Files
Mini-Nav/hw/rtl/cam_top.sv
SikongJueluo cbafc4524e feat(cam): migrate noise generation from xorshift64 to xorshift128
- Replace NOISE_GEN_BITS/NOISE_SAMPLE_BITS parameters with unified NOISE_BITS
- Use xorshift128 (random128) instead of xorshift64 for PRNG
- Add flip_mask_next combinational helper for single-cycle mask computation
- Add random_enable signal to advance PRNG only on accepted noisy writes
- Simplify FSM by removing mask_group_idx counter
- Update parameter validation: GROUP_BITS (= HASH_BITS/NOISE_BITS) must equal 64
- Update ref_model.py and tests to match new seed convention: {seed, seed}
- Update Makefile and sweep_noise.py with renamed parameters
2026-05-05 20:19:22 +08:00

97 lines
3.3 KiB
Systemverilog

`timescale 1ns/1ps
`include "cam_params.svh"
module cam_top #(
parameter bit NOISE_EN = 1'b1,
parameter int NOISE_RATE_NUM = 1,
parameter int NOISE_RATE_DEN = 100,
parameter int NOISE_BITS = 8,
parameter logic [63:0] NOISE_SEED = 64'hB504_F32D_B504_F32D
) (
input logic clk,
input logic rst_n,
// Write interface (handshake)
input logic wr_valid,
output logic wr_ready,
input logic [(`ROW_BITS)-1:0] wr_addr,
input logic [(`HASH_BITS)-1:0] write_hash,
// Query interface
input logic query_valid,
output logic query_ready,
input logic [(`HASH_BITS)-1:0] query_hash,
// Result interface
output logic result_valid,
input logic result_ready,
output logic [(`ROW_BITS)-1:0] top1_index,
output logic [(`SCORE_BITS)-1:0] top1_score,
`ifdef SIM_DEBUG
output logic [(`NUM_ROWS)*(`SCORE_BITS)-1:0] score_debug_flat,
`endif
output logic busy
);
// ── Internal signals ──
logic storage_wr_ready; // cam_noisy idle
logic match_query_ready; // match_engine idle
logic match_busy; // match_engine scanning/result pending
// ── Internal valid forwarding ──
logic storage_wr_valid;
logic match_query_valid;
// ── Half-duplex arbitration (write-priority) ──
// When both wr_valid and query_valid are high, write wins.
assign wr_ready = storage_wr_ready && match_query_ready;
assign query_ready = storage_wr_ready && match_query_ready && !wr_valid;
assign busy = (!storage_wr_ready) || match_busy || (!match_query_ready);
// ── Internal valid forwarding (only assert to sub-modules when top-level accepts) ──
assign storage_wr_valid = wr_valid && wr_ready;
assign match_query_valid = query_valid && query_ready;
// ── Shared read bus ──
wire [(`LANES)*(`ROW_BITS)-1:0] rd_addr_lanes_flat;
wire [(`LANES)*(`HASH_BITS)-1:0] rd_hash_lanes_flat;
cam_noisy #(
.NOISE_EN (NOISE_EN),
.NOISE_RATE_NUM (NOISE_RATE_NUM),
.NOISE_RATE_DEN (NOISE_RATE_DEN),
.NOISE_BITS (NOISE_BITS),
.NOISE_SEED (NOISE_SEED)
) u_noisy (
.clk (clk),
.rst_n (rst_n),
.wr_valid (storage_wr_valid),
.wr_ready (storage_wr_ready),
.wr_addr (wr_addr),
.write_hash (write_hash),
.rd_addr_lanes_flat (rd_addr_lanes_flat),
.rd_hash_lanes_flat (rd_hash_lanes_flat)
);
match_engine u_match (
.clk (clk),
.rst_n (rst_n),
.query_valid (match_query_valid),
.query_ready (match_query_ready),
.query_hash (query_hash),
.result_valid (result_valid),
.result_ready (result_ready),
.result_row (top1_index),
.result_score (top1_score),
.busy (match_busy),
.rd_addr_lanes_flat (rd_addr_lanes_flat),
.rd_hash_lanes_flat (rd_hash_lanes_flat)
`ifdef SIM_DEBUG
,.score_debug_flat (score_debug_flat)
`endif
);
endmodule