Icarus Verilog problem (never mind!)

David Betz

Edit: Ignore this. It seems my problems had to do with cutting and pasting something from a web page. There must be some non-printing characters in this code that are causing me trouble.

I'm trying to use Icarus Verilog to continue developing a simple CPU that I designed ages ago. After installing iverilog, I tried one of the sample programs and got an error. Is this valid Verilog syntax?

always #5 clk = !clk;

The entire module containing this is:

module test;

  /* Make a reset that pulses once. */
  reg reset = 0;
  initial begin
     # 17 reset = 1;
     # 11 reset = 0;
     # 29 reset = 1;
     # 11 reset = 0;
     # 100 $stop;
  end

  /* Make a regular pulsing clock. */
  reg clk = 0;
  always #5 clk = !clk;

  wire [7:0] value;
  counter c1 (value, clk, reset);

  initial
     $monitor("At time %t, value = %h (%0d)",
              $time, value, value);
endmodule // test

I tried commenting out the offending line but then I get an error in the line:

  output [WIDTH-1 : 0] out;

in this module which is also part of the sample:

module counter(out, clk, reset);

  parameter WIDTH = 8;

  output [WIDTH-1 : 0] out;
  input 	       clk, reset;

  reg [WIDTH-1 : 0]   out;
  wire 	       clk, reset;

  always @(posedge clk)
    out <= out + 1;

  always @reset
    if (reset)
      assign out = 0;
    else
      deassign out;

endmodule // counter

I find it odd that the sample code won't compile and run.