verilator/test_regress/t/t_force_subnet.v

// DESCRIPTION: Verilator: Verilog Test module
//
// This file ONLY is placed under the Creative Commons Public Domain.
// SPDX-FileCopyrightText: 2021 Wilson Snyder
// SPDX-License-Identifier: CC0-1.0

// verilog_format: off
`define stop $stop
`define checkh(gotv,expv) do if ((gotv) !== (expv)) begin $write("%%Error: %s:%0d:  got='h%x exp='h%x\n", `__FILE__,`__LINE__, (gotv), (expv)); `stop; end while(0)
// verilog_format: on

module t (
    input clk
);

  integer cyc = 0;

  logic [7:0] subnet;
  sub1 sub1 (.*);

  // Test loop
  always @(posedge clk) begin
    cyc <= cyc + 1;
    if (cyc == 10) begin
      `checkh(subnet, 8'h11);
      force sub1.subnet = 8'h01;  // sub1.subnet *not* the same as subnet
    end
    else if (cyc == 11) begin
      `checkh(subnet, 8'h01);
      force subnet = 8'h10;  // sub1.subnet *not* the same as subnet
    end
    else if (cyc == 12) begin
      `checkh(subnet, 8'h10);
      release subnet;  // sub1.subnet *not* same as subnet
    end
    else if (cyc == 13) begin
      `checkh(subnet, 8'h01);
      release sub1.subnet;
    end
    else if (cyc == 13) begin
      `checkh(subnet, 8'h11);
    end
    //
    else if (cyc == 99) begin
      $write("*-* All Finished *-*\n");
      $finish;
    end
  end

endmodule

module sub1 (
    output logic [7:0] subnet
);
  assign subnet = 8'h11;
endmodule