verilator/test_regress/t/t_interface_star.v

// DESCRIPTION: Verilator: Verilog Test module
//
// This file ONLY is placed under the Creative Commons Public Domain.
// SPDX-FileCopyrightText: 2017 Wilson Snyder
// SPDX-License-Identifier: CC0-1.0

module t (
    input clk
);

  integer cyc = 1;

  counter_io c_data ();

  counter_ansi c1 (
      .clk,
      .*
  );

  counter_ansi c2 (
      .clk,
      .c_data
  );

  always @(posedge clk) begin
    cyc <= cyc + 1;
    if (cyc == 20) begin
      if (c_data.value != 12345) $stop;
      $write("*-* All Finished *-*\n");
      $finish;
    end
  end
endmodule

interface counter_io;
  integer value;
endinterface

module counter_ansi (
    input clk,
    counter_io c_data
);

  always_ff @(posedge clk) begin
    c_data.value <= 12345;
  end
endmodule : counter_ansi