Files
mlkem-sync/sync_rtl/sample_cbd/TB/tb_sample_cbd_xsim.v
FallenSigh d4c3fc86fc feat(tb): add Vivado XSIM Verilog testbenches for all 10 sync modules
Add file-based vector testbenches ( + ) for:
- mod_add_sync, rng_sync, poly_arith_sync, comp_decomp_sync
- s_bram/sd_bram, sha3_chain_top
- ntt_core, poly_mul_sync
- sample_cbd_sync, sample_ntt_sync

Each module includes:
- tb_<module>_xsim.v: Vivado XSIM testbench
- gen_vectors.py: Python vector generator (stdlib only)
- vectors/<module>_input.hex: test input vectors
- xsim_run.tcl: compile + elaborate + simulate script
2026-06-25 20:48:38 +08:00

258 lines
9.5 KiB
Verilog

// tb_sample_cbd_xsim.v - Vivado xsim testbench for sample_cbd_sync
//
// Reads test vectors from a hex file using $readmemh.
// Each line is a packed hex word: {eta_i[1:0], nonce_i[7:0], seed_i[255:0]}
// - seed_i[255:0] : 64 hex chars (LSB = seed_i[0])
// - nonce_i[7:0] : 2 hex chars
// - eta_i[1:0] : 1 hex char (2 or 3)
// - Total: 67 hex chars (266 bits), zero-padded to fill 4-bit nibbles
//
// Drives sample_cbd_sync, waits for valid_o, collects 256 coefficients,
// and writes results to an output file.
//
// Usage:
// xvlog -sv sample_cbd_sync.v TB/tb_sample_cbd_xsim.v
// xelab tb_sample_cbd_xsim -s tb_sample_cbd_xsim
// xsim tb_sample_cbd_xsim -R
//
// Prerequisites:
// - Generate vectors: python3 TB/gen_vectors.py
// - Output file: vectors/sample_cbd_input.hex
`timescale 1ns / 1ps
module tb_sample_cbd_xsim;
// ================================================================
// Parameters
// ================================================================
parameter VECTOR_FILE = "sync_rtl/sample_cbd/TB/vectors/sample_cbd_input.hex";
parameter RESULT_FILE = "sync_rtl/sample_cbd/TB/vectors/sample_cbd_result.hex";
parameter EXPECT_FILE = "sync_rtl/sample_cbd/TB/vectors/sample_cbd_expected.hex";
parameter MAX_VECTORS = 32;
parameter TIMEOUT_CYCLES = 10000;
parameter N_COEFFS = 256;
// ================================================================
// DUT signals
// ================================================================
reg clk;
reg rst_n;
reg [255:0] seed_i;
reg [7:0] nonce_i;
reg [1:0] eta_i;
reg valid_i;
wire ready_o;
wire [11:0] coeff_o;
wire valid_o;
reg ready_i;
wire last_o;
// ================================================================
// DUT instantiation
// ================================================================
sample_cbd_sync u_dut (
.clk (clk),
.rst_n (rst_n),
.seed_i (seed_i),
.nonce_i (nonce_i),
.eta_i (eta_i),
.valid_i (valid_i),
.ready_o (ready_o),
.coeff_o (coeff_o),
.valid_o (valid_o),
.ready_i (ready_i),
.last_o (last_o)
);
// ================================================================
// Clock generation: 100 MHz (10 ns period)
// ================================================================
initial clk = 1'b0;
always #5 clk = ~clk;
// ================================================================
// Vector memory (loaded by $readmemh)
// 266 bits per word: {eta_i[1:0], nonce_i[7:0], seed_i[255:0]}
// Hex: 67 chars = 268 bits, top 2 bits zero-padded
// ================================================================
reg [267:0] vector_mem [0:MAX_VECTORS-1];
integer vec_count;
integer idx;
integer cycle_count;
integer result_fd;
integer coeff_idx;
// Test result tracking
integer pass_count;
integer fail_count;
// ================================================================
// Hex-to-ASCII conversion helper (for output file)
// ================================================================
function [7:0] nibble_to_ascii;
input [3:0] nibble;
begin
if (nibble < 4'd10)
nibble_to_ascii = 8'h30 + {4'd0, nibble}; // '0'-'9'
else
nibble_to_ascii = 8'h41 + ({4'd0, nibble} - 4'd10); // 'A'-'F'
end
endfunction
// ================================================================
// Main test sequence
// ================================================================
initial begin
vec_count = 0;
// Load vectors from hex file
