
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// Pipeline: 2 priming cycles + CHIRPS_PER_SUBFRAME data cycles
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if (fft_sample_counter <= 1) begin
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fft_sample_counter <= fft_sample_counter + 1;
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end else if (fft_sample_counter <= CHIRPS_PER_SUBFRAME + 1) begin
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fft_input_valid <= 1;
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if (fft_sample_counter == CHIRPS_PER_SUBFRAME + 1) begin
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fft_input_last <= 1;
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state <= S_FFT_WAIT;
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fft_sample_counter <= 0;
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processing_timeout <= 1000;
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end else begin
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fft_sample_counter <= fft_sample_counter + 1;
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end
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end
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end
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S_FFT_WAIT: begin
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if (fft_output_valid) begin
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doppler_output <= {fft_output_q[15:0], fft_output_i[15:0]};
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// Pack: {sub_frame, bin[3:0]}
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doppler_bin <= {current_sub_frame, fft_sample_counter[3:0]};
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range_bin <= read_range_bin;
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sub_frame <= current_sub_frame;
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doppler_valid <= 1;
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fft_sample_counter <= fft_sample_counter + 1;
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if (fft_output_last) begin
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state <= S_OUTPUT;
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fft_sample_counter <= 0;
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end
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end
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if (processing_timeout == 0) begin
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state <= S_OUTPUT;
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end
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end
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S_OUTPUT: begin
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if (current_sub_frame < NUM_SUBFRAMES - 1) begin
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// Advance to next sub-frame; same range bin, next FFT
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current_sub_frame <= current_sub_frame + 1;
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fft_sample_counter <= 0;
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state <= S_PRE_READ;
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end else begin
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// Finished all NUM_SUBFRAMES for this range bin
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current_sub_frame <= 0;
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if (read_range_bin < RANGE_BINS - 1) begin
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fft_sample_counter <= 0;
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state <= S_PRE_READ;
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end else begin
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state <= S_IDLE;
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frame_buffer_full <= 0;
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end
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end
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end
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endcase
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status <= {state, frame_buffer_full};
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end
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end
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// ----------------------------------------------------------
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// Block 2: BRAM address/data & DSP datapath — synchronous reset
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// ----------------------------------------------------------
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always @(posedge clk) begin
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if (!reset_n) begin
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mem_we <= 0;
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mem_waddr_r <= 0;
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mem_wdata_i <= 0;
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mem_wdata_q <= 0;
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mult_i <= 0;
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mult_q <= 0;
|
|
mult_i_raw <= 0;
|
|
mult_q_raw <= 0;
|
|
window_val_reg <= 0;
|
|
fft_input_i <= 0;
|
|
fft_input_q <= 0;
|
|
read_range_bin <= 0;
|
|
read_doppler_index <= 0;
|
|
end else begin
|
|
mem_we <= 0;
|
|
|
|
case (state)
|
|
S_IDLE: begin
|
|
// AUDIT-S3 fix: gate BRAM write on frame_armed so stale
|
|
// data_valid arriving before frame_start_pulse cannot
|
|
// overwrite addr 0 of the buffer. Same gate as the FSM's
|
|
// S_IDLE → S_ACCUMULATE transition above, so the two blocks
|
|
// stay coherent.
|
|
if ((frame_start_pulse || frame_armed) && data_valid && !frame_buffer_full) begin
|
|
mem_we <= 1;
|
|
mem_waddr_r <= mem_write_addr;
|
|
mem_wdata_i <= range_data[15:0];
|
|
mem_wdata_q <= range_data[31:16];
|
|
end
|
|
end
|
|
|
|
S_ACCUMULATE: begin
|
|
if (data_valid) begin
|
|
mem_we <= 1;
|
|
mem_waddr_r <= mem_write_addr;
|
|
mem_wdata_i <= range_data[15:0];
|
|
mem_wdata_q <= range_data[31:16];
|
|
|
|
if (write_range_bin >= RANGE_BINS - 1 &&
|
|
write_chirp_index >= CHIRPS_PER_FRAME - 1) begin
|
|
read_range_bin <= 0;
|
|
// Start reading from chirp 0 (long PRI sub-frame)
|
|
read_doppler_index <= 0;
|
|
end
|
|
end
|
|
end
|
|
|
|
S_PRE_READ: begin
|
|
// First chirp of current sub-frame + 1 (address-then-data pipe).
|
|
// Generalised: chirp_base = current_sub_frame * CHIRPS_PER_SUBFRAME.
