/********************************************************************** * always_comb inferred sensitivity lists -- includes signals read by * functions * * Author: Stuart Sutherland * * (c) Copyright 2003, Sutherland HDL, Inc. *** ALL RIGHTS RESERVED *** * www.sutherland-hdl.com * * Used with permission in the book, "SystemVerilog for Design" *  By Stuart Sutherland, Simon Davidmann, and Peter Flake. *  Book copyright: 2003, Kluwer Academic Publishers, Norwell, MA, USA *  www.wkap.il, ISBN: 0-4020-7530-8 * * Revision History: *   1.00 15 Dec 2003 -- original code, as included in book *   1.01 10 Jul 2004 -- cleaned up comments, added expected results *                       to output messages * * Caveat: Expected results displayed for this code example are based * on an interpretation of the SystemVerilog 3.1 standard by the code * author or authors.  At the time of writing, official SystemVerilog * validation suites were not available to validate the example. * * RIGHT TO USE: This code example, or any portion thereof, may be * used and distributed without restriction, provided that this entire * comment block is included with the example. * * DISCLAIMER: THIS CODE EXAMPLE IS PROVIDED "AS IS" WITHOUT WARRANTY * OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED * TO WARRANTIES OF MERCHANTABILITY, FITNESS OR CORRECTNESS. IN NO * EVENT SHALL THE AUTHOR OR AUTHORS BE LIABLE FOR ANY DAMAGES, * INCLUDING INCIDENTAL OR CONSEQUENTIAL DAMAGES, ARISING OUT OF THE * USE OF THIS CODE. *********************************************************************/module test;  bit [1:0] sel;  bit [7:0] a2, b2, c, d, e, data;  always_comb begin  // infers @(data, sel, c, d, e)    a2 = data << 1;    b2 = decode();    //...  end  function decode;  // function with no inputs    begin      $display("   decode function called");      case (sel)        2'b01: decode = d | e;        2'b10: decode = d & e;        default: decode = c;      endcase    end  endfunction  initial begin    $display("\nExpect decode function to called 7 times ");    $display("(first call may or may not print before this message)\n");    c = 1; d = 3; e = 5;    #1 data = 7;    #1 c = 2;    #1 d = 4;    #1 e = 6;    #1 sel = 2'b01;    #1 $finish;  endendmodule