/* * Copyright (c) 2001 Stephen Williams (steve@icarus.com) * * This source code is free software; you can redistribute it * and/or modify it in source code form under the terms of the GNU * General Public License as published by the Free Software * Foundation; either version 2 of the License, or (at your option) * any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA */ /* * This program tests the magic $signed system function. */ module main; reg [3:0] a; initial begin a = 4'd12; // The expression should not change the bit pattern in any way if ($signed(a) !== 4'b1100) begin $display("FAILED -- $signed(%b) === %b", a, $signed(a)); $finish; end if ($signed(a) == 4) begin $display("FAILED -- $signed(%b) == 4", a); $finish; end // The >= should do a signed comparison here. if ($signed(a) >= 0) begin $display("FAILED -- $signed(%b) > 0", a); $finish; end $display("PASSED"); end // initial begin endmodule