verilator/test_regress/t/t_param_bit_sel.v

// DESCRIPTION: Verilator: Verilog Test module
//
// We see Verilator assumes a 1-bit parameter is a scalar rather than a 1-bit
// long vector. This causes the following code to fail.
//
// Other event drive simulators accept this.
//
// This file ONLY is placed under the Creative Commons Public Domain.
// SPDX-FileCopyrightText: 2013 Jeremy Bennett
// SPDX-License-Identifier: CC0-1.0

module t (
    input clk
);

  // At this point it is ambiguous whether a is scalar or vector
  parameter A = 1'b0;
  wire b = A[0];
  // Note however b[0] is illegal.

  always @(posedge clk) begin
    if (b == 1'b0) begin
      $write("*-* All Finished *-*\n");
      $finish;
    end
    else begin
      $stop;
    end
  end

endmodule