|
|
read_doppler_index <= current_sub_frame * CHIRPS_PER_SUBFRAME + 6'd1;
|
|
|
|
// BREG priming: window coeff for sample 0
|
|
window_val_reg <= $signed(window_coeff[0]);
|
|
end
|
|
|
|
S_LOAD_FFT: begin
|
|
if (fft_sample_counter == 0) begin
|
|
// Pipe stage 1: multiply using pre-registered BREG value
|
|
mult_i_raw <= $signed(mem_rdata_i) * window_val_reg;
|
|
mult_q_raw <= $signed(mem_rdata_q) * window_val_reg;
|
|
window_val_reg <= $signed(window_coeff[1]);
|
|
// Advance to chirp base+2
|
|
read_doppler_index <= current_sub_frame * CHIRPS_PER_SUBFRAME + 6'd2;
|
|
end else if (fft_sample_counter == 1) begin
|
|
mult_i <= mult_i_raw;
|
|
mult_q <= mult_q_raw;
|
|
mult_i_raw <= $signed(mem_rdata_i) * window_val_reg;
|
|
mult_q_raw <= $signed(mem_rdata_q) * window_val_reg;
|
|
if (2 < CHIRPS_PER_SUBFRAME)
|
|
window_val_reg <= $signed(window_coeff[2]);
|
|
// Advance to chirp base+3
|
|
read_doppler_index <= current_sub_frame * CHIRPS_PER_SUBFRAME + 6'd3;
|
|
end else if (fft_sample_counter <= CHIRPS_PER_SUBFRAME + 1) begin
|
|
// Steady state
|
|
fft_input_i <= (mult_i + (1 << 14)) >>> 15;
|
|
fft_input_q <= (mult_q + (1 << 14)) >>> 15;
|
|
mult_i <= mult_i_raw;
|
|
mult_q <= mult_q_raw;
|
|
|
|
if (fft_sample_counter <= CHIRPS_PER_SUBFRAME - 1) begin
|
|
mult_i_raw <= $signed(mem_rdata_i) * window_val_reg;
|
|
mult_q_raw <= $signed(mem_rdata_q) * window_val_reg;
|
|
// Window coeff index within sub-frame
|
|
begin : advance_window
|
|
reg [4:0] win_idx;
|
|
win_idx = fft_sample_counter[3:0] + 1;
|
|
if (win_idx < CHIRPS_PER_SUBFRAME)
|
|
window_val_reg <= $signed(window_coeff[win_idx]);
|
|
end
|
|
// Advance BRAM read: chirp_base + (counter + 2).
|
|
// The last useful read is data[chirp_base + CPS-1], needed
|
|
// by mult_i_raw at counter=CPS-1. Working back through the
|
|
// 2-cycle BRAM-then-multiply pipeline, the last NBA that
|
|
// matters is at counter = CPS-3 (= 13 for CPS=16) which
|
|
// schedules read of base+CPS-1. After that, advancing
|
|
// would address chirp base+CPS or base+CPS+1 — past the
|
|
// end of the highest sub-frame's data window (e.g. chirps
|
|
// 48 / 49 with sub_frame=2 in a 48-chirp frame), which is
|
|
// outside MEM_DEPTH = RANGE_BINS * CHIRPS_PER_FRAME. The
|
|
// would-be values are never consumed, but the reads
|
|
// would still drive an out-of-range mem_read_addr. Stop
|
|
// the read pointer at the last useful chirp instead.
|
|
if (fft_sample_counter <= CHIRPS_PER_SUBFRAME - 3) begin
|
|
read_doppler_index <= current_sub_frame * CHIRPS_PER_SUBFRAME
|
|
+ {2'd0, fft_sample_counter[3:0]} + 6'd2;
|
|
end
|
|
end
|
|
|
|
if (fft_sample_counter == CHIRPS_PER_SUBFRAME + 1) begin
|
|
// Reset read index for the next sub-frame (or wrap to 0
|
|
// when we've finished all NUM_SUBFRAMES).
|
|
if (current_sub_frame < NUM_SUBFRAMES - 1)
|
|
read_doppler_index <= (current_sub_frame + 6'd1) * CHIRPS_PER_SUBFRAME;
|
|
else
|
|
read_doppler_index <= 6'd0;
|
|
end
|
|
end
|
|
end
|
|
|
|
S_OUTPUT: begin
|
|
if (current_sub_frame < NUM_SUBFRAMES - 1) begin
|
|
// Transitioning to next sub-frame for the same range bin.
|
|
read_doppler_index <= (current_sub_frame + 6'd1) * CHIRPS_PER_SUBFRAME;
|
|
end else begin
|
|
// All sub-frames done for this range bin
|
|
if (read_range_bin < RANGE_BINS - 1) begin
|
|
read_range_bin <= read_range_bin + 1;
|
|
read_doppler_index <= 6'd0; // Next range bin starts with sub-frame 0
|
|
end
|
|
end
|
|
end
|
|
|
|
default: begin
|
|
// S_FFT_WAIT: no BRAM-write or address operations needed
|
|
end
|
|
endcase
|
|
end
|
|
end
|
|
|
|
// ==============================================
|
|
// FFT Module — 16-point
|
|
// ==============================================
|
|
xfft_16 fft_inst (
|
|
.aclk(clk),
|
|
.aresetn(reset_n),
|
|
.s_axis_config_tdata(8'h01),
|
|
.s_axis_config_tvalid(fft_start),
|
|
.s_axis_config_tready(fft_ready),
|
|
.s_axis_data_tdata({fft_input_q, fft_input_i}),
|
|
.s_axis_data_tvalid(fft_input_valid),
|
|
.s_axis_data_tlast(fft_input_last),
|
|
.m_axis_data_tdata({fft_output_q, fft_output_i}),
|
|
.m_axis_data_tvalid(fft_output_valid),
|
|
.m_axis_data_tlast(fft_output_last),
|
|
.m_axis_data_tready(1'b1)
|
|
);
|
|
|
|
// ==============================================
|
|
// Status Outputs
|
|
// ==============================================
|
|
assign processing_active = (state != S_IDLE);
|
|
// NOTE: frame_complete is a LEVEL, not a pulse. It is high whenever the
|
|
// doppler processor is idle with no buffered frame. radar_receiver_final.v
|
|
// converts this to a single-cycle rising-edge pulse before routing to
|
|
// downstream consumers (USB FT2232H, AGC, CFAR). Do NOT connect this
|
|
// level output directly to modules that expect a pulse.
|
|
assign frame_complete = (state == S_IDLE && frame_buffer_full == 0);
|
|
|
|
endmodule
|