$readmemh(VECTOR_FILE, vector_mem);
// Count non-zero/X entries to determine actual vector count
begin
integer found_end;
found_end = 0;
for (idx = 0; idx < MAX_VECTORS; idx = idx + 1) begin
if (!found_end && (vector_mem[idx] === {268{1'bx}} || vector_mem[idx] === {268{1'bz}}))
found_end = 1;
else if (!found_end)
vec_count = vec_count + 1;
end
end
if (vec_count == 0) begin
$display("ERROR: No vectors loaded from %s", VECTOR_FILE);
$display(" Check that the file exists and is in the correct format.");
$display(" Each line: <67 hex chars> = {eta, nonce, seed}");
$finish;
end
$display("INFO: Loaded %0d test vectors from %s", vec_count, VECTOR_FILE);
// Open result file
result_fd = $fopen(RESULT_FILE, "w");
if (result_fd == 0) begin
$display("ERROR: Cannot open result file: %s", RESULT_FILE);
$finish;
end
// Initialize DUT inputs
seed_i <= 256'd0;
nonce_i <= 8'd0;
eta_i <= 2'd2;
valid_i <= 1'b0;
ready_i <= 1'b1; // always ready to accept output
// Reset sequence: rst_n low for 3 cycles, then high
rst_n <= 1'b0;
repeat (3) @(posedge clk);
rst_n <= 1'b1;
@(posedge clk);
pass_count = 0;
fail_count = 0;
// ============================================================
// Process each vector
// ============================================================
for (idx = 0; idx < vec_count; idx = idx + 1) begin
begin
reg [255:0] vec_seed;
reg [7:0] vec_nonce;
reg [1:0] vec_eta;
// Extract fields from packed vector_mem
// vector_mem[267:0] = {2'b0, eta_i, nonce_i, seed_i}
vec_seed = vector_mem[idx][255:0];
vec_nonce = vector_mem[idx][263:256];
vec_eta = vector_mem[idx][265:264];
$display("INFO: Vector %0d - eta=%0d, nonce=0x%02h, seed[0:31]=%0h...",
idx, vec_eta, vec_nonce, vec_seed[31:0]);
// Drive DUT with input
seed_i <= vec_seed;
nonce_i <= vec_nonce;
eta_i <= vec_eta;
valid_i <= 1'b1;
@(posedge clk);
valid_i <= 1'b0;
// Wait for valid_o, then collect all 256 coefficients
// The DUT uses ready/valid handshake; we set ready_i=1
coeff_idx = 0;
cycle_count = 0;
// Write vector header to result file
$fwrite(result_fd, "# VECTOR_%0d eta=%0d nonce=0x%02h seed=0x%064h\n",
idx, vec_eta, vec_nonce, vec_seed);
while (coeff_idx < N_COEFFS && cycle_count < TIMEOUT_CYCLES) begin
@(posedge clk);
cycle_count = cycle_count + 1;
if (valid_o) begin
// Capture coefficient
begin
integer k;
reg [3:0] nib;
for (k = 2; k >= 0; k = k - 1) begin
nib = coeff_o[(k*4)+:4];
$fwrite(result_fd, "%c", nibble_to_ascii(nib));
end
end
coeff_idx = coeff_idx + 1;
if (last_o)
$fwrite(result_fd, " # last at coeff_idx=%0d", coeff_idx);
$fwrite(result_fd, "\n");
end
end
if (cycle_count >= TIMEOUT_CYCLES) begin
$display("ERROR: Timeout on vector %0d (got %0d/%0d coefficients)",
idx, coeff_idx, N_COEFFS);
fail_count = fail_count + 1;
end else if (coeff_idx != N_COEFFS) begin
$display("ERROR: Vector %0d incomplete (got %0d/%0d coefficients)",
idx, coeff_idx, N_COEFFS);
fail_count = fail_count + 1;
end else begin
$display("INFO: Vector %0d PASSED (%0d coefficients in %0d cycles)",
idx, coeff_idx, cycle_count);
pass_count = pass_count + 1;
end
// Wait for DUT to return to IDLE before next vector
@(posedge clk);
end // inner begin block
end
// ============================================================
// Summary
// ============================================================
$fclose(result_fd);
$display("========================================");
$display("TEST COMPLETE");
$display(" Total vectors: %0d", vec_count);
$display(" Passed: %0d", pass_count);
$display(" Failed: %0d", fail_count);
$display(" Results written to: %s", RESULT_FILE);
$display("========================================");
$finish;
end
// ================================================================
// Timeout watchdog (global)
// ================================================================
initial begin
#(TIMEOUT_CYCLES * 10 * 100); // TIMEOUT_CYCLES * 10ns * extra margin
$display("FATAL: Global simulation timeout reached");
$finish;
end
endmodule